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Full text of "The anatomy and physiology of the horse : with anatomical and questional illustrations : containing, also, a series of examinations on equine anatomy and physiology, with instructions in reference to dissection, and the mode of making anatomical preparations : to which is added, glossary of veterinary technicalities, toxicological chart, and dictionary of veterinary science"

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University of Pennsylvania 

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EXPLANATION OF FIGURE I. 





OSSEOUS STRUCTURE. 


1. 


Frontal bone. 


2. 


Parietal 


3. 


Occipital. 


4. 


Temporal. 


5. 


Nasal. 


6. 


Lachrj-mal. 


7. 


Malar. 


8. 


Superior maxillary. 


9. 


Anterior " 


10. 


Inferior " 


U. 


Cervical vertebrae. 


33. 


Scapula. 


34. 


Humerus. 


From 4 to 7 is the zj-gomatio arch. 


c. 


Alveolar processes. 




MUSCLES OF THE HEAD, NECi^ AND SHOtlLDEH. 


# 


Ligamentiim colli. 


a". 


Trapezius. 


b". 


Rhomboideus longus. 


c". 


Scalenus. 


e". 


Sterno scapularis— pectoralis traasv^rauK 


/"■ 


Antea spinatus. 


9"- 


Postea spinatus. 


h". 


Teres. 


c. 


Dilator naris lateralis. 


d. 


" " anterior. 


e. 


Orbicularis oris. 


f. 


Nasalis longus. 


9- 


Levator labii superioria. 


h. 


Buccinator. 


i. 


Zygomaticus. 


J- 


Retractor labii inferioris. 


k. 


Masseter. 


I. 


Abducens aurem. 


m. 


Attolentes ct adducens aurem. 


n. 


Retrahentes aurem. 


o. 


Adducens vel deprimens aurem. 


P- 


r. Tendon of the splenius and complexus m^er. 


9- 


Obliquus capitis superior. 


s. 


Splenius. 


t. 


Obliquus capitis, inferior. 


u. 


Levator humeri. 


V. 


Sterno ma.xillaris. 


X. 


Subscapulo-hyoideus. 



VEIMB. 



1. Temporal vein. 

2. Facial vein. 

3. Jugular vein. 
10. Parotid gland. 



.\ 



THE 



^JSr^TOMY A.^D PHYSIOLOaY 



THE HORSE: 



ANATOMICAL AND QUESTIONAL ILLUSTRATIONS. 



CONTAINING, ALSO, 

A SERIES OF EXAMINATIONS ON EQUINE ANATOMY AND PHYSIOLOGY, WITH INSTRUO 

TIONS IN REFERENCE TO DISSECTION, AND THE MODE OF MAlilNG 

ANATOMICAL PREPARATIONS. 



TO WHICH IS ADDED, 

dlossarg of Mtmnx^ f a^nkHlitieg, Siontologkal Cfeart, anJr gidiimafg of ^tkxmti^ §amt. 



GEORGE H. DADD, M. D., V. S., 

AUTHOE OF "the MODEEN HORSE DOCTOR," "CATTLE DOCtOE," BTC.j SIC 



NEW YOEK: 
PUBLISHED BY C. M. SAXTON, 

AGRICULTURAL BOOK PUBLISHER. 
1863. 



NEW BOLTOJt 
CiiHTEfi 



P123 

m3 



Entered according to Act of Congress, in the yetl X36e, br 
JOBttJ P. JEWETT AND OOMPAKY, 

In the Clerk's Office of the Difltrict Court of the District of Maseachusects. 



MIHOTVPED UV THE AMERICAN STEI!i;OTllE COMrAIfT, 
rUCENIX liL'ILDlNG, BOSTON. 



PREFACE. 



American Veterinary Literature has hitherto possessed no work devoted to 
the o.natomy and physiology of the Horse; consequently such subjects are 
either discussed theoretically and imperfectly, or else fail to be noticed. But 
a new era is now dawning upon Veterinary Science ; a spirit of inquiry is 
abroad; and the people of this Republic find themselves in possession of some 
of the most magnificent specimens of "live stock" to be found in the world. 
The natural inquiiy is, "How shaU we protect oun property?" And the 
conclusion anived at is, "Veterinary science offers the vonly probaljle and 
practicable security against the numerous casualties incidental to the habitats 
of the I}arn and stable." 

Hitherto, much indifference has been manifested regarding this science, in 
consequence of the difficulty encovmtered in its study, for want of proper 
text-books and teachers ; and its unsatisfactory residts when tested by men 
unacquainted with its fundamental principles. The Avell-known works of 
English and French authors furnish all the necessary information, yet their 
cost is beyond the means of many, and, therefore, their cu-cidation is very 
limited. 

In view, therefore, of supplying the above deficiency, which is disclosed in 
the barrenness of our anatomical and physiological knowledge, and for the 
purpose of furnishing a work that shall come within the reach and financial 
means of all men, the author has imdertaken the double task ; and it is hoped 
that the eflfoi't will not be thought untimely. 

There are a vast number of highly educated physicians in this country 
who are often urged by their employers to give advice in the management, 
medical and surgical treatment, of the infer m' orders of creation ; yet decline 
to do so, in consequence of a lack of authoritative knowledge regarding 
anatomy, physiologv, therapeutics, and pathclosy. To such, whose sympathies - 
lean in the right direction, and who are willing to give counsel, and lend a 
helping hand in the restoration of a sick or dying animal, this work is offered, 
and the author, therefore, submits it to their candid perusal and criticisiu. 

The work, however, is principally intended for veterinary surgeons, teachers 
of the art, and students of veterinary medicine, whose wants the author 
V professes to have some knowledge of; and he has endeavored, to the best of 
his ability, to cater to the same. 

The necessity for such a work, at the present time, is evident from the facts, 
that three veterinary colleges have lately come into legislative existence, and 






!V PREFACE. 

it is very natural to suppose that, ere long, many candidates for the honors of 
these institutions will knock at the door of science, and seek admittance ; they 
must then need fexi-hooks ; and, in view of furnishing a part of what the author 
foresees every teacher and student must necessarily need, he offei's this, not as 
a work pregnant with his own ideas, for that were presumptuous, when anat- 
omy and physiology are the texts ; but, as a work carefully prepared from the 
writings of our best authorities, the work may be considered as the legitimate 
offspring of scientific observation and experience. 

Another argument in favor of the necessity that will soon exist for a text- 
book of anatomy and physiology is founded on the fact, that agricultural 
colleges will soon be endowed in every State of the Union ; many already 
exist ; and each will, probably, endow a professorship of veterinary science. 
With such, and among the young and aged men that may seek for knowledge^ 
the author hopes that his work may find favor; and, if such should be the result, 
he will have the satisfaction of knowing that he has not labored in vain. 

There are other classes of men that need a work of this description; namely, 
the husbandman, the horse-o\\mer, and the horse-lover, as well as the purely 
scientific man. The three first, incited by laudable sentiments, or pecuniary 
motives, will read the following pages, and study the anatomical illustrations ; 
some with veneration of that Avonderful piece of mechanism, a horse's structure; 
others for the purpose of making themselves acquainted with the form, action, 
and capacities of the same. 

The imreli) scientific man, who desires to inform himself how veterinary 
science is to be studied, — what are its legitimate objects, and its appi'opriate 
sjihere, — will read these pages with considerable profit. 

GEORGE H. DADD. 

Boston, January, 1857. 



REMARKS L\ REGARD TO THE COMPOSITION OF THIS WORK. 



The plan of the anthor, in the commencement of this work, was to prepare a 
ycompMc manual of examinations on the Anatomy and Physiology of the Horse ; 
but, finding that he could not bring the matter within the prescribed limits, the 
plan was speedily abandoned. The examinations, excepting those descriptive 
of the osseous structure, are intended, either to ehcit some physiological fact, 
or to introduce topics that have not been treated of in the body of the Avork. 

In attempting to furnish the public with a systematic treatise on Anatomy 
and Plnsiology, it will be obvious that the author must necessarily avail 
himself of the labor of others ; for, as regards the science of anatoni};, no one 
has anything new to ofter. The industrious anatomists and dissectoi's of early 
times have borne oft' all the laurels, and there remains but httle, if anything, 
for future discovery. As regards physiology, also, there are very few facts to 
discover; we now allude, however, to practical physiology — that science which 
teaches us the functions of the animal body, or the vises of its parts. Tlie 
author has, however, occasionally stepped beyond the details of practical 
physiology, and has endeavored to throw some light on the complex combina- 
tions in which vital phenomena present themselves, and the nature of their 
dependencies one upon another. Matter of this kind he has thought best to 
introduce in the fonn of examinations. 

In preparing this work, the author has endeavored to select the most recent 
and rehable information. The following list of authors consulted and com- 
piled from, together with the foot notes and the writers' names appended, will 
serve to indicate the principal sources on Avhich the anthor has relied for 
information: 

Mr. PercivaU's Anatonvj of the Horse has been freely employed in composing 
the anatomical part of the work. The description of the abdominal viscera 
is from the pen of Mr. Gamgee, and was written as a ^;/-<>c essay, and pub- 
lished in the London Veterinarian. Carpenter's Phi/siolof/i/, general and compar- 
ative, is also quoted. Liebig's Chenmtry, Hooper's Dictionar//, PercivaU's IUppo- 
patholof///, Roget's Outlines of PJv/siologj/, have also been consulted, and extracts 
made from the same. The illustrations, not otherwise indi'L'ated, are by Girard; 
explanations, translated by the author. For the loan of 'the French plates, the 
author is indebted to C. C. Grice, V. S., of New York City. 

The plan of the examinations was suggested to the author by Ludlow's 3Iamtal 
of Examinations, — a work which he fonnerly, while studying medicine, had 
occasion to use. The subject matter, in this work, of course dift'crs from that -of 
the former. 

In preparing the "Definitions of Veterinary Technicalities," and "Diction- 
ary," the author has availed himself of the works of Cooper, Hooper, Cleve- 
land, Blaine, Mahew, and White ; and, regarding the method of making ana- 
tomical preparations, etc., the works of Parsons., Pope, and Swan, have been 
consulted. ' G. H. D. 



CONTENTS. 



PASI 

Preface, - 3 

Remarks regarding the composition of the work, -.-- 5 

Remarks on the osseous, cartilaginous, and ligamentous structm-es, ------ 1 1 

TegL'MENT.uiY System. — On the hair of horses ; examinations on the common integument ; physiol- 

ogj' of the skin, of the cellular membrane, of the adipose tissue ; examinations on the same, 14-17 

Of the Extekx.U- Paets. — The hoof; its form, spread, color, magnitude ; the wall ; its situation and 
relation, coimection, figure, di\ision, solar border, lamina?, quarters, heels, coronarj* border and 

bars, 17-23 

The Sole. — Situation and connection, figure, arch, division, surfaces, and thickness, - - 23-25 

The Frog. — Its situation and connection, figure, division, surfaces j the cleft of the frog, its supe- 
rior surface, the sides, the commissures, toe, heels or bulb, coronarj- frog band ; development of 
hoof; structiire of the hoof; production of the hoof; properties of horn, - . - - 25-30 

ISTERX.U/ P.iRTS OF THE HooF. — The coronary substance j its situation, connection, structure, and 

organization, ..-.--.-------- 30-31 

The CtRniAGES. — Their situation, attachment, and form ; the false cartilages, and their use ; the 

sensitive laminae ; di\ision of the same ; elasticity, number, dimensions, and organization ; the 

sensitive sole ; its structure, connection, thickness, and organization ; the sensitive frog ; its 

situation, division, structure, and organization, -.-.---.- 31-34 

A tabular view of the bones of the horse, -..---.-.. 35 

Anatomy of the skeleton, introduced in the form of questions and answers, embracing a complete 

system of osteology, -------------- 36-54 

Remarks on the changes which horses' teeth undergo, with examinations on the same, - - 54-56 

Myology. ^ A table of the names and number of muscles, divided into regions, ... 57-60 

A tabular s)-nopsis of the number, name, region, situation, insertion, and action of all the 

muscles, .-....--....-.-- 61-78 

On Dissection'. — Dissecting instruments; subjects suitable for dissection; rules in reference to 

dissection of muscles, .....------.. 79-80 

AxATOsncAL Prep.ul\tions. — Injecting instruments; directions for using the s)Tinge, - 80-81 

On the Different kinds of Injections. — Formulae for coarse warm injections ; fine injections; 
minute do; plaster injection ; cold injection; as regards the course of injections ; quicksilver 
injections ; mode of injecting the hmphatics with quicksilver ; method of injecting the lac- 
teals, and parotid gland ; wet preparations ; preparations by distension ; method of prepai'ing 
and distending the lungs ; menstrua for preserving specimens ; method of preserving the brain 
and lungs ; method of macerating and cleaning bones ; to render bones flexible and transpa- 
rent ; method of cleaning and separating the bones of the cranium ; exposition of Mr. Swan's 
new method of mjiking dry anatomical preparations, -------- 81-87 

Digesti^'e System. — The mouth, hps, cheeks, gums, palate, tongue, salivai-y glands, pharjiix, 
oesophagus, and nasal fossa ; cavity of the cranium ; the orbits and cavities of the nose ; the 
mouth, peritoneum, stomach, intestines ; the vessels, nerves, and li,-mphatics of the intestines ; 
the spleen, Uver, pancreas, kidneys, supra-renal capsides, ureters, bladder, urethra, - - 87-119 

Generative Organs of the M.ale. — Vasa deferentia, vesiculae seminales, ejaculatory ducts, pros- 
trate gland, Cowper's glands, --..--..•.-- 119-121 
ORG.4N3 of GEN'ER.iTloN CONTINUED. — Testicles and scrotiun, spermatic cord, epididj-mis, penis, 

and urethra, - -. 121-125 

Female Organs of Generation, ------------ 125-128 

Physiological con.siderations on the reproduction of organized beings, . . - - . 128-136 

Examination on the digestive system, 136-133 

Remarks and examinations on the eye, 139-143 

(vii) 



Vlll CONTENTS. 

RESPrRATOEY SYSTEM. — Observation on the same; the krj-nx, glottis, epiglottis, trachea, bron- 
chial tubes, pleura, mediastinum, lungs, bronchial glands, ------- 144-154 

ClECULATOKY System. — Remarks on the blood ; examinations resumed on the blood, pericardium, 

and heart, ..------.------ 155-157 

Aeterlu, System. — Distribution of the arteries, - - . 158-163 

A table shomng the mode of the distribution of the arteries, ------ 164-166 

Distribution of the veins, -....- - 166-168 

A table showing the mode of distribution of the veins, -------- 169-170 

The brain and its appendages ; the nervous system, --------- 171-177 

Examinations on neurology, -..--.-..-.- 177-180 

Distribution of the IjTnphatics, --.-.-.--.-. 181-184 

A glossary of veterinary technicalities, ---------- 185-193 

Toxicological chart, ..--.---. ...-- 195-209 

A dictionary of veterinary science, ----.--...- 211-287 

Appendix. — Ligamentary mechanism of articulations and joints, . . , - . 289-291 



INDEX OF THE ILLUSTRATIONS. 



FIGUllE I. — Presents two \iews : one of a portion of the osseous stnacture, shomng the head, neck, 
and shoulders ; and the other is composed of the supei-ficial muscles, covering the above parts ; 
precedes the title page. .----.-----... 

FIGUKR n. — Is a section of the osseous structure, ginng a side of the spinal column, ribs, and a part 

of thenear, anterior, and posterior extremities. ----..--. lo 

FIGURE m. — Is a representation of the supei-ficial muscles of the body, of a part of the neck, and 

of the extremities. ------- ---20 

FIGURE IV. — Has four illustrations of the hind extremities, as follows : No. 1 is a side view of tlie 
bones of the ofl'-hind leg ; No. 2 shows the muscles and tendons of the off-hind leg ; No. 3 is a 
front view of the liones of the same ; No. 4 shows the muscles and tendons in the anterioi- region, 
or front pai't, of the o3-hind extremity. --.- 30 

FIGURE V. — Presents two illustrations : the first shows the superficial muscles in the region of the '' 
head, neck, and shoulders, on the near side ; and the other is a corresponding section of the osse- 
ous structure, on wliich the insertions of the hgamentum colh into the occiput, cervical vertebra-, 
and dorsal S])ines, are shown. --------.-..-40 

FIGURE VI. — Presents four views of the forward extremities : No. 1 shows the bones which enter 
into the comjjosition of the near fore-leg ; No. 2 is a side \iew of the muscles and tendons of the 
near fore-leg ; No. 3 is an anterior view of No. 1 ; No. 4 is an anterior view of No. 2. - - 50 

FIGURE VII. — Presents four views of the near fore-extremity : Nos. 1 and 3 are side and j)ostcrior 
views of the bones of the near fore-limb ; Nos. 2 and 4 show the muscles and tendons belonging 
to the above regions. ------------.-CO 

FIGURE ^^II. — Has four views of the off-hind extremity: Nos. 1 and 3 are side and ])Ostcrior \'iews 
of tlie bones entering into the composition of the Hmb; Nos. 2 and 4 show the muscles and ten- 
dons of the same. --------..-.-. 70 

FIGUliE IX. — Presents two views : one, of the bones ; the other shows the sujierficial muscles of the 

head, neck, shoulders, and breast, viewed in an anterior direction. ----- 80 

FIGURE X. — Has two cuts; one of wliich shows a portion of the osseous framework; the other 

shows the superficial muscles belonging thereto. --------- 90 

FIGURIC XI. — Is illustrated by two cuts : one of which shows a portion of the muscles of the body, 
neck, and limbs ; it is a sort of anterior side view ; the second cut shoAvs the bones which enter into 
the comjjosition of these parts. - - - - - - - - - - - -100 

FIGURE XII.- Has two illustrations, which are the counterpart of Fig. XL, as seen from liie o]]po- 

site or posterior direction. ------.-..-.- jjg 

FIGURE Xni. — Presents a side view of the deep-seated muscles : it is taken from Mr. Blaine's " Out- 
lines," and is one of the most magnificent plates ever presented to the public. - - - - 120 
FIGURE XIV. — Is a view of the muscles and tendons of the fore and hind extremities. - - 140 

FIGURE XV. — Is illustrated -with five views of the off and near fore extremity : Nos. 1, 2, 3 show very 
distinctly the action of the flexors of the limb, as well as their location, and that of the extensor 
tendons and muscles. The triceps extensor brachii, and pectoral muscles, are also quite jiromincnt 
and easily recognized ; N'o. 4 is the same limb chvested of the soft parts ; No. 5 is an interior view 
of the near fore-leg, and shows some of the tendons and muscles which are not seen in the other 
cuts. ------ ----.[.jO 

FIGL RE XVI. — Presents five views of the hind extremities, in which the use and action of several very 
imjiortant muscles and tendons are accurately dehneated : Nos. 1, 2, 3, 4 compose the bones, 
muscles, and tendons of the near-hind extremity ; No. 5 shows the muscles and tendons on the 

inside of the near-hind leg. -- J 60 

2 (i^) 



X INDEX TO TIIK ILLUSinATIOXS. 

FIGURE XVII. — Presents two views (as seen from a posterior direction) ; one contains a great portion 
of the superficial muscles of the body and liinl)s, and the other sliows the basis of their super- 
structure. 170 

FIGURE XVni. — Is ilie skeleton of a horse, for which the author is indebted to Blaine's "Outlines 

of the Veterinary Art." - - - - - - - - - - - • - - ISO 

FIGURE XIX. — Is a counterpart of Fig. XVII., as seen from an opposite direction. ... 17 j 

FIGURE. XX. — Is an excellent representation of the muscles of one side of the head, neck, body, and 

limbs. - 211 



EXPLANATION OF FIGURE II. 





OSSEOUS STRUCTUEE. 


11. 


Cervical vertebra. 


12. 


Dorsal 


13. 


Liimb-y " 


14. 


Sacrum.' 


15. 


Cocevseal bonpo. 


1(3. 


•r._....o. 


17. 


False " 


18. 


Sternum. 


19. 


Peh-is. 


20. 


Posterior part of the pelvis, or isehiatic spines 


21. 


Inferior, or pubic region. 


22. 


Fonuu-. 


23. 


Patella. 


24. 


Tibia. 


33. 


Scapula. 


34. 


Himierus. 


35. 


Radius. 


e. 


Fibula. 


/• 


Ulnar. 



REMARKS 

ox THE 

OSSEOUS, CARTILAGINOUS, AND LIGAMExNTOUS STRUCTURES. 



The bones are the solid fmmework which 
gives stability to the whole fabric, and af- 
ford fixed bearings upon which the powers 
regulating the varied inovetnents oj)erate. 
The bones, then, are considered as the most 
dense and solid structures of the animal 
frame : affording support, and in many parts 
protection, to some of the softer parts ; at. 
the same time, the leverage which regulates 
the action of a limb is derived from the 
osseous structure. 

On making an examination of a bone, 
we find that its external surface is the hard- 
est part, and it difl'ers very much in thick- 
ness in difl'erent bones, and in different 
animals. The long bones (or cylindrical) 
of the horse contain less marrow, and are 
more cancellated within, than the bones of 
the human subject: in many of the former 
the whole arena is occupied by cancelli. 
The bones of the ribs have an osseous plat- 
ing differing in thickness in various sub- 
jects, and within is a cellular structure which 
may be termed diploe. 

The marrow, as it is termed, is a soft 
substance of an oleaginous character, con- 
tained in an infinite luimber of sacs, depos- 
ited and suspended in the cavities of bones 
and in the cancelli. The marrow sacs are 
composed of a delicate vascular membrane, 
which isolates them from each other, and 
prevents the marrow from gravitating or 
passing into the osseous structure. 

Bones present the appearance of lamellas 
yet they are fibrous; the fibres of the cylin- 
drical bones are longitudinal; in the flat 
bones they have a radiated appearance, and 
in the short and peculiar shaped bones, the 



fibrous arrangement is more irregular and 
difficult to trace. 

The basis of the osseous structure is 
nearly the same as the membranous parts,* 
beii;g composed of fibrous lamintc or plates, 
which are connected together so as to form, 
by their intersection, a series of cells anal- 
ogous to those of the cellular structm-e. 
This theory has been disputed by some 
distinguished physiologists ; the moderns 
contend that the osseous fabric is cellular.f 

Bones are invested, on their exterior, ex- 
cept those parts plated with cartilage, with 
a membrane termed periosteum. Through 
this medium an arterial and venous com- 

* " The analysis of a bone into its two constituent parts 

is easily effected by the agency either of acids or of heat. 

j By macerating a full-grown bone for a sufficient time in 

diluted muriatic acid, the earthy portion of the bone, 

: amounting to nearly one-third of its weight, is dissolved 

I by the acid; the animal portion only remaining. This 

animal basis retains the bulk and sliape of the original 

bone, but is soft, flexible, and clastic ; possessing, in a 

word, all t!ie properties of membranous parts, and coiTes- 

I ponding in its chemical character to condensed albumen. 

! A portion of tliis solid animal substam-e aH'ords gelatin by 

j long boiling in water, especially under the pressure, ad- 

1 mitting of a high temperature, to whicli it may be su'i- 

' jectcd in I'apin's digester. On the other liantl, by sub- 

! jecting a bone to the action of fire, the animal part alone 

j wiil he consumed, and the earth left untouched, preserv- 

I ing, as before, the form of the bone, but having lo.st the 

material whicii united the particles, presenting a fragile 

mass whicli easily crumbles into ])Owder. This earthy 

I basis, wiien chemically examineil, is found to consist prin- 

I cipally of phosphate of lime, which comi)Oses eighty-two 

I hunilrcdths of its weight ; and to contain also, according 

to Berzelius, minute portions of Hnate and carbonate of 

lime, together with the jihosphates of magnesia and of 

soda." — Hoyet. 

t The best authority in support of the cellular theory is 
Scarpa. I'crclvall advocate.^ the laminated and (ihrous 
theories. 

(11) 



12 



ANATOMY AND PHYSIOLOGY OF 



inuiiication is established between the dense 
and soft parts. The periosteum is anal- 
ogous to the fibrous textures, being com- 
posed of numerous inelastic fibres of great 
strength and density. 

The inner surface of the periosteum is 
connected with the bone by the vessels pass- 
ing from Ihe one to the other, and also by 
numerous prolongations, which pervade the 
osseous substance. 

The blood-vessels of the periosteum are 
numerous, and are easily demonstrated by 
injection. 

CARTILAGE.* 

The structure which appears most inti- 
mately connected with the osseous is carti- 
lage. It is a firm and dense substance, 
apparently homogeneous in its texture, semi- 
pellucid, and of a milk-white or pearly color. 

The surface of cartilage is smooth and 
uniform, presenting neither eminences nor 
cavities, pores nor inequalities. It has, 
however, minute capillary vessels, the diam- 
eters of which are too small for ocular 
demonstration. Notwithstanding its den- 
sity, it has a minute circulating apparatus, 
which is demonstrated in diseases known 
as spavin and ringbone, in which absorp- 
tion of cartilage occurs. 
^^j, Cartilaginous structures are chiefly com- 

* " Tlje incdiaiiical pniperty wliich partii-tilarly distiii- 
guislics carlilaj.'C is clastkity, a quality vvliioli it possesses 
in a greater degree than any other animal structure, ami 
which adapts it to many useful purposes in the eeonomy. 
Hence it forms the basis of many parts where, contrary to 
the puqioses answered by the hones, ])lianey and resistance 
as well as firmness are required ; and hence cartilage is 
employed when a certain shajie is to he preserved, to- 
gether with a capability of yielding to an external force. 
The flexibility of cartilage, however, does not extend 
beyond certain limits ; if these be exceeded, fracture takes 
place. Great density bestowed upon an animal sti'uciure, 
indeed, appears to he in all cases attended Hn'tli a jn'opor- 
tionate degree of hrittleness. These mechanical proper- 
ties of cartilages, as well as their intimate structure, 
although nearly homogeneous in all, are subject to modifi- 
cation in diH'erent kinds of cartilage. Cartilages are 
c((\ercd with a line membrane, termed the perirhoiuli-itim, 
analogous in its structure and office to the periosteum, 
which Hc have already had occasion to point out among 
the fibrous membrane.'!, as investing the bones." — I\ogcl. 



posed of gelatin, albumen, and phosphate 
of calcium. 

Cartilage occurs in two forms, temporary 
and permanent. The former prevails pre- 
vious to adult life ; the latter are identical 
with Ihe permanent structures after the 
animal has migrated from colthood. 

There are three or four ditlerent forms of 
cartilages, viz : the membriform, interosseal, 
articular, and inter-articular. 

The membriform are iibro-cartilaginous ; 
they furnish a basis of support to the softer 
parts, supply the place of bone, and give 
form, shape, and firmness, to parts unossi- 
fied. By their elasticity, they admit of con- 
siderable variation of figure and form, yield 
to external pressure, and recover their proper 
shape as soon as pressure is removed. This 
kind of cartilage is found in the nostrils, 
ears, larynx, and trachea. 

The interosseal cartilages pass from one 
bone to another, adhering firmly by their 
extremities to each. They permit of an 
increase of extent or motion, as observed 
between the ribs; when macerated, they are 
divisable into laminEe of an oval shape, 
i which are united by fibres passing obliquely 
between theiu. 

The articular cartilages are those plates 
of articular substance which adhere firmly 
and inseparably to the surfaces of bones 
which are opposed to each other in the 
joints, or over which tendons and ligaments 
play. The elastic resistance of this carli- 
lage has a powerful tendency to lessen the 
shocks incident to sudden and violent 
actions. 

The inlrr-artinilar cartilages do not dif- 
fer in com[)osition from the preceding. 
They are attached to the inside of 1h(^ cap- 
sular ligament, by which Ihoy are reiulen^d 
somewhat movable; anti, being interposed 
between the bones of the knee and hock, 
allow them a greater latitude of motion, 
while at the same time they contribute to 
adapt their surfaces more perfectly to each 
other. The structure of these cartilages is 
laminated. 



THE HORSE. 



13 



FIBRO-CAIITILAGINOUS STRUCTURES. 

Fibro-cartilage appears to be of an in- 
termediate nature between ligament and 
cartilage. Having a fibrous texture united 
to a cartilaginous basis, it combines the 
characteristic properties of both of the above 
textures. 

Fibro-cartilaginous structures are found 
to unite the bodies of the bones of the ver- 
tebrcB ; they then get the name of inter- verte- 
bral substance. They impart great elasticity 
to the spine, and also diminish the effects of 
concussion. 

LIGAMENTOUS STRUCTURES. i 

The ligamentous structures are dense; 
possess a considerable degree of solidity in 
some parts, wlule in others they are modi- 
fications of fibrous membrane. The liga- 
mentous system includes a number of parts 
which have received difierent names, such 
as ligaments, tendons, faschia aponeurosis, 
capsules or bursa; mucosa?; and fibres of 
ligamentous matter also enter into the com- 
position of other organs, imparting to them 
different degrees of mechanical strength. 
The ligamentous structures vary ; we find 
tliat in some places they are expanded into 
faschia, etc., at others they collect into dense, 
cnlongated cords. The first division in-' 



eludes fibrous membranes, fibrous capsules, 
tendinous sheaths, and aponcarosc?. 

Fibrous membranex : these resemble or- 
dinary membranes, only that their fibres are 
denser. The periosteum is a membrane of 
this description, and the diu-a mater has a 
similar structure. 

Fibrous capsules are presented in the 
form of sacs, which surround various ten- 
dons and joints. These capsules are also 
lined by a synovial membrane, which secretes 
the synovia. 

Tendinous sheaths are formed by fibrous 
membranes which surround the tendons, in 
those parts that are subjected to friction, or 
liable to displacement, during the action of 
the muscles which move the joint. 

Aponenro:rs arc those extended sheets 
of fibrous texture which in some instances 
form coverings of parts, while in others 
they constitute points of attachment to 
muscles. In the former case they are termed 
faschiae, and either surround the muscles of 
a limb, forming a sheath for it, or else invest 
or confine some particular muscle. 

In the latter case the aponeurosis presents 
brodd or narrow surfaces and fibres which 
give attachment to particular portions of 
muscle. 



ANATOMY AND PHYSIOLOGY. 



TEGUMENTARY SYSTEM. 

ON THE HAIR OF HORSES. 

IIaik is a peculiar tegumentary appendage, 
characteristic of tile horse and other mam- 
mals. It is developed on the interior of 
follicles which are formed by a depression of 
the true skin. These follicles are lined by a 
continuation of the epidermis, the cells of 
which are developed in peculiar abundance 
from a spot at its deepest portion ; the dense 
exterior of the cluster thus formed being 
known as the bulb of the hair, while the 
softer interior is termed its pulp. The 
elementary parts of hair are: a cortical or 
investing substance of a dense horny tex- 
ture ; and a medullary or pith-like sub- 
stance, of a much softer character, occupy- 
ing the interior. The cortical envelope of 
hairs is 3 ccrlji^uation of the outer scaly 
layers of the epidermis that lines the follicle ; 



whilst the medullary is derived from the 
deeper stratum whose cells are produced in 
unusual abundance at the ccecal extremity ; 
and it is by the constant development of 
new cells at this point, that the continual 
gi'owth of the hair is kept up. 

An excoriation or moulting of the hair, 
which falls off, is replaced by a new growth, 
which as it comes to maturity assumes the 



original color. 



This change in the covering 



with which nature has so wisely clothed 
the horse, usually takes place either in spring 
or autumn, or at both periods. The hair 
of the mane and tail, however, is not sub- 
jected to these periodical changes; hence, 
it acquires considerable calibre and length. 

By analysis, the hair yields carbon, hy- 
drogen, nitrogen, oxygen, and sulphur, and 
its variation in color is due to the presence 
of different shades of matter which infil- 
trates the cortical substance. 



EXAMINATIONS ON TIIK CO:\niON«?NTEGUMENTS. 



Q. Of how many parts do the common integuments 
consist ? — A. Three : cuticle, cutis, and rete-mucosnm. 

Q. Describe the cuticle or epidermis? — .-1. It is a 
thin, traiisi)areut, tough, and elastic porous membrane, 
serving as an envelo])e to the cutis, or ti'ue sldn. It is 
composed of flexible lamella', so arranged as to bear 
some analogy to tlie scales of fish ; it pervades the 
whole body, and insinuates itself into ])orous struc- 
tures and follicular passages, inlets, and outlets of the 
system ; it is supposed to be continuous from the moutli 
to the anus. 

Q. Describe the pores or ]:erforatIons. — ,1. There 
are three. First, those siu'rountUng the hair. Sec- 
ondly, exhakmt pores. Thirdly, absorbent pores. 

Q. llow is the cutis designated? — A. As the cutis 
vera, or true skin. j 

Q. What is the structure of the cutis? — A. It is of j 
a fibrous texture, tougli, elastic, vascular, and highly! 
sensitive, and is what we commonly denominate leather. ! 



Q. What are the attachments of the cutis? — A. 
The cutis is attached to the subjacent parts by cellu- 
lar membrane, in some places so tensely that little or 
no motion is admitted of; in others so loosely that it 
admits of being thrown into folds. About the forehead, 
upon the bach, around the tail, and upon the pasterns, 
it can scarcely be pinched up ; but upon the sides of the 
face and necl;, upon the ribs, along the flanks, and upon 
the anus and thighs, it will easily admit of duplication. 

Q. AVliat varieties are there in the density of the 
cutis ? — .1. It varies in den.sity, not only where it covers 
different jiarts in the same animal, but in horses of 
different breeds and temperaments, it varies very essen- 
tially. 

Q. What is the organization of the rete mucosum? 
A. It is composed of a fine, delicate, laminated tissue, 
interposed between the cuticle and cutis, and serves as 
their connecting medium, and is supposed to secrete 
the coloring matter of the external surface and hvlr. 

(14) 



ANATOMY AND PHYSIOLOGY OF THE IIOKSE. 



15 



niYSIOI.OGY OF THE SKIN. 

The skill is hii^hly sensitive ; yet those 
persons vvho arc in the habit of making free 
use of the whip scarcely ever realize the 
fact. The author has an impression that 
the skin of a horse is more sensitive than 
that of man ; for example, let a small quan- 
tity of turpentine be applied to a horse's 
back, — very soon he evinces signs of pain, 
which cannot be elicited wh^ a man be- 
comes the subject of the same experiment. 
Every horse-owner, also, must have noticed 
the uneasiness a horse manifests when a 
common fly, or gad-fly, alights on him; and 
in a variety of other ways the highly sensi- 
tive state of a horse's skin admits of dem- 
onstration. 

The skin is one of the principal emunc- 
tories of the body, from the surface of which 
passes off a large quantity of morbid fluid 
in the form of perspiration, sensible or in- 
sensible, as the case may be. The skin is 
(he great external outlet; and, should the 
kidneys or any other organ fail to play their 
part in eliminating useless fluids, the skin 
opens its flood-gates, and thus purifies the 
body. The amount of fluid exhaled from 
the external surface has been the subject of 
some very interesting experiments, and the 
results are truly astonishing. 

OF THE CELLULAIl MEMBRANE BENEATH THE 
SKIN. 

This tissue abounds in almost every part 
of the body; thus, says Carpenter, "it binds 
together the ultimate fibres of the muscles 
into minute fasciculi, unites these fasciculi 
into larger ones, these again into still larger, 
which are obvious to the eye, and these into 
the entire muscle ; and also forms the mem- 
branous divisions between distinct muscles. 
In like manner it unites the elements of 
nerves, glands, etc., binds together the fat- 
cells into minute masses, these into larger 
ones, and so on; and in this manner pene- 
trates and forms a considerable part of all 
llic softer tissues of the body. It also serves 
as the bed in which blood-vessels, nerves, 
and lymphatics may be carried into the 
substance of the different organs." 



This tissue consists of a net-work of 
minute fibres and bands, which arc inter- 
woven in every direction, so as to leave in- 
numerable areolfe or spaces, which commu- 
nicate freely with one another. 

Of these libres, ^mc are of the yellov/ or 
elastic kind, but the majority arc composed 
of the white fibrous tissue; and, as in the 
other form of elementary structure, they 
frequently present the form of broad flat- 
tened bands, or membranous shreds, in 
which no distinct fibrous arrangement is 
visible. The proportion of the two forms 
varies, according to the amount of elasticity 
or simple resisting power which the en- 
dowments of the part require. The inter- 
stices or areolae are filled, during life, with 
a fluid which resembles very dilute serum 
of the blood ; consisting chiefly of water, but 
containing a sensible quantity of common 
salt and albumen. It is the undue accumu- 
lation of this fluid which constitutes drop- 
sical eflusion, the influence of gravity upon 
the seat of which, shows the free communi- 
cation that exists among the interstices. 
Tliis freedom of communication is still 
more shown, however, by the fact, that 
either air or water may be made to pass, by 
a moderate continued pressure, into almost 
every part of the body containing cellular 
or areolar tissue, although introduced only 
at a single point. In this manner it is the 
habit of butchers to inflate veal; and 
impostors have thus blown up the scalps 
and faces of their children, in order to ex- 
cite commiseration. The whole body has 
been thus spontaneously distended with air 
by emphysema in the lungs; the air having 
escaped from the air-ceUs into the surround- 
ing areolar tissue, and thence, by tlie con- 
tinuity of this tissue with that of the body 
in general at the root or apex of the lungs, 
into the entire fabric. 

The structure of the serous and synovial 
membranes is essentially the same as the 
above. The true cellular membrane is 
sometimes termed reticular, while that con- 
taining fat is called adipose. 



16 



ANATOMY AND PHVSIOI.OGV (1F 



ADIPOSE OR FATTY TISSLK. 

The adipose tissue is composed t>f it^o- 
lated cells, which appropriate fatty matter 
from the blood after the same manner as 
the secreting ceUs appropriate the elements 
of bile, urine, and inilkT " The portion of 
fatty matter separated from the circulating 
fluid to form adipose tissue, is only that 
which can be spared from the other pur- 
poses to which they have to be applied ; and 
hence the production of this tissue depends, 
in part, upon the amount of fatty matter 
taken in as food* This is not entirely the 

* " Depuxition. — In almost all animals that are licaltliv, 
copions (bod of a nutritive kind, combined witli little labor, 
will increase the deposition of fat ; but in tlie human sub- 
ject, and, indeed in many quadrupeds, the animal spirits 
a|)pcar to have very considerable influence over this secre- 
tion. We sec numberless examples of people, who ajipear 
to enjoy t!io best bodily health, and yet are coustantlv 
inca^'rc, though their food and habits of life tend to an op- 
jiositc state ; and we may occasionally observe horses and 
do.Ljs, particularly circumstanced, in which, from their 
natural leanness, or poorness u]x>n the rib, sometiiing of 
a mental nature would appear to be operating ; indeed, it 
is a well known truth, that if j-ou separate a horse of an 
irritable disposition from others with whom he is accus- 
tomed to be stalled, he will fall away in condition, in con- 
sequence of (to use the vulgar expression) freltiiif/ from 
beiny alone; and so much does this act of segregation affect 
some, that I have known them even refuse their food. 
Those horses are commonly the fattest that are fed on 
cisily digestible food — such as braised or scalded corn, 
roots of a nutritive kind, chopped hay, etc., and that 
have little or no exerci.se : a fact well appreciated by tlie 
horsc-ilealer, wliose horses urafine and Jit for side, but in- 
capable of fatigue. 

Absorption. — Constitutional diseases, generally speak- j 
ing, extenuate the body, and more particularly such as are 
of the acute or painful description ; hence, the irritation j 
caused by a simjrle puncture in the foot, will, if it be of j 
long duration, induce a state of emaciation : under which 
circumstances, the absorbents are supposed to act with more 
than ordinary effect, and to take up the adeps from the 
interior of its cells. "-Perc/m// 



case, however, as some have maintained; 
for there is sufficient evidence that animals 
may produce fatty matter by a process of 
chemical transformation, from the starch or 
sugar of their food, when there is an unusual 
deficiency of it in the aliment." Liebig 
writes : " Whatever views we may entertain 
regarding the origin of Ihc fatty constitu- 
ents of the body, this much, at least, is un- 
deniable, thaffjhe herbs and roots consumed 
by the cow contain no butter; that, in the 
hay or other fodder of o.xen, no beef-suet 
exists ; that no hog's-lard can be found in 
the potato refuse given to swine ; and that 
the food of geese or fowls contains no 
goose nor capon fat. The masses of fat 
found in the bodies of these animals are 
formed in thek organism ; and, when the 
full value of this fact is recognized, it entitles 
us to conclude, that a certain quanlity of 
oxygen, in some form or other, separates 
from the constituents of their food, for 
without such a separation of o.xygen, no 
fat could possibly be formed from any one 
of these substances." 

The chemical analysis of the constituents 
of the food of the graminivora shows in 
the clearest manner that they contain carbon 
and oxygen in certain proportions; which, 
when reduced to equivalents, yield the fol- 
lowing series : 

" In vegetable fibrine, albumen, and cas- 
einc, there are contained, for — 
129 cq. carbon, 

In starch, 120 " 

" cane sugar, 120 " " 

" gum, 120 " 

" sugar of milk, 120 " " 

" grape sugar, 120 " " 



36 cq. oxygen. 
100 " " 
110 " 
110 " 

120 " " 
140 " " 



EXAMIXATIOXS RESUMED. 



rKLI.UI..^E MEMBRANE. 
Q. What is the ])rincipal use of cellular mcnihranc? 

— A. It is employed in uniting, covering, and defending 
various ])arts of tlic body. 

Q. Does cellular differ fi-om serous or nenous mem- 
branes ? — .1. No, they are all resolvable into the same 
constituents. 

Q. How docs the ])eriosteum differ from the above ? 

— A. It i,rc.sent,.s itself in a more condensed form. 



Q. IIow do capsules of joints differ fi-om common 
cellular membrane? — J. They are a modification of 
it, under a condensed form. 

Q. In what part of the animal does cellular mem- 
brane exi.st in greatest abundance? — A. Immediately 
beneath the skin ; ujjon the ribs, and about the breast, 
and under the jaws, in the scrotum, on the inside of 
the elbow and tliigh. 



THE HORSE. 



17 



" Now in all fatty bodies there are con- 
tained, on an average: 

" For 120 cq. carbon, only 10 eq. oxygen. 

" Since the carbon of the fatty constit- 
uents of the animal body is derived from 
the food, seeing that there is no other 
source from whence it can be derived, it is 
obvious, if we suppose fat to be formed 
from albumen, fibrine, or casein, that for 
every. 120 equivalents of carbon deposited 
as fat, 26 equivalents of oxygen must be 
separated from the elements of these sub- 
stances ; and, further, if we conceive fat to 
be formed from starch, sugar, or sugar of 
milk, that for the same amount of carbon 
there must be separated 90, 100, and 110 
equivalents of oxygen from these com- 
pounds respectively. 

" There is therefore but one way in which 
the formation of fat in the animal body is 
possible, and this is absolutely the same in 
wliich its formation in plants takes place ; 



it is a separation of oxygen from the ele- 
ments of food." 

OF THE EXTERNAL PARTS. 

THE HOOF.* 

" The hoof is the horny case or covering 
nature has provided for the protection of 
the sensitive parts of the foot. It may be 
said of itself to constitute such a shoe or 
defence, as enables the animal in his wild 
state to travel about in quest of food, not 
only without injury to the structures under- 
neath it, but with a degree of elasticity that 
preser\'es his whole frame from concussion. 
Were one forced into any comparison of 
the sort, it must be admitted that the hoofs 
of animals bear some anatomical affinity 
to the human nails, or claws of other 
animals ; though they are vastly superior 
in physiological importance to any such 
appendages as these. 

* Pcrcivall's Anatomy. 



EXAMINATIONS RESUMED. 



ADIPOSE TISSlii:. 

Q. What is the fatty matter contained in the adipose 
cells composed of? — A. Stearine, margarine, and 
oleine. 

Q. How do they appear when isolated? — -4. The 
two former are solid, and the latter is fluid. 

Q. How are they preserved in a fluid state in the 
animal body? — A. By the ordinai-y temperature of 
the body. 

Q. What are the observable (hflerenccs in color 
occurring in different parts of the body, and in animals 
of diverse temperaments? — ,1. In .some parts of the 
body it is white, in others it has a yellow tinge ; in 
animals of hinphatic and nervous temperaments it is 
wliitej in the sanguine it has somewliat of a red 
tinge ; in the bilious it presents a yellow ajjjjcarance. 

Q. The fat at the ordinaiT temjierature of the hnng 
body being fluid, how is it retained m the fat cells with- 
out transudation ? — A. The intervals of the fat cells 
are traversed by a minute net-work of blood vessels, 
fi'om which they derive their secretion ; and it is prob- 
ably by the constant moistening of their walls with a 
watery fluid, that their contents are retained. 

Q. What are uses of the adipose tissue? — A. It is 
intended to fill up spaces ; forms a sort of cushion or 
pad for the support of movable parts. It also acts as 
a non-conductor of heat, thus preser\ing the animal 
temperature; it serves as a reservoir of combustible 
3 



' matter, at the expense of which the resjiiration may be 
maintained when other materials ai'e deficient. 

Q. Suppose you desh-ed to fatten a horse or an ox, 
what method should you adopt? * — A. I should keep 
the animal at rest, and furnish him with an abundance 
of nitrogemzed food. 

Q. In what vegetable constituents does nitrogen 
abound ? — ^-1. In vegetable fibrine, albumen, and 
caseiiie. 

[ * Experience teaches us that, in poultry, the maximum of fht ia 
obtained by tying the fet^t. and by a medium temperature. These 
animal:^ in sucheircumsur,<-es may he compared to a plant possessin;; 
in the hijrliest dei^reethe power of converting all the food into parts of 
its own structure. The excess of the constituents of blood fomtj 
fle.ih and other org;inized ti^uci, while that of starch, sugar, etc., U 
converted into fat. When animals are f.ittened on food destitute of 
nitrogen, only cert^iin parts of their structure increzisy in size. Thus, 
in a goose, fattened in the method above alluded to. the liver become!? 
three or four times larger than in the same animal, when well fed 
with free motion, while we cannot say that the organized structure 
of the liver is thereby increased. The liver of a goose fed in the 
ordinary way is firm and elastic ; that of the imprisoned animal is 
soft and spongy. The difference consists in a greater or less expan- 
sion of its cells which are filled with fat. 

In some diSKises, the stjirch, sugar, etc., of the food obviously do not 
undergo the changes which enable them to .a.ssist in respiration, and 
con.sequentty to be converted into fat. Thus, in diabetes Ulellitus, 
the starch is only converted into grape sugar, which is expelled 
from the body without further change. 

In other diseases, as for example in inflammation of the liver, we 
find the blood loaded ^vith fat and oil; and in the composition of the 
bile there is nothing at all inconsistent with the supposition that 
some of its constituents m.iy be transformed into lat. 



•.•^-* 



13 



ANATOMY AXD PHVSIOLOGV OF 



" Form. — Saiiibel viewed tLe fciot as 
'the segment of an oval, opened at the 
back, and nearly round in front.' To a 
conamon observer, the hoof exliibits a coiioid 
form ; (he part resting upon the ground 
being the basis, the vacuity above, the ob- 
truncated apex. Mr. Bracy Clark asserts 
that tliis view is incorrect, and that the 
general figure of the hoof is a cylinder, 
very obliquely truncated upon its ground 
surface. This he demonstrates in two 
ways ; either by rolling up a piece of paper 
into the shape of a cylinder, and afterwards 
cutting one of its ends in a very slanting 
direction ; or by taking a carpenter's square, 
and placing one limb beneath the foot 
across the quarters, then sloping the other 
backward against the side of the quarters, 
parallel to the front, when the edge of the 
iron will be found parallel to the wall of 
the hoof. This corrected view of its figure 
will serve to account for the general equi- 
formity manifest in the hoof, and also for 
the undeviating correspondence found to 
exist between its slope or slant, as well in 
front as behind, which in an ordinary or 
healthy foot may be estimated at an angle 
of 45°. Around the coronet, where the 
hoof unites with the skin, the cylinder is 
cut directly across its perpendicular — at 
right angles with it : it is the oblique trun- 
cation of its ground-surface that occasions 
the slant, which latter we may consequently 
increase at pleasure by any means that 
augment the former, viz. : by lowering the 
heels ; by cutting away a prominent frog ; 
or by putting on thin-heeled shoes. At the 
same time that we increase the slant of the 
hoof, we increase the obliquity of the pas- 
terns, and likewise proportionately augment 
the ground-surface of the hoof, from heel to 
toe, the breadth remaining unaltered ; and 
in the same ratio, consequently, extend the 
surface of tread.* 

" Spread. — By the spread, is meant the 
inclination the hoof manifests, when left 
unshod, around the toe and sides, to bulge 

* For fiirilRT elucidation on the cylindrical form of the 
foot, consult Mr. Bracy Clark's works on the Foot of the 
Horse. 



or protrude at bottom, whereby its ground- 
surface becomes augmented, particularly 
around the outer quarter. To a certain ex- 
tent tliis is worthy of observation; although, 
in my opinion, it is to be regarded i-ather as 
an effect of pressure than one of abstract 
growth. The surface of inclination upon 
which the horn is produced has no such 
spread, nor can the hoof itself be said, /row 
grou'th alone, to have any such natural ten- 
dency ; but, as it continues to grow and 
shoot beyond the inner foot that produced 
it, and to which it was so intimately united, 
it yields to the pressure of the anima'.'s 
weight, and bulges or spreads out, and 
inore at the outer side than the inner, in 
consequence of the pressure tending more 
in that direction. K we examine a num- 
ber of hoofs of neglected growth, and con- 
sequent exuberance and deformity, of va- 
rious descriptions, we may discover thai, 
in them all, the spread seems to have been 
the first or incipient deviation from that line 
of growth viewed as consistent with the 
health and well-doing of the foot. It ij 
only in the unshod hoof that any spread is 
found : as soon as the ground-surface comc.-j 
to be confined by a shoe, pressure can no 
longer exert its influence to produce such 
consequences. 

" Mr. Goodwin aptly observes, that 'to 
take the form of the hoof correctly, we must 
strip it of its exuberant or superfluous 
parts, the same as one would pare the su- 
perabundant growth off our own nails. 
The neglect of this necessary preparative 
has led to a considerable difference of 
opinion about the natural, healthy, or true 
form of the ground-surface of the foot. 
Mr. Bracy Clark, I conceive, has inclined 
to the side of error in this particular ; 
though, in the substitution of the cylin- 
drical for the conical figure of the entire 
hoof, he has certainly the advantage of 
other -writers. His natural foot is one 
with great spread to it, much of which 
the smith would find it necessary to de- 
prive it of, even on the first shoeing ; and 
the protuberance of the outer quarter 
(which Mr. C. points out as an attribute 



THE HORSE. 



19 



of health) being wholly owing to the spread, 
will, of course, disappear with the annihi- 
lation of the spread.' * 

" Although RL-. Goodwin has not here 
explained what he conceives to be the 
origin or cause of the spread, it is evident 
we both concur in viewing it rather as a 
deviation from health or nature than a cir- 
cumstance worthy of the consideration it 
has been accounted of by Mr. Clark. 

" Color. — Hoofs are black or white, or 
some intermediate shade, or they may ex- 
hibit a black and white striped or marbly 
aspect. It is an old observation, and one 
that passes current among us at the present 
day, that black or dark-shaded hoofs pos- 
sess greater strenglh and durability, and 
indicate less proneness in the feet to dis- 
ease, than such as are composed of white 
or striped horn. The rationale of which 
appears to be, that white horn (the same as 
white hair) is the product of parts weaker 
by nature than such as produce dark or 
black horn, and, being wealier, consequently 
are more liable to disease, less able to resist 
those impressions that tend to disorder. 
White hoofs are more porous than black 
ones, and consequently absorb moisture and 
lose it again by evaporation with more fa- 
cility: a fact that may probably aid us in 
accounting for the failures attributed to 
them. 

" Magnitude. — It requires no veterinary 
skill to discover any very material dispro- 
portion in the magnitude of the foot : it 
will strike us at once as being large or 
small, in comparison to the limb or the size 
of the animal. A foot of any description 
that is out of proportion is to the horse 
possessing it more or less objectionable : 
but, for all that, these out-of-proportion feet, 
abstractedly considered, have their advan- 
tages as well as their disadvantages. Sain- 
bel tells us, that a large wide hoof, by ex- 
tending the surface of tread, ' will increase 
the stability and firmness of the fabric ; ' 
but then, he adds, ' this partial advantage 
grows into an evil when it becomes applied 

* Goodwin's New System of Shoeing, edit, second, 
pase 33. 



to a body capable of translation, and con- 
sidered in a state of actual motion ; be- 
cause, then, the mass and weight of the 
foot overburthen the muscles of tiie ex- 
tremity.' And because, I would add, the 
surfaces of contact being greater, the attrac- 
tion of cohesion becomes greater, and so 
much the more muscular force is required 
to raise the foot (particularly in moist 
ground) from the earth. Besides which, a 
large foot is apt to become objectionable 
from its striking, during action, the opposite 
leg. On the other hand, it is contended, 
that a large foot will not sink so deep into 
soft ground as a small one, and conse- 
quently will not demand so great an effort 
of strength to draw it out. This is an 
argument, however, that can only hold good 
under the supposition, that in both cases 
the muscular sireugth is equal, which wc 
know but rarely to happen, — in general, 
broad or flat-footed horses possessing supe- 
rior strength ; small, narrow-footed ones, 
superior speed. There cannot be a doubt 
about a large foot being unfavorable for 
speed, a small one for stability ; neither 
one nor the other can be indiscriminately 
found fault with ; both within certain limits 
possess their respective advantages ; though 
to turn out as sucii, they each of them re- 
quire to be combined with suitable confor- 
mation and action. 

" Large bulky hoofs are found to be 
mechanically weaker than others, in conse- 
quence of being composed of a thin, soft, 
porous description of horn. Sainbel ascribes 
all this to ' a relaxation of the fibres com- 
posing the hoof: in which case, the diame- 
ters of the vessels are increased, the porosi- 
ties are multiplied, and the fluids abound 
in them in too great quantities ; conse- 
quently this kind of foot is soft, tender, and 
sensible.' S.Tiall feet, on the contrary, in 
general possess a close -woven horn, thick 
in substance, and consequently prove strongj 
they are rather oval than circular in figure, 
with great depth of substance, and are 
found to be of a durable nature. ' In feet 
of this description,' says Sainbel, ' from the 
too close union and too close tension of 



20 



AXATOMY A.\D PHYSIOLOGY OF 



their fibres, the vessels destined to conduct 
the nutritious fluid are contracted and 
obliterated ; Avhencc proceeds that dryness 
of the part which renders the horn brittle 
and liable to split.' * 

" Division. — To the common observer 
the hoof appears to consist of one entire 
or indivisible case ; but the anatomist finds, 
by subjecting it to maceration, or coction, 
or even to putrefaction, that it resolves 
itself into three separate pieces : still, so 
long as the hoof maintains its integi'ity, 
such is the force of cohesion existing be- 
tween these three parts, that we as easily 
rend it in any other place as dissever one 
of its jointures. These constituent parts 
are the tvall, the sole, and the//-o^. 

THE WALL. 

" The wall or crust is the part of the 
hoof which is visible while the foot stands 
upon the ground. It forms a circular 
bovindary-wall or fence inclosing the inter- 
nal structures. On taking up the foot, we 
find the wall prominent all round beyond 
the other parts, making the first impression 
upon the ground, and evidently taking the 
largest share of bearing. It is the part to 
which the shoe is nailed. It is, in fact, the 
most important division of the hoof; ap- 
pearing to form (in the words of Mr. Clark) 
' the basis or first principle in the mechan- 
ism of the hoof, the other parts being all 
subordinate to this.' 

" Siiuations and Relations. — The wall 
takes its beginning at the coronet, from the 
terminating circular border of the skin, 
with which it is intimately united ; their 
line of union being concealed by a row of 
overhanging hairs. From the coronet the 
wall descends in an oblique direction to 
the bottom of the foot, where it em- 
braces the sole, and terminates in a cir- 
cular projecting border. The anterior and 
lateral parts of the hoof are formed entirely 
by the wall ; but at (he posterior part, in- 
stead of the heels of the v.'all being con- 
tinued one into the other so as to complete 
the circle, they become inflected, first down- 

* Sainbel's Lectures on tlie Elements of Farriery. 



ward, afterwards forward and inward, and 
are elongated in the latter direction until 
they reach the centre of the bottom of the 
foot, where they terminate : these inflec- 
tions or processes of the wall constitute the 
bars. Altogether, the wall may be said to 
form about two-thu'ds of the entire hoof. 

" Connection. — Superiorly, around the 
coronet, the wall is united with the skin; 
inferiorly, within its circumferent border, 
with the sole ; posteriorly, between its heels, 
with the heels of the frog; inferiorly, be- 
tween the bars, with the sides of the frog ; 
and internally, with the sensitive laminae. 
Let us now consider the wall in its detached 
or separate state. 

" Fig-ure. — That of a hollow cylinder, 
having the sides presented to the ground cut 
much aslant, and whose circle exhibits a 
hiatus or deficiency behind, from the lateral 
boundaries of which issue two narrow pro- 
cesses or appendages. Taking a lateral 
view, the wall assumes a conical shape, 
being broad and deep in front, and gradually 
narrowing as it stretches backward. 

^^ Division. — For facility of reference, and 
in aid of our descriptions, we distinguish 
in the wall. First, the toe; secondly, the 
quarters; thirdly, the heels; fourthly, the 
superior or coronary border ; fifthly, the in- 
ferior or solar border ; sixthly, the lamince 
or lamella; lastly, the bars or appendages. 

" The Toe forms the bow or front of the 
hoof, and comprehends about two-thirds of 
the superficies of the wall. It is the deep- 
est, broadest, and thickest part of the wall ; 
for reasons that will appear hereafter. It 
exhibits a degree of slant about equal, nat- 
urally, to an angle of forty-five degrees; 
though there are variations from this which 
(as was explained before) will be found, in 
a measure, to be dependent upon the oblique 
truncation of the cylinder. When we come 
to understand the physiology of this part, 
however, a more operative and efficient 
cause for this variation will be found in the 
weight the wall has to sustain, and in its 
own mechanical strength or force of resist- 
ance : on which principle it is that light 
horses, thorough-breds, and ponies, as well 



'? 



EXPLANATION OF FIGURE III. 



MUSCUI,AR STRUCTURE. 

a". Trapezius. 

6. llliomboidcus longiis. 

c-''. Scalenus; and /. Si)!emus. 

e'. I'ectoralis transversali.''. 

f. Antea .spinatu.s. 

r/'. Pnslea spinatus. 

D. Scrralus magnus. 

b\ Intercostales. 

c. ObKquus externus abdominis. 

iV. Obliijuus internus abdominis. 

e'. Erector coccygis. 

./'. Depressor coccygis. 

(/'. Compressor coccygis. 

//'. r. Gluteii muscles. J- Triceps abductor. 

K. ]5lceps abductor femoris. 

»('. Tensor vagina'. ^ 

n\ Rectus. 

«'. Vastus externus. 

»■'. s'. Gastrocnemius externus, and plantaris. 

»'. Elexor jjedis accessorius ; its lleshy belly. 

)/'. I'eroneus. 

x'. E.\tensor iiedis. 

7i". Teres major. 

i". I.atissimus dorsi. 

J. I'ectoralis magnus. 

K. Humero cubital. (Pectoral region.) 

v. .Scapulo-ulnaris. 

j»". »". Triceps extensor bracliii. 

o". I'ectoralis transvcrsalis. 

;>". Flexor metacarpi externus. 

K. V. Levator humeri, and Stcrno maxillaris. 

.»". Extensor metacarpi magnus. 

x". Extensor pedis. 

At the inferior part of the abdomen tlie letter /;. occurs; it should be 4. 4 
The .subcutaneous thoracic vein h., however, serves to indicate the region of 
tlie rectus abdominalis. 

7. The sheath. 

*. Ligaraentum colli. 

A. (Region of the back.) Levatores costarura. 



THE HORSE. 



21 



as mules and asses, have upright or strong 
feet (i. c), walls but moderately sloped; 
whereas heavy horses, cart-horses, and 
coach-horses, have commonly flat or iceak 
feet (i. e.), walls that slant immoderately. 
And (as was before observed) upon the 
degree of obliquity of the wall must very 
much depend that of the pasterns. In esti- 
mating the slant or slope of the wall, it is 
proper to distinguish between that which is 
consequent on the detruncation of the hoof, 
and such as is the effect of a burthen under 
which the wall succumbs. The depth of 
horn in front of the toe, measuring from the 
termination of the skin to the most promi- 
nent point below (and supposing the hoof 
to be cut and ready to receive the shoe), 
may be rated at about three and a half 
inches. The bow or degree of convexity 
of the toe in front must depend upon its 
obliquity as well as upon the circularity of 
the foot. The thickness of the horn com- 
posing the toe may be estimated at three- 
eighths of an inch, or from that to half an 
inch, and this substance is the same from 
immediately beneath the coronary circle to 
the junction of the wall with the sole ; at 
which part there is. an accession of horny 
matter to block up the interstices between 
the laminse, and also to fill the angular 
vacuity that would otherwise exist here 
between the wall and sole. In the fore-feet, 
the toe is thicker in substance than either 
the quarters or heels ; but (we have it from 
Sainbel) ' in the hind, on the contrary, the 
heels and quarters are generally thicker than 
the toe.' 

" The Quarters are the portions of the 
wall intermediate between the toe and the 
heels. They are commonly described as 
standing upright, and, according to a car- 
penter's square set against the wall, so they 
appear to do ; this is not, however, the view 
the anatomist ought to take of their posi- 
tion : to him the oblique course of their 
component fibres, together with the slant of 
their laminae, demonstrate that they slope 
in the same manner and degree as the toe 
does. The quarters do not run in straight 
lines from before backward, but by theii- 



prominence describe gcnllccurves, the outer 
making a wider sweep than the inner. 
This gives the hoof altogether a sort of 
ticisted appearance, and makes the inner 
part of the toe look more projecting than 
the outer; a deviation that seems principally 
to have originated in the spread, and one, 
methinks, that has had more attention given 
it than any consequences attachable to it 
render it deserving of. The quarters range 
in depth from two to three inches ; and 
measure in thickness from one-fourth to 
three-eighths of an inch. 

" The Heels are the two protuberant por- 
tions of the wall by which it is terminated 
posteriorly. They are the shallowest, and 
thinnest, and (in connection) only flexible 
parts of the wall. Though their surfaces 
recede from the perpendicular, they main- 
tain the same slope as the toe and quarters. 
At their angles of inllection, from which 
are continued the bars, they form (in con- 
junction with the heels of the sole) pouches 
or sockets into which are received the heels 
of the sensitive foot. In depth they range 
from one and a half to two inches. In sub- 
stance they do not exceed a quarter of an 
inch, the outer heel being rather thicker than 
the inner. 

" TJie Superior or Coronary Border is the 
circular, attenuated, concavo-convex part 
entering into the composition of the coronet. 
Its extent is marked exteriorly by the whitish 
aspect it exhibits, and also by some partial 
separation and evcrsion of the outer flakes 
of horn around its junction with the wall 
below. Externally, it assumes the same 
character as the wall below it ; but its in- 
ternal surface is altogether ditlerent. In- 
stead of possessing laminae, the surface is 
smooth and uniformly excavated, being 
moulded to the form of the sensitive coro- 
net, and everywhere presenting numerous 
pores for the purpose of receiving the secret- 
ing villi. Superiorly, the coronary border 
presents two edges, having a groove be- 
tween them for the reception of the termi- 
nating border of the cutis. It is this gi-oove 
that marks the reception of the coronary 
border into two parts : the internal edge 



22 



AXATOMY AND PHYSIOLOGY OF 



belonging to the inner part, which is the 
beginning of the wall itself; the external 
edge to the white band by which the other 
is embraced, and to which Mr. Clark has in 
particular drawn our attention, under the 
appellation of Coronary Frog-band. This 
covers the proper or veritable coronary bor- 
der of the hoof; having, through its fibres, 
which are very fine, a sort of dove-tailed 
conneciion with it. As it recedes backward, 
it grows broader to that degree, that its 
breadth at length becomes doubled ; being 
about half an inch broad in front, and one 
inch behind. It is thickest around its mid- 
dle parts ; its inferior edge, like the superior, 
becoming attenuated, until it grows so fine 
as to end in imperceptible union with the 
substance of the wall, giving it its beauti- 
fully polished surface : from the heat, how- 
ever, to which the hoof is artificially exposed, 
the thin part below the coronet often grows 
arid, splits from the crust, and becomes 
everted ; turning, at the same time, in con- 
sequence of dryness, of a whitish complex- 
ion. Posteriorly, we find it continued round 
the heels of the wall and frog, and from 
thence across the back of the cleft, forming 
altogether a complete circle, and everywhere 
showing itself to be the medium of connec- 
tion between the skin and the hoof. It has 
been already stated that the cutis terminates 
in a circular border, let into a groove around 
the summit of the wall: the cuticle, how- 
ever, does not end here — it is continued 
down ; in fact, we trace it to the horny 
band we have been describing, the one being 
continuous in substance with the other. In- 
deed, the only detectible differences in them 
are, that one is thicker than the other, and 
grows hard, and dry, and white, from the 
effects of heat upon it from without, and 
the want of moisture from within. This 
cuticular origin and assimilation may be 
demonstrated in the putrefied foot; -or, bet- 
ter still, in the foot of the foetus. The band 
is broader at the heels than elsewhere, in con- 
sequence of the greater breadth of exposed 
cutis at those parts. In its texture it is 
fibrous, and its fibres pursue the same direc- 
tion as those of the wall, from which they 



differ only in being of a finer texture. Mr. 
Bracy Clark appears to entertain some sin- 
gular notions in regard to the structure, but 
more particularly the uses, of this part; 
which, in the respect 1 bear for theix author, 
I shall consider, when the time may arrive 
for me to treat of the physiology of the 
foot. 

" The Inferior or Solar Border offers but 
little worthy of observation. It constitutes 
the ground or wearing surface of the wall, 
and is the part to which we nail the shoe. 
It grows thicker and more exuberant around 
the toe than in other places, and, from its pro- 
jecting beyond the sole, presents a conven- 
ient and suitable hold for the nails of the 
shoe. Around the anterior and lateral parts, 
it embraces the sole ; behind, it joins the 
bars, which two points of union form two 
principal bearing places for the shoe. The 
inferior border possesses a larger circumfer- 
ence than the superior, in consequence of 
the oblique detruncation of the hoof. 

" This is a part that requires paring down 
every time the horse is shod. Such is its 
exuberating nature, that (like the human 
nail), were it not continually kept worn 
down, or broken, or cut off, it would elon- 
gate very considerably, and gradually turn 
up, exhibiting forms not only of the most 
unsightly but even grotesque description, 
and proving incommodious to a degree to 
be almost entirely destructive of progres- 
sion. 

" The Lamina (better named lamellce) 
consist of numerous narrow thin plates or 
processes, arranged with the nicest order 
and mathematical precision upon the inter- 
nal surface of the wall. They extend, in 
uniform parallels, in a perpendicular direc- 
tion from the lower edge of the superior 
border down to the line of junction of the 
wall with the sole ; and are so thickly set 
that no part of the superficies remains un- 
occupied by them. They are likewise con- 
tinued upon the surfaces of the bars. In 
the recent subject they are found soft, yield- 
ing, and elastic ; but from exposure they 
become dry and rigid. 

" Every lamellae exhibits two edges and 



THE HORSE. 



23 



two surfaces. By one edge it grows to the 
wall ; the other, which is somewhat attenu- 
ated, hangs loose and floating within the 
cavity of the hoof. The surfaces, which are 
two lateral, are smooth, and, considering 
the magnitude of the lamella itself, of enor- 
mous extent ; so much so that it might be 
said almost to be constituted entirely of 
superficies. And this leads us to the con- 
templation of the great and magnificent 
design which Nature evidently had in view 
in their formation, viz., the production of 
ample surface within a small space, an end 
that has been obtained through the means 
of multiplication. Mr. Bracy Clark pro- 
cured from the late Thos. Evans, L.L. D., 
mathematical teacher of Christ's Hos- 
pital, a calculation of what their united 
superficies amounted to ; and it appeared 
to afford an increase of actual surface more 
than the simple internal area of the hoof 
would give of about twelve times, or about 
212 square inches, or nearly one square foot 
and a half. 

" The lamellae exhibit no diflerences but 
in their dimensions. In length they corres- 
pond to the respective depths of the wall ; 
being longest, and likewise broadest, around 
the toe, and gradually decreasing towards 
the hinder parts. 

" In composition they are horny. Viewed 
through a microscope, Mr. Clark discovered 
in their substance two planes of fibres, ' the 
one running in parallel lines to the axis of 
the hoof, the other obliquely intersecting 
these.' When stretched, they exhibit signs 
of elasticity ; but this appears greater in 
the transverse than in the perpendicular 
direction. 

" By means of its lamellae, the wall 
presents a superficies of extraordinary am- 
plitude for the attachment of the coffin- 
bone. A structure consisting of similarly 
formed lamellae envelops the bone, and these 
are dovetailed in such a manner with the 
horny lamellae, as to complete a union 
which, for concentrated strength, combining 
elasticity, may vie wdth any piece of animal 
mechanism at present known to us. 

" The Bars are processes of the wall, in- 



flected from its heels obliquely across the 
bottom of the foot. For a long time, by 
farriers, they were confounded with the sub- 
stance of the sole, an error that owed its 
origin and perpetuation to the malpractice 
they exercised in paring the foot — incut- 
ting both bars and sole down, without any 
distinction, to a common level. In the 
natural healthy foot the bars appear, exter- 
nally, as elongated sharpened prominences, 
extending from the bases of the heels into 
the centre of the foot, between the sole and 
the frog ; posteriorly, they lire continuous 
in substance with the wall, with which they 
form acute angles ; anteriorly, they stretch 
as far as the point of the frog, constituting 
two inner walls or lateral fences between 
that body and the sole. Sainbel conceives, 
from their position, that they offer resistance 
to the contraction of the heels. Their in- 
ternal surfaces exhibit rows of lamella, 
continued from those lining the wall, but 
which are here sliort^ and in their direction 
transverse, two circumstances referable to 
the narrowness and inflection of the bar. 
Towards the extremity of the bar they 
gradually gi-ow shorter, and less distinctly 
marked, until we at length lose all vestige 
of any more of them. While the promi- 
nence of the bars is such as to give them a 
secondary bearing upon the groitnd, their 
sharpened forms will sink them more or 
less deeply into every impressible surface. 

"the sole. 
" The sole is the arched plate entering 
into the formation (as its name impfies) of 
the bottom of the hoof: or, to adopt Sain- 
bel's definition, ' it is that part which covers 
the whole inferior surface of the foot, ex- 
cepting the frog.' It is a very just practical 
observation of Mr. Coleman's, that although 
a knowledge of every part of the foot is in- 
dispensably necessary to render us scientific 
overseers of the farrier's art, no individual 
part requires such undivided attention, as 
regards shoeing, as the sole, since the suc- 
cess of this mechanical operation mainly 
depends on the paring and defence of this 
arched horny plate. 



24 



ANATOMY AND rilVSIOLOGY OP 



"Situation and Conner/ion. — It fills up 
the interspaces between the outer and inner 
walls (or bars) of tiie crust. I differ in 
opiiiion from those who describe it to sur- 
round the toe of the frog. I hold its circum- 
fcrent support and connection to be the wall 
of the hoof, to which it is firmly cemented 
by nn interstitial horny matter, filling the 
crevices between the laminas. 

'• Figure. — The circumferent outline of 
the sole measures about two-thirds of a cir- 
cle, the remaining third being omitted to 
form a triangular-shaped hiatus or opening 
for the reception of the frog and bars. This 
circular form, however, is by no means true, 
or even invariably the same, in its dimen- 
sions. Generally, the longitudinal exceeds 
the transverse diameter. Its greatest diam- 
eter is shown by a line extended from either 
heel across its middle to the opposite point 
of the toe. 

" Arch. — Commonly, the sole presents 
an arch of more or less concavity interiorly, 
and convexity superiorly. But it is not a 
regular or uniform arch, being one that 
rather waves or undulates, so as to bear a 
comparison, made of it by Mr. Clark, ' to 
the mouth of a bell extremely extended or 
flattened.' Like that of the bell, the arch 
is highest in the middle, from which it 
slopes, laterally, down to a flat, subsequently 
to rise again around its border, in order to 
present a dilated surface for attachment 
towards the waU. There is, however, vast 
variety in the degree of arch of the sole: in 
some feet it is of surprising depth ; in 
others, the arcli is converted into a flattened 
surface ; and yet both seem to perform 
equally well. In the hind feet the sole is 
generally more arched than in the fore, and 
approaches in figure nearer to the oval than 
the circle. 

"Division. — In the sole we distinguish 
an anterior part or toe; a middle or central 
part ; two points or lieels ; and two surfaces. 
These divisions are not very well defined : 
Jut they prove serviceable in aid of our de- 
scriptions. The toe of the sole is the part 
encircled by the toe of the wall, against 
which it abuts, and to which it is intimately 



united by horny matter, the two together 
forming a stout bulwark of defence to those 
parts of the internal foot included between 
them. The points or heels are the two pos- 
terior salient angles received into the angu- 
lar intervals between the outer and inner 
walls or bars. Although naturally the 
least exposed, these are the parts most sub- 
ject to injury or pressure from the shoe, 
being the seat of that disease mistakenly 
called corn. The middle or centre of the 
sole is the portion more immediately sur- 
rounding the fore parts of the frog, and 
would (were the sole a regular arch) be the 
most elevated part ; but, in general, we find 
the sole flattened hereabouts ; the highest 
parts of the arch being the angles alongside 
of the bars ; the lowermost, those around 
the toe. 

" Surfaces. — Of the surfaces, the supe- 
rior (as was mentioned before) is unevenly 
convex ; the inferior, eorrespondently con- 
cave. The former is everywhere pitted, 
particularly about the heels, with numerous 
circular pores, running in an oblique direc- 
tion, the marks of which remain evident 
upon the inferior surface Likewise. These 
pores are the impressions made in the soft 
horn by the villi of the sensitive sole, from 
whose orifices the horny matter is produced. 
They also form the bond of union between 
the horny and the sensitive soles : which is 
of a nature so strong and resisting, that it 
requires the whole strength of a man's arm 
to effect their separation — an operation of 
a cruel description that was wont to be 
practised in times past, under the fallacious 
notion that ' drawing the sole ' was extir- 
pating the malady. 

" Thickness. — The natural thickness of 
the sole may be estimated at about one- 
sixth of an inch. There will be found, 
however, variations from this standard in 
different horses ; and it will also very much 
depend on the part selected for measiure- 
ment. The portion of the sole most ele- 
vated from the gi-ound — that which forms 
a union with the bars — is nearly double 
the thickness of the central or circumferent 
parts ; and netxt to this, in substance, comes 



THE HORSE. 



25 



tlie heel. I do not find that the sole 'grows 
thinner from the circumference to the 
centre,' as lias been stated by an author 
of celebrity. 

"the frog. 

" The frog is the prominent, triangular, 
spongy body, occupying the chasm left by 
the inflection of the bars. 

" Situation and Connection. — The frog 
is fitted into the interval between the bars ; 
the three, altogether, filling up the vacuity 
ill the sole, and thereby completing the 
circle, and establishing the solidungulous 
character of the foot. The frog extends 
forward, towards the toe, about two-thirds 
of the longitudinal diameter of the ground- 
surface of the hoof, terminating a little be- 
yond the central point (or what would be 
the central point) of the sole — or rather; 
shooting directly through it, so as to anni- 
hilate the spot. Posteriorly, it is embraced 
by the heels of the waU; laterally, it pos- 
sesses firm and solid junctions with the 
bars, and through their medium with the 
sole : and these unions are efi'ected not by 
simple apposition and cohesion of surface, 
but by a lamellated structure, apparent on 
the sides both of the frog and bars, by which 
the parts are reciprocally dovetailed into 
each other. Lamella; are discoverable upon 
its sides, even all round the toe of the frog; 
and this is a circumstance that confirms me 
in my belief that the bars reach thus far. 

" Figure. — The frog may be caUed pyra- 
midal, or cuneiform, or triangular in figure; 
its outline forming the geometrical figure 
denominated an isosceles triangle. I know 
of no comparison so familiarly apt as that 
of resembling it to a ploughshare : not only 
do they both correspond, as near as such 
comparisons can be expected to do, in out- 
line and make, but they likewise exhibit a 
singular coincidence in function ; the frog, 
like the ploughshare, being intended by its 
point to plough or divide the surface of the 
earth, and in that manner serve as a stay or 
stop to the foot. 

" Division. — Wc distinguisii in the frog 
two surfaces, an inferior and a superior; 

4 



two sides ; a point or tor ; and two bulbs or 
heefs. 

" Surfaces. — Both surfaces of the frog 
manifest striking irregularities, and these 
are respectively reversed, making one sur- 
face the exact counterpart of the other. In 
other respects, the only dilTerence they ex- 
hibit, is, that the superior exceeds the in- 
ferior both in length and breadth. 

" The inferior surface presents to our 
view a remarkable cavity, broad, deep, and 
triangular in its shape, bounded on the 
sides by two sloping prominences, which 
divaricate from the convexity forming the 
toe of the frog, and terminate, after a short 
divergent course, at the heels. This cavity 
or hollow is denominated 

" The Cleft of the Frog: with seeming 
reference to the relationship existing, 
through its presence, between the horse's 
foot and the cloven one of tiie ox, deer, 
sheep, etc. In consequence of its sides 
sloping inward, the cleft at bottom gapes 
wide open ; but along the top is roofed by 
a simple linear mark running from before 
backward. The horn is kept continually 
soft and pliant within the cleft by a pecu- 
liar secretion from the sensitive parts it 
covers, the odor of which is notorious. 

" The solid wedge-like portion of horn 
in front of the cleft, extending from it to 
the point of the toe, has been observed by 
Mr. Clarli to exhibit, in the natural foot at 
its full growth, 'a considerable bulbous en- 
largement,' which, by way of distinction, 
he calls the cushion of the frog. On making 
a perpendicular section of the foot, Mr. C. 
finds this part is situated ' nearly opposite 
or under the navicular bone.' And it would 
appear (according to this author) that this 
' rotundity, or swell of the frog,' is never 
reproduced after it has once been annihi- 
lated by the knife of the smith. 

" The superior surface of the frog, eveiy- 
where continuous, uniform', and porous, 
being the counterpart in form of the infe- 
rior, presents us with nothing but reverses : 
where the one is hollow or depressed the 
other rises into swells and eminences, and 
vice versa. This accounts for our finding 



26 



ANATOMY AND PHYSIOLOGY OP 



the part opposite to the cleft elevated into 
a conspicuous eminence, bounded on its 
sides by two deep channels, and a hoUow 
of broader but sliallowcr dimensions in the 
front. To this central conical elevation 
Mr. Clark has given the name of frog-stay, 
from some novel notions he entertains of its 
physiology. Such a bold promontory of 
horn rising in the middle of broad and 
deep channels is well calculated to form 
that dovetailed sort of connection with the 
sensitive foot, which greatly augments their 
surfaces of apposition, and establishes their 
union beyond all risk or possibility of dislo- 
cation. It is a part which (as far as my 
observations " on it have extended) grows 
and becomes developed together with other 
parts of the foot ; and one that is apt to 
vary in its relative volume in different feet. 
In front of the frog-stay, the lateral borders, 
bounding the hollow in the middle, describe 
a waving line, which, near half-way to the 
point of the toe, exhibits a dip or impres- 
sion : Ihis marks the impression of the 
navicular bone, and is the part immediately 
opposite to the ' cushion of the frog,' — a 
coincidence important to be borne in mind, 
as tending to throw some light on the na- 
ture of this new-christened structure.* 

" The Sides are the parts by which the 
frog establishes its union with the borders 
of the triangular vacuity in the hoof into 
which it is admitted. Along their superior 
borders they are transversely lamellated, or 
rather indentated, in order that they may be 
fitted to the internal surfaces of the bars, 
which exhibit a similar structure. 

" The Commissures are the two deep 
triangular-shaped hollows between the bars 
and the sides of the frog. It being only 
the superior borders of these parts that are 
engaged in their union, their broad, unat- 
tached parts, below, form the boundary 
walls of the commissures. Looking into 
the interior of the hoof, we discover that 
the commissures, internally, are converted 
into rounded promontories, similar in ap- 

* In f.ict, llic cushion of the frog appears to be nothing 
more tlian a bulge of tlie ])art produced by the saperin- 
camb','nt pressure of the navicular bone. 



pearance and texture to the one in the mid- 
dle — the frog-stay — on the sides of which 
they are rising. In the natural state, 
the commissures must unavoidably get 
plugged with dirt, or whatever the animal 
may happen to tread upon ; a circumstance 
from which some far-fetched notions have 
been extracted concerning their use. 

" The Toe or point of the frog is the ante- 
rioi-, undivided, elongated portion ; that which 
forms the apex of the pyramid or wedge — 
the acute or extended angle of the triangle 
— the only part displaying that prominent 
or rounded form that would waiTant us in 
using the epithet ' conical ' to the frog. It 
possesses solidity of substance, firmness of 
texture, and luxuriance of growth in an 
eminent degree ; facts well known to the 
farrier, who, in paring the foot, seldom fails 
to make more free with this than any other 
part of the frog. 

" The Heels or bulbs of the frog are the 
posterior protuberant parts embraced by the 
heels of the wall, and separated from each 
other by the cleft, forming, together, the 
base of the wedge or triangle. They pre- 
sent greater depth of substance than the 
toe, but are of a softer, more spongy tex- 
ture, and are less resisting and stable, in 
consequence of being deprived of mutual 
support by the division of the cleft. Ante- 
riorly, the heels unite with the lateral promi- 
nences bounding the cleft ; inferiorly, they 
present two surfaces of tread to the ground, 
eivdently designed to take ~a share in the 
bearing of the foot ; posteriorly and supe- 
riorly, they exiiibit a bulbous fulness, in 
consequence of receiving at this part a sup- 
plementary covering from a production 
which has been (in the description of the 
wall) adverted to, under the appellation 
given it by Mr. Clark, of 

" Coronary Frog-band. — It was there 
stated, that the coronary groove (the gi-oovc 
or canal in the coronary border of the cutis) 
broadened considerably as it descende'd to 
and turned round upon the heels ; in like 
manner does the horny band produced by 
it broaden, and not only grow broader but 
thicker in substance, and consequently in 



THE HORSE. 



-27 



the same degree augments the substance of 
the heels, occasioning that swell of them 
which has suggested the appellation ' bulb.' 
The horny band itself is everywhere lamel- 
lated upon its internal surface ; but these 
broadened parts of it display lamellae of a 
much bolder character, and consequently 
render their union with the heels so much 
the more intimate and enduring. The in- 
ferior edge of the band is denticulated, and 
the denticulations become so interlaced 
with the lamellated fibres of the wall, that 
their union is rendered, in the ordinary 
state of the hoof, altogether imperceptible. 
For drawing our attention to this part^we 
are indebted to Mr. Clark ; and, insomuch 
as he considers it to be a production of the 
cutis (not having any connection with the 
glandular circle that secretes the wall), and 
to serve the purpose of ' uniting the sensible 
parts with the insensible,' I agree with him. 
I find something very similar to this gi-ow- 
ing upon the human nail, issuing from the 
superior edge of the terminating border of 
the cutis, and continued from the cuticle, 
which proceeds for some way upon the nail, 
uniting it more closely and firmly with the 
cutis, and protecting the latter from exter- 
nal injury. This production is no more the 
beginning of the nail itself than is the so- 
called //■og--band the commencement of the 
wall : they are both distinct parts, though 
but supplementary ones, and seem to be of 
a nature partaking both of horn and cuti- 
cle. It has no more important relation to 
the frog, in my opinion, than it has to the 
wall : it serves the same purpose to both, 
— that of strapping up the heels of the 
frog and binding them in closer and more 
intimate connection with the neighboring 
parts. Were I asked what other use it ap- 
peared to have, I should say, that it was 
formed to cover and protect from injury ths 
new-formed horn of the hoof, guarding it in 
its passage downward, until it has acquired 
substance and hardness sufficient to resist 
external impressions of itself. • 

"developiment of the •amot. 
" During the early months of fcetality, no 



horn or hoof is to be found. Tlie foot is 
covered with a substance, white, firm, and 
elastic, resembling cartilage in its appear- 
ance, but proving more of the nature of 
cuticle on examination, which supplies the 
place of hoof. At the coronet this substance 
takes its origin from the cutis, being found 
to be continuous with the cuticle ; but that 
which covers the bottom of the foot is a 
production from the sensitive sole and frog. 
Altogether, it possesses the general form 
and appearance of the hoof, differing how- 
ever in these particulars — that the sub- 
stitute for the wall is comparatively thin in 
its substance; while that which grows from 
the bottom of the foot is enormously thick, 
and, instead of being shaped into sole and 
frog, exuberates to a degree to constitute 
club-footedness. About the same period 
at which the pastern and coffin-bones take 
on ossification, horn makes its appearance 
underneath this cuticular wall, in the forra 
of plates descending from the -coronet, ex- 
hibiting with peculiar distinctness the lamel- 
lated structure. The horny wall becomes 
considerably advanced before we perceive 
any change in the bottom of the foot. At 
length, horn is detected forming underneath 
the cuticular substance, which, increasing in 
thickness, gradually represents sole and frog. 
Not, however, in an undeveloped state ; for 
even at birth these parts are yet concealed 
by the exuberant cuticular covering, now 
become loose in its texture, and shaggy and 
ragged, in consequence of not receiving any 
further supply from the parts that produced 
it, and of being near its decadence ; for it 
not long after falls off, disclosing sole and 
frog both ready formed. 

"structure of the nooF. 
" Horn is found to differ in its texture or 
quality, not only in the many animals in 
which it is met Vi'ilh, but in different parts, 
and even in the same part of the body of 
the same animal. That which composes 
the hoof of the horse is a remarkable ex- 
ample of this. How different is the hora 
of the frog from the horn of the wall ; and 
yet neither of them agree in texture with 



28 



ANATOMY A.VD PHYSIOLOGY OF 



1he sole. The horny substance of the wall 
is resolvable into fibres, bearing a resem- 
blance to thick or coarse hairs, which in the 
entire hoof are so intimately matted and 
glued togetiier, as to have the appearance 
and strength of solidity. By close and ac- 
curate inspection these fibres may be seen 
descending in parallel lines, taking the 
obliquity of the wall, from the coronet to 
the inferior or solar border; they do not run 
promiscuously, but are arranged in rows, 
forming sorts of beds or strata, lying one 
upon another — a disposition made manifest 
in the foot of tlie fcetus. A clean-cut trans- 
verse section of the wall exhibits upon its 
surface numerous minute, circular, whitish 
spots, which grow larger and more distinct 
towards the internal part, and through a 
glass appear to be hollow or tubular. 
These spots I take to be produced by sec- 
tions of the horny tubes, apparently contain- 
ing a wliitish matter, a sort of pith, or pulp, 
or gelatinous instillation which pervades 
them from their origin from the villi of the 
coronary circle; the same as hairs derive 
their unctuous matter from the bulbs pro- 
ducing them, and (as this matter does the 
hair) renders the horny fibre tougli and 
elastic-^in fact, imbues it with the pecuhar 
attributes so well known to smiths by the 
appellation of living horn ; the epithet 
"living" being iiere used to denote the ob- 
vious differences the hoof of a living animal 
evinces from one that has been long detached 
from the body, or that is dead. We are too 
apt to believe that the various agents known 
to act upon the dead hoof or horn must 
take similar efl'ect on the living ; and upon 
this erroneous belief we employ hot and 
cold water, etc., etc., in treating disease of 
the feet, forgetting that we have opposed to 
our remedies the resisting or self-preserving 
j)roperties of living horn. 

" The sole, as well as the wall, is fibrous 
in its structure; but its fibres appear to be 
of a finer quality, and, in course, are very 
much shorter : they, however, take an ob- 
lique direction, from behind forwards, fol- 
lowing the same degree of slope as those 
of the wail. They issue from the villi 



penetrating the superior surface. To iho 
fineness of its fibres, combined with the rel- 
ative magnitude of the tubular canals, and 
consequent proportions of horny and gela- 
tinous sitbstances, may be ascribed the 
comparative softness and elasticity of the 
sole. 

" The frog, however, displays these 
qualities in such a remarkable degree as to 
appear, in fact, to be composed of quite 
another kind of horn ; though, on examina- 
tion, we find it to evince the same fibrous 
structure, the only ]3erceivable difi'ercnces 
being the comparative fineness of the fibres 
and their proportionably greater tubularity : 
their direction is oblique, correspondent with 
those of the wall. 

" PRODUCTION OF THE HOOF. 

" The wall is produced by the coronary 
substance, a sensitive and glandular part we 
shall have occasion soon to examine. Its 
villi, by some peculiar, mysterious, secretory 
process, convert the blood circulating 
through them into a soft pulpy gelatinous 
matter, which by exposure becomes hard 
horn,des.'ending from the villous point that 
produced it, in the form of a tubular fibre, 
down to the sole. The fibres are united 
together at their very origin, but their tubes 
or canals diminish, the lower they descend; 
which accounts for the porous or honey- 
comb-like structure of the interior of the 
coronary border and the comparative solidity 
of the parts below. The outer layers or 
strata of fibres are found to be more com- 
pact and of closer texture than the inner; 
which arises, in part, from the villi produc- 
ing them being removed to a greater dis- 
tance, and to the comparative smallness of 
their canals, and which, consequently, the 
sooner become obliterated. The use of 
Mr. Clark's coronary frog-band becomes 
now more apparent, serving, as it evidently 
does, to cover and protect these external 
fibres until they grow sufficiently firm and 
solid of themselves to bear exposure and 
resist casualties. 

" The se"nsitive laminae make no addition 
to the substance or tliickness of the wall : 



THE HORSE. 



29 



they simply produce the horny lame?lla; 
arranged along its interior; as one proof 
of which, the wall measures as much in 
thickness at the place where it quits the 
coronet as it does at any point lower down. 
Other demonstrations of this fact come 
every day before such practitioners as have 
to treat canker, quittor, sandcrack, and 
other diseases of the feet. 

" The horny sole is a production from the 
villi of the sensitive sole ; after the same 
process as that by which the horny frog is 
secreted from the villi of the sensitive frog. 

" In a state of health of the foot, the se- 
cretion of horn is unceasingly going on. 
Disease or injury of the glandular parts may 
diminish or altogether suspend the process; 
disease, under certain other forms, appears 
also to have the effect of increasing it; but 
whether we have any artificial means of 
eiVecting this, seems questionable. The 
V\all grows from above downwards. If a 
mark be made in any part of the wall, it 
will remain until it grows down and be- 
comes cut otT below, at the inferior border; 
and by observations made on the gradual 
descent and disappearance of these marks, 
calculations may be formed of the period 
of time required for the renewal or restora- 
tion of the wall. 

"properties of HORN. 

" Horn is a tough, flexible, elastic sub- 
stance, consisting of tubular fibres, more or 
less intimately connected together, taking 
the direction from the surface of the body 
on which it grows. Its property of tough- 
ness or resistance much depends on its con- 
dition in regard to moisture ; for if it is 
exposed to a degree of heat sulRcient to 
abstract nmch of its natural juice or imbibed 
moisture, it loses its flexibility and tough- 
ness, and becomes brittle. On the other 
hand, saturated with moisture, it is con- 
verted into a soft and highly flexible sub- 
stance, but at the same time becomes weak 
and unresisting. This known effect aids us 
to account for the flat-footedness of horses 
reared in low, fenny, or marshy situations ; 
the hoof being constantly in a state of 



saturation with moisture, the wall and sole 
yield to the superincumbent burthen of the 
body, and the latter grows flat (instead of 
remaining concave or arched), and even in 
some instances bulges. If oily or unctuous 
applications have any effect in softening the 
hoof, they appear to do so by filling the 
crevices and interstices between the fibres 
on the surface, and in this vnanner checking 
or suppressing evaporation. Horn takes a 
high and beautiful polish. Although much 
inferior in transparency to tortoise-shell, it 
may be worked up to bear so near a resem- 
blance to it as to be often, in manufactures, 
substituted for it, as in combs, etc. The 
hoof admits of an elegant polish ; and in 
that altered and improved state has been 
manufactured into articles no less useful 
than valuable and ornamental:* even the 
hoofs of the living animal may, by being 
kept clean, and when dry rubbed with lin- 
seed oil, be numbered among the ornamen- 
tal beauties Nature has bestowed upon 
quadrupeds. 

" By chemical analysis horn has been 
found to consist of membranous substance, 
having the properties of coagulated albumen, 
and of some gelatine. The horns of some 
animals, the deer species, from containing 
bone, become exceptions to this. Mr. 
Hatchett burnt five hundred grains of ox's 
horn, and the residuum proved only one 
and a half grain, not half of which was 
phosphate of lime. 

" Shavings of hoof thrown into nitric 
acid become soft, and speedily melt into a 
yellow mass, which in about eight hoitrs 
disappear in complete solution. 

" The same thrown into sulphuric acid 
turn black, in becoming soft, and require 
thrice the time for their solution. Muriatic 
acid also turns horn black, and corrodes 
it, but has so little effect towards its solu- 
tion, that after ten days a piece of hoof 
soaked in it was found to have become only 
more brittle or rotten. Common vinegar 
will turn horn dark-colored, but does not 

* The Ec-lipsc Iioof, presented liy liia Majesty at Ascot 
II.1CCS, as tlie reward of the best horse on the turf, forms 
a notable illustration of tliis. 



30 



ANATOMY AND PHYSIOLOGY OF 



appear to have any power in impairing its 
texture, or, at least, in dissolving it. Liquor 
potassse will not only turn it black, but will 
corrode the horn of the hoof. Ammonia 
does not change its color, but slowly destroys 
its texture, rendering it brittle and rotten. 

"INTERNAL PARTS OF THE 
FOOT. 

"The internal, sensitive, organic parts of 
the foot, comprise the bones, ligaments, ten- 
dons, coronary substance, cartilages, sensitive 
lamincE, sensitive sole, and sensitive frog. 

" The bones entering into the composition 
of the foot are the coffin and navicular 
bones: to which may be added (as forming 
part of the coffin-joint, and consequently 
having intimate relation to them), the coro- 
net bone. 

" The tendons immediately connected 
with the foot are those of the extensor pedis 
and the flexor pedis perforans : the former 
being inserted into the coronal process ; the 
latter into the posterior concavity of the 
coffin-bone. 

"the coronary substance. 

" A less inappropriate name for the part 
commonly called the coronary ligament.* 

" To revert, for the sake of elucidation 
here, to former description — after the hoof 
has been detached by a process of macera- 
tion or putrefaction, in a perfectly entire, 
uninjured condition, it presents around its 
summit a circular groove, bounded in front 
by a soft whitish substance, having a thin 
edge, and being of a nature between horn 
and cuticle ; and behind, by an attenuated 
margin, more horny in its character, whose 
thin edging is denticulated or serrated. Into 
this circular groove or canal is received the 
terminating margin of the cutis: the cuti- 
culo-horny layer of the hoof, in front of it, 
having every appearance of being a continu- 
ation of the cuticle. 

" Situation — Dimension. — The coronary 

* Averse as I nm to changing or altering names, noth- 
ing less than a palpable contriidiction, in regard lioth to 
structure and function, would have induced me to do so in 
the present instance. 



substance occupies the concavity formed 
upon the inside of the superior or coronary 
border of the wall of the hoof: it is the 
part constituting the basis of the circular 
prominence commonly distinguished in the 
living animal as the coronet. It is broadest 
around the toe of the wall, diminishing in 
breadth towards the quarters and heels, and 
being somewhat broader around the outer 
than the inner side. It is thickest in sub- 
stance around its middle and most promi- 
nent parts, growing gradually thinner both 
above and below. 

" Connection. — Externally, the coronary 
substance is connected with the hoof; and 
the connection appears to be principally, if 
not entirely, of a vascular nature : the sur- 
face of the wall presenting a porous honey- 
comb-like texture, and the villi or vessels 
issuing from the coronary substance enter- 
ing the pores, and thus establishing an inti- 
m.ate and extensive vascular union between 
these organic and inorganic parts. Inter- 
nally, the coronary substance is connected 
with the coffin-bone, the extensor tendon, 
and the cartilages, by a fine, dense, copious 
cellular tissue, which at the same time forms 
a bed for the assemblage and ramification of 
the blood-vessels concerned in the secretion 
of the wall of the hoof. Superiorly, its 
union with the skin is so intimate and com- 
pleti^, that one has been thought to be a 
continuation of the other ; and, so far as 
meets the eye of a common observer, they 
might be taken as such ; but, when we 
come to examine them by anatomical tests, 
we not only find a line of external demar- 
cation between them, but discover such 
difference of internal structure as forbids 
the adoption of this delusive notion. As it 
descends upon the coffin-bone, the coronary 
substance not only grows thinner, but in 
growing attenuated becomes imperceptibly 
gathered or puckered into numerous points, 
from which issue a like number of plaits or 
folds, which afterwards form the sensitive 
laminee. It is worthy of remark, that the 
part of the bone upon which this transfor- 
mation takes place is smaller in circumfer- 
ence than the coronet; consequently the 



EXPLANATION OF FIGUEE IV. 



NO. 1. — OSSEOUS STRUCTURE. 

OFF-HIND EXTREMITY. 

22. Femur or thigh bone. 

23. PateUa. 

24. Tibia. 

25. Os calcis. 

26. Astragalus. 

27. One of the tarsal bones. 

28. Metatarsi magnum. 

29. The sessamoids. 

30. Os suffraginis. 

31. Os coronae. 

32. Os pedis. 
e. The fibula. 

The above explanation will answer for •• Xo. 3," of this plate. 

m 

NO. 2. — MUSCULAR STRUCTURE. 

SIDE VIEW OF THE OFF-HIND EXTREMITY. 

J. Triceps. 

)i. Rectus. 

o'. Vastus. 

r. s'. Gastrocnemii and perforans. 

o. 0. Flexor pedis accessorius. 

«'. (At the hock.) The insertion of the gastrocnerhius uito the point of the hock. 

a;'. Extensor pedis. 

y. if. Feroneus. 

V. (Beneath the pastern.) Flexor perforatus and perforans. 

z. Biftuxation of the suspensory Ugameiit. 

S,-. The hoof. 



NO. 4. MUSCULAR STRUCTURE. 

A>'TERIOR VIEW OF THE OFF HIND EXTREMITY. 

H. Rectus. 

o'. Vastus externus. 

J. Triceps abductor tibialis. 

y. y'. Peroncus. 

x\ x\ Extensor pedis. 

y. Flexor pedis accessorius. 

8. Bifiircation of the susjiensor)' ligament. 

5. Saphena veui. • 

i{. The hoof. 



THE HORSE. 



31 



same measure of coronary substance which 
but tensely and smoothly covered the latter, 
admitted of being disposed in gathers or 
folds so soon as it reached the former. Pos- 
teriorly, the coronary substance forms a 
junction, indeed becomes continuous in 
substance, with the heels of the sensitive 
frog. 

" Structure. — The coronary substance 
discloses tinree different parts in its com- 
position : 1. A fibro-cartilaginous circling 
band, forming the substratum and basis of 
the entire structure. 2. A culicidar cover- 
ing, so called from its resemblance in tex- 
ture to the cutis. 3. A nettuork of blood- 
vessels, reposing upon the former, and 
covered by the latter. The cartilaginous 
structure, freed fi-om its vascular connec- 
tions, is found to be wrought in the form 
of a coarse, opeU; irregular network, and 
appears designed mainly for the purpose of 
affording a bed for the lodgment and rami- 
fication of the blood-vessels destined to pro- 
duce the wall. The looseness of its con- 
nection, added to its own elasticity, renders 
this substance peculiarly adapted to accom- 
modate itself to the motions of the coffin- 
joint, and thus preventing those movements 
from operating prejudicially to the super- 
imposed glandular structm'e. 

" Organization. — The coronary sub- 
stance may be ranked among the most vas- 
cular parts of the body : no gland even 
possesses, for its magnitude, a greater abun- 
dance of blood-vessels, or of blood-vessels 
(taking them generally) of larger size ; nor 
does there exist any part in which greater 
care appears to have been taken to arrange 
its vessels so as to insure an uninten-upted 
supply of blood. These vessels it is that 
produce the wall : and there is every reason 
to believe that they perform this office 
without any assistance from the vessels of 
the laminae. 

" THE CARTILAGES 

" Are two broad, scabrous, concavo-con- 
vex, cartilaginous plates, erected upon the 
sides and wings of the coffin-bone. Pro- 
fessor Coleman calls them ' the lateral car- 



tilages,' in contradistinction to two others 
he has named ' the inferior cartilages.' 

" Situation. — The cartilages form the 
postero-lateral parts of the sensitive foot, 
extending the surface considerably in both 
these directions. 

" AUacliment. — The cartilages are fixed 
into fossae excavated in the supero-lateral 
borders of the coffin-bone. Their anterior 
parts become united, on each side, with 
descending lateral expansions from the ex- 
tensor tendon, and are also attached to the 
coronet bone by cellular'membrane. Their 
posterior parts surmount the alcB or wings 
of the bone, to which they are firmly fixed, 
and from which they project backwards, 
beyond the bone, giving form and substance 
to the heel. Supposing one of the carti- 
lages to be divided into two equal parts by 
a line drawn horizontally across its middle, 
the superior half, which extends as high as 
the pastern-joint, is covered by skin only ; 
and on that account is quite perceptible to 
the feel, and (in form) to the sight, as the 
animal stands with his side towards us. 
The lower half is covered, superiorly, by 
the encircling coronary substance; inferiorly, 
by sensitive laminae : consequently, over all 
by the hoof, which envelopes both the coro- 
nary substance and the laminae. The ex- 
treme posterior ends of the cartilages incur- 
vate downward and backward ; but, being 
overreached by the heels of the sensitive 
frog, any abrupt or exposed termination of 
them is prevented. Around these points 
also the coronary substance makes its in- 
flections upon the sensitive frog, thereby 
giving them additional substance and sup- 
port. 

" Form. — Considered in the detached 
state, the cartilage in its general figure de- 
scribes an irregular quadrangle, of which 
the supero-anterior and infero-posterior an- 
gles are the most projecting ; the latter at 
the same time being incurvated inwards. 
Externally, the cartilage is pretty regularly 
convex ; internally, it is unevenly concave, 
the suiTOunding border turning inwards into 
the substance of the sensitive frog. The 
posterior part of the cartilage is somewhat 



32 



ANATOMY AND rHYSIOLOCY OF 



thinner than tlic anterior, and has several 
foramina llirough it — throe or four of 
large size — which transmit vessels to the 
frog. 

" The False Cartilages. — From the in- 
ferior and posterior sides of the true carti- 
lages, proceed in a direction forward — 
tovi'^ards the heels of the coffin-bone — two 
fibro-cartilaginous productions, to which 
Mr. Coleman has given the name of ' infe- 
rior cartilages.' If they are to be consid- 
ered as cartilages at all, I prefer denomi- 
nating Wiem false ; they being, as well in 
structure as in use, different from the true 
or lateral cartilages. They spread inwards 
upon the surface of the tendo perforans ; 
become united at their inner sides with the 
superior margin of the sensitive frog ; are 
covered interiorly by the sensitive sole ; and 
at the same time assist in the support of 
the sensitive frog. They are triangular in 
their figure, and are arched in the same 
manner as the sole. 

" Use. — Their use appears to me to be, 
to fill up the triangular vacant spaces left 
between the tendo perforans and heels of 
the coffin-bone, thereby completing the sur- 
face of support for the sensitive frog, and 
extending that for the expansion of the 
sensitive sole. Bone in these places must 
have proved inconvenient by more or less 
impeding the impression upon, and con- 
sequent reaction of, the sensitive frog. 

"the sensitive LAMhNjE OR LAMELLA. 

" So is denominated the laminated, mem- 
branous, vascular structure clothing the wall 
of the coffin-bone. 

" Production. — The sensitive laminae 
appear to be derived from the coronary sub- 
stance — the one, in fact, seems to be a con- 
tinuation from the other; for if, in a foot in a 
putrid condition, we attempt to part them 
by force, we may make an artificial rent 
somewhere, but can find no natural separa- 
tion between them. The cuticular covering 
of the coronary substance having descended 
upon Ihc coffin-bone, the circumference of 
which is less than that of the coronet, be- 
cause thereupon gathered into numerous 



little plaits or folds, which proceed in paral- 
lel slanting lines down the wall of the bone : 
a transformation it may be dilficult lo ex- 
plain, since the laminee unfolded would 
occupy a much larger surface than the 
coronet ; at the same time, it is one that 
has its parallels in the animal constitution, 
and a remarkable one in the instance of the 
ciliary processes. 

" Division. — According to this mode of 
derivation, every lamina consists of one 
entire plait or duplication of substance, 
having its inumrd sides intimately and in- 
separably united ; its outward sides being 
the surfaces of attachment for the horny 
laminae. It has also two borders : one op- 
posed to the coffin-bone, the other to the 
hoof; and two ends or extremities, one issu- 
ing out of the coronary substance, the 
other vanishing in the sensitive sole. 

" Structure. — The substance of the la- 
mina; when held to the light evinces a 
degree of transparency ; although its nature 
is extremely dense, and it possesses extra- 
ordinary toughness and tenacity. Veteri- 
nary writers and lecturers have endowed 
the laminas with a high degree of elasticity: 
but it appears to me that the property 
is referable to their connections, and not 
one that is inherent in their own sub- 
stance. 

" Elastic Structure. — This is a substra- 
tum of a fibrous periosteum-like texture, 
attaching the laminae to the coffin-bone, in 
which it is that the property of elasticity 
resides to that remarkable extent usually 
ascribed to the lamins themselves : indeed, 
so elastic is it found to be, that it can be 
made to stretch and recede the same as a 
piece of India rubber. Its fibres take a 
direction downward and baclcward. At 
the same time, it affords a commodious bed 
for the ramification of blood-vessels issuing 
from the substance of the bone, in which 
they are (particularly in the si retched con- 
dition of the substance) protected from in- 
jurious compression and consequent inter- 
ruption to their circulation. 

^^ Number. — In round numbers we may 
estimate the lamina at about 500; not in- 



THE HORSE. 



3.3 



eluding those of the bars. They vary,] 
however, in number : I have reckoned up- 
wards of 600. 

'^ Dinioixions. — In lengtli ihey decrease 
from around the toe towards the sides and 
heels in a corresponding ratio with the 
wall ; those in front, the longest, being 
rather more than two inches in extent ; the 
shortest, those at the heels, being rather less 
than one inch. In breadth there is no vari- 
ation : all measure alike, one-tenth of an 
inch. 

" Organization. — The laminee are highly 
organized, though they are not equally so 
with either the sensitive sole or sensitive 
frog ; nor are they so red as those parts : 
and the obvious explanation of this i.s, 
that (over and above what is requisite for 
their own nutrition) all the blood they have 
occasion for is only that which is suffi- 
cient for the secretion of the horny la- 
minae. 

'•THE SENSITIVE SOLE. 

" The sensitive sole, or (as Sainbel calls 
it) the fleshy sole, is the fibro-vascular sub- 
stance covering the arched concave, or 
ground surface, of the cotRn-bone ; in fact, 
is the part corresponding to the horny sole. 

" Structure. — The same kind of elastic 
fibrous structure that sustains the laminae 
is found constituting the groundwork of the 
sensitive sole ; only thai in the latter case it 
is closer, denser, and firmer in its texture. 
Upon this is spread a remarkably beautiful 
venous network. And the whole is en- 
veloped in an outer cuticular covering, 
derived from the heels and frog, from which 
are sent villous processes, loaded with the 
points of arteries into the porosities of the 
horny sole: not, however, perpendicularly 
downward, but in an oblique direction — 
downward and forward — the same in 
which the horny fibres grow. 

" Connection. — Around the circumfer- 
ence of the coffin-bone, the sensitive sole 
is connected with the fibrous substance de- 
scending from the wall, together with the 
tapering, vanishing points of the laminar. 
In the centre, it is united with the bars and 



frog. But its principal attachment consists 
in its being firmly rooted into the sole of 
the coffin-bone ; a connection that receives 
considerable addition from the blood-vessels 
issuing out of the substance of the bone. 

" Thickness. — The sensitive sole varies 
in thickness at ditl'erent places. On an 
average, it may be said to measure one- 
eighth of an inch in thickness. In the vi- 
cinity of the frog, it is something less than 
this. At the heels, it possesses double that 
thickness. . 

" Organization. — This is one of the 
most vascular and sensitive parts in the 
body. Independently of the much ad- 
mired venous network expanded over the 
fibrous substance of the sole, arteries enter 
it issuing from the substance of the bone, 
and penetrate its villi, which, by taking this 
course, elude alJ compression and obstruc- 
tion : there are also others — the nutrient 
arteries ; but these have an external origin, 
from the inferior coronary artery. The 
chief assemblage of arteries takes place 
within the villi, upon the cuticular surface 
— those issuing out of the interior of the 
bone simply passing through (without ram- 
ifying within) the fibrous substance : so 
that, if the substance of the sole is laid 
open by transverse section, the incised 
edge, near the surface, exhibits a deep red 
tint ; while the interior, nearer the bone, 
has a pinkish or -pale red aspect. 

"the sensitive frog. 

" Under this head is included the cleft, 
cuneiform body, projecting from the bottom 
of the foot, together with the substance 
continued from it and filling the interval 
between the cartilages. Sainbel calls it 
' the fleshy frog.' 

" Division. — We distinguish, in the 
sensitive as in the horny frog, an apex or 
toe ; two heels, separated by the cleft ; and 
a portion intermediate between these, which 
is the body. 

" Situation and Connection. — The sensi- 
tive frog occupies the posterior and central 
parts of the bottom of the foot, forming in 
the tread a firm and secure point d^appui 



'Si 



ANATOMY AND PfrVSIOLOGV OK THE HOKSE. 



Being in the hoofless foot equally jiroini- 
nent with the projecting edge of the coffin- 
bone, one might be led to infer that the 
horny frog should take the same line of 
bearing with the crust. The frog, alto- 
gether, is lodged in a capacious irregular 
space, bounded superiorly by the tendo- 
perforans and common skin, laterally by the 
cartilages, and inferiorly by the homy frog : 
with all which parts it has connections ; 
besides being continuous with the sensitive 
bars and sole, and at the heels with the 
coronary substance. On its sides aje two 
shallow, ill-defined hollows, corresponding 
to the commissures of the horny frog, into 
which are received the horny prominences 
opposed to them. 

" Structure. — Entering into the com- 
position of this body we distinguish four 
parts: An exterior or cuticular covering; 
a congeries or network of blood-vessels ; a 
fibro-cartilaginous texture ; and an elastic 
interstitial matter. 

" The exterior or cuticular covering in- 
vests the prominent bulbous portion of the 
frog, and also gives a lining to the cleft. 
Superiorly, it is continuous with the sldn 
descending upon the heels ; anteriorly, with 
the cuticular covering of the coronet ; infe- 
riorly, with that of the sole. Numerous 
villous processes sprout from its surface, 
and enter the porosities in the interior of 
the horny frog, taking a direction down- 
ward and forward, the same as that in 
■which the fibres of the horn grow. 



" The vascular covering succeeds the 
cuticular, lying immediately underneath it. 
It consists of a network of blood-vessels, 
principally veins, but which are not so 
thicldy set as upon the sole. 

" The fibro-cartilaginous case comes next. 
We find it spread over those parts most 
subjected to pressure, and to be, in many 
places, one-fourth of an inch in thickness. 
From its interior are sent ofT numerous 
processes, pervading the elastic matter of 
the frog, forming so many septa intercross- 
ing one another, and dividing it without any 
notable regularity into many unequal com- 
partments. In the posterior and bulbous 
parts, the septa exist in greater numbers, 
and are closer arranged than in the middle 
parts. The fibres of this vaginal substance 
run obliquely downward and forward, and 
become intermixed around the borders with 
those of the bars and sole. 

" The elastic interstitial matter, however, 
composes the bulk of the sensitive frog. 
It consists of a pale yellowish soft sub- 
stance, which has been mistaken for fat or 
oil, and hence has been named 'the fatty 
frog.' When cut deeply into, it exhibits a 
granulated appearance, and the fibrous in- 
tersecting chords become apparent, putting 
on the ramous arrangement of a shrub or 
tree. Altogether, the sensitive frog forms 
a peculiar, spongy, elastic body, for which 
we lack some more appropriate name." 



A TABULAR VIEW OF THE BONES OF THE HORSE. 



BONES OF THE CRANIUM. 

Number. 

Frontal, 1 

Parietal 2 

Temporal, two pairs, 4 

Occipital, ...... 1 

Ethmoid, 1 

Sphenoid, 1 

BONES OF THE FACE. 

Nasal, 2 

Superior and anterior maxillar)', . . 4 

Malar 2 

LacrjTnal, ...... 2 

Palatine, 2 

Superior and inferior turbinated, . . 4 

Vomer, 1 

Lowerjaw, 1 

TEETH. 
Incisors, . . . . . x . .12 

Canine, 4 

Molars, . 24 

BONE OF THE TONGUE. 

Os Hyoideus, 1 

BOXES OF THE E.\K. 

Malleus, 2 

Incus, 2 

Stapes 2 

Orbiculare, 2 

BONES OF THE SPINE. 

Cer\ical, ....... 7 

Dorsal, 18 

Lumbar (sometimes G are found), . . 5 

BONES OF THE SACRUM AND T.UL. 

Sacral 1 

Coccygeal (tail), about . . . .15 

BOXES OF THE CHEST. 

Ribs, on each side 18, ... . 3G 

Sternum, .... . . 1 

PELVIS. 

Innominata (or bones inthout a name), . 2 
BOXES OF THE SHOULDER. 

Scapidar, . . .... 2 



BONES OF THE ARM. 

Humeral, 2 

BONES OF THE FORE-ARM. 

Radial and ulnar. The ulnar being, in the 
adults, connected mth the radius, we shall con- 
sider them as one bone. Radial, . . 2 

BONES OF THE KNEE. 

The carpal bones are thus named.: 

(J f Scaphoid, | f Pisiform, 

a J Lunar, « J Trapezoid, 

g I Cuneiform, g | Magnum, 

E 1^ Trapezium. S [_ Unciform. 

Eight bones to each knee, ... 16 

BONES BELOW THE KNEE. 

Metacarpal, 2 

Splents 4 

Pastern, 2 

Coronet, ...... 2 

Sessamoid, ...... 4 

Nancular, 2 

Pedal or foot bones, 2 

BONES OF THE HIND EXTREMTIT. 
Femur, ....... 2 

Stifle, 2 

BOXES OF THE LEG. 

Tibia and fibula. These we shall consider as 
one to each extremity, .... 2 

BONES OF THE HOCK. 

Astragalus, ...... 2 

Os C'alcis, 2 

Cuboid, . 2 

Cuneiform, ...... 6 

BONNES OF THE LEG. 

Two camions and four splents, ... 6 

BONES BENEATH THE CANNON. 

Pastern, 2 

Coronet, 2 

Sessaraoids, ...... 4 

NaTOular, 2 

Pedal or foot bones, .... 2 

Total number of bone.s, . . 238 
Tlie correct technical nomenclature of the above 
bones will be found in " Osteology," wliich see. 

(35) 



ANATOMY OF THE SKELETON- OSTEOLOGY. 



OSSEOUS SYSTEM OF THE 
HORSE. 

In the form of answers to a series of 
questions, the student will become ac- 
quainted with the name, location, form, use, 
and general peculiarities of the various 
bones composing the horse's skeleton. 

Q. What is understood by the natural 
skeleton ? — A. The term is applied when 
the whole bones are held together by their 
natural attachments : ligaments, cartilages, 
and synovial membranes. 

Q. Why is the term, artificial, sometimes 
applied to the skeleton ? — A. Because the 
bones, having been divested, by maceration 
or otherwise, of their connecting ligaments, 
etc., are united artificially, by wire and 
plates of metal. 

BONES OF THE CRANIUM. 

Q. Enumerate the cranial bones. — A. 
Frontal, two parietal, occipital, four tempo- 
ral, ethmoid, sphenoid : ten. 

FRONTAL BONE (oS FRONTIs). 

Q. Describe the situation of -the frontal 
bone. — A. It occupies the antero-superior 
part of the cranium in the region known as 
the forehead. 

Q. What are its peculiarities ? — A. In 
form it is irregular, having two surfaces 
and four borders. Its surfaces are flat 
externally, concave internally. Its internal 
surface is divided by a septum into anterior 
and posterior concavities. The posterior 
one is occupied by a portion of the anterior 
lobe of the cerebrum ; the anterior consti- 
tutes the frontal sinuses, they being sepa- 
rated from each other by the nasal spine. 
The concavity is further divided into shal- 
low chambers by imperfect septa. 



Q. Describe the borders of the os frontis. 
— A. They are denticulated and squamous. 
The posterior is arched, describing segments 
of two circles. The anterior or nasal is 
waving, inclines backwards and outwards. 
The frontal border is straight, anteriorly 
broad and triangular. The ethmoidal or 
outer border is irregular, and unites with 
the lachrymal, sphenoid, and ethmoid bones. 

PARIETAL BONES (OSSA PARIETALIa). 

Supposing the horse to be an adult, we 
shall consider these bones as one. 

Q. What is the situation of the parietal 
bone ? — A. It occupies the mesio-superior 
part of the cranium. 

Q. Describe the same. — A. Its form is 
quadrilateral : vaulted, concave internally, 
and convex externally. It has two sur- 
faces and four borders, denticulated and 
squamous. 

Q. What is observable on the convex sur- 
face? — A. A longitudinal messian crest, 
bifurcating anteriorly ; which indicates the 
location of the sutures, now obliterated by 
age. Between the bifm-catures arises an 
eminence above the cranial surface. 

Q. Describe the appearance of the inter- 
nal surface? — A. It is indented by, and 
receives, the lobular eminences of the cere- 
brum, and it is also furrowed by arterial 
ramifications which supply the diu-a mater. 

TEMPORAL BONES (oSSA TEMPORUm). 

Q. What portion of the cranium do the 
ossa temporum occupy ? — A. Its sides and 
base. 

Q. How do these bones differ from those 
in man ? — A. In man they are divided into 
three portions, squamous, petrous, mastoid ; 
yet in reality they are united. . In the horse 

(36) 



ANATOMY AND PHYSIOLOGY OP THE HORSE. 



57 



they constitute four distinct bones, two on 
each side. 

Q. Name them. — A. Two ossa tempo- 
rum, pars squamosa, pars petrosa : four. 

Q. Describe their appearance. — One 
pair is composed of lamina;, vaulted ; form 
ovoid, surmounted by irregular projections ; 
the other pair are solid and convex. 

OCCIPITAL BONE (oS OCCIPITls). 

Q. What is the situation of the os occi- 
pitis ? — A. It is located in the postcro- 
superior and inferior parts of the cranium. 

Q. What is its form ? — A. Convex 
externally, irregular, having an occipital 
tuberosity and condyles. 

Q. What are the connections of this 
bone ? — A. It unites, superiorly, with the 
parietal bones ; inferiorly and anteriorly with 
the sphenoid ; laterally, with the temporal, 
and it articulates posteriorly with the atlag. 

Q. What is the foetal state of the bone ? 
A. It is easily separable into four portions. 

Q. State its use. — A. It forms the pos- 
terior and inferior parts of the cranium, 
protects this portion of the brain, and gives 
exit to the spinal cord. 

SPHENOID BONE (oS SPHENOIDEs). 

Q. What is the situation of the os 
sphenoides ? — A. It passes from one tem- 
poral region to the other, across the antero- 
inferior part of the brain. 

Q. What are its general divisions? — A. 
It is divided into body, situated in the mid- 
dle, alas or wings, on each side, and tvvo 
pterygoid processes, considered as legs. 

Q. To what bones is it connected? — A. 
Occipital, ethmoid, squamous-temporal, pal- 
ate, and vomer. 

ETHMOID BONE (oS ^THMOIDEs). 

Q. What part of the cranium does the 
OS agttmoides occupy ? — A. Anterior to 
the sphenoid, and is the boundary of the 
cranial, and commencement of the nasal, 
cavities. 

Q. Describe its form. — A. The posterior 
portion bears resemblance to a bird with its 
wings extended, having no legs, but a long 



erected neck and a small round head; the 
anterior part consists of a slim, brittle, 
porous, spongy structure of considerable 
volume. 

Q. What are its connections ? — A. 
With the sphenoid, frontal, vomer, and 
superior turbinated bones; and with the 
cartilaginous septum of the nose. 

BONES OF THE FACE. 

Under this head we shall consider the 



Ossa nasi, ..... 


2 


" maxillaria superiora, . 


2 


" maxillaria anteriora, . 


2 


" malarum, . . . . 


2 


" lacrymalia, .... 


o 


" palati, ..... 


2 


" turbinata, superiora et inferiora, 


4 


" vomer, ..... 


1 


Os maxillare inferius (lower jaw,) 


1 



I'otal, 



18 



We shall now consider these bones in the 
above order. 

NASAL BONES (ossa NASi). 

Q. How many nasal bones are there ? — 
A. Two. 

Q. Where are they situated? — A. In 
the superior part of the face. 

Q. Describe their form? — A. They re- 
semble the form of a pear ; are broad pos- 
teriorly, pointed anteriorly ; they are convex 
externally and concave internally. 

Q. To what bones are they connected ? 
— A. To the frontal, superior and anterior 
maxillaria, and lachrymal. 

Q. Wliat is theu'use?— A To defend 
the nares, and retain in position the septum 
nasi. 

SUPERIOR MAXILLARY BONES (oSSA MAXIL- 
LARIA superiora). 

Q. Where are they situated? — A. In 
the supero-lateral parts of the face. 

Q. Describe their form ? — A. They are 
somewhat irregular — tri-lateral; from the 
centre (which is thickest) they taper, the 
anterior part being much thinner than the 
posterior. 

Q. How are they divided? — A. Each 



38 



AXATOMY AND PHYSIOLOGY OF 



bone lias a facial, palatine, and nasal sur- 
face. It has also nasal, alveolar, and pala- 
tine borders, and two extremities : posterior, 
which forms the maxillary tuberosity ; 
anterior, or dental extremity. 

Q. What are the connections of the ossa 
maxilaria ? — A. With the squamous tem- 
poral, nasal, anterior maxiUary, malar, 
lachrymal, palate, and inferior turbina'ted 
bones. 

ANTERIOR MAXILLARY BONES (osSA JIAXIL- 
LARIA ANTERIORa). 

Q. What is the situation of these bones? 
— A. They are placed in the supero-anterior 
and antero-lateral parts of the face. 

Q. What is the general form of these 
bones ? — A. Very irregular ; consisting of 
a broad, thick base, turned forwards, from 
which is sent off a thin flexible plate ; and 
a narrow, elongated, tapering portion 
turned backwards. 

Q. How is each bone divided ? — A. Into 
three surfaces and three borders. 

Q. Describe the surfaces. — A. The 
superior or nasal surface is smooth, con- 
vex, and oblong. The inferior or palatine 
is vaulted, it contributing to the formation 
of the palate ; within it, of an oval form, is 
the interdental space, which is occupied by 
two thin, flexible plates, the palatine pro- 
cesses, denticulating along the sides with 
each other. In the side of the bone is a 
deep hollow, for the reception of that por- 
tion of the superior maxillary bone v.^hich 
holds the tiisk ; and the remainder of the 
surface, posteriorly, is articulated with the 
same. The anterior or labial siLrface is 
broad, smooth, and convex, and gives at- 
tachment to the depressor labii suporioris, 
and gums. 

Q. Describe the borders. — A. Tiie 
anterior border is broad and curved, and is 
composed of two laniince, formed apart and 
divided into septa for the insertion of six 
incisors. The posterior border is naiTOw 
and sloped, and denticulates with the nasal 
bone. The internal border is broad, 
quadrilateral, curved, and denticulates with 
its fellow, forming thereby the superior 



maxiUary symphysis, through which runs 
the foramen incisivum, for the transmission 
of the palatine arteries. 

Q. How is this bone connected? — A. 
It connects with the superior maxillary and 
nasal bones, and with its fellow. 

MALAR BONES (oSSA MALARUm). 

Q. What is the situation of the ossa 
malarum? — vl. They occupy the antero- 
external part of the orbit. 

Q. Describe their form. — A. Irregularly 
triangular, presenting a broad basis forwards. 

Q. How is the bone divided ? — A. Into 
three surfaces, three angles, a basiform and 
an apiform extremity. 

Q. Name the surfaces. — A. Facial, 
maxillary, and orbital. 

Q. Describe the same. — A. The facial 
surface is divided into two portions by the 
zygomatic spine ; the upper division is 
smooth and nearly flat; the lower ]")art is 
narrow and roughened, for the insertion of 
the masseter muscle. From this surface, 
posteriorly, arises the zygomatic process, 
which is very obliquely sloped oflT, and 
laminated for adaptation to the process 
of the same name, meeting it from the tem- 
poral bone, the two together forming the 
zygomatic arch. The maxillary surface is 
concave. The orbital surface has a smooth 
concavity which forms the infero-external 
part of the orbit. 

Q. Describe the angles. — A. There are 
three, superior, inferior, and posterior. The 
superior constitutes the external portion of 
the orbital circumference. The inferior 
forms the zygomatic spine. The posterior 
is not so prominent nor defined, but forms 
an irregular link with the superior maxillary 
bone. 

Q. What of the extremities ? — A. The 
anterior extremity is broad, irregular, and 
denticulated, and articulates with the Supe- 
rior maxillary and lachrymal bones. The 
posterior or apiform extremity forms the 
zygomatic process. 

Q. With what bones do the ossa mala- 
rum connect? — A. With the temporal, 
superior, maxillary, and lachrymal bones. 



THE HORSE. 



39 



LACHRYMAL BONES (oSSA LACHRYMALIa). 

There are tvvo lachmyral bones : we shall 
describe but one, considering that they are 
both alike, as indeed are those ahready refer- 
red to, in a plural sense. 

Q. What is the situation of the lachry- 
mal bone ? — A. It occupies the antero- 
external part of the orbit. 

Q. How is it divided ? — A. Into three 
surfaces and five borders. 

Q. Name the surfaces. — A. Liternal, 
external, and orbital. 

Q. Name the borders. — A. External 
and internal facial, nasal, and external and 
internal orbital. 

Q. What is observable in the orbital ex- 
cavation of this bone? — A. The laclirymal 
fossa. 

Q. What occupies this fossa or groove ? — 
A. The lachrymal vessels, sac, and duct. 

Q. With what bones is it connected ? — 
A. With the frontal, nasal, malar, and supe- 
rior maxillary bones. 

PALATE BONES (oSSA PALATi). 

Q. What is the situation of the palate 
bones ? — A. They are placed in the infe- 
rior posterior part of the face, adjoining the 
base of the cranium. 

Q. What does the palatine surface form? 
-=-yl. The palatine arch or roof of the 
mouth. 

Q. What of the nasal surface ? — A. It 
forms the posterior surface of the nasal 
outlet. 

Q. What other surfaces do these bones 
present? — A. Ethmoidal and orbital. 

Q. To what part of the bone is the vel- 
um palati attached? — A. To the palatine. 

Q. How are the palate bones united to 
the superior maxillary? — A. By their supero 
and infero lateral borders ; each being den- 
ticidated. 

Q. What other connections have the pal- 
ate bones ? — A. They are joined to the 
frontal, ethmoid, sphenoid, vomer, and in- 
ferior turbinated bones. 

TURBINATED BONES (oSSA TVRBINATA SUPE- 
RIORA ET INFERIORa). 

Q. Where are the ossa turbinata located ? 



— A. Within the nasal cavity : the superior 
above, and the inferior below. 

Q. What is their form, and how are they 
divided ? — A. In form they are oblong, thin, 
foliated, convoluted, scroll-like, and cavern- 
ous. They are divided into external and 
internal surfaces ; superior and inferior ex- 
tremities. 

Q. How many bones are there? — A. 
Four. 

Q. Describe the bones. — A. Their ex- 
ternal surface is convex, and presents series 
of longitudinal grooves which mark the 
ramifications of smaU blood-vessels. The 
internal surface is cellular, being unequally 
divided by transverse septa. Their interior 
is capacious ; they are open superiorly and 
closed anteriorly. They are porous and 
elastic. The superior bone exceeds in 
volume the inferior, and makes its convolu- 
tion from below, its superior border being 
attached ; whereas, the reverse is the case 
with the inferior one. 

Q. What are their connections ? — A. 
The turbinated bone is connected above with 
the ethmoid ; and laterally, with the nasal 
bone. 

VOMER. 

Q. From what does the name of this 
bone arise ? — A. From its resemblance to 
a ploughshare. 

Q. What are its uses ? — To divide the 
nasal chambers and permit the expansion 
of olfactory nerves. 

Q. What is inserted into its superior 
groove ? — A. The septum narium. 

Q. What are its connections ? — A. It 
unites with the ethmoid, sphenoid, superior 
and anterior maxillary, and palate bones. 

LOWER JAW. LNFERIOR MAXILLARY BONE 

(oS MAXILLARE INFERIUs). 

Q. What is the situation of this bone ? — 
A. It composes the inferior and posterior 
parts of the face. 

Q. What is the foetal state of the bone ? 

— A. In the fcetal state it is divided, at its 
inferior junction, by a connecting cartilage, 
hence the part has been called its symphysis. 

Q. How is the bone divided ? — A. Into 



40 



ANATOMY AND PHYSIOLOGY OF 



body, neck, sides, and branches ; external 
and internal surfaces, and corresponding 
borders. 

Q. What do you understand by these 
terms ? ^ — A. Body signifies the anterior 
part reaching posterior to the tusks ; neck 
signifies the contracted part, immediately 
posterior to the body; sides are the parts 
comprehended between the neck and the 
branches ; the branches are the parts poste- 
rior to the neck, which terminate in the con- 
dyles. As regards surfaces, the external is 
convex, rounded, rough, and porous, and 
affords attachment for muscle and gum. 
The internal surface is concave, rough, and 
porous, and answers for the attachment of 
muscles and gum, and as a channel for the 
tongue, and attachment for the frcenum 
linguae. 

Q. What do you understand by borders ? 
— A. Each superior border exhibits six 
alveolar cavities for the molar teeth; the 
septum is composed of osseous laminse. 
The inferior border is thin and irregular. 
The posterior border is broad and roughened 
for the insertion of muscles. 

GENERAL INQUIRIES. 

It is now presumed that we understand 
the location and names of the different bones 
composing the cranium and face; and, be- 
fore we proceed further, it may be profitable 
to make some general inquiries regarding 
the bqny structure. 

Q. Is not the number of bones greater 
during colthood than at mature life ? — A. 
Yes, many of the bones separable at that 
period become united in the adult. 

Q. How are bones divided ? — A. They 
are divided into long or cylindrical, broad 
or flat, and thick. 

Q. What do you vmderstand by epiphy- 
sis of bones? — A. The region where car- 
tilage is interposed between bones that 
finally become ossified. 

Q. What is the structure of bones? — 
A. They consist of a cellular, reticular, and 
vascular parenchyma, and of osseous mat- 
ter deposited in it : their base, therefore, 
is the same as that of the soft parts. 



Q. Are bones vascular ? — A. Yes. 

Q. How can you demonstrate their vas- 
cularity ? — A. By numerous small fora- 
mina and by the tinge they receive from the 
coloring matter of the food. 

Q. Name the investing membrane of 
bones ? — A. Periosteum. 

Q. What is its organization ? — A. Fi- 
brous. 

Q. Of what use is this periosteum ? — 
A. It limits the growth of bones, is the 
medium of circulation and nutrition, and 
affords attachment for ligaments and mus- 
cles, and favors the free articulation of the 
latter. 

Q. What does its internal surface se- 
crete ? — A. An oleaginous fluid, depos- 
ited in the cellular structure and cavity of 
bones. 

Q. What are foramina? — A. Holes 
perforating the substance of bones. 

Q. What are sinuses ? — A. Occurring 
in bones, they are large cavities with small 
openings. 

Q. What are sinuosities? — A. Superfi- 
cial but broad irregular depressions. 

Q. What are furrows ? — A. Long, nar- 
row, and superficial canals. 

Q. What are notches? — A. Cavities in 
the margin of bones. 

Q. What are fossae? — A. Deep and 
large cavities on the surface of bones. 

Q. What are glenoid cavities? — A. 
Cavities for articulation. 

Q. What are tubercles? — A. SmaU em- 
inences. 

Q. What are tuberosities ? — A. Rough 
elevations. 

Q. What are spines? — A. Long pro- 
jections upon a bone. 

Q. What are heads? — A The round 
tops of bones. 

Q. What are necks ? — The narrow por- 
tion of bones beneath their heads. 

Q. What are processes ? — A. Short pro- 
jecting portions of bones. 

THE TRUNK (REMARKS ON THE SAMe). 

We shall now consider the peculiarities 
of the trunk ; which comprehends the verte- 



EXPLANATIONS OF FIGURE Y. 



MUSCULAR STRUCTUKE. 
LATERAL VIEW OF THE HEAD, NECK, -VXD SHOULDER. — Till: HEAD. 

a. Orbicularis ])alpcl)raruni. 

b. Levator palpobra'. 

c. Dilator naris lateralis, 

d. " " anterior. 

e. Orbicularis oris. 
_f. Nasalis longus. 

(/. Levator labii superioris. 

?'. Zygomaticus. 

j. Retractor labii inferioris. 

Jc. Buccinator. 

A'. Masseter. 

I. Tcm])oraIis. 

in. Attolentcs et abducens aurcn:. 

/'. Facial veins. 

THE NECK. 

*. Lijcamentum colli. 

6". Rhomboideus longus. 

s. A portion oi' the splenius. 

a". Scalenus. 

e". Pectoralis transversalis. 

o. Abducens vel deprimens aurem. 

r. Tendon of the splenius and conijilexus major. 

t. Obliquus capitis inferior. 

tt. Levator humeri. 

V. Sterno maxillaris. 

X. Subscapulo hyoideus. 

3. Jugular vein. 

REGION OF THE SHOULDER. 

a". Trapezius, 
y". Antea spinatus. 
g". Postea spinatus. 
Ji". Teres major. 

OSSEOUS STRUCTURE. 



» 


Liganientum colli, or subclavium, 


1. 


Temporal bone. 


2. 


Parietal bone. 


4. 


Zygomatic arch. 


6. 


Nasal bone. 


G. 


Lachrymal lione. 


7. 


Malar. 


8. 


Sui)erior maxilla. 


9. 


Anterior 


10. 


Liferior " 


b. 


The neck of the same. 


U. 


Cervical vertebrfe. 


33. 


Scapula. 


34. 


Humerus. 


a. 


The molars. 


c. 


The incisors. 


h. 


The hning membrane of the ear. 


i. 


Nasal cartilage. 



THE HOKSE. 



41 



bra! chain, thorax, and pelvis. It is gener- 
ally called the spine, or back bone, and 
extends from the occipital bone to the sac- 
rum. The spuie is divided into three 
regions, denominated cervical, dorsal, and 
lumbar. The spine, as a whole, exhibits 
three surfaces and two extremities. The 
surfaces are named superior, inferior, and 
lateral. The superior surface is flat in the 
region of the neck ; in the back and loins 
it ofl'ers a series of projections. The infe- 
rior smface is more uniform, and the lateral 
juIe 

cervical vertebrje. 

Q. How many cervical vertebree are 
there ? — A. Seven. 

Q. What is the name of the fii-st ? — A. 
It is called alias. 

Q. How does it differ from the rest ? — A. 
It has no superior spinous process nor body ; 
the vertebral hole is larger than in the 
others, and its transverse processes are very 
broad. It has three pairs of foramina : 
one posteriorly, through which run the verte- 
bral arteries ; and two anteriorly. 

Q. What is the name of the second cer- 
vical vertebra ? — A. It is named dentata. 

Q. How is it recognized from the rest ? 
— A. By its anterior projection, which in 
the human subject resembles a tooth. 

Q. W^ith what does this tooth-like pro- 
cess -articulate ? — A. It articulates with 
the infero-posterior part of the ring of the 
atlas. 

Q. Describe the third, fourth, and ffih 
cervical vertebra. — ^1. They possess the 
genuine characters of cervical vcriebrrr. and 
closely resemble each other; the third, how- 
ever, has commonly a more elevated supe- 
rior spine than either of the others, and is 
narrower across the mesio-sitperior part of 
the body (measuring from the roots of the 
ai'ticular processes), which dimension in- 
creases in the fourth, but is greatest in the 
fifth. 

Q. What of the sixth vertebral — A. It 
has no inferior spine ; and its transverse pro- 
cesses are trifid, consisting each of three 
eminences. 

6 



Q. What of the seventh ? — A. It is the 
shortest, and in its general conformation re- 
sembles the first dorsal. Its body, pos- 
teriorly, presents two semilunar articular 
depressions, constituting a part of the socket 
for the first rib. 

DORSAL VERTEBRAE. 

Q. How many dorsal vertebrce are there ? 

— A. Eighteen. 

Q. W'hat is peculiar to the dorsal ver- 
tebra; ? — A. They have each a bodi/, spinous 
process, and transverse process, and arc 
generally distinguished by the length, form, 
and direction of their spines. 

Q. How is the first dorsal vertebrce dis- 
tinguished from the rest? — A. By the 
sharpness of its spinous, and singleness of 
transverse, processes, and by the breadth of 
its articulatory surfaces. 

Q. How do the articular depressions for 
the insertion of the ribs differ in each bone ? 

— A. They are less deeply marked, as we 
proceed posteriori//. 

Q. How are the seventeenth and eight- 
eenth distinguished from the rest? — A. 
They have perfect articulatory depressions 
on the bodies for the insertion of ribs. 

LUMBAR VERTEBRAE. 

Q. How many lumbar vertebrs are 
there?— A Five. 

Q. How are the bodies of the lumbar 
vertebrce distinguished from the dorsal? — 
A. They are larger, contracted in the centre, 
and their edges are more prominent. 

VERTEBRAL CANAL. 

Q. What is the form of the vertebral 
canal? — A. In the cervical region it is ca- 
pacious and semi-oval ; through the dorsal, 
transversely oval and smaller. In the lum- 
bar it is semi-circular, of less diameter than 
the cervical and greater than the dorsal. 

Q. With what does the spinal canal con- 
nect? — A. Anteriorly, with the cranial 
cavity ; posteriorly, with the sacral canal. 

PELVIS, SACRUM, AND TAIL BOXES. 

We shall now consider the posterior 
boundary of the trunk. 



42 



ANATOMY AND PHYSIOLOGY OF 



OS SACRUM. 

Q. What is the popular name of this 
bone? — A. It is called the ^^ rump bone." 

Q. Where is it located? — A. At the 
superior part of the pelvis, between the ossa 
ilia. 

Q. What is the popular name of the 
ossa ilia? — A. They are called the haunch 
bones. 

Q. How many pieces enter into the com- 
position of the sacral bone, in the foal? — 
A. It is composed of five pieces. 

Q. How are they united ? — A. Hy fibro- 
cartilaghious substance. 

Q. What ultimate change takes place in 
this substance? — A. It becomes ossified, 
and hence the solid bone. 

Q. How is the sacral bone divided ? — A 
Into three surfaces, l^vo borders, base, and 
apex. 

Q. Describe its surfaces. — A. They are 
named superior, inferior, and lateral. The 
superior is convex, very irregular ; on its 
central line are five eminences, and laterally 
are superficial grooves pierced by the four 
sacral foramina. The inferior surface is 
smooth and slightly concave. The lateral 
smface is thick anteriorly, gradually tapering 
posteriorly ; they are roughened for the re- 
ception of the sacro-iliac figament. 

Q. Describe, briefly, the base and apex. 
— A. The base is composed of a central and 
two lateral parts. The apex is oval, and 
articulates with the anterior bones of the taU. 

BONES OF THE TAIL (oSSA COCCYGIS). 

Q. What is the situation of the ossa 
coccygis ? — A. Posterior to the sacrum. 

Q. Of how many bones is the tail com- 
posed ? — A. Fifteen. 

PELVIS OR HAUNCH BONES (oSSA INNOMINATa). 

Q. How do anatomists divide these 
bones, in the foetal state? — A. Into ilium, 
ischium, and pubes. 

Q. In the adult horse are there more 
than two bones ? — A. They are considered 
as two, yet in reality they are united at the 
pubes so as to constitute but one bone. In 



this state, however, they are denominated 
ossa innominata — unnamed bones. 

Q. What is the situation of the iliatic, 
ischiatic, and pubic portions? — xL They 
are in the anterior, superior, and lateral parts 
of the pelvic region. The ischiatic extends 
posteriorly and the pubic inferiorly. 

Q. What are the connections of the 
ossa innominata? — A. They are connected, 
anteriorly and inferiorly, to the os sacrum; 
posteriorly and inferiorly, to each other, 
forming the symphysis pubis ; laterally, 
with the thigh bones. 

Q. What are the uses of the pelvis? — 
A. It affords an arch for supporting the 
posterior parts. It contains the urinary or- 
gans, rectum, etc., gives protection to blood- 
vessels and nerves, and origin and insertion 
to various muscles and ligaments. 

. CHEST OR THORAX. 

The thorax or chest is formed by the 
dorsal vertebrae, superiorly ; ribs, laterally ; 
and sternum, inferiorly. It also affords pro- 
tection to the principal organs of circula- 
tion and respiration. 

Q. State the number of ribs and their 
arrangement? — ^4. Their number is gener- 
ally thirty-six ; eighteen on each side, eight 
of which are termed true, and the remainder 
false, ribs. 

Q. Why are the anterior eight called 
true ribs ? — A. Because they have a direct 
cartilaginous insertion into the breast bone 
or sternum. 

Q. Why are the posterior ten termed 
false ribs ? — A. Because they are indi- 
rectly connected with the sternum. 

Q. What is the general conformation 
of a rib ? — A. It is lengthy, curved ; con- 
vex outwardly or laterally ; terminating in 
a sharp border posteriorly, which forms a 
posterior convexity. On the inner surfaces 
it is concave, and of course the reverse of 
the external. 

Q. What are the variations in ribs ? — 
A. They vary in length, degree of cinrva- 
ture, and obliquity of direction. 

Q. How shall we divide each rib ? — A 



THE HORSE. 



43 



Into a body, external convexity , internal 
concavity, a superior and inferior termina- 
tion , anterior and posterior edges. 

Q. What do you understand when the 
teim, head, is applied to a rib? — A. It 
signifies its protuberance — its superior 
portion; presenting a smooth convexity for 
articulation with the bodies of vertebrss. 

Q. Where is the neck of a rib situated? 
A. Immediately below the head. 

Q. What is the difference between the 
anterior and posterior edges of the ribs ? — 
A. The anterior edge is circular and the 
posterior is sharp. 

Q. Where is the tubercle of the rib 
situated ? — A. Posterior to the head , at 
the root of the neck. 

Q. How is the first rib distinguished 
from the rest ? — A. It is the shortest and 
thickest, and is almost straight. 

Q. How does the second rib differ from 
the first ? — A. It is longer, less dense, 
and has a greater curvature in the region of 
its neck. ■ 

Q. How do the ribs differ from the 
second to the seventh ? — A. They increase 
in breadth. 

Q. How do they differ in length ? — A. 
Up to the ninth. 

Q. How do they differ in curvatvire ? — 
A. Gradually up to the eighteenth, which 
is the most curved of all. 

BREAST BONE (sTERNUM). 

Q. What is the situation of the sternum ? 
— A It occupies the anterior and inferior 
portion of the thorax. 

Q. How does it differ from the human 
sternum ? — A. In the human subject it is 
composed of three pieces ; in the adult 
horse it is considered as a single bone. It 
is made up, however, of seven irregularly 
formed bones. 

Q. What is the structure of the ster- 
num ? — A. It is composed of an osseous 
cellular substance and cartilages. 

Q. Name the cartilages ? — A. Erisi- 
form and cariniform. 

Q. What is the use of the cariniform 
It affords attachment to 



cartilage ? — A 



the sterno-maxillares and sterno-tliyro-hy- 
oidei muscles. 

Q. To what part of the sternum is the 
ensiform cartilage inserted ? — A. To its in- 
ferior and posterior part. 

Having now considered the bones of the 
head (with the exception of the teeth), and 
hyoides (appendages), spine- thorax, and 
pelvis, we now commence on the bones 
composing the extremities. These are four 
in number, disposed in pairs, and known 
as the fore and hind extremities. Our 
examination will be conducted with refer- 
ence only to one fore, and one hind, ex- 
tremity ; presuming that a description of the 
bones on one side will suffice for those on 
the other. 

- FORE EXTREMITIES. 

Q. What is the situation of the fore 
extremities ? — A. They occupy the antero- 
lateral parts of the trunk, from which they 
proceed inferiorlij. 

Q. How are the bones divided ? — A. 
Into shoulder, arm, knee, leg, pastern, coro- 
net, and foot. 

Q. Name the bones composing eack 
region ? — A. 

SHOULDER BONES. 

Scapida, Humerus. 

AR5I BONES. 

Ra<lius, Ulnar. 
BONES OF THE KNEE. 



g f Scaphoid, 
^ J Lunar, 
■S I Cuneiform, 
S [^ Trapezium. 



t rPisifonn, 
~ J Tra])ezoid, 
I I Os Magnum, 
£ I Unciform. 



BONES OF TlUi LEG. 

Large Metacarpal. 
Two smaU Metacarpal (splents.), 

LN THE REGION OF THE FCTLQCK. 

Two Sessamoid Boues. 

PASTKIN BONE. 

Os Suffraginie. 

■CORONET BONE. 

Os Corona". 

FOOT BONES. 

Na\icular and Coffin-beaes. 



44 



ANATOMY AND PHYSIOLOGY OF 



Q. How many bones compose one of 
the fore extremities ? — A. Twenty -one. 



OF THE SHOULDER. 



Q. The shoulder being composed of the 
scapula and humerus, what portion of the 
thorax do they occupy ? — A. They occupy 



its antero-lateral region. 



SCAPULA, (shoulder blade). 

Q. What is the position of the scap- 
ula ? — A. It occupies the antero-lateral 
parts of the thorax. 

Q. Describe the bone. — A. It is trian- 
gular, broad, and thin superiorly ; narrower 
and thicker inferiorly ; its external surface 
is uneqtially divided into two superficial 
concavities, named fossas antea, et postca 
spinatre. Its internal surface is smooth, yet 
excavated. 

Q. Describe the borders. — A. The su- 
perior has a thin, roughened summit for 
the insertion of the cartilage of the scap- 
iila ; the anterior is thin in its upper half, 
yet below it becomes rounded ; the posterior 
is obtuse and rounded. 

Q. How does the scapula terminate in- 
feriorly ? — A. By a glenoid cavity. 

Q. What are the connections of the 
scapula ? — A. It has a ligamentous con- 
nection with the spines of some of the dorsal 
vertebra; to the thorax, it is connected by 
muscular faschite; and its inferior connec- 
tion is by means of the glenoid cavity, to 
the head of the humerus ; this latter forms 
the shoulder joint. 

Q. Is diere anything remarkable about 
the shoulder joint? — A. Its most remark- 
able feature is, the great disproportion in 
size between the head of the humerus and 
the glenoid cavity. 

Q. How is this disproportion in magni- 
tude compensated for? — A. By an exten- 
sive capsular membrane, which admits of 
extensive motion. 

Q. AVhat are the insertions of this cap- 
sular membrane ? — A. It has a circular 
insertion into the rough margin of the 
glenoid cavity, and also around the neck of 
the humerus. 



Q. How is this membrane protected in- 
ternally and externally ? — A. Internally it 
is clothed with a synovial membrane ; ex- 
ternally by adherent muscles. 

HUMERUS. 

Q. What is the situation of the 
humerus ? — A. It is situated beneath the 
scapula, occupying a diverse direction, viz., 
downwards and backwards, and is in con- 
tiguity with the lateral parts of the thorax. 

Q. Describe the form of the humerus. 
— A. It is irregular, cylindroid, having a 
convoluted appearance, and its superior 
extremity is much larger than the inferior. 

Q. How is this bone divided ? — A. 
Into a body, superior and inferior extremi- 
ties. 

Q. Describe the bodi/. — A. It is angu- 
lar, with sides, contracted superiorly and 
flattened and rounded inferiorly. From its 
superior-anterior-lateral margin projects a 
roughened tuberosity, into which the leva- 
tor humeri is inserted. The lateral part of 
the body is lioUow or excavated. The in- 
ner side is somewhat roughened and promi- 
nent. 

Q. Describe the superior extremity. — 
A. The superior extremity being much 
larger than the inferior, presents a head 
and several tubercles : it has a projecting, 
hemispherical surface, designed for exten- 
sive articulation. It presents a smooth 
surface, yet has an irregular, indented 
groove for the insertion of a capsular liga- 
ment. 

Q. What is the use of the tubercles ? — 
A. The anterior, three in number, serve as 
articulations for the flexor brachii to tra- 
verse. The fourth serves as a protection 
against dislocation. 

Q. Describe the inferior extremity. — A. 
It consists of two heads or condyles, sepa- 
rated by deep ovoid fossse into which is 
received the olecranon of the ulna. 

Q. What are the connections of the 
humerus ? — A. Superiorly, it connects 
with the scapula ; inferiorly, it articulates 
with the radial and ulnar extremity of the 
Os Brachii. 



THE HORSE. 



45 



OS BRACHII (arm bone). 

Q. Describe the location of the os 
brachii. — A. It is located beneath the tho- 
rax, in the inferior region of the Immerus. 

Q. How does this bone differ from those 
of the human subject ? — A. By being con- 
solidated into a single bone. 

Q. How is it divided ? — A. Into radial 
and tdnar portions. 

Q. Describe the radial. — A. It consists 
of a body, superior and inferior extremi- 
ties. The body is lengthy, compared with 
other bones of the fore extremity ; posteri- 
orly it is excavated and roughened ; ante- 
riorly it projects with a smooth, cylindrical 
surface. 

Q. Describe the superior extremity. — 
A. The superior extremity presents an in- 
terrupted articulatory surface, having a 
central eminence, with two cavities, which 
correspond to the articulations of the os 
humerii. 

Q. Describe the inferior extremity. — 
A. It appears to consist of three articulatory 
surfaces, which correspond with those of the 
bones of the carpus. 

Q. Describe the ulnar portion of the os 
brachii. — A. It presents a tapering trian- 
gular projection, firmly connected with the 
radius; at its junction with the same, it 
presents a semilunar concavity ; this, with 
the articulatory surface of the radius, forms 
the humero-brachial articulation. 

Q. Name the projection of the ulnar, 
commonly termed point of the elbow. — A. 
Olecranon. 

Q. What muscle is inserted into the ole- 
cranon ? — A. The triceps extensor brachii. 

Q. What is the state of this bone in 
early colthood ? ■ — A. It is composed of two 
pieces named radius and ulnar, which after- 
wards become consolidated. 

Q. With what bones does the inferior 
portion of the os brachii articulate ? — A. 
With the scaphoid, lunar, and cuneiform 
bones. 

BONES OF THE KNEE (cARPUs). 

The bones of the knee correspond to the 
•wrist, or carpus, of man. 



Q. How are these bones arranged ? — A. 
They are ranged in two rows, or tiers ; one 
of the number, trapezium, is located in the 
posterior part of the carpus. 

Q. Name the bones of the first row ? — 
A. Scaphoid, lunar, cuneiforme, trapezium. 

Q. Name the bones crossing the second 
row ? — A. Pisiform, trapezoid, magnum, 
unciform. 

Q. What is the general form and situa- 
tion of each of the bones of the first row? 
— A. The OS scaphoides is semi-ovoid in 
form, its superior surface is sigmoid and 
smooth, the inferior surface is somewhat 
oval, and rests upon the trapezoides and 
magnum of the second row. Its internal 
surface comes in contact with the os lunare. 
The OS lunare is the second bone of the first 
row; it articulates superiorly with the 
brachii ; inferiorly, with the ossa magnum 
and unciforme; its superior surface is trian- 
gular ; inferior, oblong ; on one side, inter- 
nally, it articulates with the scaphoid, on 
the other with the cuneiforme. The cunei- 
forme is known as the external, yet smallest 
bone of the knee. Its superior surface is 
concave ; inferior, smooth ; its internal sur- 
face articulates with the os lunare, and pos- 
teriorly it unites with the trapezium. 

Q. What is the general form and situa- 
tion of each of the bones of the second 
row ? — • A. The os trapezoides is situated 
on the inner side of the knee, resting on the 
inner splent bone, and articulating with the 
OS magnum ; its form is that of an irregular, 
curvated, flattened cone ; its superior surface 
is convex, and its inferior flat. The os 
magnum is the middle bone of the second 
row, and is known as the largest bone of 
the knee. Its superior surface presents two 
articulatory surfaces, one sigmoid and ob- 
long for the OS lunare, and the other ovoid 
and flat, to correspond with the sm-face of 
OS scaphoides; its interior surface is flat, 
and articulates with large metacarpal bone. 
The OS unciform is situated on the outer 
side of the second row, and in form resem- 
bles a blunt hook; its superior surface is 
convex ; its inferior irregular, articulating 
with the outer splent and cannon. The os 



i- 



46 



ANATOMY AND PHYSIOLOGY OF 




trapezium is situated in the posterior part 
of the carpus, and presents two smooth sur- 
faces for articulation with the ossa cunei- 
forme and brachii. Its external, lateral sur- 
face is convex ; its internal concave ; its 
superior border gives attachment to the 
flexores metacarpi ; and into the inferior is 
inserted a ligament. The ossa pisiform ia 
— for sometimes there are two present — is 
situated posterior to the trapezoides ; its 
form is orbicular or pea-shape. 

METACARPAL BONES. 

The metacarpal bones are three in num- 
ber, viz : metacarpi magnum, 1 ; metacar- 
\u parvTtm, 2. There seems, however, so 
great a disproportion between the os mag- 
num and ossa parva, that the former may 
be considered as the principal support of 
the fore extremities. 

Q. What is the situation of the metacar- 
pus ? — A. Immediately beneath the carpus. 

Q. Describe the form of the metacarpi 
magnum. • — A. It is a long cylindrical 
bone, presenting on its anterior surface a 
circular, smooth appearance ; its posterior 
surface is somewhat flattened and depressed. 

Q. How is the bone divided 1 — A. Into 
a body, and tAvo extremities. 

Q. Describe the extremities. — A. The 
superior presents a smooth articulatory sur- 
face, tapering towards its outer edges, yet 
more depressed on its inner and posterior 
part ; in the anterior region is a roughened 
prominence, for the insertion of the extensor 
metacarpi, and on the lateral side of the 
bone are eminences which afford insertion 
for the lateral ligaments. The inferior ex- 
tremity presents a pulley-like surface, with 
two unequal condyloid surfaces, separated 
by a seini-circular eminence, which corre- 
sponds to a counterpart found on the supe- 
rior cud of the sufFraginis. 

Q. What are the articulations of the 
metacarpi magnum ? — A. It articulates su- 
periorly with the carpus; inferiorly, with the 
OS suflragiuis ; j^osteriorly and laterally, with 
the ossa icssamoidea and metacarpi parva. 

OSSA METACARPI PARVA (sPLEXT BONEs). 

Q. How many bones compose the ossa 



metacarpi parva ? — A. Two : external and 
internal. 

Q. Describe their situation. — A. They 
are attached to the lateral and posterior 
parts of the metacarpi magnitm. 

Q. How do you divide them ? — A. Into 
bases, middles, and apices. 

Q. Describe the base. — A. It is sur- 
mounted by a smooth qrtictolatory surface, 
corresponding to the inferior portion of a 
part of the knee joint. ' 

Q. Describe the middle. — A. It is tri- 
facial : Ihe anterior surface is roughened 
for the insertion of inter-articular tissue, 
which connects it with the cannon ; the inner 
surface is excavated ; the outer surface is 
rounding, and terminates, posteriorly, acu- 
minately. 

Q. Describe the apex. — A. It tapers, and 
ends in a tubercle, which curvates in an 
inferior and superior direction. 

Q. How do the ossa metacarpi parva 
differ ? — A. The external is generally larger 
than the internal, and has a broader articu- 
latory surface. 

Q. What bone does the external splent 
articulate with ? — A. The unciform. 

Q. What bone does the internal splent 
articulate with ? — A. The trapezoid. 

Q. How are the splents connected to the 
cannon ? — A. By cartilago-ligamentous tis- 
sue. 

Q. What changes does this cartilaginous 
tissue undergo, subsequent to adult life ? — 
A. In a majority of cases it becomes ossified. 

PASTERN BONE (oS SUFFRAGINIs). 

Q. Describe the location of this bone. — 
A. It is located beneath the cannon, and 
takes an oblique direction from tiie same ; 
it articulates superiorly with the cannon ; 
posteriorly with the ossa sessamoidea. 

Q. Describe the form of the os suffra- 
ginis. — A. It is a flattened cylinder, yet its 
superior portion is more bulky than tlie in- 
ferior; it is generally considered as being 
about one-third the length of the cannon, 
and is divided into a body, superior and 
inferior extremities. 

Q. Describe the body of the os staffra- 



THE KORSE. 



47 



giniff. — ^1. The body presents two sui'faces, 
anterior and posterior; the anterior is con- 
vex, the posterior flattened and uneven ; it 
lessens in bulk in an inferior direction. 

Q. How is the superior extremity of the 
pastern bone recognized from the inferior ? 

— A. The superior is the largest, and pre- 
sents two shallow articular cavities; between 
them is a groove, v.iiich receives the central 
eminence of the inferior extremity of the 
cannon bone. The inferior extremity is 
much smaller than the superior; it is bi- 
convex, and consists of two articular con- 
vexities, separated by a transverse shallow 
depression. 

SESSAMOID BOXES (OSSA SESSAMOIDSa). 

Q. Where are the two sessamoids situ- 
ated ? — A. At the posterior part of the 
articulation formed~ by the cannon and 
pastern bones. 

Q. What is the form of these bones ? — 
A. Trapezoid : three sides present triangular 
faces, whose apices unite in one point, which 
is directed upwards ; the bases of the same 
form a fourth side, which is turned down- 
wards ; and are therefore divided into three 
sides, base, and apex. 

Q. Give a general description of the 
faces or surfaces of these bones. — 'A. They 
are known as anterior, posterior, and lateral 
faces ; the anterior are excavated, smooth, 
and articulatory, and along their inward 
borders — which are opposed to each other 

— are levelled off, so that the two form a 
groove for the reception of the central 
eminence of the inferior portion of the can- 
non. The posterior surfaces are convex and 
rough ; the lateral surfaces are grooved and 
roughened ; the bases are narrow and uneven. 

Q. What appears to be the object in ex- 
cavating the anterior surfaces of these 
bones? — A. To extend the articulatory 
surface of the pastern joint, and admit of 
extensive anterior and posterior motion. 

Q. For what purposes are the posterior 
surfaces roughened ? — A. For the insertion 
of the suspensory ligaments. 

Q. What occupies the cavity which 
occurs in consequence of uniting the inter- 



nal surfaces of these bones ? — A. The flexor 
tendons. 

Q. What ligaments are inserted into the 
bases of these bones? — .di^The long 
short, and crucial ligaments. 

CORONET BONE (oS CORONiE). 

The OS coroncB is situated beneath, or 
rather interiorly, to the pastern, and may 
therefore be termed the inferior pastern ; 
it occupies a location between the superior 
pastern and coffin bone. 

Q. Describe the os coronae, or inferior 
pastern. — A. It presents a square body; its 
breadth, however, somewhat exceeds its 
longitudinal measurement. It has four sur- 
faces, viz., superior, inferior, anterior, and 
posterior ; the superior surface is bi-concave, 
corresponding to the projections of the 
superior pastern ; the inferior surface is bi- 
convex, consisting of two condyloid prom- 
inences, separated by a slight transverse 
depression, corresponding to the articulatory 
surface of the coffin-bone ; the anterior sur- 
face is convex, yet rough and irregular ; the 
posterior surface is quite smooth, yet exca- 
vated. 

Q. What are the connections of the os 
coronffi ? — A. It connects with the pastern, 
coffin, and navicular bones. 

BONES OF THE FOOT. 

THE COFFIN BONE (oS PEDIs). 

The coffin bone is considered as the base 
of the osseovTS structure of the fore extremity. 

Q. What is the form of the coffin bone ? 
— A. It presents a semilunar outline ; an- 
teriorly and superiorly it is convex ; pos- 
teriorly and interiorly it is concave ; it is 
divided into wall, sole, tendinous surface, 
articulatory surface, and wings. 

Q. Describe the wall. — A. It is a 
miniature of the form of the hoof; it exhibits 
a porous and furrowed surface, and has in- 
numerable perforations, varying in size and 
form ; its superior part is surmounted by 
the coronal process; the inferior edge of the 
wall is somewhat oval, and is notched and 
serrated. 



48 



ANATOMY AND rilYilOLOGY OP 



Q. What are the uses of the porosities 
and furrows ? — A. Tliey serve as so many 
attachments for the fibrous tunic of the 
sensible hiniinas 

Q.^V'liat name is generally applied to 
'the* largest o{ the perforations found in the 
eotlin bone ? — A. They are termed for- 
amina. 

Q. What occupies these foramina? — 
A. Blood-vessels and nerves. 

Q. Describe the sole of the eotlin bone? 
— ^-1. The sole exhibits a broad, uniform, 
concave surface, resembling in most cases 
the figure of the inferior part of the hoof; it 
has porosities similar to those formed on 
the wall ; it is bounded anteriorly and later- 
ally by the cireumferent edge of the wall; 
posteriorly, by a sharp, imeven, semi-circular 
edge, which divides it from the tendinous 
surface. 

Q. What do we find on the tendinous 
surface? — A. 1st, a rough depression in 
its fore and middle part, marlung the inser- 
tion of the tendo jierforans. 'Jndly, tsvo 
lateral grooves, passing obliquely inwards, 
and terminating each in a large foramen. 
Srdly, a porous space intermediate between 
the two former divisions, into which is fixed 
the inferior navicular ligament. 

Q. What occupies the lateral grooves? — 
A. The trunks of the arteries and nerves 
which occupy the interior of the coffin bone. 

Q. What are the peculiarities of the ar- 
ticulatory sirrfaee of the coffin bone ? — A. 
It has two lateral depressions, which extend 
posteriorly to the alte ; a broad eminence 
runs transversely between them ; this emi- 
nence is terminated in front by the coronal 
processes, having an incurvation backwards; 
behind it, the surface is bevelled off, to 
which part is opposed the navicular bone ; 
the depressions alluded to are deepened by 
the prominent edge running around the an- 
terior and lateral parts. 

Q. What portion of the coffin bone does 
the articulatory surface occupy ? — ^1. The 
superior part. 

Q. What is the form of this surface? — 
A. It is half-moon shaped. 

Q. Describe the alse, or wings ? — They 



consist of a protuberance on the posterior 
part of each side of the coffin bone ; the 
protuberance, however, is generally bifid; 
the lower portion which is the largest, is 
in-egular and asperous, and projects in a 
posterior direction ; the upper portion is tu- 
bercular, yet smooth; between the divisions 
of the akc is a notch, which, at a certain 
period in the life of the animal becomes a 
perfect foramen. 

Q. What is attached to the irregular sur- 
face of the larger division of the kite ? — A. 
The cartilage of the foot. 

Q. What is affixed to the tuberculated 
portion of the alse ? — A. The coffin liga- 
ments. 

Q. What vessel passes tlu-ough the 
notch ? — A. The lateral artery. 

Q. What is there remarkable about the 
structure of the coffin bone ? — A. It has a 
spongy, fragUe texture, pervaded in every 
direction by minute canals for the trans- 
mission of blood-vessels and nerves ; it dif- 
fers very essentially from many bones of 
the body, which, in healihy subjects, are 
remarkable for compactness and solidity. 

NAVICULAR BONE (oS NAVICULARe). 

Q. What is the general form and division 
of the navicular bone ? — A. It is semi-lu- 
nar: its lunated border, however, only forms 
about one third the circle of its dimensions; 
it is divided into two surfaces, two borders, 
and two extremities. 

Q. Where is this bone situated ? — A. 
At the posterior part of the coffin joint. 

Q. Describe the superior and inferior sur- 
faces of the navicular bone. — A. The 
superior surface bears a corresponding 
aspect to the articulating surface of the 
coffin bone, having two superficial lateral 
depressions, with an eminence between 
them. The inferior siufaee is also articu- 
latory ; and exhibits lateral depressions yet 
more superficial than the superior; it has 
also an eminence across the middle, nar- 
rower yet more prominent than the former. 

Q. Name the tendon which articulates 
over the inferior surface. — A. Tendo per- 
forans. 



THE HOUSE. 



49 



Q. Dcscribo thn bordors. — A. Thobor-j 
ders arc lunatod and slr.iiglit: the luiiated| 
is broadest in the centre, and narrows to- 
wards tlie exirernities ; superiorly it lias a 
smooth narrow strip of surface along the 
middle, which is adapted to the bevelled 
portion of the articnlatory surface of the 
coffin bone ; the part beneath is fluted and 
porous, into which is inserted a ligament 
which connects it with the codin bone. 
The straigiit border is thinner than the 
opposite one ; superiorly it is rough and 
porous ; inferiorly it is smooth and lipped. 

Q. What is the form and direction of 
the extremities of ihv. navicular bone? — A. 
They are obtusely pointed, one directed 
outward and the other inward. 

Q. What ligaments are inserted info the 
extremities ? — A. The lateral ligaments. 

HIND EXTREMITIES. 

Q. What is the situation of the hind 
extremities? — A. They occupy the inferior 
and posterior parts of the pelvis, and sup- 
port the posterior parts of the trunk. 

Q. How are the bones of the hind ex- 
tremities divided? — A. They are thus 
divided: Femur, stifle, thigh, hock, leg, pas- 
tern, coronet, and foot. 

Q. Name the bones comprising these 
parts. — A. 

FEMUR. 

STIFI.K liONK. 
ratella. 

THIGH nO.VES. 

Tibia and Filiula. 

HOCK I!ONl;S. 
A.stragalus, ()s calcls. 

Culjoid bone, 
Three Cuneiform bones. 

BONES OF Tin; li;g. 

Metatarsi Mngnum. 

Metatarsi Parva, two bones (splents). 

PASTER.\ JOINT. 

Ossa Schsamoidea (two bones), 
Os Suffi-nginis (pastern). 

COROXIT. 

Os Coronae. 

BOXES OF THE FOOT. 

Os Pedis and Os Naviculare. 



Q. Where is the femur situated? — A. 
Between the pelvis and thigh bones. 

Q. How is it divided? — A. Into a body 
and two extremities. 

Q. What are the peculiarities of the 
superior extremity? — A. It consists of two 
parts: a hemispherical, smooth, articnlatory 
head, directed upwards and inwards, and 
joined to the body by a flattened neck, 
and exhibiting on its inner side a fissure, 
into which is fixed the teres or round liga- 
ment. The other part is a large irregular 
projection at the base, and posterior to the 
same is a deep oval cavity; at the superior 
part is a roughened crest; inwardly it pre- 
sents a concave, smooth surface. 

Q. What is the proper name of the pro- 
jection ? — A. The great external tro- 
chanter. 

Q. What muscles are inserted into the 
the same? — A. The gluteii. 

Q. What is inserted into the concave 
smooth surface? — A. The capsular liga- 
ment. 

Q. What is the form of the body of the 
OS femoris ? — A. It is cylindrical. 

Q. How does it correspond in size and 
weight with other bones of the body ? — A. 
It is the longest and weightiest. 

Q. W^hat is the form of inferior extrem- 
ity? — A. It is broad and thick, and has a 
trochleal prominence and two condyles. 

Q. Give a description of the same. — yi. 
The articular or pully-like surface anteriorly 
consists of a broad, semi-circular groove 
bounded on either side by a prominence ; 
the condyles much resemble each other, 
excepting that the external is the thickest, 
and the internal most projecting; they 
exhibit prominent, convex, articnlatory sur- 
faces ; pn their sides are rough eminences; 
between them is a deep fossa ; at the base 
of the external condyle is a pit. 

Q. What articulates over the pulley-like 
surface ? — yl. The patella or stifle bone. 

Q. What is inserted into the rough emi- 
nences ? — yl. The lateral ligaments. 

Q. What occupies the fossa ? — A. The 
inter-articular ligament 



50 



ANATUiMY AND PHYSIOLOGY OF 



Q. What is inserted into the pit? — A. 
The tendon of the extensor pedis. 

Q. What is the state of this bone during 
colthood ? — .4. Extremities are attached to 
the body of the bone by means of cartilage. 

Q. Wiiat changes do the extremities 
undergo just prior to adult life ? — A. They 
become consolidated with the body of the 
bone. 

STIFLE BONE (paTELLa). 

Q. What is the situation of the patella? 

— .1. It is situated on the anterior and infe- 
rior extremity of the femur. 

Q. What is its general form ? — A. 
Quadrangular, convex externally, UTegularly 
concave internally. 

Q. How is it divided? — A. Into three 
surfaces and four angles. 

Q. Describe the surfaces. — A. The an- 
terior surface is convex, yet quite prominent 
rn the centre ; it has a roughened surface, 
and is porous. The superior surface is 
angular, uneven, and roughened. The pos- 
terior surface is articulatory, and unequally 
divided by an eminence running across it 
into two shallow concavities, which are 
adapted to the condyles of the inferior ex- 
tremity of the femur. 

Q. Describe the form of the angles of the 
patella. — A. They are obtuse. 

Q. Why is the anterior surface of the 
bone roughened ? — A. For the insertion of 
tendinous and ligamentary attachments. 

Q. What is implanted into the uneven 
and roughened part of the superior border? 

— A. The tendons of the rectus and vasti 
muscles. 

Q. What is inserted into the inferior and 
lateral angle ? — A, The ligamentum pa 
tella. 

Q. What are the connections of this 
tone ? — A. It is connected to the inferior 
portion of the femiu- by tendinous and 
capsular ligaments ; to the tibia it is con 
nected by similar ligaments. 

THIGH BONES (tibia AND FIBULa). 

In consequence of a horse having a very 
large femur, and that bone appearing to 



enter into the composition of the haunch, 
the tibia and fibula are termed thigli bones, 
althougli in man they are termed bones of 
the leg ; the fibula of the horse, however, is 
a very small, slender bone, affixed to the 
superior part of the external side of the 
tibia. 

Q. What is the situation of the thigh 
bone ? — A. It is situated between the stifle 
and hock. 

Q. What is the form of this bone ? — A. 
It is long, straight, prismatic ; its superior 
extremity is larger than the inferior. 

Q. What is its direction ? — A. Oblique 
in a contrary direction to the femur. 

Q. How is the tibia divided ? — A. Into 
a body, superior and inferior extremities. 

Q. What is the general form of the 
body ? — A. It is irregularly triangular, the 
posterior face is broadest, the anterior angle 
is rounded, and the sides are roughened. 

Q. What is peculiar to the superior ex- 
tremity of the bone? — A. We find two 
irregular ovoid articulatory surfaces, corre- 
sponding to the eminences on the inferior 
extremity of the femur ; these are separated 
by an acute elevation, and two fossa, into 
which is inserted the lateral ligament. 

Q. Describe the inferior extremity. — A. 
It is flattened, and has two deep articular 
grooves running in an anterior and posterior 
direction ; its exterior margin is roughened. 

Q. What are its connections ? — A. It 
connects with the femur and patella supe- 
riorly ; inferiorly, with the bones of the hock. 

fibula. 

Q. What is the situation of the fibula? 
— A. At <he posterior part of the tibia. 

Q. How is it connected to the tibia ? — 
A. By cartilago-ligamentous substance. 

Q. What is the form of the two ends of 
the bone? — A. The superior is bulky, flat- 
tened from side to side, and roughened. 
The inferior is slender and tapering, and 
extends about half way down the tibia. 

BONES OF THE IIOCK (taRSUS). 

The tarsus, or hock, comprises a part of 
the osseous structure of the horse, that 







S<1 




EXPLANATIONS OF FIGURE VL 



KO. 1.— FORE EXTREMTITES. 

/. The Ulna. 

34. Humerus. 

35. Radius. 

36. Carpus. 

37. Metacarpus. 

38. Sessamoids. 

s. or 39. Os suffraginis. 

40. Os coronop. 

41. Os pedis. 

The above description also answers for No. 3, — the bony structure. 

NO. 2. — MUSCULAR STRUCTURE. 

LATERAL VIEW OF THE NEAK-FORE E.\TEEMITY. 

s". Extensor metacarpi magnus. 

i". Humero cubital. 

n". Levator humeri. 

p". Flexor metacarpi extemus. 

a;", x". Extensor pedis. 

m". u." v". Flexors. 

«". Flexor tendons. 

y. Extensor tendon. 

z. Suspensory hgament. 

&{. The hoof. 

NO. 4. 

ANTEEIOR VIEW OF THE NEAE-FOEE EXTREMITY 

s. Extensor metacarpi magnus. 

t. Extensor metacarpi obliquus. 

x". Extensor pedis. 

y". Extensor suffraginis. '^ 

If. The hoof 

8. Bifurcation of the suspensorj' hgament. 



THE HORSE. 



51 



e\ery veterinary student should aim to be 
well acquainted with ; it is a part that seems 
to be, in this country, more liable to anchy- 
losis and exostosis than any other region ; 
here is the seat of spavin, and no one can 
possibly understand the nature of such dis- 
ease unless he be conversant with the ana- 
tomical mechanism of the hock. The hock 
corresponds to the tarsus or instep of man, 
and is composed of six bones, viz., os calcis, 
astragalus, os cuboides, ossa cuneiformis ; 
which comprise three small bones, viz., ex- 
ternal, internal, and middle cuneiforme. We 
shall first consider the os calcis, 

"Q. What is the situation of the os cal- 
cis ? — A. It forms the posterior projec- 
tion icnown as the point of the hock — the 
superior and posterior bone of the tarsus. 

Q. Give a general description of the 
bone. — A. Its figure is kregular ; presents 
a body, tuberosity, posterior surface, and 
base ; the body is most bulky at its inferior 
part ; as a whole, it is irregularly convex ; 
concave and expanded at its base, where 
it presents four surfaces for articulation 
with the astragalus ; the tuberosity is ob- 
long, flattened on each side, and terminates 
in a rougii tubercle, into which is inserted 
the tendons of the gastrocnemii. It is sit- 
uated on the superior part of the hock. 

THE knuciclt; bone (astragalus). 

Q. What is the situation of the astra- 
galus ? — A. It is situated in the superior 
part of the hock, and is the principal sup- 
port of the tibia. 

Q. How do you distinguish it from 
other Ixincs ? — A. It is readily distin- 
guished by its double pulley-like articula- 
tory surfaces, which consist of two semi- 
circular prominences, having between them 
a deep groove, well adapted to receive the 
projection found on the inferior extremity 
of the tibia. 

Q. What is the. appearance of the pos- 
terior surface? — A. It has four articulatory 
sui-faces, corresponding to those of the os 
calcis. 

Q. What is the appearance of the base 
or inferior extreniitv ? — A. It has an irre- 



gularly flattened articulatory surface, which 
comes in contact with the large cuneiform 
bone. 

CUBOID BONE {os CUBOIDES). 

Q. What is the situation of the cuboid 
bone ? — A. On the outer part of the 
hock. 

Q. How is the bone divided ? — A. Into 
four surfaces, viz., external, internal, supe- 
rior, and inferior. 

Q. How do you distinguish the externa? 
from the internal surface ? — A. The exter- 
nal surface is Jjroad, irregular, curved, and 
roughened ; on (he other hand, the internal 
is excavated, and has three articulatory 
surfaces. 

Q. How does tlie superior surface difi'er 
from the inferior? — A. The superior sur- 
face has two articulations, with a fossa 
between them ; the inferior surfaces are 
smaller, and correspond, one to the articula- 
tory head of the splent bone, and the other 
to the cannon. 

large- cuneiform bone (os cuneifotime 
magnum). 

Q. What is the situation of the cunei- 
form bone ? ■ — A. Directly beneath the 
astragalus. 

Q. What is the appearance of this bone ? 
— A. It presents a triangular form ; its 
acute termination being in a posterior direc- 
tion, it has superior and inferior surfaces, 
sides, and angles. 

Q. How is the superior surface distin- 
guished from the inferior? — yL The supe- 
rior surface has a uniform articulatory 
surface, with the exception of a small, 
rough grove running to its centre, from the 
outer side, which terminates in a central 
pit. The inferior surface is rather convex, 
yet presenting a flat appearance ; its poste- 
rior angle has an articulatory surface, cor- 
responding to that of the cuboid bono. 

Q. What are the articulations of this 
bone ? — A. It articulates with the astra- 
galus, cuboid, middle and small cjjoei- 
form bones. 



52 



ANATOMY AND PHYSIOLOGY OP 



jiiddle cuneiform bone (os cuneiforme 
medium). 

Q. What is the situation of the middle 
cuneiform bone ? — A. It is situated be- 
neath the large cuneiform. 

Q. What is the relative size of the ossa 
cuneiformia? — A. The one beneath the 
astragalus is (he largest; the middle is the 
medium; and that at the posterior part of 
the hock is the smallest. 

small cuneiform bone (os cuneiforme 
parvum). 

Q. What is the situation of the small 
cuneiform bone ? — A. It is situated at the 
posterior ipart of the hock. 

Q. What are the articulations of this 
bone ? — A. It articulates superiorly with 
the internal angle of the large cuneiform ; 
anteriorly, with the same angle of the mid- 
dle cuneiform ; posteriorly, with the inter- 
nal splent bone and cannon. 

HIND CANNON (oS METATARSI MAGNUm). 

Q. What is the popular name of the 
hind cannon ? — A. Shank-bone. 

Q. How does it compare in length with 
the cannon of the fore extremities ? — A. It 
is about one-sixth part longer than the fore 
cannon. 

Q. Is there any difference in the supe- 
rior surfaces of the fore and hind cannons ? 
— A. Yes ; the superior surface of the fore 
cannon corresponds to the surfaces of the 
inferior bones of the carpus ; the superior 
extremity of the hind cannon closely resem- 
bles the surfaces of the middle and small 
cuneiform bones, and also that of the 
cuboid. 

Q. How do the hind and fore cannons 
differ in conformation ? — A. The bone of 
the hind extremity is more circular and 
prominent, anteriorly, than the forward 
me. 

HIND SPLENTS (METATARSI PARVa). 

Q. What is the situation of the metatarsi 
parva ? — A. They are situated at the pos- 
terior part of the hind cannon. 

Q. How are the hind splents recognized 



from those of fore limbs ? — A. The hind 
splents are longer than the fore ; their bodies 
are more circular and prominent forward, 
and the superior extremities correspond (o 
a part of the cuneiform and cuboid bones ; 
while the superior extremities of the forward 
splents correspond to a portion of the in- 
ferior row of the bones of the knee. 

We now come to the bones articulating 
beneath the inferior extremity of the hind 
cannon, viz., pastern, sessamoid, coronet, 
colHn, and navicular bones. These, according 
io the opinion of Mr. Percivall, "so closely 
resemble their fellows of the fore extremity" 
that we sh;ill dispense with examinations 
regarding them, merely remarking that the 
bones of the hind feet are generally broader 
in a lateral and posterior direction than 
those of the fore ; the pastern and coronet 
bones are somewhat longer than their fellows 
forward. 

BONES OF THE EAR. 

Q. Name the bones of the ear. — A. 
Malleus, incus, stapes, and orbiculare. 

Q. What is the form of the malleus? — 
A. It appears to resemble a mallet. 

Q. Name the long process or handle. — • 
A. Manubrium. 

Q. To what is the manubrium attached? 

— A. To the membrana tympani. 

Q. Describe the form of the incus. — A. 
It is said to resemble a blacksmith's anvil, 
but, probably, approaches nearer to the 
figure of a molar tooth ; it has a depression 
on its surface, which receives the head of 
the malleus. 

Q. Describe the stapes. — A. It resem- 
bles in form a common iron stirrup, yet has 
a more triangular appearance. 

Q. With what bone does it articulate? 

— A. The OS orbiculare. 

Q. Describe the OS orbiculare. — A. It is 
the smallest bone of the body, not exceeding 
in size a grain of muslard-sccd. 

Q. What is its use in the mechanism of 
the ear? — A. It forms the medium of 
junction and communication between the 
incus and stapes, and facilitates the motions 
of the latter bones. 



THE HORSE. 



53 



BONE OF THE TONGUE (oS HYOIDES). 

Q. What is the situation of the os 
hj'oides ? — A. It is located at tlic root of 
the tongue, at the anterior part of the larynx. 

Q. How is the bone divided? — A. Into 
a body and four horns. 

Q. What is the form of the body ? — A. 



sharp. The converse is the case with regard 
to the permanent teeth. 

Q. What is the popular theory regarding 
the periods of cutting the teeth? — A. A 
foal is said, at birth, to be in the act of cut- 
ting twelve molars, three on each side of 
the jaw bone ; at this time, there is no ap- 



In shape, it resembles a spur, consisting of pearance of incisors ; and when they do 

appear, wliich period will be about the 
second or third week from birth, sometimes 
sooner, the front incisors of the upper jaw 
are the first to show themselves, and be- 
tween the fourth and fifth week, they are 
succeeded by the middle incisors ; the side 
or lateral incisors make their appearance 
between the si.xth and tenth month. The 
animal is then said to have a full set of 
temporary teeth. After the animal has at- 
tained his first year, the fourth molars make 
their appearance. Between the period of 
the first and second years, the fifth molars, 
in each side of the jaw, are apparent. Be- 
tween the second and third years, the front 
permanent incisors displace the temporary, 
and, at the same time, the first temporary 
molars are shed, and replaced by the perma- 
nent. Between the thii'd and fourth years, 
the middle temporary incisorsare succeeded 
by the permanent, and about the same time 
the second temporary molars are shed. 
During the interval of the fourth and fifth 
years, the lateral permanent incisors appear ; 
the sixth and last, permanent molars are 
up, and then the tusks also appear. At this 
period the horse is said to have a full mouth ; 
a complete set of permanent teeth.* 

We have now arrived at an era (or rc- 



neck and branches ; the neck is inserted 
into the root of the tongue, and the branches 
are in a posterior direction, embracing the 
superior border of the thyroid cartilage. 

Q. What is the appearance of the horns ? 
— A. There are two long and two short 
horns; the short, or inferior, ascend oblique- 
ly from their articulations with the body of 
the bone, and terminate in oblong, smooth 
extremities. The long or superior horns 
constitute two long, flattened, thin bones, 
extending backward in a horizontal direc- 
tion from the summits of the inferior horns. 

Q. What are the connections of the os 
hyoides? — A. It is connected with the 
temporal bone, larynx, pharynx, tongite, and 
some of the mttscles of the neck. 

OF THE TEETH. 

Q. How many teeth do we find in the 
jaws of the adult horse ? — A. Forty. In 
the mare, however, the canine teeth are 
generally imperfect or undeveloped. 

Q. How are the teeth divided? — A. 
Into three classes, viz.: incisors, or nippers; 
molars, or grinders ; canini, or tusks. 

A. Enumerate each class. — A. There 
are twelve incisors, twenty-four molars, and 
four canine. 

Q. Is there anything peculiar about the 
development of horses' teeth? — A. Yes; 
the teeth with which the animal is furnished | 



* On this side the Athintic we are not in possession of 
any rcliahle information as regards the periods of cuttin;,' 
, and shedding teeth ; we have to dejiend entirely on Engiisli 
during Colthood are termed temporary, and j ^utliority. Tlieir theory is. that the .age of a rac'e-liorse shall 
are generally shed ere the animal arrives at be reckoned from the month of Jlay in the year of his 

the age of five ; the temporary teeth are 
twenty-four in number, twelve incisors and 
twelve molars ; they differ from what is 
termed the "permanent set," in being small- 
er and whiter, and in having necks or con- 
tractions at the superior part of the fang, 
and the eminences on their face are quite 



birtli, without any in(|uiry whatever as to the season, 
month, or day of foaling ; so tliat tJie produce of Januarj- 
arc actually four months older than by reckoning, or as 
their ages appear on the calendar, and these are called 
early fuals ; w liereas those foaled in March are denomi- 
nated late. These thia are more arbitrary than truthful ; 
may suit the convenience of English turfmen, but will not 
pass current among our breeders, — who, generally, pay 
/utiiicular attention to the time of foaling, and date the 
birih of the colt aecordin^lv 



54 



a:;atom\" axd physiology oj 



markable period) in the age of (lio horse ; 
have briefly considered a series of changes 
which the teeth of a colt undergo, up to 
the period of maturity, and shall now turn 
our attention to the changes observed in 
the process of wear and tear of the perma- 
nent teeth. 

REMARKS ON THE CHANGES 
WHICH A HORSE'S TEETH 
UNDERGO. 

The nippers or front teeth of a fuU- 
moutlicd horse, just having shed all the 
temporary ones, present a beautiful ap- 
pearance : the contrast between the lily 
whiteness of the teeth, and the rose-tinted 
color of the gums and their membranes, are 
never so much the subject of admiration as 
at this period. 

Teeth, when first cut, present a sharp 
border externally, from which a gi'adual 
depression commences until the internal 
border is reached ; in the coui'se of about 
a year, in consequence of friction on the 
external, and gi-owth of the internal, the 
surface presents two elliptical enamelled 
rims, one of which borders the face of the 
tooth, the other encircles the depression or 
pit. 

Within this pit is a black incrustation, 
which is denominated " bean " or " mark ; " 
at a period of about three years from the 
time of cutting the permanent teeth, the pit 
or cavity is consolidated or filled up, and 
the surface of the tooth is worn down so as 
to present a comparatively smooth one. 
We must not expect, however, to find the 
face of the teeth uniform ; for cribbers, and 
voracious feeders, deface the surfaces very 
mucii, which gives to the teeth the appear- 
ance of age. Still, a good judge, who takes 
into consideration not only the appearances 
of surfaces, but also the form and direction 
of the teeth themselves, is not apt to be 
deceived regarding the age of a full-mouthed 
horse. 

Pessina, from whose work I\Ir. Percivall 
quotes, concludes that — 
. " At the age of eight (in most horses). 



the disappearance of the marks vs perfect: 
the teeth are all oval, the central enamel 
upon the face is triangular, and nearer to 
the outward than the inward border, and 
the cavity of the tooth appears A\athin the 
outward border like a yellowish band carried 
from one side to the other. 

" At nine years, the front teeth appear 
round, the middle and the lateral contract 
their oval faces, and the central enamel di- 
minishes and approaches the inward border. 

" At ten, the middle teeth become round, 
and the central enamel has approximated 
the inward border and is rounded. 

" At eleven, the middle teeth are rounded, 
and the central enamel is almost worn off 
the posterior incisors. 

" At twelve, the lateral teeth are rounded, 
the central enamel has quite disappeared : 
the yellow band has grown wider, occupies 
the centre of the face of the tooth, and 
the central enamel continues in the teeth 
of the upper jaw. 

" At thirteen, all the incisors are rounded, 
the sides of the front teeth spread out, and 
the central enamel continues in the upper 
jaw, but is round and approaches the inward 
border. 

" At fourteen, the faces of the front inci- 
sors put on a triangular appearance, the 
middle gi-ow out at their sides, and the cen- 
tral enamel of the upper teeth diminishes, 
but still exists. 

" At fifteen, the front teeth have become 
triangular, the middle enter upon that 
figure, and the central enamel of the upper 
jaw is still visible. 

" At sixteen, the middle are triangular, 
the lateral commence that shape, and the 
enamel of the upper teeth has disappeared. 

" At seventeen the triangular figures of 
the posterior jaw are completed; but their 
triangles are equilateral until the eighteenth 
year. Then their sides lengthen in succes- 
sion from the front to the lateral teeth, in 
such a manner that — 

" At nineteen, the front teeth are flat- 
tened from side to side ; 

" At twenty, the middle incisors have 
taken on the same shape ; lastly — 



i: 



THE HORSE. 



55 



" At twenty-one the lateral teeth are also 
flattened." 

Professor Pnssini * " systematically di- 
vides the lifetime of the horse, which he 
computes at thirty years, into six periods, 
that take their rise from and are determined 
by an equal number of changes the teeth 
naturally undergo, in regular succession. 

" The first period is that during which 
the animal retains all or any of his mUk 
teeth ; it extends from birth to the fifth year. 

" The second period includes the sixth 
year, and continues so long as the marks 
remain visible upon the faces of the pos- 
terior incisors; which is generally about 
three years. 

" In many instances, however, and espe- 
cially among horses that have been kept at 
pasture, the faces of the front teeth, and 
sometimes those of the middle, are worn off 
earlier. 

" The third period is that during v.'liich 
the teeth retain the oval form. As the pits 
and marks degenerate, the face of the tooth 
slowly and gradually undergoes a deviation 
of figm-e, from that of a pretty regular ellip- 
sis, whose long to its short axis bears the 
proportion of sLx to tliree, to an irregular 
one, in which these proportions are as five 
to four. This period requires, on an aver- 
age, the space of six years for its comple- 
tion ; the front teeth enter it in the seventh 
and conclude it at the expiration of the 
twelfth ; the middle pass through it one 
year later; and the lateral, cr side teeth, one 
year later still. 

" In the fourth period the faces of the 
teeth assume a circular figure, and hence 
have been denominated round. At the 
commencement of this period, the breadth 
of the face to its thickness is as 5 to 
4 ; at the conclusion, it measures in an 
inverse ratio, as 4 to 5 ; about the middle 
of it, the diameters are equal. This period 
also endm-es six years ; so that the front 
teeth, which enter it in the thirteenth year, 
complete it by the expiration of the 
eighteenth ; the middle follow one year 
later ; the lateral, one year later still. 

* See Percivall's Lectures. 



" During the fifth period, the face of the 
teeth deviates by slov/ degrees from the 
round, and passes into the triangular state. 
In the beginning, its thickness exceeds its 
breadth as 5 does 4 ; in the end, as 6 does 
3. It is the professor's opinion, yet uncon- 
firmed by experience, that this period, like- 
wise, on an average, includes a space of six 
years ; the front teeth, therefore, complete 
it with the twenty-fourth, the middle with 
the twenty-fifth, and the lateral with the 
twenty-sixth yearc-. 

" The sixth and last period is one, in the 
course of which an additional angle is 
projected from the anterior or inferior part 
of the tooth ; Pcssina distinguishes it by 
the epithet biangular; he has never met with 
a horse that had lost his teeth from age ; 
but he has seen their faces elliptrical con- 
trariwise, looking outwards or forwards. 
This period is unlimited. 

" In the anterior, or upper jaw, the marks 
disappear from the front teetii in the course 
of the ninth year ; from the middle in the 
tenth; and from the lateral in the elev- 
enth. 

" What progi'ess these upper teeth have 
not made in transformation during the 
second period, equivalent with the poste- 
rior, they gain it in the third ; notv.-ith- 
standing the depth of pit, their proportions 
are then the same. They continue three 
years longer in the second, and consequently 
are only three in the third period; so that, 
by the twelfth year, the third period is 
completed by the front upper teeth, and 
so on. During the fourth, fifth, and last 
periods, the changes are alike, and equally 
perceptible in either jaw. 

" So far, the upper teeth are entitled to 
an equal share of our regard; though, in 
the generafity of cases, they need not be 
inspected. In such a remarlcable man- 
ner the lateral teetli of the upper jaw wear 
away so that they often appear as if 
notched or indented. 

" In regard to the tusk or tush, Pessina 
remarks that he has found the least regu- 
larity in its changes of any tooih. The 
very facts that tlie tushes are not in all 



56 



ANATOMY AND PHYSIOLOGY OF THE HOESE. 



horses cut at the same age, that they have 
little or no attrition against each other, and 
that they are worn by the tongue and food, 
sometimes more, at others less, should lead 
us to draw conclusions from them with 
great caution ; in fact, as indications of 
age, they can only be trusted to when they 
accord with the incisors. The tush or 
tusk makes its appearance by the fifth, and 
is completely evolved by the sixth year. 
In the seventh, the apex of the cone is 
worn off. In the eighth, its furrows grow 
shallow ; in the ninth they are obliterated. 
Then the apex gradually wears away , in 
the twelfth year it becomes round ; from 
which time, though it gradually becomes 
shorter, its shape varies but little. But it 
is not uncommon to see the tush blunted 



like an acorn in the ninth year, nor to find 
it still pointed in the sixteenth year. 

" Pessina concludes his account of the 
changes to which the teeth are subject, 
by observing, that, as they are dependent 
on wear, which is no law of nature, but 
an effect of mechanical and accidental 
causes, they cannot, but under certain lim- 
itations, be implicitly relied on." 

We are now supposed to be in posses- 
sion of some of the most important facts 
tending to elucidate the changes which the 
teeth undergo ; and, in view of making our- 
selves more conversant with this subject, 
we shall re-commence our examinations, 
for it is a matter of the highest importance 
that a veterinary surgeon shall understand 
the method of ascertaining a horse's age. 



EXAMINATIONS ON THE TEETH. 



Q. Does the evolution of the tush ahvays indicate 
that the animal is five years of age ? — A. No. It lias 
been seen between the third and fourth years. 

Q. Wliich teeth do you jjlace the most reliance on 
in ascertaining the age of a horse ? — ,-l. The side or 
lateral of the lower jaw. They make their appearance 
last; their pits are the last to disappear; after the 
age of eight or nine, however, the pits in the incisors 
of the upper jaw are also indicative of age; they, being 
deeper, of course remain some time after all vestiges 
of the same have disapjjcarcd in the lower jaw. 

Q. In adult life is there any continued accretion or 
after-growth of the teeth ? — A. Yes. If it were not 
60, the animal would, in course of time, hav^to gather 
food, and grind the same with liis gums ; for, acccord- 
ing to the law of loear and tear, destruction of the in- 
struments — grinders of food — must more or less reg- 
ularly take place. 

Q. What changes take place as the horse advances 
in age, in the inclination of the incisors ? — A. They 
acquire a horizontal direction. 

Q. How is this change of direction compensated for 
in the grinders ? — A. The faces of the latter are worn 
doTMi by friction, and thus the nippers come in contact. 



Q. Are there not times when the consumption of the 
faces of the teeth, by friction, is not in proportion to 
growth, in issue from the socket .' — A. Yes. 

Q. "What is the result? — A. The faces of the grind- 
ers do not come in contact, and the food is, conse- 
quently, im])erfectly masticated. 

Q. How is tliis rectified ? — A. By sawing off the 
nippers to their natural length. 

Q. Taldng it for granted that there is a time when 
the teeth cease to grow, how do you account for the 
lengthy teeth observed in aged horses? — A. The fang 
shrinks, and is carried upward in the lower and down- 
ward in the upper jaw, and the gums also shrink; thus 
we get length of teeth. 

Q. What are the general appearances of age, uncon- 
nected mth the teeth? — A. The muscles of the head 
and face condense, and give to the same a lean appear- 
ance ; the cavities above the eyes are dee]) ; the gums 
and ])alate become pale and callous ; the sul)ma.\illary 
space is capacious, and gray hairs make their appear- 
ance in various places ; the neck appears small and 
wiry, the withers sharp, the back curves, and the 
limbs a])peai- sinewy. 



MYOLOGY. 



PUELIJIIXARY KE:\IACKS ON THE MUSCLES. 

To the naked eye, the muscles appear to 
be composed of fasciculi, or bundles of 
fibres, which are arranged side by side in 
the du-ection in which the muscle is to act, 
and which are united by areolar tissue. 
These fasciculi when separated appear like 
simple fibres, but when examined under a 
microscope are found to be themselves fas- 
ciculi, composed of miimter fibres, bound 
together by delicate filaments of areolar tis- 
sue. By carefully separating these, we may 
obtain the ultimate muscular fibre. This 
fibre exists under two forms, (he striated 
and non-striated. The former is chiefly 
distinguished by the transversely-striated 
appearance which it presents. The non- 
striated consist of a series of filaments 
which do not present transverse markings. 
At an early stage of the development of 
muscular fibre", however, there is no differ- 
ence in the forms of cither striated or non- 
striated. Both are simple tubes, containing 
a granular matter in which no definite 
arrangement can be traced, yet presenting 
enlargements occasioned by the presence of 
nuclei. But, whilst the striated fibre goes 
on in its development, until the cells of the 
fibrilliE are fully produced, the non-striated 



fibre retains throughout life its original 
embryonic condition ; the contents of the 
tube remaining granular. The non-striated 
muscular fibre is the kind of structure proper 
to the muscular coat of the alimentary 
canal, bladder, uterus, trachea, bronchial 
tubes, etc. They seem to be arranged in a 
parallel manner into bands or fasciculi, 
without any very definite points of attach- 
ment. On the other hand, striated muscular 
fibre has attachments to its extremities of 
fibrous tissue, through the medium of which 
it exerts its contractile power on the part 
it is destined to move. 

At the truncated extremity of the striated 
muscles we find tendons. To the ordinary 
observer, tendons appear to unite abruptly 
with muscular fibre; but this is not the case, 
for tendinous fibres are distributed over the 
whole muscle, crossing it diagonally in both 
directions, so as to form a double-spirally 
extensible sheath ; the tendinous fibre finally 
collects at the extremity of a muscle, and 
forms the tendon. 

Each muscle is surrounded by cellular 
membrane, which dips into its substance, 
and, by means of the fat which its cells con- 
tain, lubricates the parts, and thus guards 
against friction. 



A. TABLE OF THE NAMES AND NUMBER OF MUSCLES, DIVIDED INTO REGIONS. 



SUBCUTANEOUS EEGION (BENE.4TH THE SKIN). 

1. Panniculus carnosus. 

AURICULAR EEGION (MUSCLES OF THE EAR). 

2. Attollcntcs maximi. 

3. Attollcntcs antcriores. 

4. Attollentes posteriores. 

5. Anterior concha?. 

6. Posterior conchx. 

7. Retrahentes extern!. 

8 



8. Retrahentes interni. 

9. Alxlucens vel deprimens auris. 

PALPERAL REGION (MUSCLES OF THE ETELIDS). 

10. Levator palpebral siiperioris. 

11. Orbicularis palpebrarum. 

OCULAR REGION (MUSCLES OF THE EYE). 

12. Levator palpebrae superioris intemus. 

13. Levator oculi. 

(57) 



5S1 



ANATOMY AND PHYSIOLOGY OF 



14. Depressor oculi iiitenius. 

lo. Ahiluctor ocuU externus. 

16. Adductor oculi iiitenm.s. 

17. Obliquus superior. 

18. Oblii|iius iMtcrlor. 

19. Hctitictor oculi. 

A-NTliUIOR MAXII.LAKY UKGIO.V (MUSCLES OF THE NOSE 
ASV I'ACK). 

20. Zygomaticus. 

21. Le\-ator lal)ii superloris aliqua; nasi. 

22. Dilator naris lateralis. 

23. Xasalis longiis lahii superioris. 

24. Caaiiuis vel levator aiigiili oris. 

25. Buccinator. 

26. Depressor lahii iuilrioris. 

27. Levator mcnti. 

28. Dilator iiariiim anterior. 

29. Nasalis bre\is laliii su])erioris. 

30. Depressor labii superioris. 

31. Orbicularis oris. 

POSTEIUOK lL'i.\lLL.UlY RIXION (JIUSCLF-S OF TlIE IIE.\U 
.^NI) tIlr.EK.S). 

32. Temporalis. 

33. Masseter. 

34. Stylo-maxillaris. 

3ij. PteiTgoideus internus. 

36. Pterygoideus externus. 

HYOIDE.VL REGIO.N (jIUSCLIiS BETWEEN TIIE BE-OJCIIES 
OF THE LOWER JAW). 

37. Digastricus. 

38. Mylo-hyoideus. 

39. Genio-liyoidcus. 

40. Hyoideus magnus. 

41. Hyoideus jiarvus. 

42. Stylo-hyoideus. 

GLOSSAL REGION (MUSCLES OF THE TONGUE). 

43. Hyo-glossus longus. 

44. Hyo-glossus brevis. 

45. Genio-hyo-glossus. 

46. Lingualis. 

PH.UITNGIAL UKGION (MUSCLES ABOUT THE PIIXRYN.X). 

47. Hyo-pharyugeus. 

48. Palato-pharjngeus. 

49. Stylo-pliaryngcus. 

49^. Constrictor pharjngis, anterior. 

50. Constrictor pharyngis, raedius. 

51. Constrictor ])hanngis, posterior. 

LAEYNGHU, KEGION (MUSCLES ABOUT THE LARYX.X). 

52. Hyo-tliyroideus. 

53. Crico-thjToideus. 

54. Crlco-arytenoideus posticus. 

55. Crico-arytenoideus lateralis. 

56. ThyTO-arytenoidcus. 

57. Arytenoidcus. 

58. Hyo-epiglottideus. 



PALATINE REGION (.MUSCLES OF THE PALATE). 

59. Tensor palati. 

60. Circiimilexus palati. 

MUSCLES OF THE XECK. 

IIUMERO-CERVICAL REGION (MUSCLES SITUATED OX THE 
UI'PEK .VNU LOWER PARTS OF THE NECK). 

01. Ithomboideus longus. 

02. Levator humeri. 

L.4TERAL CERVIC.U. REGION (SIDE OF THE NECK). 

03. Splenius. 

04. Complexus major. 

65. Trachelo-mastoideus. 

66. Spinalis colli. 

SUPERO-CEKTICO-OCCIPIT.AL REGION (MUSCLES SITUATED 
ABO'S'E THE HHiD). 
G7. Complexus minor. 
08. Kectus ca])itis jiosticus, major. 

69. Rectus cajjitis ])0sticus, minor. 

70. Obliquus capitis, superior. 

71. Obliquus cajjitis, inferior. 

IXF1;RI0R CERVICAL REGION (MUSCLES SITUATED I.V 
THE ANTERIOR PART OF THE NECK). 

72. Sterno maxillai-is. 

73. Storno-thyro-hyoideus. 

74. Subscapulo-hyoideus. 

75. Scalenus. 

76. Longus colli. 

INFERIOR CERTICO-OCCIPIT.Ai REGION (MUSCLES CU- 
NEATH THE BASE OF THE ATLAS). 

77. Rectus capitis anticus, major. 

78. Rectus capitis anticus, minor. 

79. ObHquus capitis, anticus. 

MUSCLES OF THE CHEST. 

DORSO SCAPULAR REGION (MUSCLES SITUATED ABOUT 
THE SHOULDER BLADE). 
SO. Trapezius. 
8L Latissimus dorsi. 

82. Rhomboideus hreris. 

PECTOPvAL REGION (MUSCLES SITUATED IN FRONT OP 
THE BREAST liOXE). 

83. Pectoralis transversus. 

84. Pectoralis magnus. 

85. Pectoralis par^■us. 

COSTAL REGION (MUSCLES SITUATED E.\TERNAL AND 
INTERNAL TO THE RIBS). 

86. Serratus magnus. 

87. Intcrcostales cxterni. 

88. Intercostalcs intcrni. 

STEPJsAL REGION (.MUSCLES OF THE BREAST BONE). 

89. Lateralis sterhi. 

90. Sterno-costales extern!. 

91. Sterno-costales interiii. 



THE HORSE. 



59 



DORSO-COSTAL REGION (MUSCLES ON THE SIDES .UJD 
UPPER PART OE THE CHEST). 

02. Superficialis costarum. 

93. Transvcrsalis costarum. 

94. Levatores costai'um. 

DORS.VL REGION (MUSCLES OE THE BACK, A-VTERIOR TO 
THE LUMB.tR ^^2RTEBRa:). 

95. Longissimus dorsi. 

96. Spinalis dorri. 

97. Semi spinalis dorsi. 

DLiPIIRAGJLiTIC REGION. 

98. Diaphragm or midriff. 

MUSCLES OF THE ABDOMEN. 

LUMBAR REGION (JIUSCLES OE THE LOINS). 

99. Semi s]-,inalis lumborum. 

100. IntertrauKversalcs lumborum. 

101. Sacro lumbalis. 

102. Psoas Magnus. 

103. Iliacus. 

104. Psoas parvus. 

ABDOMIN;VL REGION (MUSCLES OE THE AUDOMEN). 

105. Obliquus externus abdominis. 

106. Obliquus internus abdominis. 

107. Transvcrsalis abdominis. 

108. Rectus abdominis. 

ANAL REGION (jIUSCLES OF THE ANUS). 

109. Retractor ani. 

110. Spliincter ani. 

GENITAL REGION (MUSCLES OF THE MALE ORGANS OF 
GENERATION). 

111. Cremastcr. 

112. Erector penis. 

1 13. Triangularis penis. 

114. Accelerator urinic. 

The muscles in the genital regions of the female are 
named : Erector Clitoridis, Sphincter Vaginae. 

COCCYGEAL REGION (MUSCLES OF THE TAIL). 

115. Erector coccygis. 

116. Depressor coccygis. 

117. Curvator coccygi.<;. 

118. Compressor coccygis. 

MUSCLES OF THE FORE EXTREMiriES. 

E.XTEEN,VL SC^VPLTAR REGION (MUSCLES OS THE OUT- 
SIDE OF THE SHOULDER P.LADE). 

119. Antea-spinatus. 

120. Postea-spinatus. 

INTERNAL SCAPUL.UI REGION (MUSCLE ON THE INSIDE 
OF SHOULDER BLADE). 

121. Subscapularis. 

POSTERIOR SCAPULAR REGION (MUSCLES BEHIND TIU: 
SHOULDER BLADE). 

122. Teres major. 

123. Teres minor. 



A.VTERIOR IIUMER,4.L REGION (MUSCLES IN FRONT OF 
THE OS HUMERI). 

124. Coraco-humeralis. 

125. Flexor brachii. 

126. Hiuncrahs externus. 

POSTERIOR IIUME.RAL REGION (MUSCLE.S BEIIIMl THF. 
08 HUMERI). 

] 127. ^ , (' Ca]iut magnum. 

I 128. |i| I Caput medium. 

I ''^^- i^S'^1 Caput parvum. 

I 130. ^s=' 1^ Anconeus. 

! MUSCLES OF THE AR.M AXD FORE LEG. 

.O.TEUI0R BUACH10-CRUR.AL REGION (MUl5CLi;S IN FR0N1 
OE THE AR.M). 

131. Extensor raetacarpi magnus. 

132. Extensor pedis. 

133. Extensor suftraginis. 

134. Extensor metacarpi obliquus. 

SUPERFICIAL POSTERIOR I!iL\CHIO- CKUllAL REGION 
(MUSCLES ON THE E.XTERNAL SIDE OI' THE ARM). 

135. Flexor metacarpi externus. 

136. Flexor metacar];i mcdius. 

137. Flexor metacai-pi internus. 

138. Flexor accessorius sublimis. 

DEEP POSTERIOR BRACHIO-CRUEAI. REGION. (THESE 
MUSCLES ARE SITUATED BENE.\ni TJIE FORMER.) 

139. Flexor pedis ]icrforatus. 

140. Flexor pedis perforans. 

141. Flexor jiedis accessorius jirofundus. 

142. Lumbrici, anterior. 
1424. Lumbrici, ])ostcrior. 

MUSCLES OF THE HIND ILXTRl'MITIES. 

GLUTE.U, REGION (MUSCLES OF THIC SUPiailOR PART 
OF THE QUARTER). 

143. Gluteus externus. 

144. Gluteus ma.ximus. 

145. Gluteus minimus. 

I PELVI-TROCHA-VTERLVN REGION (:MUSCL1:S SII-UATED -AT 
I THE UPPER PART OF Till-: TIIICIl liONl:). 

I 146. PjTiformis. 

147. Obturator externus. 

148. Obtm-ator internus. 

149. 150. Gemiiu. 

ANTERIOR ILIO-FEMORAL REGION (MUSCLES SITUATEB 
AT THE FORI-; PART OF THE IIAUNdl)- 

151. Tensor vagina^. 

152. Rectus. 

153. Triceps vasti. 

154. Rectus parvus. 

INTERN.AL ILIO FE.MOR.VL REGION (MUSCLES SITUATES 
AT THE I.VNER PART OF THE IIAUXai), 

155. Sartorious. 



60 



ANATOMY AKD PHYSIOLOGY OP 



loG. Gracilis. 

157. PcctineuB. 

158. g^c C Adductor brevis. 

159. .1 3 s Adductor iongus. 
IGO. t^'g C Adductor magnus. 

rOSTERIOR ILIO-FEMOllAI. REGION (MUSCLES O.V THE 
OUTER AND POSTERIOR F.ART OF THE HAUNCH). 

IGl. Biceps abductor. 
1G2. Abductor tibialis. 

MUSCLES OF THE THIGH AND LEG. 

ANTERIOR AND FEMORO-CRURAL REGION (MUSCLES IN 
FRONT OF THE TIBU). 

1G3. Extensor pedis. 

1G4. Peroncus. 

165. Fle.\or metatarsi. 

SUPERFICIAL POSTERIOR IT:M0R0-CRURAL REGION 
(5IU.S(I,i:s IN THE REGION OF THE HOCK). 

1G6. Gastrocnemius cxternus. 

167. Gastrocnemius internus. 

168. Plantaris. 

DEEP POSTERIOR FEMORO-CRUR.U, REGION (MUSCLES 
WHICH ARE FOUND BENE.WH THE FORMER). 
1G9. Po])litcus. 

170. Flexor pedis. 

171. Flexor pedis accessorius. 

The muscles of the internal ear are named: 

Laxator tympani, 2 

Mcmhrana "..... 2 

Tensor " 2 

Stapedius, ..... 2 

Total, 8 

RECAPITULATION. 

W(; shall now recapitulate, as regards 
what lias preceded, in reference to the iitim- 
ber of muscles ; for there exist various 
opinions regarding the same. It may be 
jH'oper for us to bear in mind, however, that 
VRTEUiNARY SCIENCE, here, is yet in its in- 
fancy ; and it is well known to some prac- 
titioners, that there are several muscles 
which remain to be named by some future 
compiler of veterinary literature. But for 
all practical purposes we know enough of 
the anatomy of the horse. The industrious 
individual, however, who not only desires to 
make himself conversant with what is al- 
ready known, but aims to improve in the 



future, will not rest satisfied with the pro- 
ductions of his predecessors. To such an one 
we bow with due deference, and encourage 
him to proceed in the work of progression. 
There is a fine field for exploration, and a 
discerning public are ready and willing to 
crown the industrious laborer with the laurel 
of merit. 

In the preceding table, the number of 
muscles, including those marked 49 1-2 and 
142 1-2, appears to be 173; among these 
are ten single ones, which are thus expressed: 



Whole number, 
Deduct single ones, 



Pairs, 



Multiply by 



173 
10 

163 
2 



Single muscles, ..... 326 
Add muscles of the internal ear, four pairs, 8 

334 

Single muscles, as above added, . .10 

344 

It appears, therefore, that there are in the 
system of the horse three hundred and forty- 
four muscles. 

It should be borne in mind, that in the 
preceding classification all are considered as 
muscles. Among them are found tendons, 
which are component parts, or rather ap- 
pendages, to the same. Mr. Percivall says 
there are, in tlie horse, 151 pairs, and 10 
single muscles; add the four pairs of the in- 
ternal ear, which he has omitted in the cal- 
culation, and we get 155 pairs. On page 
72, " Hippopathology," the number of 

muscles is, — 

312 

Add muscles of the ear, omitted, . . 8 



The author's estimate, 



320 
344 

24 



DiiTerence, ..... 

Probably the above author considers the 
• 24 " as tendons. 



^ 



•f^ 




■^^ 







EXPLANATION OF FIGURE VII. 



NO. 1. — OSSEOUS STRUCTURE. 

35. Radius. 

g. Trapezium. 

36. Lower row of the carpal bones. 

37. Metacarpi magnum. 

38. Sessamoids. 

39. Os suifi-aginis. * 

40. Os coronae. 

41. Os pedis. 

NO. 2. — MUSCULAR STRUCTURE. 

INTERj;.\L VIEW OF THE NEAR-FORE LEG. 

o". Pectoralis transversalis. 

g". Flexor metacarpi medium. 

>•". " " internus. 

s". Extensor metacarpi magnus. 

i". " " obliquus. 

?t". ti". Flexors pedis — perforatus et perforana. 

r". Suspensory ligament. 

x'\ Extcusor pedis. 

z. 8. Bifurcation of the suspensory ligament. 

8. The hoof. 

NO. 3. 

The description of No. 1 answers also for No. 3. The letter/", is intended to 
point out the location of the ulna, into which is inserted the triceps. 
g. Region of the carpus. 

NO. 4. 

n". Triceps extensor brachii. 

o". PectoraUs transversahs. 

o'. P". Flexor metacarpi extemus. 

g". Flexor metacarpi medius. 

j(". Fleshy belly of the perforatus. and perforans. 

x". Extensor pedis. 

</". Extensor suflraginis. 

2". «". v". Flexor tendons. 

i{. Hoof. 



THE HORSE. 



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NO. 1.— OSSEOUS STRUCTURE. 




22. 


Femur. 




23. 


Patella. 




24. 


Fibula. 




25. 


Os calcis. 




26. 


Astragalus. 




27. 


Inferior row of the tarsal bones. 




28. 


Metatarsi magnum. 




29. 


Sessaraoids. 




30. 


Os suffraglnis. 




31. 


Os coronse. 




32. 


Os pedis. 






The above explanations will ser\'e to illustrate No. 3. * 


* are the metataisi 




parva. 





NO. 2. 

INSIDE VIEW OF THE OFF-HIND. LEG. 

g. Rectus. 

p\ Vastus internus. 

q'. X. X. Extensor pedis. 

q. Extensor metatarsi. 

r'. v'. Gastrocnemius externus et internus. 

t. Peroneus. 

u. The insertion of the gastrocnemius. 

«'. Tendon of the flexor metateirsi. 

z'. Suspensor)- Hgaments. 

^■. The hoof. 

5. 5. The saphena vein. 

K. Abductor fenioris. 

8. Bifurcation of the suspensory ligament. 

u'. (Beneath the pastern) Perforatus et perforans. 

NO. 4. 

E. J. Biceps, showing the manner in which it bifurcates. 

»•'. Gastrocnemius internus. 

f. Flexor metatarsi internus. 

v\ Flexor pedis accessorius. 

5. " " externus. 

u'. Liscrtion of the gastrocnemius. 

y'. Peroneus. 

«. u\ v'. Flexors of the foot. 

&{. The hoof. 



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t-( 



ON DISSECTION. 



No man can ever expect to become a 
practical anatomist nor pathologist, unless 
he practise dissection. It is the only possi- 
ble way by which he can familiarize him- 
self with the healthy structural organiza- 
tion of the horse. Having made himself 
acquainted with the healthy aspect of the 
various parts, their uses, etc., he next is 
able to judge of the various grades of 
textural change which occur and exist, 
between the part that has been studied 
under its healthy aspect, and that which 
has now departed from its healthy con- 
dition. Thus, in the prosecution of the 
study of anatomy, the student linally be- 
comes a pathologist ; and, although lie may 
be a beginner, he places himself in a posi- 
tion only a few removes from the old and 
experienced practitioner, and can venture 
to " measure a lance " with the renowned 
knights of the healing art. 

DISSECTING INSTRUJIENTS. 

The dissector should supply himself with 
a beak-pointed scalpel (which is one of Ger- 
man- origin), for superficial dissection, and 
a myology knife, strong and rounded at its 
point. For the dissection of blood-vessels 
and nerves, a more delicate and pointed 
scalpel is needed. The forceps should be 
sti-ong, and armed at the points Vv-irh teeth ; 
two pair of scissors are needed, one 
pointed and the other blunt ; a saw and 
blunt chisel, for opening the cranium. A 
blow-pipe, curved needles, and a few extra 
scalpels, are all that the student requires. 

SUBJECTS SUITABLE FOR DISSECTION. 

For demonstration of the muscular sys- 
tem, a well-proportioned and fully-developed 
subject should, if possible, be selected, and 



one that has died suddenly, or been kOled 
in consequence of some accident, is to be 
preferred. For making wet and diy prepa- 
rations, lean, emaciated subjects should be 
selected. The lymphatic system is best 
shown on animals of a flabby and cedema- 
tous organization. Young animals are the 
best subjects for dissection, in view of de- 
monstrating the circulatory and nervous 
systems. 

RULES IN REFERENCE TO DISSECTION OF THE 
MUSCLES. 

As there are abundance of subjects to be 
had in the United States, and it being in- 
convenient for one individual to dissect a 
whole subject, he had better divide it into 
six parts, viz. : 1st, The head and neck. 
2nd and 3rd, The anterior extremities, 
which include the thorax, its contents, and 
the diaphragm. 4th and 0th, The poste- 
rior extremities, to which belong the pelvic 
and abdominal viscera. 6th, Those viscera 
which cannot be advantageously divided, 
as the heart, stomach, bladder, organs of 
generation, &c. Should the dissector de- 
cide to commence on the ivhole subject, he 
first removes the skin, in order to expose 
the panniculus carnosus ; this will require 
some care, as some of the fibres of this 
subcutaneous muscle are intimately con- 
nected with the former. There are various 
ways of removing Ihe skin: the author pre- 
fers to commence on the back, and dissect 
off towards the feet. Supposing the sub- 
ject to lie on the off-side, we commence an 
incision at the anterior part of the nasal re- 
gion, and continue the same upward until 
we arrive at the occiput ; we then in- 
cline the scalpel from the superior part of 
the neck, in order to avoid the mane, and 

(79) 



80 



ANATOMY AND niYSIOLOGY OP 



continue the incision along the lateral part 
of i\\e dorso lumbar spines until the coccyx 
is reached; the overlapping portion can 
then be dissected, and turned over to the 
ofl-side, so as to expose the tendinous in- 
sertions of the panniculus into the ligamen- 
tum nucha?, etc., etc. The panniculus being 
exposed, it may be divided into three parts, 
viz. : 1st, The Cervical portion, which com- 
prises the head, neck, shoulders, and fore- 
arms. 2nd, The Thoracic portion. 3rd, 
The Abdominal portion. 

Having traced the attachments of the 
panniculus, the muscles then engage our 
attention ; they being composed of nearly 
parallel fibres, the manner of displaying 
them is indicated. The cellular tissue 
should if possible be detached with the 
skin and panniculus ; without this precau- 
tion the surface of some of the coarser 
muscles would have a mangled appearance. 
The knife should always follow the direc- 
tion of the muscular fibres, and the part on 
which a muscle is to be dissected should be 
placed, if possible, in such a situation as to 
produce a forcible extension of that muscle; 
thus, in tracing the origin and insertion of 
a muscle, the dissector becomes acquainted 
with its use. 

After exposing the external layer of mus- 
cles they may be detached from their in- 
sertion, or divided in their centre ; if di- 
vided, we thus preserve the two points of 
origin and insertion. The deeper seated mus- 
cles may be demonstrated in the same way. 

In the dissection of muscles the scalpel 
should be used in a free and prompt man- 
ner; the strokes should be long and bold, 
using the little finger to steady the move- 
ment of the hand. In making autopsies 
and in examining the viscera, the subject is 
generally placed on his back. 

ANATOMICAL PREPARATIONS. 

It is highly important that every student 
should be acquainted with the methods of 
making wet and dry preparations, and of 
injecting the blood-vessels; for specimens 
of this kind are the best means of familiar- 
izing us with the structui'cs of quadi'upeds. 



and such, when properly prepared, possess 
a real and practical value. 

INJECTING INSTRUMENTS. 

Pole describes three kinds of instruments 
used in making injected preparations. 

The first consists of a brass syringe, 
made of various sizes ; the nozzle is adapted 
to pipes into which the syringe is to be in- 
serted ; a short pipe, with stop-cock, also 
accompanies the syringe, which is to be • 
applied between the syringe and cither of 
the pipes. ^ 

The second is a similar instrument, only 
much smaller ; its pipe is very minute, and 
its piston is furnished with a ring, so that 
the thumb may be used to throw its con- 
tents into a vessel. 

The tliird instrument is generally used 
for injecting the glands and lymphatics with 
quicksilver. It consists of a glass tube, 
terminating with a steel end, and having an 
extremely fine steel pipe, which screws on 
to the latter. The syringe used by the 
author of this work is one manufactured in 
England (and can be found in some of our 
agricultm'al stores), for the purpose of syr- 
inging plants ; it has the most accurate 
bore and finely-adjusted piston of any in- 
strument now in use, and being of medium 
size it can be used for either large or minute 
injections. Some alterations, however, have 
to be made in the nozzle and pipes fitted 
accordingly. 

DIRECTIONS FOR USING THE SYRINGE. 

In using the syringe, a certain amount of 
tact or experience is necessary, and the be- 
ginner must not feel disappointed should he 
fail in a first or second attempt ; for some 
little oversight might frustrate the whole 
process. Everything should l^c in readiness, 
such as ligatm-es, forceps, scissors, sponge, 
hot and cold water, etc. 

The pipes should be inserted into the ves- 
sels, and confined there by strong ligatures; 
and, before the syringe is introduced, its noz- 
zle must be turned upwards, and the piston 
pressed until aU the air and froth arc ejected ; 
then introduce the nozzle into the stop-pipe 




^ 

# 




EXPLANATION OP FIGURE IX, 





OSSEOUS STRUCTURE. 


1. 


Frontal bones. 


2. 


Parietal. 


3. 


Occipital. 


4. 


TemporaK 


5. 


Nasal. 


6. 


Lachrj-mal. 


7. 


Malar. 


8. 


Superior maxillary. 


9. 


Anterior " 


10. 


Inferior " 


11. 


Cervical vertebrse. 


16. 


The true ribs. 


18. 


The sternum. 


33. 


The scapula. 


34. 


The humerus. 


c. 


The incisors. 


d. 


Dorsal spines. 




MUSCULAR STRUCl'URE. 




ANTERIOR VIEW. 


a". 


Trapezius. 


c". 


Scalenus. 


e". 


Pectorahs transvcrsalis. 


/"■ 


Antoa spinatus. 


9"- 


Postea spinatus. 


m. 


Teres major. 


IS» A portion of the trice])s e.xtensor braehii. 


& 


The faschial covering of the splenius. 


S. 


The masseter. 


9- 


Levator labii superioris. 


f- 


NasaUs longus. 


e. 


Orbicularis oris. 


c. 


Dilator narium lateralis. 


d. 


Dilator narium anterior. 


m. 


I. Attolentes et abducens aurem. 


b. 


Levator palpebrsc. 


a. 


Orbicularis palpebrarum. 


o". 


Pectoralis magnus. 


u. 


Levator humeri. 


r. 


Sterno maxillaris. 


X. 


Subscapulo hyoideus. 


2. 


Maxillary vein. 


3. 


Jugular vein. 



THE HORSE. 



81 



and press the piston steadily until a sensible 
resistance is felt. If much force be used, 
rupture of a vessel may take place. After 
a prudent force has been applied for some 
time, the sj-ringe may be withdravrn, pre- 
viously securing the stop-cock. A steady 
and uniform pressure on the piston will be 
more likely to secure uniform injection than 
force, or sudden jerks. Should the first in- 
jection fail to fill the vessels, it must be 
immediately followed liy a second. When 
injecting through a very small pipe, the in- 
jector must be patient, and steadily con- 
tinue the pressure on the piston. 

When using warm injections, the syringe 
must be kept icarm by immersing it in hot 
water, and the part to be injected must also 
be kept at the same temperature, by the 
same means. 

DIFFERENT KINDS OF INJEC- 
TIONS. 

There are six kinds of injections now in 
use, viz., the cold, coarse, and fine injection, 
the minute, the mercurial, and, finally, the 
plaster of Paris injection. The five first 
are most employed ; the plaster of Paris is 
objectionable because it is easily fractured. 

FORMULAE FOR COARSE WAn:W INJECTIONS. 

Red. — Beeswax, sixteen ounces; white 
resin, eight ounces ; turpentine varnish, sLx 
ounces ; vermilion, three ounces. 

First liquify the wax, resin, and turpen- 
tine varnish, in an earthen pot, over a slow 
fire, or in a water bath ; then add the Ver- 
million, pre^aously reducing it to a fine 
powder, so that the coloring ingredients 
may be intimately and smoothly blended, 
then add the same to the above ingredients, 
and, when they have accrued due heat, the 
injection is fit for immediate use. 

Yellow Injection. — Take beeswax, eight 
ounces; resin, four ounces; turpentine var- 
nish, three ounces ; yellow ochre, one ounce 
and a quarter. 

White Injection. — Clarified beeswax, 
eight ounces; resin, four ounces; turpen- 
tine varnish, three ounces ; flake white, two 
oixnces and a quarter. 
11 



Pale Blue Injection. — Take the preced- 
ing ingredients, and add to them a small 
portion of indigo. 

Black Injection. — Beeswax, resin, and 
tm-pentine varnish in the above proportions; 
and add lamp-black ad libitum. 

The same rules are to be observed in pre- 
paring all the injections. 

roUMUL.E FOR FIXE INJECTIONS. 

Red. — Brown and white spirit varnishes, 
of each four ounces ; turpentine varnish, 
one ounce; vermilion one ounce. 

Yellow. — Brown and white spirit varnishes, 
of each four ounces ; turpentine varnish, one 
ounce ; king's yellow, one ounce and a half. 
To make a white injection, add to the last 
formula two ounces of flake-white instead 
of king's rjeUoic. 

Blue. — Brown and white spirit varnishes, 
of each four ounces ; turpentine varnish, one 
ounce ; Prussian blue, one ounce and a 
half. This may be made black by adding 
ivory black instead of Prussian blue. 

FORMUL.E FOR MINUTE INJECTIONS. 

The liquifying principle in minute injec- 
tions is " sizc,^' v.-hich is made in the fol- 
lowing manner : 

Takf^ fine transparent glue, one pound, 
break it into pieces; put it into an earthen 
pot, and pour on it three pints of cold water ; 
let it stand twenty-four hours, stirring it 
occasionally with a sticl; ; then set it over a 
slow fire until it is perfectly dissolved ; 
skim off all the scum from the surface, and 
strain the remainder through flannel ; it 
will then be fit for the coloring ingredients. 

Minute Red Injection. — Size, one pint; 
vermilion, three ounces and a half 

Yelloiv. — Size, one pint ; king's yellow, 
two ounces and a half 

White. — Size, half a pint ; flake white, 
one ounce and three quarters. 

Blue. — Size, half a pint ; fine blue smalt, 
six ounces. 

PLASTER INJECTION. 

Before mixing the plaster of Paris, the 
pipes must be secured to the mouths of 



82 



ANATOMY AND PHVSIOLOGV OF 



the vessels at which the injcc\ioii is to 
enter. Plaster of Paris (to which some 
of the preceding dry coloring materials, 
suitable to the fancy, can be added) must 
be put in a mortar and rubbed with a 
pestle in order to pulverize it completely ; 
water is then to be added until the mixture 
is of the consistence of cream ; the syringe 
being in readiness, it is to be filled and im- 
mediately injected into the vessels. In the 
author's opinion, liiis injection is only suit- 
able for injecting lirst-class vessels, for it 
coagulates or '■'■sets" so ciuickly that it 
cannot be used as a minute injection. It is 
said that a small quantity of olive oil, in- j 
corporatcd with the liquid plaster, retards 
its coagulation ; yet if too much were 
added it would spoil the preparation. 

The moment tiie parts are injected the 
syringe should be washed out in cold 
water, and when the injection " sets " in 
the veins, the pipes must be removed and 
lilcewise cleansed. 

FORMUL.E FOR COLD INJECTION.?. 

Dr. Parsons recommends, for coarse cold 
injections, the foilov\ing formula : Take 
coloring matter and grind it in Ixiilcd lin- 
seed oil, on a painter's marble, until it has 
acquired the consistence of common white 
lead, as eold at tlie stores. After being 
finely Icgivated, a little lime-water, in pro- 
portion of two table-spoonsful to a pint, is 
to be incorporated by stirring. At the mo- 
ment of lining the syringe with the injec- 
tion, there should be added to it about one- 
third of its measure of Venice turpentine, 
which should be stirred in briskly and used 
immediately, as it very soon hardens. 

For a temporary cold coarse injection, 
white lead ground in oil answers every 
purpose ; it requires no addition of lime- 
water, because the lead is generally adul- 
terated with carbonate of lime, which 
hardens the mixture, and it can be colored 
to suit the taste, or the vessels can be 
colored with a pencil brush, before varnish- 
ing. 

For filling the arteries, to dry and pre- 
serve, red lead is the best and cheapest 



material ; vermilion, however, lesembles 
more the color of arterial blood. 

Whatever part we expect to inject with 
warm injections, must be immersed in water 
very hot, — not hot enough, hoVv'ever, to crisp 
the vessels. Attention to this matter is 
highly important, in view of successful in- 
jection. 

THE COURSE OF INJECTIONS. 

Injections must follow the course of the 
circulation ; the arteries, however, having 
no valves, are easily injected in any direc- 
tion; but the veins are fm-nishcd with nu- 
merous valves, which prevent the How of 
injection from the heart. Sometimes it is 
necessary to break these valves by means 
of a small whalebone probang. In the 
region of valves are often found coagula- 
tions, which must be washed out before the 
injection can be introduced ; and tliis, also, 
must be performed in the direction of the 
circulation. Small pipes are to be intro- 
duced, and warm water must be thrown in, 
v.lnch can be made to escape tlu'ough an 
incision made with a lancet in a region ap- 
proaching the right auricle. The incision 
can afterwards be closed by suture, or 
otherwise. Many of the veins of the 
horse, however, are destitute of valves, and 
therefore admit of injection in a direction 
conh'ary to their circulation. 

To inject a portion of tlie animal, — the 
l;nec or hock, for example, — it is necessary 
to secure all the branches o'f the vessels that 
have been divided where it is separated 
from the body. Tire part is then to be in- 
jected in the same manner as if we were 
injecting the whole body. 

QUICKSII.VER INJECTION AND PREPARATIONS. 

Tlie fluid specific gravity and beautiful 
metallic lustre of quicksilver render it val- 
uable for displaying minute vessels. Dr. 
Parsons remarks that the principal objec- 
tion to its general use is the continuance of 
its fluidity, which renders dissection, after 
injection, almost impracticable. Yet there 
are some very fine specimens of quicksilver 
injections of glands and deep-seated lym- 



THE HORSE. 



83 



phatics, in the WaiTen museum of this 
dry, that cannot be surpassed by any other 
kind of injection. The same authority re- 
marks, that the spccilic gravity of quick- 
silver, when supported in a column, is such 
as to exert strong pressure upon a blood- 
vessel or lymphatic that receives it, and 
therefore in some cases a syringe is unne- 
cessary. It is to be borne in mind that 
the force of the injection depends upon the 
perpendicular height of the column, and 
not on its diameter, and the former may be 
such as to burst the vessel. The injections 
should ahvays be conducted in a shallow 
dish or tray, so that the quicksilver may not 
be wasted. When injecting the lym- 
phatics, it id necessary to be provided with 
small lancets, straight, curved, and deli- 
cately-pointed fine needles, which must be 
armed with waxed threads. For common 
blood-vessel preparations, glass tubes of 
the shape of a straight blow-pipe are 
needed. 

INJECTING THE LYJIPUATICS Vv'lTlI JIEKCUUV 
OR QUICKSILVER.* 

In injecting the lymphatics, otur success 
depends, perhaps, more on the body we 
choose, than on any other circumstance: 
bodies slightly anasarcous, if they be ema- 
ciated, are the best. From the valvular 
structure of the lymphatics, it is necessary 
to inject from the extremities towards the 
trunli. 

It is almost impossible for one person to 
succeed in injecting the lymphatics without 
assistance ; there are so many things requi- 
site, besides merely holding the tube in the 
vessel, thai an assistant is indispensable. 

It is very necessary, before beghmiiig, to 
see that the injector has within his reach 
sharp-pointed scissors, knives, forceps, lan- 
cets, pokers for tubes, jieedles, and waxed 
threads, so ari'anged that they can be used 
instantly, for it will often happen that it 
will bj impossible for eitlier the assistant 
or the operator to take his eye for a mo- 
ment off the vessel, without losing it. 

* Sir Chai-lcs Bell 



When injecting the superficial lympha- 
tics, we first cut off a portion of skin, so as 
to expose the loose cellular texture ; having 
found a lymphatic vessel, it must be seized 
by the forceps and dissected from tne sm-- 
roundiug substance. Having hold of it 
with the forcep, snip it half across with fine 
scissors, and into the incisioa introduce the 
tube containing the mercury, A poker or 
director is often necessary for the purpose 
of creating a vacuum ; a few drops of mer- 
cury then introduced by the side of the 
director will open the way for more ; the 
dkector being withdi-avxii, the mercury flows 
into the lymphatics. 

K the vessel to be injected be a large 
one, it must be secured by ligature around 
the iHpe. The quicksilver is to be pressed 
onward, elevating or depressing the pipe 
so as to regulate the force of the injeciion. 

In injec'iing a gland, we inust en- 
deavor to find ihe vessel that has the most 
influence in filling it. Having found it, 
we secure the other vessels -and fill the 
gland through the former channel. 

The; vessels or glands injected with 
mercury should be dried as quickly as pos- 
sible, and varnislied, or else preserved in 
spirits of turpentine, 

METHOD OF INJECTING THE LACTEALS. 

Take a small i:)orliou of ihe intestine 
and mesentery, and make an incision in 
one of ihc most conspicttous lacteals, as 
uear a;_; possible to its origin in the intes- 
tine ; then iulroduce the point of the injec- 
ting tube, and conduct the operation agi-ec- 
ably to the preceding rules. "When the 
quicksilver flows out of any of tiie divided 
vessels, they must be repaired by an assis- 
tant; when as many of the lacteals are 
filled as will receive the quicksilver from 
this orifice, inti-oduce the pipe into another, 
and rcjjcat the process as before, and so 
on, mitil as many of them are filled as can 
be; then inflate the intestine and suspend 
it in the air to dry, after which it may be 
preserved by varnishing both inside au£ 
out. 



8-i 



AXATOriY AND niYSIOLCCY OF 



DIRECTIONS FOR INJECTING THE PAROTID 
GLAND. 

This should be injected before removal, 
on account of the numerous vessels by 
wliich it is attached to the adjacent parts. 
Before commencing the operation, the skin 
over the region of the gland and duct must 
be raised, in view of searching for the duct; 
having found it, an opening must be made 
into it v.-ith the point of a lancet, suffi- 
ciently large to introduce the point of (he 
steel injecting pipe ; wlien introduced, con- 
fine the duct upon it by a ligature witli a 
single knot, v.diich shall serve when the 
pipe is withdrawn to secure the ciuicksilver 
in the gland. The gland having been filled, 
the pipe withdrawn, and the duct secured, 
we proceed with all possible care to dissect 
the gland from its situation. Any branches 
of vessels going off to surrounding parts 
must be secured by means of a small 
curved needle, armed with a single ligature, 
after whicli they may be divided with 
safety. The gland being removed, and all 
extraneous tissue dissected off, it should be 
placed in water to extract the blood, etc. 
This \\t11 require about thirty-six hour.;; the 
water, however, must be frequently changed; 
the gland can then be spread on a piece of 
pasteboard and exposed to di'y. It makes 
the most beautiful preparation, when pre- 
served in a glass vessel containing pure 
spirits of turpentine. 

CREAKING DOWN THE VALVES. 

Many of the glands, the surface of the liver 
included, can be injected contrary to the 
circulation of the lymph. When the quick- 
silver passes at first freely into the lympha- 
tics, and suddenly stops, it will be necessary 
to force it forward by gentle pressure with 
the edge of a spatula, in the direction in 
which it seems most likely to run ; by this 
means the valves arc broken dov.'u. The 
valves of the superficial lymphatics of the 
liver arc easily broken down in this way, 
but tiie valves in some of the lymphatics 
arc iimcii firmer, consequently not so easily 
broken down. 



WET PREPARATIONS. 

PREPARATIONS BY DISTENTION. 

Hollow organs may be distended tor 
preservation with antiseptic liquids, air, 
wool, hair, cotton, plaster, quicksilver, etc. 

Wet preparations bij distention, with 
spirits of wine, oil of turpentine, etc. 

The intention, in distending preparations 
by spirits, is to give them their natural 
figure, to exhibit more fully the parts of 
which they are composed, their vascularity, 
and occasionally some morbid or preter- 
natural appearance. 

i\IETHOD OF DISTENDING AND PREPARING 
TIIE LUNGS. 

The lungs taken from a sheep or calf 
make a very good substitute for those of 
the horse, which are too bulliy for ordinary 
use. 

The pulmonary arteries and veins should 
fii'st be filled with red-colored injection ; then 
immerse the lungs in oil of turpentine, con- 
tained in a vessel, large enough to admit 
them without compression; then inject into 
the trachea such a quantity of the above 
fluid as shall dilate them without danger of 
rupture. Then secure the trachea by liga- 
ture. In the same manner we proceed with 
other parts. If a portion only of an organ 
or a part of some viscera be required, we first 
secure the lower orifice' by ligature ; inject 
as above, and then apply a ligature to the 
upper opening. It can then be suspended 
in spirits of wine or turpentine. 

ANTISEPTIC MENSTRUA FOR PRESERVING 
SPECISIENS. 

Alcohol -— Spirits of Wine. — This is one 
of the principal fluids now in use for the 
preservation of specimens. It may be used 
of various strengths, according to the size 
and thickness of the specimen to be pre- 
served. 

All those that are thick and bulky should 
be put into pure rectified spirits : smaller 
ones may require only one half the quantity 
of alcohol with water; and such as are thin 



THE HORSE. 



85 



and membranous, can be preserved in com- 
mon New England rum. 

Turpentine. — This also is an excellent 
antiseptic, and is highly recommended by 
Parsons and others, for cartilages, fibro-car- 
tilages, and fibrous membranes. 

The acids used are, sulphiu-ic, nirric, mu- 
riatic, acetic and pyroligneous. Dr. Parsons 
states that Dr. Hayden, surgeon dentist, in 
Baltimore, has succeeded in preserving 
anatomical preparations in a superior man- 
ner,- with pyroligneous acid. It should be 
rectified and diluted with water. Acids, 
however, cannot be used when the prepara- 
tion contains bone. 

METHOD OF PRESERVING THE BRAIN'. 

The following mixture is a very excellent 
menstruum for preserving the brain and 
nerves : Take alcohol, eight parts by weight; 
oxymuriate of mercury, one jjart. Rub the 
oxymuriate in a mortar, and gradually add 
the alcohol. The brain should remain in 
this mixture for twenty or thirty days, when 
it may be withdrawn from the liquid, dried, 
and varnished. 

MI-TIIOD OF MAKING A DRY PREP.IRATION OF 
THE AIR-VESSELS OF THE LUXGS. 

Throw the lungs of a horse into a barrel 
of v.ater and allow them to macerate for 
several months, during the summer season ; 
then, by repeated washing, cleanse the bron- 
chia, etc., from the parenchyma, dry, and 
varnish them. 

iHETHOD OF MACERATIXG AND CLEANING 
BONES. 

Remove as much of the flesh, ligaments, 
etc., as can conveniently be done with the 
knife ; then lay them in clean water, and 
change the same daily for about a week, or 
as long as it becomes discolored with blood. 
They are now to remain without changing, 
till putrefaction has thoroughly destroyed 
all the remaining flesh and ligaments, which 
will take from three to five months, more or 
less, according to the season of the year or 
temperature of the atmospiiere. In the ex- 
tremities of large cylindrical bones, holes 



should be bored, about the size of a quill, 
to give the water access to their cavities 
and a free exit to medullary substance. As 
the water evaporates from the vessel, it 
should be so far renewed as to keep the 
bones imder its surface, or they wiU acquire 
a disagreeable blackness, and dust should 
be excluded by keeping the vessel constantly 
covered. When the white textures are de- 
stroyed, the bones must be scraped and 
again laid in water for a few days, and 
well washed and scrubbed with a coarse 
brush ; then immerse them in lime-water, 
or a solution of pearlash, made with two 
ounces to the gallon of water, and after a 
week they are to be again washed in cleai 
water. They are then to be bleached oa 
the seashore, where they can be daily washed 
with sea-water.* 

M. Bogros approves of the above plan of 
maceration, but at the conclusion of this he 
directs them to be boiled four hours in a 
strong solution of carbonate of potass, or 
in soap suds, adding hot water as fast as it 
evaporates. They ai-e then to be washed 
frequently in cold water, and dried each 
time quickly, and then moistened (not 
steeped) in weak mm-iatic acid. The com- 
mon bleaching liquor in a diluted state will 
whiten bones, but they shoidd not be im- 
mersed in it any length of time. 

When bleached, they may be varnished 
with the white of an egg.j 

TO RENDER SOLID BONES FLEXIBLE AND 
TR.\NSPARENT. 

One-half of the inferior jaw bone, or the 
scapula, are the most suitable bones for the 
above purpose. Alacerate either or both 
until they are properly cleansed. Then im- 
merse in a mixture consisting of water, 
twenty-fiveparts ; muriatic acid, one part. If 
the bone is kept well covered during a 
period of about seven months, it will become 
flexible like cartilage ; but as the phosphate 
of lime in the bone will neutralize some of 
the acid, a minute quantity may from time 
to time be added. 

* I'ok- on " Clcansinj; Bones." 

t Piirsons on " Macerated Preparations." 



86 



AXATdMY AXD PHYSIOLOGY OF 



TTheii tlie preparation becomes flexible, 
immerse in warm water ; then give it sev- 
eral washings in cold water to remove the 
acid ; dry, and immerse in a glass vessel of 
oil of turpentine ; it will assume a beautiful 
transparency, exhibiting the blood-vessels. 

METHOD OF CLEANING AND SEPARATING THE 
BONES OF CEANIUM. 

Take the head of a young colt, remove 
the skin and muscles, and wash out the 
brain, previously breaking it down with a 
stick or probe ; macerate and cleanse it as 
before directed ; then fill the cranial cavity 
with dry corn from the husk, immerse it in 
water, and the corn as it swells forces open 
the suturuses, so that they can be readily 
separated by the hand. "Wash, dry, and 
bleach the bones, and then cover them with 
colorless varnish. 

A BraEF EXPOSITION OF ME. SWAn's NEW 
METHOD OF MAKING DRIED ANATOMICAL 
PREPARATIONS.* 

The new method has been adopted by 
Usher Parsons, M. D., Professor of Anat- 
omy and Physiology, from whose work the 
following selections are made : 

DIRECTIONS FOE MAKING DRIED PREPARATIONS. 

The part of a limb, chosen for injection, 
must be as free from fat as possible. A so- 
lution of two ounces of oxymuriate of mer- 
cury in half a pint of rectified spirits of wine, 
is to be injected into the arteries ; the next 
day inject as much white spirit varnish, to 
which one-fifth of white spirit varnish has 
been added, and some vermilion ; the limb 
is then to be put into hot water, where it is 
to remain until properly heated, wlien the 
coarse injection is to be thrown into the ar- 
teries and veins, if required, bearing in mind 
l^e course of the circulation ; the valves of 
the veins can be broken down by a whale- 
bone probe, if necessary. If the veins arc 
to be injected, it is better to wash the blood 
out of them with water before the solution 

* Professor Chaussier claims to be the original discov- 
erer of this method. 



of oxymuriate of mercury is thrown into the 
arteries. 

After tlie limb has been injected, it is to 
be dissected. Every time it is left, and 
sometimes during dissection, it is advisable 
to cover those parts which have been ex- 
posed, with a damp cloth. There ai'e great 
advantages to be derived from previously in- 
jecting the limb in oxymuriate of mercury, 
for a limb thus injected undergoes very little 
change in many days, and, when the dissec- 
tion is recommenced, the parts will be found 
in the same state in which they were left, 
and destitute of any offensive odor. 

The oxymuriate of mercury is the best 
agent for arresting the putrefactive process. 

After the dissection is finished, the limb, 
or part, must be immersed in a solution of 
oxymuriate of mercury for a fortnight or 
more. 

The solution of oxymuriate of mercury 
must be contained in a wooden vessel, as 
metallic vessels do not answer. 

The limb, or part, having been in the 
solution during the above period, it should 
be taken out, dried, varnished, and, if neces- 
sary, painted. 

SOLUTION OF HARDENING THE BRAIN AND 
OTHER TISSUES. 

Take of oxj-muriate of mercuiy, one ounce ; 
muriate of ammonia, thirty-five grains ; py- 
roligneous acid, one pint. Hub the oxymu- 
riate of mercury and muriate of ammonia 
together in a mortar, then add half a pint of 
pyroligneons acid. ^ 

OXYMURIATE OF JIERCUEY IS A YALU.\DLE 
ANTISEPTIC. 

• 

Dr. Parsons relates, that, when a piece of 
fiesh had been immersed in a solution of 
oxymuriate of mercury until it was com- 
pletely changed, and afterwards put into a 
large vessel containing water for some days, 
though the greater part of the oxymuriate 
of moi'cury was thus washed away, it did 
not even then appear in the least degree 
putrid. I procured half of the head and 
neck of a large horse, which I first injected 



THE HORSE. 



87 



with the solution of o.\y muriate of mercury, 
but as the putrefactive process was not thus 
sufficiently stopped, without dissecting off 
the skin I immersed it in the solution of 
oxymuriate of mercury for several days ; 
and, as no marks of puti'efaction remained 
(the offensive smell being entirely removed), 
I then put it into a vessel containing a 
large quantity of water for two or three 
days more, by which means nearly all the 
solution was removed from it. 1 was thus 
able to proceed with the dissection during 
the hot weather, without being in the least 
incommoded either by the smell or soreness 
of the hands, and without finding the instru- 
ments acted upon in any degree, that ren- 
dered the process at all objectionable. By 
putting a wet cloth over it when I left it, I 
was further enabled to make a very minute 
dissection of the nerves, which I could not 
otherwise have done, without the use of a 
large quantity of spirits of wine, and then 
not with half the convenience and pleasure 
I have thus experienced. 

ON VARNISHES AND PAINTS. 

The following are the recipes for the 
manufacture of paints and varnishes: 

WHITE VARNISH. 

Canada balsam, spirits of turpentine, of 
each three ounces ; mastic varnish, two 
ounces. Put them into a bottle and shake 
them together until they are properly 
mixed. 



MASTIC VARXISH. 

This may be made by putting four 
ounces of powdered mastic into one pint 
of spkit of turpentine, to be kept in a 
stoppered bottle. It should be shaken every 
day until the greater part of the mastic 
is dissolved. 

TURPENTINE VARNISH. 

Turpentine varnish is made by melting 
Venice tmpentine over a slow fije, and add- 
ing to it as much spirits of tm'pentine as 
wUl reduce it to the consistence of syrup. 

WHITE PAINT. 

Three ounces of the best white paint, 
and one ounce of spirit of turpentine, are 
to be put into a bottle and shaken together. 
When it is used with the varnish, a bottle 
of each should be mixed together. 

PAINT FOR THE MUSCLES. 

This is made by grinding on a slab a 
small quantity of " lake" with white var- 
nish, to which one-fourth part of turpen- 
tine varnish has been added. 

Dr. Parsons directs that varnish should 
be laid on with a fine camels'-hair pencil 
brush, as large as occasion may require. 
Hollow preparations should have the var- 
nish pom-ed into them, and, after turning 
them about in all directions, it is to be 
drained out as clear as possible. 



DIGESTIVE SYSTEM. 



OF THE MOUTH. 

It may be observed here (as preparatory 
to tlie description of this part), that, in 
quadrupeds in general, the facial angle is 
one of vei ■ considerable obliquity, in con- 
sequence ol the prolongation of that part 
of the head which corresponds to the face 
in the human subject ; and this develop- 
ment of feature is in none more striking 
than in the horse and dog. Consequently, in 
these animals, the nose and mouth are 
cavities of large dimensions. And in the 
horse, the mouth appears to have been thus 
prolonged, not only to enable him to col- 
lect his food with more facility, but also 
that he rriight subject greater parcels of it 
at a time to the action of the grinding 
teeth, whereby the processes of mastication 
and deglutition are greatly accelerated. 

" Conformation. — The mouth is con- 
structed in part of bone, and in part of 
soft materials. The superior and anterior 
maxillary and the palate bones form the 
roof; the inferior maxilla, the lower part; 
the incisive teeth, the front ; and the 
molar teeth, the sides. The lips, cheeks, 
soft palate, gums, and buccal membrane, 
constitute its soft parts. The tongue occu- 
pies its cavity, and the salivary glands are 
appendages to it. 

"lips. 

" General Conformation. — The lips, two 
in number, superior and inferior, are at- 
tached to the alveolar projections of the su- 
perior and inferior maxills, by the muscles 
that move Vn^m ; by the cellular tissue en- 
tering into theit composition; and by the 
membrane that lint. ^hem. Their borders 
surround and bound -H^e orifice of the 



mouth, and are united together on either 
side; which points of union are denomi- 
nated their commissures, or the angles or 
corners of the mouth. Exteriorly, the lips 
are creased down the middle by perpen- 
dicular lines of division ; exhibit little 
papillary eminences upon their surface ; 
and present a softer and shorter coating of 
hair than what is found in ordinary places, 
out of which project several long straggling 
horse-hairs or luhiskers. The inferior lip 
is altogether smaller, and is thinner in sub- 
stance, than the superior ; and is distin- 
guished by a remarkable prominence about 
its centre, from which grows a tuft of long 
coarse hairs, vulgarly designated as the 
beard. 

" Structure. — The lips are both muscu- 
lar and glandular in their composition. 
Several small muscles,* arising from the 
maxillary bones, are inserted into them, and 
endow them with great self-mobility : one 
alone, consisting of circular fibres, is inter- 
woven in their substance without having 
any other connection ; this is denominated 
the orbicularis oris, or sphincter labiorum, 
from its use, which is that of closing the 
mouth. This muscle is an antagonist to 
all the others ; they raise or depress the 
lips, or draw them to one side ; but this 
contracts them, and occasionally projects 
them in such a manner that the horse can 
exert with them a prehensile power, which 
is most remarkably evinced at the time that 
he is picking up grain from a plain surface ; 
indeed, the act of nibbling our hands with 
his lips demonstrates this faculty, and also 
the force with which he can employ it. The 
lips are lined by the same membrane that 
lines other parts of the cavity of the mouth. 

* Percivall's Hyppopathology. 

(88; 



THE HORSE. 



89 



Beneath it are seated numerous mucous 
follicles, that elevate it everywhere into lit- 
tle papilla, which are perforated by the 
mouths of these follicular inlands, as may 
be readily seen with the naked eye by evert- 
ing either the su]5erior or the inferior lip. 
The skin covering the lipo is extremely 
thin, and possesses considerable vascularity 
and sensibility. To the tenuity of it, and 
to the shortness and scantiness of their 
pilous covering, is to be ascribed the su- 
perior sensitive faculty of these parts. 

" CHEEKS. 

" The cheeks are constituted substantially 
of the masseter and buccinator muscles, 
covered by the skin upon the outside, and 
the buccal membrane upon the inside. 
Their internal or membranous surface is 
studded with scattered mucous follicles, 
whose excretory oritices may be seen by 
everting the part. 

"gums. 
" The gums consist of dense, compact, 
prominent, polished masses, of the nature 
of periosteum, adhering so closely and 
tenaciously to the teeth and the sides of 
their sockets, that it renders the one insep- 
arable from the other, but by extraordinary 
mechanical force. Like other parts of the 
cavity of the mouth, they receive a cover- 
ing from th6 buccal membrane. 

" PALATE. 

" Two distinct parts are included under 
this head ; the hard and the soft palate. 
The hard palate is constituted of the pala- 
tine processes of the superior and anterior 
maxillary bones ; and • of a firm, dense, 
periosteum-like substance, the vaulted, in- 
ward part of which is elevated into several 
semicircular ridges, vulgarly called the bars. 
The fibres of this substance, which pos- 
sess great tenacity, are inserted into the 
pores of the bone in every part, but are 
most numerous and dense along the pala- 
tine suture : the interstices are filled up by 
a dense cellitlar tissue, through the sub- 

12 



stance of which are dispersed the ramifica- 
tions of the palatine vessels and nerves. 

" The soft palate, sometimes called the 
velum palati, is attached to the superior or 
crescentic border of the hard palate, the 
border formed by the palatine bones ; from 
v.hich the velum extends backward and 
downward as far as the larynx, and there 
terminates over the epiglottis, in close ap- 
position with that part, in a loose semi- 
circular edge. In consequence of the 
velum palati being long enough to meet the 
epiglottis, the cavity of the mouth has no 
communication with that of the nose — 
these two parts forming a perfect septum 
between them ; hence it is that a horse 
cannot respire and vomit by the mouth lilie 
a human being, in whom the velum is so 
short that there is an open space left be- 
tween it and the epiglottis, through which 
air or aliment can pass either upward or 
downward. The soft palate is composed 
of extensions of membrane from the nose 
and mouth, between which is interposed a 
pale, thin layer of muscular fibres. 

" The velum performs the office of a 
valve : it prevents the food, in the act of 
swallowing, from passing into the nose, and 
it conducts the air from the windpipe into 
that cavity, without permitting any to 
escape into the mouth. 

" OF THE TONGUE. 

" The tongue, the principal organ con- 
cerned in taste and deglutition, is lodged in 
the mouth ; filling the interspace between 
the branches of the inferior maxilla. 

'■^Duplicity. — Lilce the other organs of 
sense, it is double ; being composed of tAvo 
parts, whose union is marked by a longitit- 
dinal crease along its middle, the divisions 
having no vascular nor nervoits connection 
nor in fact any intercommunication what- 
ever; so that an animal has to all intents 
and purposes iv:o tongues, and ajjparently 
for the same reason that he has two eyes, 
(wo ears, and two noslrils. Anatomy, as 
far as v.o can carry our researches, demon- 
strates (his; perhaps we have no better 



00 



AXATOJIY AND PHYSIOLOGY OF 



proof of it, however, than what happens in 
hemiplegia, a disease in Avhich only one 
half of the body is paralytic : under these 
circumstances, in the human subject, the 
patient can only see with one eye, use one 
arm, and taste with but one (and that the 
coiTespondent) side of the tongue. 

^^ Division. — The tongue, in description, 
is commonly divided into rooti bmli/, and 
apex: by the attachments of the two former 
it is held iii its situation ; the latter is loose 
and uucoimected. 

" Atlaclunenl. — At its root, it is deeply 
and firmly inserted by several muscles which 
arise chiefly from the os hyoides and the 
inferior njaxilla : it is also connected with 
the pharynx, and with the soft palate. 
From the sides of the lower jaw, separate 
layers of the membrane of the mouth are 
reflected upon its body, farming by their 
junction a sort of bridle, which is thence 
extended to the symphysis: to this part, 
which serves to restrain the organ in its 
ijiotions, the name of frccmini lingua; has 
been given. 

'■'■rapillcv. — T!\\c dorsum ox anterior sur- 
face of this organ has a peculiar covering, 
which, though it appears to be continued 
from tlie buccal membrane, is a dirt'erent 
s^tructure altogether, and serves quite a 
different purpose. The surface of it is 
roughened, possessing a villous texture, 
everywhere studded with numerous little 
conical eminences, called papillcB, which are 
supposed to be formed out of the extremi- 
ties of the nerves, and to be the especial 
seat of the sense of taste. These papillfr 
vary in size and figure, and are more abun- 
dant and larger upon the base and along 
the sides of the organ. Interspersed witli 
them are a number of mucous follicles, 
whose apertores may be seen with the naked 
eye, througn which a mucus is discharged 
¥il)on the papillary surface, keeping it con- 
tinually moist, and rendering its percejition 
of taste more acute. 

" Structvrc. — The tongue is said to pos- 
sess a covering of common integument ; 
and certainly its strong, compact tunic has 
all the appearances of skin, and presents 



the common tests of it: the external layer 
is laminated, is bloodless, is insensible ; the 
internal or substantial part is tough, fibrous, 
vascvilar, and sensitive, in fact, is like cutis; 
and the intermediate or connecting material 
is delicate, soft, and reticular, and forms a 
bed for the lodgment of the papillfe. The 
substance of the tongue itself consists of 
an inter-union, or rather an incorporation, 
of its muscles, the fibres of which intersect 
one another, and take a variety of direc- 
tions ; but intermixed with them is a fine 
adipose tissue, to which is owing the flabby 
softness of the organ, and the peculiar 
aspect it exhibits when cut into. 

'■'■Use. — Though the tongue is empha- 
tically denominated, from its essential char- 
acter, the organ of taste, it is not the only 
])art that possesses this faculty ; for the palate, 
the pharynx, and the cesophagus, it is be- 
lieved, participate in it. The tongue, in 
addition to possessing this faculty, disposes 
of the food during manducation, and, when 
sufficiently masticated, collects and thrusts 
it, portion after portion, into the pharynx; 
and furthermore, at the time the animal is 
drinking, it is not only employed as an in- 
strument of suction, but also as a canal 
along whicli the fluid ascends into the 
pharynx. 

'■'■Organization. — Every part of this or- 
gan is plentifully supplied with blood. Its 
arteries are the lingual, branches of large 
size from the external carotids. The blood- 
vessels of either side are generally found 
free from anastomosis with one another ; if 
either of the arterial trunks is filled with 
injection, it rarely happens that the opposite 
half of the organ receives any coloring from 
it. Its nerves are the ninth pair, which run 
to the muscles, and a considerable branch 
from the fifth pair, in whose extreme rami- 
fications, which are distributed to the papilljp, 
the j)erception of taste is supposed to be 
inherent. 

"OF THE SALIVARY GLANDS. 

"Number and Names. — The salivary 
glands, properly so called, are six in number, 
three upon each side of the head ; the 



EXPLANATION OF FIGURE X. 



OSSEOUS STRUCTURE. 

(SEE PRXC£Di:fa PLATE.) 

MUSCULAR STRUCaiaE^ 

LATERAL \TEK. 

a". Trapezius. 

•. Ligamentum colli. 

h". Rhomboideus longua. 

c". Scalenus. 

f. Antea spinatus. 
g". Postea spiiiatus. 
h". Teres major. 

t". Latissimus dorsi. 

I", m". n". Triceps extensor brachii, 

S. Splenius. 

J5r. Masseter. 

a. Orbicularis palpebrarum. 

c. Dilator nai-is lateralis. 

e. Orbicularis oris. 

y. Nasalis longus. 

g. Levator labii superiorus. 
h. Buccinator. 

». Zygomaticus. 

J. Depressor labii inferioruto 

m. Attolentes. 

n. Retrahentes aurem. 

0. Abducens vel deprimens aurem • 
q. r. Tendon of the splenius and co: 
t. Obliquus capitis inferiorus. 
u. Levator humeflf 
X. Subscapulo hyoideus. 

VEINS, 

1. Temporal vein. 

2. Facial " 

3. Branch of the jugular* 
10. Parotid glan* 



Till': HOKsn. 



y.i 



parotid, Ihe submaxillary, and the sub- 
lingual. 

'• Tlio parotid, the largest of these glands, 
so called fniin being placed near the ear, 
lies within a hollow space at the upper and 
back part of the head, bounded by the 
branch of the lower jaw before, and the 
petrous portion of the temporal bone behind: 
it extends as high up as the root of the ear, 
and as low down as the angle of the jaw, 
by which latter a small portion of it is con- 
cealed. This gland, like the others of the 
same class, is enveloped in a case of dense 
cellular membrane, and is constituted, in 
structure, of many little lobes or lobuli, con- 
nected together by processes transmitted 
into the interior from this cellular covering. 
Every lobulus is composed of a distinct set 
of secretory vessels, from which numerous 
tiibidi arise, conjoin, and at length form one 
main branch; these branches, which corre- 
spond in number to the lobuli, unite and 
re-unite until they end in one common ex- 
cretory duct\ The duct emerges from the 
inferior part of the gland, runs along the 
inner part of the angle of the jaw, and 
crosses over ihe posterior edge of the bone 
immediately above or behind the submaxil- 
lary artery and vein: in I he remainder of 
its coiuse it corresponds to the border of 
llie masseter, and, about opposite to ihe 
second anterior molar tooth, pierces ob- 
liquely ihe buccinator, and terminates l^ a 
tubercular eminence upon tbe internal sur- 
face of the buccal membrane.* 

" The submaxillary gland, of amaller 
volume than the parotid, lies in the sjjace 
between the angles of the jaw, to which, and 
to the muscles thereabouts, it is loosely 
attached by cellular membrane: a portion 
c^ it is also generally found proceeding 

*T() cxiiosc tliis iliK't, ;it or near il-i i.^sui; from llii' 
jrlaiul, an incision s oiilil lie ciin-ii'il alon;^ the posterior 
iiorUcT of llic hrant-h of tile lower jaw : first, dividing: tlie 
f-lvin ; seconiUv, the jianniciilns; tliirilly, llie cellular tissue 
immediately covering the dnct, wliidi is readily dis- 
tinguished liy its glisteniii'; pellucid aspect. By extending 
the incision around the angle of the jaw, directing i'. 
towards tlio inner edge of the hone, tlie <hiet will he found 
making its first turn ; here, liowcver, it is loilged in a 
lio'low, dec]ily luiricd m cellular lisr'ue. 



backward as far as the trachea. Its struc- 
ture is siiuilar to that of the parotid gland. 
The submaxillary duct issues near the 
centre of the gland, creeps along the under 
and imier border of the tongue, close to the 
lower edge of the sublingual gland, and 
terminates by a little mammiform elongation 
of membrane, vulgarly called the barb (bar- 
billon) or pap, upon the freermm linguas, 
about half an inch above its attachment to 
the symphysis. Among the other ridiculous 
and mischievous practices of farriers is that 
of snipping ofl" these processes. They 
were seemingly designed as valves, to pre- 
vent the insinuation of alimentary matters 
into the ducts. The coats of this vessel are 
extremely thin and translucent. 

" The sublingual gland is still smaller in 
volume than the submaxiMar}-, though, al- 
together, one much resembles the other in 
figure. It lies along the under part of the 
tongue, covered by the buccal membrane, 
where, from the lobular uneven ness it gives 
to the surface, its situation is well marked. 
Its ducts penetrate the membrane by the 
side of the frrenum lingua. 

" The use -of (lie aalirari/ glands is to 
secrete a saline limpid fluid, called sa/h-a-; 
which is conveyed and poured by their 
duets into the mouth during manducation:: 
here it is mixed with the food, mollifying it, 
and rendering it more easy of digestion, and 
at the same time facilitating the jiassage of 
the alimentary bolus into the stomach. 

" OF THE PlUnVNX. 

" The pharynx is a fiumel-i-haped sac, 
lodged in the throat ft)r the recep'.ion of the 

, food. 

' " Sili!(iliii». — The pharynx is contiguous 
to the gutt-ural ]X3Uches, superiorly; the 
larynx, inferiorly ; and the aiUerior ])ortions 
of the parotid glands and branches of the 
jaw, laterally. Posteriorly, it is coniinuous 
in substance with the esojihagus ; anteriorly, 
it presents an opening to the mouth. 

" Attechment. — In front, to the os hyoides 
and palate bones : below, to the larynx ; 
behind, it grow.s narrow and ends in the 
esophagus. 



92 



AXATOMY AND PHYSIOLOGY OP 



"Structure. — The pharynx is in part 
muscular, and in part membranous. Ol" 
the muscles belonging to it the constric- 
tors are those that more immediately enter 
into its composition. They are so dis- 
posed as to give the membrane forming 
the sac a complete Meshy covering, which 
is rendered the more uniform by their 
proximate ilbres being indistinguishably 
blended: thus the muscles form the most 
substantial part of the pharynx. The 
lining membrane, which is of the mu- 
cous class, is soft and thicic in substance, 
and palely tinged with red in color, and is 
papillary and in places rugose upon its sur- 
face ; being perforated by the ducts of 
numerous fc)llicles which discharge a mucus 
that preserves glibness and moisture to its 
interior. The membrane itself is (wiiere it 
meets them) continuous both with the buc- 
cal membrane and that wiiich lines the 
oesophagus. 

" Although the pharynx is designed for 
the reception of the food, it does not open 
directly into the mouth ; the two cavities 
are separated from each other by the soft 
palate and epiglottis. Except in the act of 
swallowing and coughing, they have no 
communication : in the former case, the 
velum is pressed upward by the food 
against the posterior openings of the nose ; 
in the latter, the larynx is depressed by a 
convulsive action of the muscles in the 
vicinity. Into the cavity above the velum 
there are four openings — two of the cham- 
bers of the nose, one of the larynx, and one 
of the oesophagus : the eustachian tubes do 
not open into tiie pharynx ; they end in 
two large membranous pouclies at the 
upper part of the fauces. The opening 
leading into the oesophagus is constantly 
closed, except when alimentary matters are 
passing to or from the stomach ; so that air 
received into the pharynx through the nose 
can pass nowhere else but into lhe wind- 
pipe; but if food be returned from the 
stomach, it will be regurgitated into the 
nose; at least, only that poriion of it i 
which enters the ph;irynx at the moment j 
that the larynx is depressed in the act of ] 



vomiting, can be thrown into the mouth, 
in lhe same way that air is in the act of 



coughing. 



" OF THE fHSOPlIAGUS. 



" The cejophagus, or gullet, is the tube 
througli which tlie food is conducted from 
the pharynx into the stomach. 

" Course. — It has its beginning from the 
pharynx, and is there ])laced at the upper 
ard back part of llie hirynx, taking the 
first part of its course above and behind the 
trachea, between that tube and tlie cervical 
vertebrae. Having proceeded a short way 
down, it inclines to the left, and soon after 
makes its appearance altogether on the left 
side of the tracliea, and continues so placed 
during the remainder of its passage down 
tiie neck : tliis explains why we look for the 
bolus during the act of swallowing on the 
/eft, and not on the right side of the ani- 
mal. In company with the trachea, the 
esophagus enters the thorax between the 
first two ribs, at which place, running above 
that tube, it quits its companion for the 
superior mediastinum, which cavity it 
traverses below and a little to the right of 
the posterior aorta. Immediately beneath 
the decussation of the crura, the esophagus 
pierces the substance of the diaphragm, 
and enters the stomach, at a right angle, 
about (ho centre of its u)ipcr and anterior 
part. 

" Strurliire. — The oesophagus presents, 
externally, a strong, red, muscular coat ; in- 
ternally, one remarkable for its whiteness, 
which in its nature is cuticular. The mus- 
cular coat is conijiosed of two orders of 
niires — a longitudinal, forming an out- 
ward layer ; and a circular, an inward 
layer : the former will shorten the tube, and 
perhaps dilate it for the reception of food ; 
the latter, by successive contraclions of the 
canal, will transmit the food into lhe 
stomach. The second, or iiiternal coat, ij 
called the cuticular, from its analogy to the 
cuticle of the skin. Although it is contin- 
uous v/ith the membrane of the ])harnyx, 
it is of a totally different composition : it is 
thinner, but it is much more compact and 



THE HORSE. 



93 



stronger in its texture, and, I believe, is 
botli insensible and inorganic. It adheres 
to the muscular covering by a fine cellular 
tissue, the extensibility of which gives full 
play to the latter ; and admits, during the 
empty or collapsed state of the tube, of the 
former being thrown into many longitudinal 
plica or folds ; as is demonstrated by mak- 
insr a transverse section of the tube : such 
appearances result from the contraction of 
the one coat, and the want of proportion- 
ate elasticity in the other. Between the 
two tunics, imbedded amongst the connect- 
ing cellular tissue, arc numerous follicular 
glands, whose ollicc is to pour forth a mu- 
cous secretion upon the internal surface of 
the lining membrane, to render the passage 
of food along it glib and free from any 
friction. 

" NASAL FOSS.E.*' 

" The nasal fossae are the two chambers 
or lateral cavities, whose external openings 
are (he iiostrUs. Their loaHs or external 
parletcs are almost entirely osseous; and to 
the OSSEOUS SYSTEM (page 45) the reader 
must turn for a description of the manner 
in which the fossae are formed, and of the 
bones entering into their formation. But, 
in addition to bone, they are cartilaginous 
in their constitution. 

" The cartilages of the nose are Jice in 
number: — of which one (the septum nasi) 
is situated inlernallij; liie other four (enter- 
ing into the composition of the nostrils) cx- 
ternally. 

" The septum nasi is the vertical carti- 
laginous partition interposed between the 
nasal fosste. It exhibits four borders. The 
inferior one is received into the groove of 
the vomer ; while the superior presents a 
lengthened channel between two elevated 
edges, into which is admitted the internal 
crest formed by the union of tiie nasal 
bones. Its posierior border is affixed to the 
ethmoidal plate : its anterior serves to sus- 
tain the cartilages forming the nosti'ils. 
Both its sides arc completely covered by the 
Schneiderian membrane. 

* Hippopatliolojy. 



"Nostrils. — Four in number: two on 
each side, distinguished by the epithets true 
and false. 

" The true nostrils are the large, ovoid, 
and ever-open orifices so conspicuous ex- 
ternally. They have for the base of their 
structure four pieces of fibro-cartilage, 
which are involved in doublings of the 
common integument. Each nostril is formed 
of tAvo Hcxible alee or wings : a superior or 
internal one, and an inferior or external. 
The former is supported by a broad circular 
cartilaginous plate ; the latter is crescentic 
in shape, and forms a flexure outward, 
within which is perceptible the orifice of 
the lachrymal duct. They are attached to, 
and supported by, the nasal peak and sep- 
tum nasi. 

" The false nostrils arc twp little pouches 
or cavities (having the semblance of cuts- 
ilf'-sacs), situated internally, above the true 
nostrils, into which an external opening is 
found within the commissure formed by the 
union of the two alffi. They are formed 
out of dupficatures of the skin, which is 
here thinner, and finer, and softer in its 
texture ; and, except at their entrance, are 
without hair upon their surfaces. Their 
use is not known. 

"Schneiderian viembranc. — The cavity 
of the nose is not only divided into fhe two 
nasal fossa, but each fossa is subdivided 
into the three meatus (for a description of 
which, vide page — ). Every part of these 
cavities and passages is covered by the 
Schneiderian or pituitanj membrane. This 
is a membrane of the mucous class, dis- 
tinguished for its thickness of substance, 
for its vascularity, and for its olfactory pa- 
jiilla:. It has two surfaces: an exposed 
or secreting one and an unexposed or ad- 
herent one. The secreting surface is 
smooth, and is rendered glib and shiny by 
the varnish it derives from the mucous 
secretion emitted by the numerous small 
rounded pores everywhere visible in the 
membrane, but more particularly upon the 
lower part of the septum, and upon the 
inferior turbinated bone. This surface 
exhibits a pale pink blush, the ellbct of the 



94 



ANATOMY AND PHYSIOLOGY OP 



bloodvessels spread over it, which are hei-e 
so superficial as to owe their principal de- 
fence to the mucous exudation: hence it 
is that the complexion of the membrane 
(varying with the inlluence of the atmos- 
phere and other agents) is extremely fugitive 
and uncertain. The adherent surface of 
the membrane contracts a close and firm 
adherence to the parts it covers, through 
the insinuation of its fibres into them : in- 
deed, to the bone it appears to supply the 
place of periosteum ; to the cartilage, of 
perichondrium. The substance of the 
membrane exhibits a fibrous structure, in- 
terwoven with cellular tissue ; and upon 
that — as a substratum — is spread a glan- 
dular and vascular apparatus, from which 
issues the mucous secretion ; together with 
numerous papillm, of small size, constituted 
of the terminations of those nerves from 
which the membrane derives ordinary sen- 
sation, as well as those that endow it with 
the peculiar sense of smelling. The 
Schneiderian membrane, inferiorly, within 
the nostrils, is continuous with the duplica- 
tures of skin lining those parts; superiorly 
with the membrane lining the pharynx; be- 
sides which, it is continued into the several 
sinuses of the head, through the openings 
leading from them into the nose, and like- 
wise gives them a complete covering : it is 
to be observ«^, however, that in the sinuses 
the membrane is thinner, and assumes a 
paler and more delicate aspect; its natural 
secretion is also found more sparing. The 
membrane is abundantly supplied with 
blood-vessels, as well as nerves ; and also 
possesses its share of absorbent vessels. 
Its arteries, which ramify and anastomose 
so as to form a spreading network upon the 
secreting surface, arc derived superiorly 
from the lateral nasal ; inferiorly from the 
facial andi palato-maxillary. Its nerves arc 
furnished by the first and fifth pairs. 

" Sinuses. — These cavities are formed in 
the interior of several of (he bones of the 
cranium and face: in fact, with the excep- 
tion of the membrane lining them, they are 
entirely osseons in their composition. This 
will account for their description having 



been already given (at page 4G), to which 
we must again refer. 

" Ducts. — There are two ducts belonging 
to, or connected with, the nose. One is the 
ductus ad nasum — a tube partly osseous 
and partly membranous in its composition, 
commencing at the inner angle or corner of 
the eye, within the substance of the lachry- 
mal bone, running within a canal continued 
from this bone through the superior maxil- 
lary bone, and terminating at the inner and 
inferior part of the nasal fossa, underneath 
the duplicature of the inferior ala, upon 
the surface of the common skin, about one- 
fourth of an inch from its junction with 
the Schneiderian membrane, by an orifice 
large enough to admit a crow-quill. The 
other duct is the ductus communis 7iarium, 
which pursues its course along underneath 
the vomer to the pharynx ; after arising from 
two lateral branches springing from oblong 
apertures in the floor of the nostrils." 

INTERNAL PARTS. 

COJIPEEIIENDrN-G Tin: CAVITIES OF THE CR-iXIUJI, OR- 
BIT, XOSE, ,VND MOUTH. 

I. CAVITY OF THE CRANIUM, 

Constructed for the lodgment of the 
brain with its appendages, is in form ovoid, 
flattened inferiorly, broader anteriorly than 
posteriorly ; its antero-posterior or long 
diameter measuring about seven inches ; its 
transverse or lateral diameter about four 
inches; its vertical or perpendicular diameter 
about three and a half inches. At the same 
time it is to be observed, that, al'.hough the 
general form of the cavity is the same, its di- 
mensions may and do vary in difl'crcnt heads. 
The eight bones composing the cranium all 
present internally surfaces more or less con- 
cave, which, united, form the cavity under 
consideration ; hence it is that the interior 
is not regular or uniform, but presents to 
view different hollows, which are adapted 
to disfinct prominences of the cerebral mass. 

Division of the interior surface into roof 
and base of (he cranium: 

The roof is formed by the frontal, parietal, 
and occipital bones: its superficis is larger 



THE HOKS.' 



95 



than the extent of iho base, and it is with- 
out any apparently defective places, observ- 
able in the latter. It presents — 1st. On 
the inesian line from front to back, //ic sag'it- 
( a/ groove, for the longitudinal sinus formed 
by t/ic frontal and paric/ii/ crests, crossed 
towards the front by l/ie roronut suture, and 
bounded posteriorly by the parietal protu- 
berance, \o which is attached the tentorium, 
and behind wiiich is the occipital capula, for 
covering the cerebellum. 2nd. On either 
side, along the .same line, the cerebral con- 
cavities of the frontal bone ; the coronal 
suture, the boundary line between them 
and the parietal concavities ; the transverse 
grooves, [or the lateral sinuses; and, sunk 
within them, the lambdoidal suture. 

The base is formed by the temporal, 
sphenoid, ethmoid, and occipital bones. It 
presents — 1st. On the middle line, from 
before backwards, the crista galli, ai^d on its 
sides the ethmoidal fossa and cribriform 
plates, bounded laterally by the internal 
orbital plates of the frontal bones, and there 
pierced by the internal orbital foramina ; the 
concave surface of the body of the ethmoid 
bone ; the optic hiatus leading to the optic 
foramina; a transverse suture between the 
ethmoid and sphenoid bones. Upon the 
sphenoid bone, the pituitary fossa, bounded 
laterally by the two optic fossa ; the latter 
leading to the foramina lacera orbitalia, 
over which are the spinal foramina ; a trans- 
verse elevated line denotes the place of 
junction of the sphenoid with the occipital 
bone. Belonging to the occipital bone, are 
the basilar fossce and the occipital hole. 2d. 
On either side, in the same dixeciion, the inter- 
nal surface of the iving of the ethmoid bone, 
rather more convex than concave, for the 
support of the anterior lobe of the cere- 
brum ; the concavity of the icing of the .sphe- 
noid bone, for the reception of the middle 
lobe ; the concavity of the squamous part of 
the temporal bone, for lodging the posterior 
lobe ; and the sutures bounding these three 
cerebral surfaces. The foramen lacerum 
basis cranii, formed between the wing of 
the sphenoid anteriorly, the basilar process 
of the occipital bone internally, and the 



petrous portion of the temporal bone exter- 
nally and posteriorly: it is wide and irregu- 
lar before, nan'ow behind, and is distin- 
guished into the sphcno-occipital and lempo- 
ro-occipilul hiatus. The petrous portion of 
the temporal bone, presenting a narrovv^ 
triangular surface foi->.vards and upwards, 
which contributes to the posterior cerebral 
concavity ; a broad, smooth, but uneven sur- 
face inwards, against which inclines tlie 
cerebellum, and upon which we distinguish 
— a, the orifice of the meatus auditor ius in- 
ternus ; b, a transverse prominence, and sev- 
eral cerebral indentations ; c, an irregular 
convexity downwards, which forms the 
boundary wall of the labyrinth ; d, a fissure 
separating it from the former. La.stly, the 
sutures, uniting the petrous to the squamous 
portion and to the occipital bone. Of the 
occipital bone a part of the internal surface 
assisting in the formation of a concavity for 
the cerebellum, by the convolutions of which 
it is indented ; the surface even and smooth, 
and slightly excavated below this, for the 
support of the medulla oblongata ; still 
lower, the condyloid foramina, through wliich 
the ninth pair of nerves pass out. 

II. THE ORBITS, 

Two in number, are formed for the lodg- 
ment, attachment, and protection of the 
eyes and their appendages. 

Figure. — Symmetrical. The cavity, 
which is extended horizontally backward 
and inward, has, viewed in front, a pyra- 
midal aspect : the base, represented by the 
front, has four sides, and four angles ; one 
only of the sides, however, is sufficient in 
extent to reach the apex, the others being 
all more or less imperfect. A line drawn 
in a horizontal direction through the axis 
of this figure, inclines more outwards than 
forwards, more forwards than downwards, 
intersecting another horizontal line projected 
directly forward at an angle of about 70°, 
and one extended laterally, directly outward, 
(at right angles with the former), at about 
20° : the inclination downward, however, 
will in course vary with the erect position 
of the head. 



96 



ANATOMY AND PHYSIOLOGY OF THE HOI;SE. 



Slnictxrc. — The orbit is composed of 
unequal portions coming from four of the 
bones of the cranium, and from three of 
those of the face : viz., the frontal, ethmoid, 
sphenoid, and temporal bones; the malar, 
lachrymal, and palate bones. 

Division — Into sides, angles, base, and 
apex. 

Siiles. — The superior side or roof of the 
cavity consists only of the frontal arch; 
which is concave and smooth internally, to 
make room for the lachrymal gland, and 
has anterior and posterior borders, sharp and 
slightly curvated. The inferior side or floor ! 
of the orbit is formed by the orbital surfaces 
of the lachnjinal and malar bones, is broader 
than the roof, though, like it, is ^ficient as 
a whole. It comprises the orbital portion 
of the lachrymal suture : it is terminated in 
front, by a smooth, rounded, curvated border; 
behind, nearly midway between the base 
and apex, by a shorter and straighter border. 
The internal or nasal side, the broadest and 
only complete one, is formed principally by 
the internal orbital process of the frontal 
bone, into the notch of which is received the 
OS planum: the ethmoid bone further con- 
tributes, and also the sphenoid and palate 
bones, the three constituting that irregular 
termination of the cavity behind which 
represents the apex. The frontal orbital 
plate is smooth and slightly concave, and is 
united below by a continuation of the trans- 
verse suture with the lachrymal bone. Its 
border in front, though slightly curvated, is 
very irreg-ular, having several notches and 
one or two small foramina in it; it also 
presents a lillle tubercle, to which the lach- 
rymal caruncle is attached. The external 
or zygomatic side is formed principally by 
■the zygomatic process of the malar bone, that 
of the temporal contributing but little : it is 
concave, and smooth internally, somewhat 
broader below than upwards ; is intersected 
obliquely by the zygomatic suture, and has 
an interior border, smooth and curvated, a 
posterior one, sharp and straight. 

Angles. — The supero-intcrnal angles, one 
before, the other behind, are formed by the 
beginning of the frontal arch, through which, 



midway bet^veen them, passes the supra- 
orbital foramen. The infero-internal angle 
includes the lachrymal fossa. The sujDcro- 
external angles, one anterior, the other pos- 
terior, are intersected by the suture uniting 
the frontal and zygomatic arclics. The 
infcro-external angles, particularly the ante- 
rior, are rounded and smooth. 

Base. — Of the circumfercnt border, the 
superior and internal parts, about two-fifths 
of the entire circle, are formed by the os 
frontis ; the inferior and internal parts, about 
one-fifih, by the lachrymal bone; and the 
remaining two-fifths by the malar and tem- 
poral bones, in the proportion of three parts 
of the former to one of the latter. 

The apex or back of the orbit, formed by 
the ethmoid, sphenoid and palate bones, is 
pierced by five foramina: the two round are 
the internal orbital and optic, which are 
ranged in a row with two oval and larger 
in size, the supero-posterior and infero-pos- 
tcrior orbital; the one behind is the spinal 
foramen. 



in. 



-CAVITIES OF THE NOSE, 



Comprehending the nasal fosste or cham- 
bers, and the sinuses. These cavities occupy 
about two-thirds of the internal space of 
the superior maxilla, the remaining third 
belonging to the cranium ; from which they 
are partitioned by the cranial septum of the 
frontal bone, in union with the cribriform 
plates and crest of the ethmoid. 

The nasal fossas may be said to include 
about two-thirds of the entire space de- 
voted to the olfactory cavities. They con- 
stitute the interior of 1 he proboscis; have 
four boundary walls, one above, one below, 
and two laterally ; are separated from each 
other by a septum ; but are open both be- 
fore and behind. 

The superior wall presents an irregular 
concave formed by the internal surfaces of 
the nasal bones, the cells and grooves of tlie 
ethmoid, and small portions of the nasal 
surfaces of the palate bones. 

The inferior wall is horizontal ; it extends 
forward beyond the superior, but is con- 
siderably overreached by that wall poste- 



THE HORSE. 



97 



riorly : it is formed by the palatine por- 
tions of the anterior and superior maxillary, 
and by llie palate bones. The surface is 
transver.-cly coneave, and presents a sligiit 
eminence a little behind its middle. 

Each lateral wall or side presents an 
irregular concavity, and is formed by the 
anterior and superior maxillary and the 
palaie bones. To it are attached the supe- 
rior and inferior turbinated bones, by which 
the fossa is divided into tinee separate pas- 
sages or meatus. The snpfrior meatus, 
comprised between the nasal and superior 
turbinated bones, extends from the angle of 
the lateral nasal opening, passing over the 
ethmoidal cells, to the cribriform plate, fol- 
lowing superiorly the declination of the 
wall. Tlie middle meatus, included between 
the turbinated bones, leads superiorly into 
the ethmoidal grooves and cells, and into 
the sinuses of the head, and ends below, be- 
neath the termination of the superior. This 
passage, like the former one, is narrow ; but 
its greatest diameter is, obliquely, in the 
perpendicular direction ; whereas the other 
measures most from side to side. It re- 
ceives the apertures' of the ductus ad 
nasum, maxillary sinus, ethmoidal grooves, 
and turbinated cells. The inferior meatus 
is the most capacious as well as the most 
direct one : it extends along the inferior 
wail, from the anterior to the posterior 
opening of the nose. 

The septum nasi is the partition separat- 
ing one fossa from the other. It is formed, 
posteriorly, by the ethmoidal plate; infe- 
riorly and posteriorly, by the vomer; supe- 
riorly and anteriorly, (and principally) by a 
broad perpendicular plate of cartilage. 

The openings of the nose are: the ante- 
rior, divided by the nasal peak and septum 
nasi into two, and formed by the superior 
borders of the anterior maxillary bones : 
the posterior, divided after the same manner 
by the vomer and septum, and formed by 
the nasal surfaces and crcscentic borders of 
the palate bones. 

The sinuses of the head communicate 
with, and may be said to constitute part of, 
the nasal cavities. They are the frontal, 



nasal, maxillary, sphenoidal, ethmoidal, and 
palatine. 

The frontal sinuses, formed within the 
frontal bones, are situated so that a straight 
line extended between the supero-internal 
angles of the orbits passes opposite to 
about the angular or deepest parts of their 
cavities. The sinus (on either side) has a 
triangular figure. The superior side or roof 
is flat, and (barring the septa) even upon 
its surface ; whereas the posterior side is 
irregular, being convex inwardly, where it 
is formed by the cranial septum ; concave 
outwardly, where it is opposed to the part 
composing the temporal fossa. The infe- 
rior side slants from behind forward, and 
from below upward, is irregular on its sur- 
face, and open or deficient outwardly, 
where the cavity communicates yvith the 
maxiUary sinus. Of the an<^les, one is 
directed upward ; another downward, ter- 
minating in the nasal sinus, with v\/hich it 
is conjoined, the tv%o forming one continu- 
ous cavity; the third points backward, and 
is directly opposite to the imaginary trans- 
verse line above alluded to. The cavity is 
traversed and divided into several unequal 
open compartments and recesses by septa ; 
the principal of wdiich is one extended be- 
tween the superior and inferior sides ; it is 
partitioned from the opposite sinus by the 
nasal spine. The sinus is but small in the 
young compared to its proportionate dimen- 
sions in the adult subject : it continues to 
increase afterwards with age, and ultimately 
extends throughout the whole of the frontal 
bone. 

The nasal sinuses, formed by the nasal 
bones above and the superior turbinated 
bones behind, are nothing more than the 
culs-de-sacs or blind terminations of the 
frontal sinuses. 

The maxillary sinuses, the largest of 
these cavities, are spacious but very iiTegu- 
larly formed. They are situated below and 
in front of the frontal. Of this sinus, on 
either side, the posterior and external walls 
are formed by the malar and lachrymal 
bones, v/hose orbital processes constitute a 
thin partition between it and the orbit; the 



ns 



ANATOMY AND PHYSIOLOGY OF 



inferior parts consist of the excavations in 
1 he superior maxillary bone ; superiorly, the 
sinus is open, being there continuous with 
the frontal : the boundary line between 
these cavities is marked by the sutiu-e 
uniting the lachrymal to the frontal and 
nasal bones on the outer side, and by the 
jjrominent crest formed by the junction of 
the superior turbinated with the ethmoid 
bone on the inner ; underneath which part, 
through a curved (and in the recent -subject 
sort of valvular) fissure, the sinus opens 
into the middle meatus, between the bases 
of Uie turbinated bones. The cavity is but 
small, and still more irregular, in the young 
subject, in consequence of the intrusion of 
the yet uncut molar teeth. 

The frontal sinus, then, terminates in the 
nasal, but both discharge themselves into the 
maxillary ; tiie ma.'^iLlary has also a blind 
termination, but empties itself into the pos- 
terior part of the middle nasal meatus. 

The splienoidal sinus is situated wdthin 
the palatine portion of the body of the 
sphenoid bone. It has no existence in the 
young subject, the bone being solid through- 
out ; but in process of growth a cavernous 
hollov,- is formed, which, from the seces- 
sion and attenuation of the laminae of the 
bone, continues to enlarge. It communi- 
cates, by two ovoid openings, with the eth- 
moidal sinuses. 

The ethmoidal sinuses are two cavities, 
separated by the perpendicular plate, situa- 
ted beneath the ethmoidal cells. They 
have openings in front, communicating with 
the lowermost and largest grooves of the 
same bone, and with the palatine sinuses. 

The palatine sinuses are formed between 
the superior maxillary and palate bones ; 
are situated below and in front of the for- 
mer ; are separated from each other by the 
vomer; and open into the maxillary sinuses: 
thev are iri'egular in form and cavernous 
interiorly. They are not to be found in the 
young subject. Some might be inclined to 
treat them as parts of the maxillary sinuses ; 
they are, liowever, as |ierfectly distinct from 
the latter as the frontal a?e. 



IV. THE MOUTH. 

The mouth is the cavity included be- 
tween the superior and inferior maxillse, 
making (in the skeleton) one common va- 
cuity with the inter-maxillary space. Its 
antero-posterior dimensions can be but 
little varied; but its supero-inferior diame- 
ter will be increased'in the ratio of the dis- 
tance to which the inferior maxilla recedes 
from the superior; the cavity during the 
distraction of the jaws assuming the figure 
of a misplaced > , the angle of which is 
turned backward. 

The mouth is formed — superiorly, by 
the palatine and superior and anterior max- 
illary bones ; inferiorly, by the inferior 
maxilla; laterally, by the molar teeth; an- 
teriorly, by the incisive teeth. Behind, 
through the posterior opening of the nose, 
it communicates with the nasal fosste. 

PERITONEUM.* 

The whole of the viscera contained 
within the abdomen proper, including the 
anterior part of the rectum, bladder, and 
vasa deferentia, are either entirely or par- 
tially covered by or in contact with perito- 
neum. This is a serous membrane reflected 
also over the parietes of the abdomen, so 
tliat a parietal and visceral or reflected por- 
tion require notice. Like other membranes 
of the same nature, it forms a closed sac, 
which, however, is not the case in the 
female, as its cavity communicates with 
that of the uterus, owing to the open state 
of the Fallopian tubes at their fimbriated 
edges. 

It is loosely connected with the abdominal 
parietes by subserous cellular tissue, and 
the same obtains with regard to its connec- 
tion with the viscera. But we find some 
parts more adherent than others, such as 
along the linea alba and cordiform portion 
of the diaphragm. Also on the organs it 
is but loosely connected with them at their 
attached border, where it forms generally a 
triangular space, occupied simply by vessels, 
nerves, and cellular tissue, and allowing of 

* Vrize ICssnv liv Mr. Gaingee. 



THE HORSE. 



99 



their distention and alteration in figure. 
On the other hand, it is more adherent as 
it extends over the free surface or margin 
of the various parts it is in contact with. 

The peritoneum being considered as ex- 
tending from the umbilicus over the ab- 
dominal parietes towards the median line 
of the diaphragm and spine, is found there 
to fold on itself, and proceed from the latter 
on to the intestine, forming the raesenters ; 
and from the former on to the liver and 
stomach, constituting ligaments. These 
folds of peritoneum are also seen extending 
from organs to other parts of the abdominal 
parietes, and these also constitute ligaments. 
Then they may be traced from one organ 
to another, giving rise to the several omenta; 
all of which wc shall more especially allude 
to as we speak of the peritoneal coat of 
each separate viscus. 

STOAIACH. 

The stomach is the dilated portion of 
the alimentary canal, intermediate between 
the oesophagus and small intestine: through 
the former it receives the ingested aliment, 
for which it acts as a reservoir diuing the 
process of chymification, the active agent 
in which is the gastric secretion. 

In the horse, as well as all other soli- 
pedes, this viscus is exceptional in not being 
the most capacious dilatation of the alimen- 
tary canal. M. Colin, in a paper published 
in the Recueil dc Medecine Veterinaire 
Pratique for June, 1849, states that the 
capacity of the horse's stomach is very 
variable. He says, that in a very small 
horse he found it only nine quarts (accord- 
ing to his evaluation by litre, which may 
be considered as thirty-four fluid ounces), 
while in one of colossal dimensions it was 
as much as 33 3-4 quarts, both having died 
at the college (Alfort) infirmary. He gives 
the average as being from 13 7-20 quarts 
to 14 3-5. Then, considering the capacity 
of the stomach in relation with that of the 
intestmes, he found it in a very small horse 
as one to thirteen, while in other two cases 
it was as one to ten. He takes the latter 



as the standard relative capacity between 
the two. 

The stomach is situated transversely to 
the long axis of the body, in the left hypo- 
chondrium, extending into the epigastrium 
and diu-ing repletion into the right hypocon- 
diiac region. However, its size and situa- 
tion vary under different circumstances, as 
to whether it be fuU or empty, adapting 
itself generally to its contents. 

The stomach is fixed on its left side to 
the diaphgrara by the ffisophagus, having 
the spleen attached to it as well. The 
duodenum then, by means of the lesser or 
gastro-hepatic omentum, suspends the 
pyloric end by getting attached to the con- 
cave surface of the liver. 

The shape of the stom.ach might be ex- 
pressed as being that of a tube bent on 
itself, and dilated along its convex border, 
so as to form t\vo cul-de-sacs ; i. e., a right 
and a left one, whilst it has two borders or 
curvatm-es, distinguished as a lesser concave 
and a greater convex one. The stomach 
has tv.'o smooth surfaces, the anterior one 
being in contact v\ith the liver and dia- 
phragm, v\^hilst the posterior one corresponds 
to the convolutions of the small intestines 
and gastric flexture of the colon. It has 
two orifices, i. e., a left oesophageal, or com- 
monly called cardiac, and a right intestinal 
or pyloric one ; the latter taking its name 
from the valve by which it is guarded. 

A circular depression round the stomach, 
midway between the cardiac and pyloric 
orifices, most visible when the organ is 
replete, marks the external division of the 
stomach into a cardiac and pyloric portion, 
coiTesponding with the pomt where the 
mucuous membrane varies in character in- 
ternally. The sacular projection at the 
cardiac portion takes the name of fundus, 
owing to its greater magnitude as compared 
\vith a smaller cul-de-sac at the pyloric end, 
the analogue of which in human anatomy 
is characterized by the appellation of antrum 
pylori. 

Having thus briefly described the striking 
peculiariries of the stomach, 1 proceed 



100 



ANATOMY AND PHYSIOLOGY OF 



with more detail to tlie consideration of 
its constituent parts, such as its coats, 
nerves and vessels. 

The coats of the horse's stomach having 
been generally described as four, it appears 
needless to altertheir nomenclature, although 
the one which I shall allude to as third 
might quite as justly be described as second, 
or merely spoken of as connecting cellular 
tissue, without regarding it as a separate coat. 

The external peritoneal tunic is found 
proceeding from the diaphragm on to the 
cardiac portion of the stomach, surrounding 
the oesophageal opening, where it is tough, 
and forms the gastro phrenic ligament. Thus 
we follow it on to the corresponding surface 
of the viscus, and, firstly, more especially 
on to the lesser curvature, where it is loosely 
connected with the other coats, and, the 
middle portion being more adherent, gives 
rise to two folds laterally, which seem to 
stretch from the cardiac to the pyloric orifices, 
to bind the two together, necessarily leaving 
a pit or cul-de-sac between them. At the 
pyloric end the peritoneum comes off" from 
the concave surface of the liver on to the 
stomach, constituting the gastro-hepatic or 
lesser omentum, the anterior layer of which 
comes from the anterior part of the concave 
surface of tlie liver, whilst the posterior 
layer comes from the posterior part of the 
same, so that the two enclose the vessels 
going to and from the porta. 

Having formed a covering to the corres- 
ponding surface of the stomach, the layers 
of peritoneum meet at the gi-eater curvature. 
In following them from this point the des- 
cription will be facilitated by alluding to 
the two separately, as they meet to form 
the gastro-splenic and gastro-colic omenta, 
as Vvell as the omental sac. In forming 
the latter, they so blend as merely to con- 
stitute a faie reticulated vascular layer, in- 
separable into two, except near (lie margins 
of the viscera. Distinguisliing Ihc anterior 
or external layer as A, and the posterior or 
internal one as B, their arrangement admits 
of exposition in the following terms: — 

A passes from the anterior surface of the 
stomach, forms the loose omentum, and gets 



on to the transverse colon and spleen. 
Reaching the latter, it is reflected over its 
superior surface at the posterior margin of 
the hiius, so as to contribute to the form- 
ation of the gastro-splenic omentum, and 
extends round the free posterior margin of 
the viscus on to the inferior surface, passing 
to the right on to the left kidney, and, 
anteriorly reaching the supero-anterior part 
of the spleen, is reflected from it so as to 
continue as the outer layer of the loose 
omentum. Further to the right, A is trace- 
able on to the inferior surface of the trans- 
verse colon, and, extending round the pos- 
terior part of the latter, is found to ascend 
up to the spine, and then turn backward 
and downward to form the mesentery. 

B, or the internal layer of peritoneum, 
passes from the posterior surface of the 
stomach till it reaches the infero-anterior 
border of the transverse colon, as well as the 
hilus of the spleen. After covering the an- 
terior surface of the colon, it ascends up to 
the pillars of the diaphragm clothing the 
anterior part of the pancreas, which is thus 
held between A and B, or layers of, I he trans- 
verse meso-colon. A little to the left of this, 
B passes on to the anterior margin of the 
hilus of the spleen, forming the inner or pos- 
terior layer of the gastro-splenic omentum. 

From this arrangement it results that the 
peritoneum, in forming the lesser or gastro- 
hepatic, the gi-eater or gastro colic, and the 
gastro-splenic omenta, closes in a space 
termed the omental sac, the interior of 
which is inaccessible except by an opening 
at the posterior part of the gastro hepatic 
omentum, whose free margin at the right 
side marks the point where it may be pene- 
trated ; this passage is termed the foramen 
of WinsloVi". It is bounded anteriorly by 
the lesser omentum, above by the liver, and 
posteriorly by the transverse colon. 

Thus, supposing the inner layer of the 
omental sac to be separable from the outer, 
and drawn out through the foramen of 
Winslow, the following parts would be de- 
prived of peritonaeum, i. e., the posterior 
surface of the stomach, the gastro splenic 
omentum of its posterior layer ; so that the 



s 

^ 




EXPLANATION OF FIGURE XL 



MUSCULAR STRUCTURE. 

o". Trapezius. 

b". Rhomboideus longus. 

,S. Splcniur,. 

c". Scalenus. 

p". Pcctoralis transvcv.^alis. 

/". Antoa spinatus. 

(/". Postca sijinatus. 

/;''. Teres major. 

»'". Latis.siraus dorsi. 

J". A portion of the cerrat'.'" niMjuus. 

A". " Iluincro rnOilal." 

r. ?;i". li". Triceps extensor brachii : inapfinim. T:icdium, et ]iar\Tjm. 

(;". Pcctoralis magnus. 

p. Flexors. 

(]". Flexor metacarpi externus. 

)■". '■ " inlernus. 

s". Extensor metacarpi magnus. 

x". Extensor pedis. 

a'. Levatores costarura. 

c'. Obliquus externus alidorainis. 

d'. Obliquus internus ah(l-...i_;j. 

r/'. Ref;ion of the patella. 

Ii'. i. Glutei muscles. 

ni'. Tensor vaginiE, 

n'. }lcetus. 

o'. Vastus externus. 

7'. Flexor metatarsi. 

»•'. fJastrocnemius exlernus. 

/'. Flexor pcdi.s accessorius. 

;/. Sierno maxillaris. 

V. Internal i)art of the levator l.„i;;3ti 

//'. I'eroneu*. 

x'. Extensor ped!>.-. 

J: Trieep' 

d. Regir. 

VEINS. 

3. Jugular vein. 

4. Subcutaneous thoracic vein. 
0. Saphena vein. 

6. "iiaAU'.l vein. 

J). Serratus magnus muscic. 

OSSEOUS STKUCTLT.E. 



rf. 

/• 

c. e. 


Dorsal spines. 

Ulnar. 

Fibula. 


16. 


True ribs. 


17. 


False ribs. 


IS. 


Sternum. 


ID. 


Ileum. 


2- 


Femur. 


23. 


Patella. 


2i. 


Tibia. 


m. 


Os humeri. 


3.3. 


Radius. 



THE HORSE. 



101 



vessels going to and from the stomach and 
spleen would remain uncovered, the anterior 
part of the transverse colon, the anterior 
surface of tlie pancreas, and inner or pos- 
terior layer of the gastro hepatic omentum. 

Next to be described to the serous coat 
is the muscular one, whicli is constituted of 
involuntary plain fibres, vv"hose thickness is 
very variable in different subjects, as well as 
in different parts of the same stomach. 
The cardiac end is more muscular than the 
jiyloric, except at the right margin of the 
latter, where it is very powerful and thick, 
as it smTOunds the pylorus. The thinnest 
part of the stomach is unquestionably the 
convex border of the lesser cul-de-sac. 

The muscular coat of the stomach is in- 
tricately arranged, and authorities differ 
vastly from each other in the description of 
the several layers constituting it. The 
number of layers entering into its compo- 
sition is three : the outer and inner ones are 
mostly continuations of the inner layers of 
the ossophagus, while the middle one is pro- 
per to the stomach. 

The outer layer is composed of the 
longitudinal fibres of the oesophagus : as 
these reach the cardiac end of the stomach, 
they form a peculiar turn, whereby the dis- 
tribution on the surfaces as a flat layer is 
facilitated. Some of the fibres of this layer 
dip down to join the deeper ones, while 
others continue onwards as the longitudinal 
fibres of the duodenum. As to the fibres 
which .proceed on to the curvatures, they 
are not so intricate, as they descend directly 
from the portion of the oesophagus opposite 
the part they supply, so that the only alter- 
ation in direction is that of diverging a lit- 
tle from each other, and pursuing the bent 
course of the corresponding gastric curva- 
ture. On the lesser one they soon become 
scanty, and are lost in the circular fibres of 
the body of the stomach : very few of them 
are traced on to the pylorus. The fibres 
proceeding on to the greater curvature are 
mingled with other considerable bundles 
taking the same direction, but vrhich are not 
traceable on to the cesophagus, as they seem 
to pass round each side of the cardia, and 



blend with the eiretalar fibres on the lesser 
curvature. 

The middle layer consists of annular 
fibres, which, tliough scanty as they encircle 
the extreme left end of the stomach, increase 
in bulk towards the middle part of the 
organ, and are especially developed at the 
lesser curvature. They again decrease over 
the antrum pylori, but are ultimately greatly 
developed for the formation of a powerful 
sphincter at the pylorus. 

The internal or oblique fibres of tlie 
stomach have somewhat the same aiTange- 
ment as the deep layer of fibres of the 
oesophagus, although not perfectly identical, 
as they are arranged like hoops placed one 
within the other ; but while in the former 
the one set enters the other without inter- 
section, in the latter there is a partial decus- 
sation by separate bundles. Thus, in real- 
ity, the oblique fibres of the stomach are 
constituted of two layers, the one proceed- 
ing from the left end of the stomach on to 
the right, which pass internally to the next 
layer : this one proceeds from the right of 
the cardia on to the fundus. Owing to the 
scantiness of circular fibres at the base of 
each cul-de-sac, the fibres are here in con- 
tact with the superficial longitudinal ones. 
The obliqtte fibres are best studied by dis- 
secting from within, and, after removing 
these, the circular fibres come into view 
with greater ease than by attempting to 
expose them from without. 

The third coat of the stomach consists 
merely of the cellular tissue existing be- 
tween the muscular and mucus coals, as 
well as connecting the former to the outer 
serous tunic, in which case it is more abund- 
ant and firm nearest the cm-vatures. There 
it is situated between the muscular and mu- 
cus coats : it was named by the ancients, 
on account of its white aspect, the Tunica 
Nervosa. It is loose in some parts and 
firm in others ; not only serving to connect 
parts together, but also to form a medium 
in which vessels ramify for the supply of 
the organ. 

The internal or mucus coat of the stom- 
ach differs in the cardiac from the pyloric 



102 



ANATOMY AND PHYSIOLOGY OF 



end, as in the former it is but a mere con- 
tinuation of the unmodified mucus lining 
of the oesophagus, being characteristic for 
its scantiness in gland and but limited sup- 
ply of blood. The most marked feature it 
possesses is that of being covered by a cuti- 
cular layer of extreme thickness, easily 
separable from t!ie basement structure be- 
neath after slight maceration or boiling. 
The cardiac portion of the gastric mucus 
lining is, in a healthy stomach, of a dirty 
white, bcdcwcd by more or less mucus, 
and thrown into folds which have a radiated 
arrangement at the cardiac orifice, whilst at 
the fundus they are concentrically an'anged. 
This portion of the membrane is also fur- 
nished with papills3 ; and Sprott Boyd, in 
an Inaugural Essay on the structure of the 
Mucus Membrane of the Stomach, pub- 
lished in the Edinburgh Medical and Surgi- 
cal Journal for 1836, describes a very marked 
])cculiarity of an interposed layer between 
the epithelium and papiilated surface of the 
mucus lining. This intermediate layer, he 
says, has a smooth equal surface, perforated 
by numerous foramina about tiie 600th of 
an inch in diameter, or perhaps a little 
smaller, the margins of which are slightly 
thickened. He afterwards states that he 
has not been able to trace in the epiithelium 
of any other animal a structure similar to 
that existing in the horse. These peculiar- 
ities in the left pouch of the stomach cease 
abruptly midway the length of the viscus, 
where the cuticular lining terminates by a 
seiTatcd edge. 

The mucous lining of the riglit end of 
the stoniach is normally of a reddish color, 
and presents a vilious, glistening aspect, 
coated thickly with mucus, and also pos- 
sessing a high degree of vascularity ; the 
epithelium is here scanty, but nevertheress 
tabular. The villous appearance above 
referred to suggests itself also when the sur- 
face is examined by the naked eye and by 
the aid of a lens ; but it is deceptive, as 
has been already remarked by Sprott Boyd, 
who correctly refers it to the raised margins 
of the arolsc which stud the surface. This 
portion of the gastric mucus membrane is 



also thrown into folds, whieli become grad- 
ually more marked towards the pylorus; 
whereas they are susceptible of obliteration 
by distention, there is one circular fold at 
the pylorus which is permanent, and so dis- 
posed as to fulfil the ofiice of a valve. 

The arteries of the stomach are derived 
from the coeliac axis, whose three divisions, 
i. e. gastric, hepatic, and splenic, all contri- 
bute to supply blood to the viscns ; but the 
first is specially destined to that office. The 
gastric artery, being the smallest of the 
three divisions, take.; a course downwards, 
forwards, and rather to the right, -across the 
pancreas, getting between the layers of the 
gastro-hepatic omentum. Being then di- 
rected to the left towards the lesser curva- 
ture, it divides into an anterior left or smaller 
branch, and a posterior right and more 
capacious as well as longer one. The an- 
terior division is destined to supply the 
anterior surface of the stomach, and more 
especially the left cul-de-sac, anastomos- 
ing with branches (sometimes called vasa 
breva), coming on to the stomach from the 
splenic. This division of the gastic also 
anastomoses with oesophageal tv.igs, which 
are occasionally of considerable size. The 
posterior or right division of the gastric 
artery, destined for the pyloric end of the 
stomach, anastomoses v^'ith some splenic 
branches, but more especially v/ith the py- 
loric branches of the hepatic artery. 

The veins returning the blood from the 
stomach are the gastric and splenic, which 
anastomose with the duodenal veins. These 
all have a few valve:;-, but they may be easily 
injected from the porta into which they 
empty, owing to their very free anastomosis. 

The lymphatics of the stomach are nu- 
merous, and in some parts very apparent, 
entering the lymphatic glands situated along 
the greater cm-vature and around the cardia, 
v/here they are numerous and large. 

The stomach is supplied with nerves 
from both the cerebro spinal and sympathetic 
or ganlionic system. The pneumogastric 
or par vagna nerves, arising from the me- 
dulla oblongata, are the main conductors 
of nervous influence to and from that vis- 



THE HORSE. 



10£ 



cus.. Their arrangement is simple, as, after 
they liavc formed various plexuses within 
the thorax, in which they mutually inter- 
cliange tibrcs, tiiey reach the diaphragm, 
and here are arranged as two nervous 
branches, i. e., a superior and an inferior 
one. The former is principally destined for 
the fundus, whilst the latter supplies the 
pyloric end, and sends branches oft' to the 
duodenum, with one or two to the solar 
plexus. 

The sympathetic fibres, destined for the 
stomach, are derived from the solar plexus, 
descending on to the viscus, in company 
with the vessels. 

INTESTINE. 

This term is applied to that portion of 
the alimentary canal extending between the 
pylorus and anus, destined for the temporary 
retention of the chymous mass, so that 
its nutrient parts may be absorbed, whilst 
its more solid, indigestible constituents, are 
collected for excretion. 

The intestine in all monogastria, but es- 
pecially in solipeda, occupies by far the 
greatest part of the abdominal cavity. The 
bonds of attachment to the various parts of 
the latter are contracted by the intestine, 
through its peritoneal investment, more 
especially to the spine, constituting mesen- 
ters, which I shall especially allude to when 
describing with more detail each portion of 
tliis capacious tube. 

Not only the attachments, but also the 
shape of the intestine, vary at different parts 
of its com-se, so that it has been deemed 
necessary to divide it, either arbitrarily or at 
natural demarcations. Thus we speak of 
the small and large intestine, the two being 
separated naturally by a marked change in 
direction, size, and confirmation. 

It is also obvious that, as the situation, at- 
tachment, and shape of each portion of the 
intestinal canal differ, so must the relations 
be equally distinct, and further mention of 
them will therefore be reserved for fuller 
exposition elsewhere. 



SMALL INTESTINE. 

This, the smallest although longest, is 
also the first portion of the intestinal tube, 
extending from the pylorus to its sudden 
termination into the large intestine. In it 
the chymified mass is subjected to the modi- 
fying influence of important secretions, 
whereby its nutritive parts are fitted for 
absorption by the vessels, which, for this pur- 
pose, are arranged in this portion of the in- 
testinal track. 

The small intestine has been divided into 
three parts: this classification is, however, 
purely conventional. Since it does not 
recognize anatomical differences for its basis, 
it might justly be presumed that this dis- 
tinction of human anatomists exhibited 
traces of imperfection, even when applied 
to the frame of man. Such being the case, 
it is no matter of surprise that, in referring 
the distinction to the intestinal canal of 
animals, the incongruities of the system 
should be still more apparent. 

Extending from the pylorus, the first por- 
tion is termed the duodenum, from its being 
considered as twelve fingers' breadth in 
length : it is, however, extended round to 
the left side of the spine, posteriorly to the 
anterior mesenteric artery. The middle, or 
floating portion of gut, takes the name of 
jejunum, and the third, or csecal portion, is 
distinctively designated ileum. 

The duodenum forms a wide curve from 
the pylorus round to the right, being situated 
under the concave surface of the fiver, pass- 
ing above the transverse colon, so as to 
attain the posterior part of the mesentery, 
and, reaching the left side of the spine, 
comes in contact with the colon, where it is 
said to end in the jejunum. The duodenum 
is fixed by the gastro-hepatic omentum to 
the concave surface of the liver, Ihc layers 
of which enclose tiie biliary and pancreatic 
ducts, whereby this bond of union is still 
farther strengthened. The peritoneum com- 
insf from the ri2;ht and spigelian lobes of the 
liver, as well as from the right kidney, forms 
a loose attachment for the duodenum by 



104 



ANATOMY AND PHi'SIOLOGY OF 



extending on to the hepatic flexure of the 
colon, after it has surrounded the first-named 
gut. The next portion of intestine is at- 
tached to the spine transversely to the long 
axis of the body ; winding round the mes- 
entery to the left of the aorta, it gets at- 
tached to the gastric flexure of the colon, 
and here it proceeds, under the name of 
jejunum, along the free borders of the 
mesentery. 

As to the shape of the duodenum, from 
the pylorus to the right of the porta, we 
find its dimensions so very great as to have 
suggested to the ancients the similitude be- 
tween it and the stomach, of which they 
regarded it in some degree as an analogue, 
as testified by the appellation " Ventriculus 
Succenturiatus," given to it by them. Fur- 
ther from the pylorus, we find it constricts 
and assumes a certain caliber, which it 
maintains till it loses its name for that of 
jejunum. 

With reference to the relations of the 
duodenum, it may be stated that they ad- 
mit of detail on account of the fixedness 
of that portion of the gut, an attribute with 
which it is endowed in contradistinction 
to the jejunum and ileum. In the first 
portion of its course, i. e., from the py- 
lorus to the posterior part of the right 
lobe of the liver, the duodenum by its 
upper surface is in contact with the con- 
cave surface of the latter organ, crossing 
the vena portae, near which it is pierced by 
the biliary and pancreatic ducts, which 
enter it at about five or six inches from the 
pylorus, forming an acute angle with each 
other. The inferior surface of the duo- 
denum rests on the transverse colon, and 
its superior margin is in close contact with 
the anterior part of the head of the pan- 
creas. 

Round to the right, the duodenum is in 
contact with the hepatic flexure of the 
colon, right and Spigalian lobes of the liver, 
as well as the right kidney. To reach the 
spine it has to cross the direction of the 
right flexure of the colon, getting behind 
the mesentery and gastric flexure of the 



colon, where it is connected with thi. left 
kidney. 

Alluding next to the general anatomical 
facts as applied to the jejunum, so called 
on account of its usual vacuity after death, 
the limit between it and (he ileum is de- 
fined by imagining the small intestine, with 
the exception of the duodenum, divided 
into five equal portions, of which the first 
two take the name of jejunum, whilst the 
last three-fifths receive that of ileum. 

The jejunum is suspended superiorly 
from the spine by an extensive fold of per- 
itoneum, termed mesentery, which serves 
also as a medium for the passage of the 
mesenteric arteries, veins and nerves, as well 
as for chyliferous vessels, to take their 
course towards the receptaculum chyli, sit- 
uated to the left of the aorta. 

The width of the jejunum is far from 
being uniform, it being more constricted at 
some points than at others: its narrowest 
part is that which is contiguous to the 
ileum. 

The ileum is the terminating portion of 
the small intestine, so called from the tor- 
tuous course it takes, emptying itself into 
the large intestine at the junction of the 
ccecum and colon, by an orifice provided 
with a valve. 

The first portion of the ileum is simply 
attached by mesentery to the spine ; but, 
in addition to this, in the last part of its 
course, the gut is connected with the caecum 
by a fold of peritoneum, which is not large 
enough to prevent them deviating more 
than an acute angle from each other. 

The ileum is, on the whole, the narrow- 
est portion of the small intestine, but the 
thickest in its coats. 

Having now especially to describe the 
structure of the small intestine, it may be 
taken as a whole, merely alluding to local 
peculiarities. 

This portion of the alimentary canal has 
four coats, to be described in the same 
order by those of the stomach, {. e. peri- 
toneal, muscular, cellular, and internal 
mucus. 



THE HORSE, 



105 



The first, or the peritonea), has nothing 
pecuUar, beyond its enclosing a little trian- 
gular space all along the upper attached 
border of (he gut. The looseness of the 
peritoneal folds attaching the small intes- 
tine is very marked ; and Colin (Soc. cit.) 
notes, (hat the mesentery is propordonately 
larger in young than in adult quadrupeds, 
so that the gradual shortening of this ex- 
plains the spontaneous reduction of exom- 
phalus or umbilical hernia. 

The second, or muscular coat, is mostly 
developed at the commencement of the 
duodenum and terminating portion of the 
ileum. It consists of white involuntary 
fibres, arranged so as to form an outer 
longitudinal layer, and an inner circular one, 
bofh of which completely encircle the gat. 

The third, or cellular coat, is similar to 
that of the stomach, in being disposed in 
tAvo layers, so as to connect the three coats 
together. It is especially condensed on the 
inner surface of the muscular coat, so as to 
take the appearance of a fibrous tunic, at- 
tached to the mucus lining by loose cel- 
lular tissue. 

The fourth, or mucus, coat is thin, hav- 
ing a velvet appearance, due to villi, pecu- 
liarly small in the intestines of the horse, 
but remarkably developed in other animals, 
especiall)' carnivora and fishes. The villi 
may be seen by a pocket lens, on a well- 
washed piece of intestinal mucus mem- 
brane, and between (hem are seen numer- 
ous foramina, which are (he openings of 
tubular glands, known as the crypts of Lie- 
berkuehn. 

In addition to the tubular glands, by dis- 
secting, from without, the muscular from 
the mucus coat, lining the commencement 
of the duodenum, we find clusters of vesi- 
cles, similar to the vesicular structure of the 
salivary and pancreatic glands. These 
form distinct layers, provided with ducts, 
which open on the free surface of the mem- 
brane ; and Dr. Todd states that Brunner's 
glands, or, as he calls them, the duodenal, 
are more developed in the horse than in any 
other animal he has hitherto examined them 
in. 

u 



We have next to treat of the solitary 
glands — glandulae solitariEe — peculiar and 
rather scanty bodies, visible at various parts 
of the small intestine. These are vesicu- 
lar, and without any opening when in the 
perfect state, surrounded by villous pro- 
cesses and Lieberkuehnian follicles. Some 
of the villi also project from the surface of 
the so-called glands, which are most ap- 
parent when distended with secretion. 

About the second half of the jejunum, 
and along the whole of the ileum, we see 
longitudinal patches, varying from half an 
inch to even three inches in length, scat- 
tered all over, but more especially situated 
near the superior or attached border of the 
small intestine, which is contrary to the 
faulty description of some recent authors. 
These patches, distinguished as Peyer's 
glands or patches, also as Agminated glands 
— Gladdulas agminatae seu aggregatee — con- 
sist of an accumulation of small bodies, each 
resembling a glandula solitaria in miniature, 
being also destitute of a natural aperture. 
Colin (loc. cit.) states that they are first 
seen at a distance of about six feet and a 
half from the pylorus, and the least num- 
ber of them he has ever counted has been 
102, whilst the utmost has been 158. 

The mucus membrane of the small in- 
testine is thrown into folds, at difi'erent, 
parts, which are transverse, and scalloped 
near the pylorus, whilst in other parts they 
are mostly longitudinal ; these are all tem- 
porary folds. There is no such arrange- 
ment as the valulcs conniventes in the small 
intestines of the horse, though recent wri- 
ters of great eminence have described them. 
About five inches from the pylorus, at 
the superior border of the duodenum, is a 
semicircular fold, which, if elevated, ad- 
mits of the finger being thrust behind it 
into the wide biliary duct. The opening 
of the pancreatic duct is also visible beneath 
this fold, but it is not so capacious as the 
one last mentioned. 

LARGE IMTESTINE. 

The large intestine constitutes the termi- 
nating portion of the alimentary canal, 



106 



ANATOMY AND PHYSIOLOGY OF 



being remarkably more developed in soli- 
pedes than in any other of our domestic- 
quadrupeds. It occupies the greater part 
of the abdomen, and most of it is loose, 
Vv'hilst its shape and other peculiarities vary 
considerably at diiferent points. 

It is divided into three parts — cEecum, 
colon, and rectum — the precise extent of 
each being defined by special anatomical 
characters. 

The position of the large intestine being 
constant, it is necessary, for sake of pre- 
cision, to speak of the whole as to the 
course it takes in forming the three divis- 
ions, extending thus between the small 
intestine and anus. 

The ctccum, or blind pouch, is the first 
gut, which protrudes in the middle on cut- 
ting through the abdominal walls at the 
linea alba. Its bend or blind extremity is 
projecting into the left hypochondriac 
region ; its body crosses obliquely the floor 
of the abdomen, to reach the right iliac 
region, where it suddenly bends at an acute 
angle, being rather constricted, and forms 
the colon. At this part the latter receives 
the ileum, and extends up the right side of 
the abdomen to the diaphragm, where it 
traverses the direction of the spine, resting on 
the ensiform cartilage ; turning round the left 
side, it attains the left iliac fossa posteriorly, 
where it forms a twist like a letter S, from 
wliich similitude it has been termed the Sig- 
moid Flexure of the Colon. The gut, 
having diminished in size, returns up the 
same side of the abdomen to the diaphragm, 
where it again crosses the spine. Being 
now on the right side, it continues back 
to a point beyond the anterior mesenteric 
artery, where it turns upward and for- 
ward, so as to come in front of the artery 
in question ; then, from right to left, so as 
to cross tlie spine for the third time, consti- 
luting the transverse colon, which is more 
capacious than the part preceding it. The 
two curves which it forms, one on the right 
and the other on the left, are respectively 
called the hepatic and gastric flexures of 
the colon. The gut so proceeds backward 
along the left side of the mesentery, being 



diminished again in size, and constituting 
the single colon, i ill we get to the posterior 
] mesentery artery, where, unaltered in other 
respects, it takes a straight course through 
the pelvis, out at l!ie anus, and hence the 
name of Rectum. 

The ca;cum so called from having only 
one outlet, being closed at its anterior part, 
or caecum caput coli, from its being the 
blind head of the colon, is vulgarly termed 
the water-bag, owing to the almost invari- 
able fluidity of its contents. 

It is situated, as I have before said, ob- 
liquely along the floor of the abdomen, ex- 
tending backwards from left to right. 

It is attached to the spine by a meso- 
cseum, which is a fold of peritoneum, com- 
ing ofl" from the spine on to the superior 
part of the pouch. There is then the fold 
already alluded to, which stretches from the 
ileum on to the cEecum, and, through the 
medium of the mesentery, indirectly con- 
necting the latter with the spine. 

The ccecum is cone-shaped, having an 
apex and a broad base. The former gene- 
rally protrudes the first, when a medium 
longitudinal incision is made into the 
abdominal walls, although it is situated 
above the left portion of the double colon, 
whilst the Liver is directly in contact with 
the floor of the abdomen. Like the other 
divisions of the large intestine, the CBBcnm 
is sacculated. The bands producing this 
appearance are three in number at the 
apex ; but between two and three inches 
from this, one of them bifmxates, so that 
four bands result, which are continuous on 
to the colon. 

The colon arising from the caecum, re- 
ceives at first the contents of the ileum, 
being situated along and occupying tlie 
greater part of the floor of the abdomen. 

The colon is generally distinguished as 
double and single. By double, is meant 
the flexures of the gut from its commence- 
ment to its gastric cm've ; whilst by the 
single colon, is understood the continuation 
of the same intestine to the part where the 
rectum commences. 

The double colon is attached by the peri- 



THE HORSE. 



107 



toneum coming off on to it from the cse- 
nim, ill the right iliac fossa, and continues 
from the outer flexure on to the inner, so as 
to keep the two in perfect apposition. Thus, 
if the abdominal parietes are cut tlirough, 
the whole of the double colon may hang 
out, with the exception of the transverse 
portion. The latter is attached to the right 
Iddney, as well as concave rurface of the 
liver, by folds of peritoneum ; to the spine 
by the transverse meso-colon ; and still 
more to the left, it is loosely attached by 
the gastrocohc omentum to the stomach 
and spleen; besides which it has a peri- 
toneal attachment to the left kidney. Then 
the single colon commencing, it is loosely 
affixed to the spine by an extensive peri- 
toneal fold, the meso-colon, similar to the 
mesentery, but smaller and to its left : this 
fold is continuous posteriorly with the meso- 
rectum. 

The relations of the (Tansverse colon are 
important, no less than interesting, inas- 
much as it is in close connection with the 
most important abdominal viscera. On the 
right, its upper surface is contiguous to the 
right kidney, as well as to the right and 
Spigelian lobes of the liver. In the middle, 
its superior surface is connected priiici- 
pally with the pancreas ; and to the left, 
but still superiorly, it approaches the left 
kidney and spleen. Anteriorly, the stomach 
also touches it, especially during repletion. 

The shape of the colon is very variable 
in different parts of its course. Thus, the 
first portion of the double colon, from the 
right iliac fossa till it forms the sigmoid 
flexure, is capacious and sacculated; the 
latter being due to the four bands con- 
tinuous on to it from the caecum. At the 
sigmoid flexure the bands are completely 
lost, so that the gut is smooth ; but, as we 
extend up towards the diaphragm, the an- 
terior band begins, and then the posterior 
one becomes apparent; so that the trans- 
verse and single portions of the colon 
are puckered by two longitudinal bands. 

The Rectum, so called from its compar- 
ative straight course through the pelvic 
cavity, arises from the single colon, a little 



anteriorly to the posterior mesenteric artery, 
and ends at the anus, where its mucus 
membrane is continuous with the common 
tegumentary covering. It is attached in its 
anterior two-thirds by a meso-rectum ; the 
posterior third is an exception 1o any other 
part of the intestinal track, in so far as it 
is connected to adjacent parts by special 
faschiEB, and at its termination by certain 
muscles hereafter to be dwelt upon. 

The size of the rectum is much the same 
as the single colon. It is puckered in its 
anterior part by two longitudinal bands ; 
and the sacculi, resulting therefrom, deter- 
mine the shape of the fsecal nxatters. 

The rectum is superiorly related to the 
spine, whilst inferiorly it comes in contact 
with the bladder, bulbous portions of the 
vasa deferentia, vesiculffi seminales, and 
prostate. 

The structure of the large intestine does 
not vary essentially from that of the small, 
! as it possesses the four coats, i. c. peritoneal, 
j muscular, cellular, and internal mucus. 

The peritoneal tunic forms an enth-e cov- 
ering to (he large intestine, with the excep- 
tion of the superior surface of the trans- 
j verse colon — which is in contact with the 
' pancreas — and the terminating portion of 
the rectum. The bands by which it unites 
the intestine to other parts have been already 
described. In addition to the peritoneum 
•forniLng an entire covering to the gut, at 
the attached margin of the flexures of the 
colon it constitutes folds loaded with fat, 
varying in width in diflerent parts, and clus- 
tered so as to have desened the name of 
appendices epiploicae 

The 

is differently developed in various parts. 
Its fibres are of the plain variety, and ar- 
ranged in two orders. The outer longitud- 
inal set is scanty in some parts, but in others 
forms the longitudinal bands above alluded 
to. These are shorter than the actual length 
of the gut itself, so as effectually to pucker 
it. The number of longitudinal bands 
varies from one (o four in various parts of 
the gut, and the shape and breadth of the 
latter is not everywhere the same. The 



muscular coat of the large intestine 



108 



ANATOMY AND PHYSIOLOGY OF 



longitudinal fibres are abundant in the rec- 
tum, but they only form bands in the ante- 
rior two-thirds, as posteriorly to this they 
uniformly surround the gut. The inner 
layer of fibres encircles the whole of the 
gut, being thickest towards the apex of the 
csEcum, as well as in the single colon and 
rectum ; at the end of the latter the inter- 
nal sphincter-ani is formed by an accumu- 
lation of the circular fibres. The circular 
fibres of the colon are engaged in forming 
the ileo-colic valve, hereafter to be described. 

The cellular coat of the large intestine 
resembles that of the small, only not so 
abundant, except at the terminating portion 
of the rectum, where it is mvich more de- 
veloped. 

The mucous lining of the large intestine 
is continuous anteriorly with that of the 
ileum, posteriorly with the common integu- 
ment. It is thin, more or less coated with 
mucus, scantier in glands than the one of 
the small intestine ; but the orifices of the 
(jieberkuehnian crypts are more apparent, 
owing to the surface here being destitute of 
villi. Saccular recesses, more or less capa- 
cious, exist in the membrane lining the 
large intestine. The diti'erence in degree 
of vascularity gives rise to difference in the 
color of the mucus coat in various portions 
of the gut: thus, that lining the csecum is 
generally more deeply colored than that of 
the colon, whilst the rectal mucus mem- 
brane is more vascular, and hence redder 
than the colic or coecal one. 

At the termination of the ileum is the 
ileo-colic or ileo-c£Ecal valve, which is con- 
stituted of two folds of mucus membrane, 
almost parallel to each other, and horizontal, 
leaving between them an eliptical orifice 
when partially drawn asunder. The folds 
consist of the circular fibres of the intes- 
tine, lined on the iimer or ileac side by the 
villous membrane of the small, whilst on 
the csecal and colic side they are covered by 
the mucus membrane proper to the large 
intestine. It is worthy of notice, that 
though muscular fibres partly enter into the 
construction of the valve, its efficiency is 
explicable on purely mechanical grounds, as 



proved by the fact, that it is competent in 
the dead body. 

The anus is the outlet of the intestine, 
which is perfectly closed, except during the 
evacuation of feculent matters, and is made 
perceptible externally by the elevation of the 
tail, being situated in a space bounded su- 
periorly by the sacrum and coccyx, lateraUy 
by the ischial tuberosities, and interiorly by 
the urethra in the male and vulva in the 
female. 

It is lined within by the mucus mem- 
brane of llie rectum, which is loose and of 
a marked red color. Its external covering 
is of comnion integument, destitute of hairs. 
Lying between the skin and mucus mem- 
brane are two circular muscles, whose office 
is to keep the anus closed and prevent con- 
stant evacuation of faeces, whilst there are 
other muscular appendages situated exter- 
nally to these, destined either to elevate or 
retract the anus, being evidently antagonis- 
tic to the sphincters. 

The internal sphincter-ani is in contact 
with the attached surface of the intestinal 
mucus membrane, and separated from the 
integument by the external one. It is con- 
stituted of the pale circular fibres of the gut, 
but towards its free edge certain colored 
fibres are apparent on it. 

The external sphincter is situated outside 
the internal one, and within the anal integu- 
ment: it is circular, and composed of red 
fibres, attached superiorly under the first 
coccygeal bone, and interiorly its fibres 
blend in the male subject in the accelerator 
uriuEB and triangularis penis, and in the 
female with the constrictor vaginae. 

The levatores-ani are two pale muscles, 
attached on each side of the first coccygeal 
bones, and, spreading downward and for- 
ward on to the rectum, form an attachment 
for the internal sphincter, and blending with 
the longitudinal fibres, so as to increase the 
tliickness of the muscular coat of the rec- 
tum. The action of these muscles must 
be that of elevating the anus, and shorten- 
ing the rectum from before backward. 

The retractors proper to the anus are one 
on each side attached to the inner surface of 



THE HORSE. 



109 



the articular extremity of tlie ischium. Ex- 
tending from before backward, and rather 
upward, they blend whh the external 
sphincter. Their action i:~ obviously that 
of retracting the anal opening. 

VESSELS, NERVES, AND LY.MPHATICS OF THE 
INTESTINE. 

The intestinal canal, as a whole, receives 
arterial blood from the anterior and poste- 
rior mesenteric arteries, hepatic branch of 
the coeliac axis, with branches from the in- 
ternal pudic. The arteries of the small in- 
testine are derived from lhe anterior mesen- 
teric, whose divisions, varying from twenty- 
four to twenty-eight, proceed to the small 
intestine, with the exception of four, which 
minister to the nutrition and functions of 
the large intestine. The branches extend- 
ing from the main trunk, at acute angles, 
proceed between the layers of the mesen- 
tery, to within one and a half or two inches 
from the gut, where they anastomose, form- 
ing vascular arches, from which the second- 
ary branches arise, and, proceeding on to the 
intestine, ramify on the several coats, espe- 
cially the mucus one. The anterior division 
of the anterior mesenteric artery, proceeding 
to the duodenum, anastomoses with the duo- 
denal branch of the hepatic artery. The 
last iliac division inosculates with the cscal 
and colic branches of the same trunk. 

The cfEcum and colon receive arterial 
blood solely from the branches derived from 
the anterior mesenteric, \\'ith a slight contri- 
bution from the posterior mesenteric arteries. 
The branches of the former originate oppo- 
site the flexure made by the caecum and 
colon. The ccecal divisions, two in num- 
ber, proceed downw^ard and forward till 
they reach the gut. The posterior one 
passes round the posterior part of the bor- 
der of the caecum, to get on the under sur- 
face of the latter, extending to the apex, in 
somewhat a straight course, and ramifying 
collaterally; at its termination it forms a 
vascular network, by anastomosis with the 
superior cascal artery. The latter one, reach- 
ing the gut, extends directly fonvard towards 
the ape.x, and comports itself like the former. 



Thus we see the flexure, formed by the 
caecum and colon, is supplied l)v collateral 
branches, from liic superior and inferior 
ca?cal mesenteric divisions, both these anas- 
tomosing on the corres|)onding surfaces with 
the colic arterial trunks. 

The two branches going to the colon ex- 
tend, about jiarailel to each other, down- 
wards and forwards and to the left, the one 
gaining the cff'cal end of the colon, whilst 
the other proceeds on to the hepatic flexure. 
Then these may be traced, the one back- 
ward and the other forward, relatively to 
the course of the gut, along its superior 
border, so as to reach the sigmoid flexure, 
where they mutually inosculate. From the 
mesenteric division going to the transverse 
colon, is a branch proceeding on to the 
single portion, which anastomoses poste- 
riorly with the posterior mesenteric. This 
vessel divides first into two branches, i. c. 
an interior colic and a posterior rectal one. 
The anterior colic branch is directed for- 
ward and downward between the layers 
of the meso-colon, and divides into four or 
five branches, which bifurcate and form 
arches, like the arteries of the small intes- 
tine, for the supply of the contiguous gut. 
The arteries of the rectum are sometimes 
spolien of as haemorrhoidals, and these are 
distinguished as anterior, middle, and pos- 
terior. The anterior lia:morrhoidals are 
formed by the hindermost branch of tiie 
posterior mesenteric artery, wiiich, passing 
into the folds of the meso-rectum, supplies 
consecutive branches to the gut, till, poste- 
riorly to the peritoneum, where the arteries 
pierce the muscular coat, and, forming a 
network of vessels, anastomose with the 
middle haemorrhoidals, which are the ramifi- 
cations of the internal pudic* These inos- 
culate with the posterior haemorrhoidals 
derived from the same source. The anus 
is then supplied with blood from the last 
named branches, as well as from perineal 
twigs of the external pudic. 

The veins of the intestine accompany the 

* This arterv sometime?, erroneously, goes by the name 
of its terminating branch — Uie artery of the bulb. 



110 



ANATOMY AND PHYSIOLOGY OF 



arteries, and arc equally distributed. The 
posterior mesenteric vein is formed by sim- 
ilar divisions to those coming off from the 
posterior mesenteric artery, and then the 
main trunk extends forwards and enters the 
porta, near the termination of the splenic. 
At this spot the veins from the small intes- 
tine, as well as from the caecum and double 
flexures of the colon, also contribute to 
form the large portal trunk. 

The nerves of the intestines are derived 
from the solar plexus, and Ihey are found in 
association with the arteries. The duo- 
denum also receives branches from the par 
vagum nerves, and the rectum and anus are 
supplied also by divisions of the two last 
sacral pairs. 

The lacteal and lymphatic vessels of the 
intestine are anatomically alike, and even 
physiologically they admit of being com- 
prehended under the same term, " lym- 
phatic," because both absorb the fluid known 
as lymph. But since the lymphatics of the 
small intestine additionally contribute to 
the function of chyliferous absorption, they 
have been distinguished as lacteals, in con- 
formity with the color of the fluid which 
they take up during the digestive pro- 
cess. 

The lacteals of the small, and lymphatics 
of the large intestine, enter a set of lym- 
phatic glands, by no means numerous, and 
of small size, situated along the attached 
border of the gut. From these the lacteals 
ascend to about twenty-five or thirty lym- 
phatic glands of larger size than the others, 
situated at a short distance from the spine, 
between the folds of the mesentery, from 
which the lyiujih is then conducted into the 
receptaculum chyli. From the large intes- 
tine the lymphatics enter, in addition to the 
intestinal set of glands, others situated in 
the lumbar region, partly between the folds 
of the meso-colon and meso-rectum, from 
which the lymph is carried into the common 
reservoir. 

The receptaculum chyli receives the fluid 
from the lymphatic vessels of all the ab- 
dominal viscera, as well as from other parts. 
It is a membranous pouch of various 



(■alibre, lying in contact with the right crus 
of the diaphragm, and right psoas muscle, 
corresponding in situation to the second and 
third lumbar vertebrae. It gradually con- 
stricts anteriorly, and crossing the aorta to 
get on its left side, enters the thorax, and 
here becomes known as the thoracic duct, 
which empties itself into the right axillary 
vein. 

SPLEEN. 

The spleen, although, possibly, not bear- 
ing any physiological connection with the 
digestive process, still, from its anatomical 
relations, conveniently admits of 4escription 
here. It is a singularly elastic organ, of a 
purplish grey color; smooth on its outer 
surface, and composed of a spongy texture, 
enclosed in fibrous tissue. The color of 
the spleen is generally darker in herbivora 
than in carnivorous quadrupeds, as in the 
latter it is more of a red color. 

It is situated in the left hypochondrium, 
and partly in the epigastrium, being at- 
tached by its outer tunic to the stomach, 
left kidney, and transverse colon. 

It is scythe-shaped, being srnall and 
pointed anteriorly, but broad posteriorly. 
It is smooth, and somewhat convex on its 
inferior surface, whilst its superior one is 
divided into two unequal halves, by a fissure 
termed the hilum. The anterior division 
is narrow, but the posterior one is broad 
and triangular in shape. The margin of 
the spleen is sharp all round. The size of 
the organ varies considerably in different 
subjects, and, according to circumstances, 
in the same animal. 

The spleen is related, by its superior 
surface, to the left end of the greater curva- 
ture of the stomach, and to the diaphragm; 
at its broad base it is in close relation with 
the left kidney ; its inferior surface is con- 
nected with both double and single portions 
of the colon. 

The spleen has two coats, a parenchyma, 
blood vessels, nerves, and lymphatics, need- 
ing separate description. 

The external coat is peritoneum, which 
forms not only a covering to the organ itself, 



EXPLANATION OF FIGUEE Xll. 



MUSCULAli STRUriTRE. 

rORWARl) TAUTS. 

*. Liganiciitum colli. 

a". Tia])czius. 

h'. Khomboideus lougus. 

c". Scalenus. 

g". Postoa .';pinatus. 

h'. Teres major. 

t". Latis.'jinuis ilnrsl. 

I". Scapulo ulnaris. 

m''. u". Triceps cxttTiSor braehii. 

p". Flexor nietacari)i externus. 

5". Flexor metacarpi mcdius. 

r. Flexor metacarpi internus. 

S". Extensor mctacari)! niagiiub. 

IS. Spleiiius. 

11. Levator humeri. 

x". Extensor pedis. 

c". Obliquus externus abdominis. 

POSTERIOR PAETS. 

/('. v. Gluteal muscles. 

f. Triceps. 

k. Uiceps abductor tibialis, posterior. 

V. Adductor tibialis intenius. 

»!. Tensor vagira;'. 

n. Region of the vastus internus. 

r. Gasti'ocnemius internus. 

I. S. Gastrocnemius txternus and internus. 

X. Extensor metatarsi. 

!/. Peroneus. 

i'. Flexor pedis acecssorius. 

e'. (f. Coccygeal muscles. 

4. Subcutaneous thoracic vein. 

5. Saphcua vein, 

6. Radial vein. 

OSSEOUS STllLCTURE. 

10. 20. 21. Tlu' iiilvis. 

11. Cc-rvicai vcrteline. 



13. 


Coccy^'cal boues. 


16. 


The true ribs. 


17. 


The false ribs. 


18. 


Sternum. 


»»o 


Femur. 


23. 


I 'ate 11 a. 


Wi. 


Scapula. 


34. 


Humerus. 


35. 


Radius. 


(?. 


Dorsal spines. 


f. 


Ulna. 



THE HORSE. 



ill 



but bonds of connection between it and 
other parts, such as the gastro-splenic omen- 
tum, and the attachment to the kidney and 
transverse colon heretofore described. This 
coat is smooth externally, rather closely 
attached to the fibrous coat internally, but 
of considerable elasticity, so as to allow the 
spleen sufficient freedom for distention. 

The second or fibrous coat, also termed 
the albugineous or clastic coat, is that closely 
applied to the parenchyma of the organ. 
It consists of yellow and white fibres, and 
in some parts, such as in the trabeculsp, 
Koelliker has found plain muscular fibres, 
which he says do not exist in the external 
portion of the fibrous tunic in the horse. 
The covering not only envelopes the outer 
surface of the organ, but sends sheaths and 
processes into its substance. The sheaths 
are purposed for covering vessels, whilst 
the processes, termed also trabeculsB, divide 
the substance of the spleen into areolse or 
interspaces, which contain a red matter, 
easily washed and pressed out, known as 
the splenic pulp. The trabeculae also arise 
as processes from the vascular sheaths, as 
well as from the external tunic. When the 
pulp has been thoroughly washed, the outer 
coat, with the trabeculEE and sheaths, have 
the appearance of a framework or skeleton. 

The splenic pulp has a medullary aspect, 
being composed of cells and blood vessels ; 
and if the organ be cut clean in any direc- 
tion, we see, besides the cut ends of vessels 
and trabeculse, certain pearlish looking 
bodies, named, from their discoverer, Malpig- 
hian Corpuscles. If divided, fluid escapes 
from the cavity which exists in their in- 
terior. They are perfectly visible to the 
naked eye, being about one-thirtieth of an 
inch in diameter ; and, with a pocket glass, 
they may be seen attached to the small ar- 
terial trunks, if the pulp has been previously 
carefully washed. 

The spleen derives its arterial blood 
through the splenic artery, which is the main 
division of the cceliac axis. "Winding be- 
tween the folds of the gastro-splenic omen- 
tum, it not only sends numerous branches 
through the hilum, and on to the surface of 



the spleen, but also supplies the stomach, 
largely inosculating with the gastric artery, 
so that the two might mutuidly perform 
each other's office, if the main trunk of 
either were obstructed. 

The splenic vein is similarly distributed 
to the artery, and it empties its blood into 
the vena ports, just anteriorly to the pos- 
terior mesenteric vein. 

The nerves of the spleen are derived from 
the solar plexus, and with the splenic artery 
enter the spleen. 

The lymphatics of the spleen are said by 
Koelliker to be scanty ; but Dr. Sharpey 
tends rather to the belief that they are 
abundant. They are arranged superficially 
and deep, both sets anastomising freely 
with each other, and, reaching the hilum, 
they enter various scattered lymphatic 
glands in the peritoneal folds, and then 
empty into the receptaculum chyli. 

LIVER. 

The liver is the largest gland in the body, 
and proportionately largest during certain 
periods of fcetal fife. It is of a dark reddish 
brown color, and destined for the office of 
biliary secretion. 

It is situated across the long axis of the 
body, in the right hypochondriac, epigastric, 
and partly in the left hypochondriac regions. 

It is attached to various parts by five 
ligaments, fom: of which are peritoneal 
folds, and one is the remnant cord resulting 
from the obliteration of the unbilical vein 
within the abdomen. These attachments 
Vv'ill be more fully described with the peri- 
toneal tunic. 

The external aspect of the liver is smooth, 
being convex superiorly and concave interior- 
ly, broad posteriorly, and sharp anteriorly. 
It has a granular appearance, and a very 
superficial inspection clearly shows that it is 
composed of lobules, about the size of a 
pin's head. 

The hepatic substance is irregularly 
divided into numerous segments by fissures, 
which either extend through the gland from 
side to side, or are mere grooves of more 
or less depth. The different segments of 



115- 



ANATOMY AND PHYSIOLOGY CT 



the gland or lobes are three principal ones 
— right, middle, and left — to which smaller 
ones are appended. 

The right lobe is the largest of the three, 
situated in the right hypochondrium, being 
thickest posteriorly and sharp anteriorly. 
The supero-posterior part of the right lobe 
is marked by a depression, for the adapta- 
tion of the anterior part of the right kidney. 
At the superior part of the right lobe is an 
excavation for the vena cava, which extends 
from behind forward, and marks off the 
division between the right and middle lobe. 
The vena cava is here more or less imbed- 
ded in the substance of the right lobe, but, 
generally speaking, it is superficial in the 
horse, and only an imperfect channel is 
formed for it. 

Projecting from the inferior surface and 
posterior part of the right lobe, is the lobulus 
spigelii, which is of considerable size, being 
broad posteriorly, and attached by its 
superior and left border, so that it projects 
anteriorly and narrows ; its apex gradually 
tapers, and has been capriciously designated, 
by the lovers of a quintuple hepatic arrange- 
ment, lobulus caudatus. 

The middle lobe of the liver is the smal- 
lest of the three; it is crossed on its inferior 
surface by the transverse fissure or porta of 
the liver, at which the vessels and ducts 
enter into and issue from the gland. The 
middle lobe in the horse is divided at its 
anterior part into five or six portions, and 
Mr. Percivall, in his Anatomy of the Horse, 
at page 259, has termed it the lobulus 
scissatus. It is traversed antero-posteriorly 
by a channel for the remnant of the um- 
bilical vein, which eventually joins the vena 
porta. 

The left lobe is the thinnest of the three, 
but occupies an intermediate position in 
length and breadth. It is very thin at its 
left margin, and gradually thickens pos- 
teriorly. At its posterior and left side is 
a depression, in which the oesophagus rests. 
Sometimes the left lobe is divided into two 
at its anterior part ; at others it is single. 

The superior surface of the liver is convex, 
and in contact with the pillars and expanded 



portion of the diaphragm. The right as 
well as the Spigelian lobes, are in relation 
posteriorly with the right kidney and right 
supra-renal capsule, inferiorly with the head 
of the pancreas, duodenum, and transverse 
colon. The middle lobe is related inferiorly 
to the pancreas, but partially separated from 
it by the vena portse. It also suspends the 
duodenum, and its left edge is loose and in 
close proximity to the flexures of the colon. 
The left lobe is related posteriorly to the 
CEsophagus, and inferiorly to the left end of 
the stomach. The pancreas also stretches 
across its posterior part, partially separating 
it from the transverse colon. 

The liver receives an incomplete covering 
of peritoneum. The latter, reflected from 
the diaphragm on to the concave surface of 
the midcUe lobe of the liver, forms a double 
membranous layer, known, in accordance 
with its shape, as the falsiform ligament, 
and holding in its free and concave margin 
the round ligament, the representative of a 
foetal structure, the umbilical vein. Fur- 
thermore, the liver is provided with a coro- 
nary ligament, that surrounds the foramen 
dextrum of the diaphragm, through which 
the vena cava passes. The lateral ligaments 
are distinguished as right and left; they 
connect each lateral lobe to the diaphragm. 

The only connections of the liver that 
remain to be mentioned are the stomach, 
duodenum, transverse colon, and pancreas 
to its inferior surface, and the right kid- 
ney to the posterior part of the right lobe. 

Dissecting off the serous tunic, it is found 
connected with the biliary surface by cel- 
lular tissue, continuous at the porta with the 
so-called capsule of Glisson. The latter 
extends into the liver as a common sheath 
to blood vessels, nerves, lymphatics, and 
biliary ducts. 

To proceed with further description of 
the liver w'ould be useless, unless first ex- 
amining the blood vessels and ducts in that 
part of their course which is external to the 
organ. The hepatic artery is quite subor- 
dinate in size, considering the magnitude 
of the organ and amount of its secretion. 
It is a branch of the cceliac axis, at first in 



Tnii i:oRSE. 



m 



contact with the pancreas, and then be- 
tween the folds of the gastro-liepatic omen- 
tum, and it r.-aciics the porta on the left 
side of liie portal vein. After jriving olV 
pancreatic and duodenal l)ranches, it di- 
vides into two, a ri^ht and a left one. The 
ri£;lit, the largest and somewhat the longest, 
penetrates into the right lobe, giving ofi' 
collateral branches, first to the middle and 
then to the right lobe itself. The left is the 
smallest division, and is distributed to the 
lobe corresponding to it in position, and also 
to the middle one. 

The liver is exceptional for having, be- 
sides an artery, another afferent vessel — a 
vein, known as the portal vein, formed by 
the splenic, which also receives the gastric 
and mesenteries, meeting each other at the 
same spot near the posterior part of the 
pancreas. From its origin, the portal vein 
takes an obli(]ue course from left to right 
through the pancreas, and being surrounded 
by nerves, it reaches the porta of the liver, 
and here divides into three principal 
branches, one for each lobe. 

At the porta we also see the biliary duct 
coming out, formed by the union of several 
branches, corresponding in number to the 
ramification of the blood-vessels. This 
duct passes through the gastro-hepatic 
omentum, meeting the pancreatic duct at 
almost a right angle, and with it opening 
into the duodenum about live or six inches 
from the pylorus. 

Having thus far considered the main 
vessels, we may examine further the inter- 
nal structure of the liver. At the porta 
the branches of the vessels and ducts are 
associated together, and surroitnded by cel- 
lular tissue, which sheaths grooves or canals, 
cut in various directions in the substance of 
the organ. These are the portal canals, 
and the cellular tissue in question is Glis- 
son's capsule. 

The vessels and ducts ramifying on the 
sheath acquire the name of vaginal branches, 
and, as they are traced between the lobules, 
they are termed interlobular. Here the un- 
assisted eye ceases to take cognizance of 
their further relation ; but, with careful dis- 
is 



section, and a common pocket lens, they 
may be traced to the lobules, which they 
enter; and the blood of the hepatic artery 
and portal vein is emptied into a common 
set of vessels, the hepatic vein. The rela- 
tion of these vessels in the lobules may be 
seen on the surface in a good injected speci- 
men of liver, where the hepatic veins have 
been injected one color, and the other ves- 
sels difiercntly. By this means the centre 
of the lobule is colored with the injection 
thrown into the hepatic veins, and the cir- 
cumference with that of the portal vein. 

The hepatic veins issuing from the lo- 
bules cross the structure of the liver in sep- 
arate grooves, formed by the coalescence of 
the hepatic particles, so that their base is in 
contact with the veins, and hence the name 
of the latter is that of the sub-lobular he- 
patic veins. These empty into the posterior 
cava by several orifices, as well as by two 
larger ones, guarded by semi-lunar valves, 
situated just at the foramen dextrum of the 
diaphragm. 

In addition to the blood-vessels and ducts 
of the liver, it is supplied with nerves from 
the solar plexus, which ramify with the ves- 
sels. 

The lymphatics of the liver are abundant, 
and arranged, like in other organs, as a su- 
perficial and deep set, which inosculate 
freely in the substance of the organ, and, 
uniting to form several branches, they issue 
from the porta of the liver, passing through 
some lymphatic glands situated round the 
fissure, and from this they advance to the 
receptaculum chyli. 

PANCREAS. 

The pancreas is a compound vesicular or 
racemose gland, being much of the same 
nature as the salivary glands. 

The pancreas occupies the interval be- 
tween the layers of the transverse meso- 
colon, along the upper surface of the trans- 
verse colon. 

Its attachments are merely cellular, with 
the exception of the pancreatic duct, which 
attaches it pretty closely to the duodenum. 

The pancreas is spoken of as having a 



114 



ANATOMY AND PHYSIOLOGY OF 



body, a head, and a tail. The body of the 
pancreas is that part stretched across the 
middle lobe, while the head i^^ lo)i,n;itudinally 
extended, being almost parallel to the vena 
porta, and situated bek)W and to the right 
of that vessel. The head is broad ante- 
riorly and rather narrow posteriorly, and 
continuous from below upward, and from 
right to left, then from behind foi-ward, 
to gain attachment to the body, so as to 
form a ring for the passage of the vena 
porta. The part to the left of this vein is 
termed the tail of the pancreas. 

The jiancreas is related by its superior 
surface to the right, left, and Spigelian 
lobes of the liver, also to the vena cava and 
aorta, which separate it from the phrenic 
crura. The posterior part of the head of 
the ]>ancreas is in relation with the right 
stapra-renal body. The tail of the pancreas 
is stretched transversely to the branches of 
the coelic axis, and attached to the left 
kidney by loose cellular tissue. The in- 
ferior surface is in contact with the trans- 
verse colon. 

On examining carefully the structure of 
the gland, it is found to consist of clusters 
of cells, from which duets arise, and these 
unite to form a main trunk, that is trace- 
able back to the tail of the pancreas, in- 
creasing in size till it reaches the anterior 
extremity of the head, where it pierces the 
duodenum together with the hepatic duct. 
Besides these clusters of cells and ducts, 
the gland contains connecting cellular 
tissue. 

The pancreas is supplied with arterial 
blood by branches from the three divisions 
of the coeUc axis, as well as from the an- 
terior mesenteric. 

The pancreatic veins empty themselves 
into the splenic. 

The nerves are derived from the solar 
plexus, and the lymphatics of the pancreas, 
on issuing from the glandular substance, 
may be traced to the common reservoir of 
chyle and lymph. 

GK.MTO UUINARV APPARATUS. 

Having already described the intra-abdo- 



minal portion of the alimentary canal, and 
its accessories, I proceed to the considera- 
tion of that portion of the genito-urinary 
apparatus as contained within the abdomen, 
in the widest acceptation of the latter 
term. By this I ntean the kidneys, and 
with them, for anatomical convenience, I 
classify the supra-renal capsules, then the 
ureters, bladder, membranous portion of 
the urethra, vasa deferentia, vesiculEB semi- 
nales, prostate and Cowper's glands, with 
which I shall conclude. 



KIDNEYS. 



The kidneys are a pair of glands, whose 
function it is to secrete urine. They are 
distinguished as right and left, being both 
situated in the lumbar region ; but, so far 
as concerns their topographical anatomy, 
notwithstanding their similarity in position, 
they need separate notice. 

The right kidney is more anteriorly situ- 
ated than the left, coming in contact with 
the posterior part of the right lobe of the 
liver, to which it is attached. It is also 
fixed to the abdominal parietes by peri- 
toneum, and to the spine by blood-vessels. 

Its shape is that of a bent ovoid, being 
more symmetrical than the left. It has two 
sttrfaces and two borders. 

Though differing in these marked general 
characters, the kidneys resemble each other 
in several equally obvious points of their 
general anatomy. Both kidneys have a 
peritoneal and an albugincous coat, both 
have an excretory duct, vessels and nerves, 
with a structure also equal in the two, con- 
stituting the bulk of the organ. Exter- 
nally to the peritoneal tunic is a more or 
less thick stratum of fat, which is more 
abundant in old than in young animals, 
when in a state of obesity. 

The peritoneal covering of the kidneys 
is incomplete, especially that of the right 
one, whose inferior surface and convex 
border are the only parts coated by it. The 
left kidney is also covered on its superior 
surface to a considerable extent, sometimes 
more and sometimes less. The attachments 
which each organ contracts through the 



THE HORSE. 



IIS 



modinm of this serous investment have al- 
ready been described. 

The albugineous tunic is fibrous, and 
partly sub-seroiis. It fonns a distinct cap- 
sule, attached to the substance of tlie organ 
by fibrous prolongations, which are iu some 
parts arranged in pits and depressions, so 
as to mark out divisions on the surface of 
the kidney. In addition to this, the albu- 
gineous coat surrounds the vessels and 
ureter at. the hilus, and enters the substance 
of the organ. 

On cutting the kidney horizontally from 
the convex to the concave border, there are 
three different parts brought into view, to 
be taken into consideration. Firstly, a 
dark conteur, of about half an inch or more 
in thickness, being generally less at the ex- 
treme ends of the kidney than at its middle, 
whicli completely encircles the central part 
of the gland, and is termed the cortical 
structure, from its being most external. 
This part of the kidney has somewhat a 
granular aspect, and, when the vessels are 
full of blood or injection, they appear more 
or less arborescent, and clustered at innu- 
merable minute but visible spots, to form 
the Malpighian tufts. Next to this is a 
lighter colored material, rather ash-colored, 
but having a reddish hue, termed the me- 
dullary substance. This term is not given 
to it from the fact that it is medullary in 
consistence, but used in the metaphorical 
sense of being internally or centrally situ- 
ated. 

Approaching still nearer to the concave 
border of the kidney, is a funnel-shaped 
cavity, with its apex towards the hilus, and 
the base bounded by the medullary sub- 
stance, which is the pelvis. The apex is 
tubular, and continuous wath the ureter, 
of which the cavity is but an expansion. 

The walls of the cavity are lined by a 
mucop.s membrane, which is loosely applied 
to the medullary substance, and thrown 
into folds, taking a radiated direction from 
the mouth of the lu-eter. Opposite the 
apex of the pelvis, the membrane is adher- 
ent to a prominent border of the medullary 
substance, concave from before backward, 



but convex from above downward, and is 
pierced by foramina, into which the fining 
membrane of the pelvis extends, so as to 
form the uriniferous tubes. On dissecting 
carefully away the mucous membranes of 
the pelvis, we reach to the fibrous tunic, 
which is not continuous on the medullary 
ridge, but merely attached to its sides, so 
as to increase the length of the boundaries 
of the cavity. 

The ureter arising from this dilatation is 
continuous outward toward the spine, and 
then backward, being related superiorly, 
as it issues from the hilus, with the renal 
vein ; and then crossing the posterior part 
of the kidney at its inferior surface, it gets 
between the peritoneum and psoas muscles, 
and is then traceable back to the bladder, 
into which it opens. 

The renal arteries, one for each kidney, 
arise at almost right angles from the aorta, 
after the latter has given off the anterior 
mesenteric. The right one is more ante- 
riorly situated, and is longer than the left 
one. After each renal artery has given off 
a branch or more to the supra-renal cap- 
sule of the same side, it divides, on reach- 
ing the hilus, into a variable number of 
branches, usually eight or ten, which pierce 
the kidney at different parts of the hilus, 
whilst a few branches proceed along the 
surface, supplying the capsule, and then 
also piercing the organ. The arterial 
branches entering the kidney have a de- 
finite aiTangement, forming a kind of arch 
superiorly to the pelvis, from which second- 
ary divisions emanate and pierce the organ 
in all directions, so as to reach the cortical 
substance, abruptly dividing into numer- 
ous branches, which eventually subdivide 
to form capiUaries. By this it is evident 
that the cortical substance is more vas- 
cular than the medullary; indeed the latter 
is very scantily suppfied with arterial 
blood. 

From the arterial terminations the venous 
origins occur, and these unite to form 
branches, having a similar arrangement as 
the arteries ; only as they reach the pelvis 
almost opposite the apex, they meet tc 



116 



ANATOMY AND PHYSIOLOGY OF 



form a wide, capacious trunlc, the renal 
vein. This is supplied with valves, not all 
of which are perfect. At the opening of 
each renal vein into the cava is a semi- 
lunar (la;), overlapping the posterior part. 

The nerves of kidneys are numerous, 
and derived from the renal plexuses of the 
sym|)athetic ; they accompany the vessels 
with which they penetrate their respective 
organs. 

Lym))hatics may be seen issuing from 
the hilus of the kidney ; they enter some 
lymphatic glands there situate, and then 
convey the lymph into the receptaculum 
chyll. 

SLPRA RENAL CAPSULES. 

These bodies, also called capsvilas supra- 
renales, seu atrabilarias, are two in num- 
ber, and belong to the class vascular 
glands, whose office is very indefinitely 
known. 

They arc situated one on each side of 
the spine, across the direction of the renal 
vessels. Their attachments are cH'ected by 
vessels, as well as by the peritoneum, on 
their inferior surface, connecting them to 
the corresponding kidney and around to the 
spine. 

The shape of the supra-renal bodies is 
muoli the same on either side, being that 
of a slightly bent ellipsis. They vary 
from three to four inches in length, antl 
from one and a half to two inches in 
breadth. 

Their concave border corresponds to the 
renal vessels, as well as to the anterior 
mesenteric arteries. The convex border is 
in contact with the inner margin of the 
liidney. The anterior extremity of the 
right one is in connection with the right 
liepatic lobe, whilst its inferior surface is 
in connection with the commencement of 
the colon. The left supra-renal capsule is 
related anteriorly to the |)ancreas, and infe- 
riorly to the transverse colon. 

The peritoneal coat of the supra-renal 
capsules is merely confined to their inlVrior 
surface. The proper substance of the 
organ is enclosed in a fibrous or albugiae- 



ous coat, which forms a distinct covering 
externally, and becomes continuous as 
sheaths to vessels internally. 

On cutting horizontally across a supra- 
renal capsule, it is found to consist of an 
outer cortical and an internal medullary 
substance. The cortical substance is a 
brownish yellow, due to fat contained in 
vesicles, which, according to Professor Hein- 
rich Frey, are smaller toward the surface 
than more internally. The medullary sub- 
stance has a greyish aspect, and vessels are 
apparent in it, as also a yellow tinge, due, 
according to the above-named author, to 
similar vesicles, as in the cortical substance, 
only much scantier in fat. 

The arteries of the supra-renal capsules 
are offsets of the rcnalsand anterior mesen- 
teric, as well as of the aorta, but very 
variable in number and origin. They are, 
however, always abundant, and enter the 
organ princijially at its concave border. 

The veins are larger than the arteries, and 
pour their contents on the left into the renal 
vein, and into the vena cava on the right. 

The nerves of the supra-renal capsules 
are very abundant, and derived from the 
renal plexus. Professor Frey states, that 
in the horse, gangloin corpuscles constitute 
one of the structural elements of the nervous 
tissue in this situation. 

URETERS. 

The ureters, one to each kidney, are con- 
duits between the kidneys and the bladder, 
for the passage of urine. Their caliber is 
various, being about one-third of an inch 
broad, but getting narrower posteriorly. 

As the ureters issue from the kidneys, 
they converge towards the spine; then pro- 
ceed suddenly backward, till they reach the 
brim of the pelvis, having thus greatly 
diverged ; here they converge again, passing 
downward and backward to reach the sides 
of the body of the bladder, which they 
pierce. 

In their course, the ureters are attached to 

the kidney and psoas parvus by loose cellu- 

i lar tissue, and by the peritoneum, which 

I suspends them, by being stretched across 



THE HORSE. 



117 



their inferior surface. After the ureters have 
crossed the spermatic and iliac vessels, they 
are received within a fold of peritoneum, 
constituting the false ligaments of the 
bladder. 

They pierce the muscular coat of the 
bladder at a distance of about three inches 
from each other, if the viscus be distended. 
They pass betvi'een the muscular and mucous 
coats for about an inch, being somewhat 
diminished in caliber, when they suddenly 
open into the cavity by an elliptical orifice, 
.so that if the bladder be distended, the sides 
of the orifice are stretched, and thus closed. 

The ureters are externally covered by a 
celluto-muscular coat, consisting of a cellu- 
lar tissue, with muscular fibres arranged, 
partly longitudinally and partly circularly, 
the latter being most internally situated. 
The ureters are internally lined by mucous 
membrane, continuous anteriorly with the 
renal pelvis, and posteriorly with the vesical 
lining. 

The membrane is loosely attached to the 
outer coat, and thrown into longitudinal 
efl'aceable folds. 

ni.ADDI'.R. 

The bladder is a dilatable musculo-mem- 
branous viscus, destined for the temporary 
retention of urine. It is situated during 
vacuity entirely within the pelvis, but when 
distended, even moderately, its fundus en- 
croaches on the proper abdominal space. 

The bladder is held in situation by the 
peritoneum coming ofl' from the rectum and 
sides of the j>ehis, so as to form a serous 
fold, which also encloses the vasa deferentia 
and vesiculcB semijiales. Besides this, the 
bladder is supplied with true ligaments, as 
well as bounded posteriorly through the in- 
tervention of the urethra. 

The shape of the bladder is pyriform, 
approaching, however, to a sphere when 
empty or partially distended- 

It presents for consideration a projecting 
anterior portion or fundus, a middle part or 
body, and a posterior one, or neck. The 
fundus is globular and regular, having fixed 
at its anterior part the two obliterated um- 



bilical arteries, and the remains of the 
urachus. The body has no precise limits, 
but may be considered as that portion on 
which the bulbous portions of the vasa- 
deferentia rest. It is circular, but if the 
bladder be much distended, it bends some- 
what backward and upward. The cervix 
vesicEB is the most constricted part of the 
organ, and marks the limit between the 
bladder and urethra. 

The bladder is related by its fundus to 
the iliac (le.xures of the colon, inferiorly to 
the pudic and ischial bones, superiorly to 
the ureters, vasa deferentia, vesiculse semi- 
nales, and middle part of the rectum. 

The bladder has three coats. The peri- 
toneal investment is merely a partial one, 
as it is rellected from the body on to the 
sides of the pelvis. It covers the superior 
surface almo.st completely, but its extent 
gradually decfines laterally and inferiorly. 
The attachments contracted by the perito- 
neum are termed false ones. Thus we 
have the two umbilical arteries, one on each 
side, enclosed by peritoneum, forming the 
two lateral false ligaments. Then the ves- 
tige of the urachus is similarly enveloped 
by peritoneum, and constitutes the anterior 
false ligament. The peritoneum coming 
off from the rectum on to the superior sur- 
face of the bladder, gives rise to a pouch, 
termed the recto-vesical pouch, or cul-de- 
sac, and laterally to the triangidar folds 
limiting the latter, known as the superior 
false ligaments. Behind the peritoneal re- 
(lection the bladder is attached to the rec- 
tum and pelvic parietes, by a continuation 
of the pelvic fascia;, which, leaving the 
inferior surface of the pelvis at the symphi- 
sis pubis, comes on to the bladder, forming 
the inferior true ligaments of the latter ; the 
fascia is then continuous on to the rectum, 
blending with the cellular coat. The pelvic 
fascia is also traced on to the prostate and 
sides of the bladder, from the posterior part 
of the obturator forameii, constituting the 
lateral true ligaments- 

Beneath this fibro-serous coat are muscu- 
lar fibres, arranged hi a peculiar manner. 
There is an outer longitudinal set, traceable 



118 



ANATOMY AND PHYSIOLOGY OF 



from the cervix forward toward the body, 
where the fibres diverge and become oblique, 
and some even circular ; thi.s layer is prin- 
cipally developed posteriorly. The inner or 
circular layer is not arranged in concentric 
rings ; but its fibres, beginning at the fund- 
us, appear to arise from various centres on 
the surface, and to be taking a direction 
more or less cm-ved in diflerent parts, so as 
to get transversely to the long axis of the 
viscus, and thus from the inner side have a 
circular appearance. These fibres are more 
decidedly circular at the neclc, and act some- 
what like a sphincter. Some of the deeper 
fibres at the neck of the bladder extend for- 
ward to each orifice of the ureter, marking 
the limit of the vesical trigon, whose office 
must be that of approaching the lips of the 
elliptical apertures. 

The mucous coat of the bladder is gener- 
ally more or less coated with mucus and 
epithelium, which guard the structm-e from 
the corroding eil'ects of the secretion it has to 
come in contact with. It is thrown into 
numerous folds, taking various directions, 
but principally concentrical tow'ard the 
fundus, and longitudinal at the cervix, all 
of which are effaceable by distention of the 
bladder, and are most prominent when the 
latter is colla])scd. At the upper part of 
the urethral orifice of ihe bladder the mucous 
lining is smooth and free from folds, mark- 
ing out a triangular space, bounded ante- 
riorly by a line drawn between the orifices 
of the ureters, and laterally by two lines 
meeting at a spot at the superior part of 
the vesical orifice. This is termed the 
vesical trigon. At its apex is a projecting 
fold of mucous membrane or uvula vesicae, 
which seems to moderate the flow of urine 
into the urethra. 

The bladder is supplied with blood from 
the internal pudic, and its veins empty into 
the internal pudic vein. 

The nerves of the bladder are derived 
from the sympathetic, and partly from the 
two last sacral pairs which supply the neck. 

The lymphalics go to glands surrounding 
the origin of the iliac arteries, termed |)elvic 
lymphatic glands, from which vessels arise, 



communicating anteriorly with the recepta- 
culum chyli. 

URETHRA. 

This canal in the male subject is not only 
purposed for the passage of urine, but also 
transmits the products of the generative or- 
gans. It extends from the posterior part of 
the bladder to the glans penis; but we shall 
only occupy ourselves with a description of 
the intra-abdominal or pelvic portion, which 
terminates at the bulb of the penis or ischial 
arch. 

It is contiiuious anteriorly with the blad- 
der, attached to the rectum and sides of the 
pelvis by fascia and loose cellular tissue 
and muscles. 

The urethra is cylindrical, of considerable 
length, and its coats of no mean thickness. 
The pelvic portion of the urethra is gener- 
ally about three or four inches long, taking 
a direction backward and somewhat up- 
ward. 

It is related superiorly to the vesiculs 
seminales, middle lobe of the prostate, and 
posteriorly it comes in contact udth the rec- 
tum, but separated from it laterally by 
Cowper's glands. 

The first or prostatic portion of the ure- 
thra is purely membranous, strengthened by 
cellular tissue and a continuation of the 
fibres of the bladder, the circular ones in 
particular, which are tibundant anteriorly. 
The posterior two-lhuxls of the pelvic por- 
tion of the urethra are covered by a thick 
red muscular layer, which completely encir- 
cles it, with the exception of that part 
coming in contact with Cowper's glands. 
This muscle is continuous behind with the 
muscular fibres of the penis, which consti- 
tute the accelerator urincc. These fibres 
are externally mixed with longitudinal ones, 
a portion of which are merely the inner or 
inferior bundles of the retractor ani, whilst 
others are derived from the triangularis 
penis ; both of these muscles tend to fix the 
urethra. Postero-suj)eriorly the fibres en- 
circling the urethra are blended with the 
external anal s'phincter. The reh-actor penis, 
which gets attached to the sacral bone, is a 



THE HORSE. 



119 



white muscle also, affording fixity to the 
pelvic portion of the urethra. 

Beneath the muscular tunic of the urethra 
we llnd a loose cellular tissue, and pos- 
teriorly also some erectile structure continu- 
ous on to the jjenis. 

On slitting open the pelvic portion of the 
urethra, to examine its mucous membrane, 
we find ihat it is smooth, glistening, and 
thrown into longitudinal folds. It isantero- 
superiorly raised by the sub-mucous tissue 
into a permanent ridge, termed the crest of 
the urethra or verumontanum. This has a 
depression about its middle, and on each 
side are the elliptical orifices of the ejacula- 
tory ducts, surrounded by the openings of 
the prostatic ducts. Posteriorly and later- 
ally are little papillated projections, pierced 
by ducts emanating from Cowper's glands. 
These tubular processes are arranged in two 
parallel lines longitudinally to the course of 
the urethra. 

The pelvic portion of the urethra is sup- 
plied with blood from the internal pudic, 
and the veins empty into the vessel of the 
same name. Its nerves are derived from 
the two last sacral and accompanying sym- 
pathetic filaments. 

The lymphatics of the pelvic urethra are 
similarly disposed to those of the bladder. 

GENERATIVE ORGANS OF THE MALE. 

The last division of our subject is that 
of the abdominal generative organs, only a 
part of the generative system, and consist- 
ing in the vasa deferentia, vesiculEE semin- 
ales, prostate and Cowper's glands. 

VASA DEFERENTIA. 

There are tw^o vasa deferentia, one from 
each testicle, for the passage of semen to 
seminal reservoirs. 

The vas deferens arises from the posterior 
part of the epididymis or globus minor, 
passing through the inguinal canals, and 
reaching the abdomen ; it is situated in the 
sub-serous tissue, taking a course upward, 
backward, and inward, to reach the brim 
of the pelvis ; then, crossing the course of 



the ureters, it gets on to the bladder, where 
it is dilated, and forms the bulbous por- 
tion. 

Its attachments are serous and cellular to 
the various parts mentioned, whilst its pos- 
terior part is connected with the urethra. 

The vas deferens is related, in its course 
from the inguinal canal, to the bladder ; 
after it leaves the constituents of the cord, 
with the ])arietes of the abdomen ; crossing 
the under surface of the iliac vessels, and 
reaching the bladder on the inner side of 
the ureter ; also lying internally to the 
.seminal vesicles, and the terminating portion 
being covered by the prostate. 

The structure of the vas deferens is simi- 
lar throughout, with the exception of the 
greater thickness of its coats at the bulbous 
portion, being thinnest where it contributes 
to form the ejaculatory duct. 

This tube, of very various length, is con- 
stituted of an outer cellular investment, not 
requiring peculiar notice; of an intermediate 
contractile and elastic tunic ; and, as its 
name implies, is composed of muscular 
fibres and elastic tissue, arranged in two 
layers, i. e., an outer longitudinal and an in- 
ner circular one, which are easily perceived. 

The internal or mucous lining is thrown 
into longitudinal folds, in the narrow part 
of the duct ; but in the bulbous part it forms 
permanent rugae, taking various directions, 
so as to enclose irregular interspaces. 

The vas deferens is supplied with blood 
principally from the artery of the cord, al- 
though the epigastric furnishes a twig to it 
as well. The bulbous portion is supplied 
also by vessels of no small calibre from the 
iliacs. 

Its nerves are from the sympathetic, as 
well as from the second and third lumbar. 

VESICUL.E SEMINALES. 

The seminal vesicles are one on each side * 
of the bladder, and act as receptacles for 
the semen. 

Each seminal vesicle extends from behind 
forward, upward, and outward, being ex- 
ternal to the bulbous portion of the vas 



12C 



ANATOMY AND PHYSIOLOGY OF 



deferens. It is alfaclicd by peritoneum 
coming off from the sides of (lie pelvis and 
rectum on to the bladder. The posterior 
part is fi.xed by cellular tissue to the pros-i 
tate and neck of the bladder. 

The seminal vesicle is pyriform, being 
about three inches long and about an inch 
broad at its fundus, but more constricted at 
its neck. It is connected with the corres- 
ponding surface of the bladder and rectum, 
but partially separated from the latter by 
the prostate. 

The seminal vesicle has an incomplete 
investment of peritoneum, covering only 
the anterior part, whilst the prostatic portion 
is covered by an outer cellular coat. Be- 
neath this is an intermediate tunic, partly 
elastic and ])artly contractile. Lavocat 
describes this muscular coat as easily studied 
after maceration in dilute nitric acid, when 
it may be found to consist of an outer 
longitudinal and inner circular layer, most 
developed at the fundus, but very thin at 
the neck. 

The mucous membrane is plicated, the 
folds enclosing similar interspaces to those 
seen in the bulbous portion of the vas 
deferens. 

The vessels are supplied by the internal 
pudic, whilst the nerves are from the lesser 
splanchnic and two last sacral pairs. 

EJACULATORY DUCTS. 

Two in number, each being the common 
outlet to its corresponding vas-deferens 
and seminal vesicle, so that their contents 
may pass into the urethra by an elliptical 
orifice each side of the depression on the 
verumontanum. 

The relations of these ducts are simply 
to the prostate and urethra. When they 
reach the latter, they pass between the mus- 
cular and mucous coat for some little dis- 
' tance, so that at first sight they appear 
shorter than what they really arc. 

The structure of the ejaculatory ducts 
consists in an outer cellular and inner 
mucous lining, both of which are very 
thin. 



PROSTATE GLAND. 

The prostate belongs to the class of 
secreting glands. It is situated on the 
commencement of the urethra and termi- 
nation of the vpsiculs-seminales, being su- 
periorly related to the rectum. Its attach- 
ments to these jmrts are merely cellular, 
although it has some connection with the 
sides of the pelvis, rectum and bladder, 
through the intervention of the pelvic 
fascia. 

It is symmetrical in figure, and very vari- 
able in size, being quite rudimentary in 
aged geldings. It is of a gray color, 
knotty to the feel, although spongy in tex- 
ture. 

The prostate consists of a middle por- 
tion or body and two lateral lobes. The 
former is in contact with the cervix of the 
bladder and urethra, the latter with the 
ejaculatory ducts and seminal vesicles. 

This gland has a posterior convex and 
an anterior concave margin, whilst it is 
llattened from above downward, although 
from its connection with other parts it is 
rendered more or less convex from side to 
side. 

The prostate is composed of an exter- 
nal fibrous or cellular coat, which forms a 
complete covering to it. On cutting the 
gland in any direction, it is observed by 
the naked eye to have an areolar appear- 
ance, being a net-work of variously disposed 
fibres, the larger ones of which are found 
to be tubular. 

The prostate opens into the urethra 
around the orifices of the ejaculatory ducts 
by numerous apertures. 

It is supplied with blood from the pudic 
vessels, and its nerves are derived from the 
lesser splanchnic and two last sacral pairs. 

COVrPER's GLANDS. 

These also belong to the class of secreting 
glands, and have sometimes been called the 
lesser prostates. They are situated ante- 
riorly to the bulb of the penis on each 
side of the membranous portion of the 
urethra. 



EXPLANATION OF FIGURE XIII. 



THE SUPERFICLU. LAYER OF MUSCLES TAKEN FROM TlIE BODY OF THE HORSE, 
SO AS TO EXPOSE THOSE >USCT.FS "WHICH .VRK MORE DEEPLY SF^Vl'ED. 

THIC UEAV ASTI NECK. 

II. Ihicciiiator. 

b. Caninus. " 

c. Retractor labii intbridris. 

1, 1. Orbicularis oris. 

2, 2, '2. Coiiijjlcxifi major. 

3, 3. Tracheli) mastoick'iis. 

4, 4. Subscapulo hyoideus. 

5. Stemo raa.\illaris. 

f), (i. Steruo thyro-hyoideus. 

7. Jugular vein. 

8. Carotid aitcry, with the eighth paii', and sympathetic nerves. 

9. Trachea. 
10. Scalenus. 

THE FORE LIMBS. 

1. Scapido ulnarius. 

"2. Caput magnum of the triceps extensor bracliii. 

3. Caput medium of the same muscle. 

4. .Anconeus. 

a. Flexor brachii. 

6. Extensor metacarpi. 

7. Extensor petlis. 

8. Extensor ractacarpi obhquus. 

10. Flexor metacarpi extcrnus. 

11. Perforans and perforatus. 

12. Ulnarius accessorius. 

13 Flexor metacarpi internus. 

14. Flexor metacarjii mcdiu.';. 

15. Perforans aud perforatus. 
1().. Extensor metacarpi. 

B. B. Radius. 

THE TliUKK .^D BACK. 

A. Scapula. ■* 

F. F. Lougissinuis dorsi. 

G. Spinalis dorsi. 
a, a. Intercostals. 

6, b. Superficiahs costarum. 

c, e. Rectus abdominis. 

d, d. Transversalis abdominis. 

e, c, e. Obhquus internus abdominis. 

f, Hollow iu the longissimus dorsi, which part of the gluteus maximus once filled. 



EXPLANATION OF riOUnii XIII. CONTINITEP. 

lUUNCII AND ULND EXTRElinT. 

r. Ilium. 

D. Ischium. 

E. Tibia. 

1. Sacio sciatic ligament. 

2. Sphincter aiii. 

;>. Deprcs.sor cuccygis. 
4. Muscles of the tail. 
i>, 5. Triceps abdijctnr tibialis. 

6. Vastu.s e.xteriiiis. 

7. Rectus. 

H. Gastrociicmii muscles. 

9. I'lantaris. 

10. Extensor pcilis. 

11. I'eroneus. 

Tl'. Klexor peJis perforans. 

l:i. Insertion of the gracilis. 

H. Gastrocnemii muscles. 

].j. Vlexor pedis accessorius. 

10. Course of the perforans tendon, inside the os calcis of the hock join!. 

17. Insertion of the gastrocnemius externus into the point of the hock. 

IR, IS, Pophteus muscles. 

19. E.xtensor pedis. 



THE HOP.SE. 



121 



Cowper's glands are covered by the tri- 
angularis penis of eacli side : they are 
about the size of a filbert. 

Their structure, as apparent to the naked 
eye, is similar to that of the prostate in 
every respect, only the excretory ducts are 
11 



ten or twelve in number for each eland 
and linearly disposed on each side of the 
pelvic urethra. 

Cowper's glands are supplied with ves- 
sels and nerves from the same source as the 
prostate. 



ORGANS OF GENERATION. 



TK.STlCl.ns A,\D SCROTUM. 

The preparation of the seminal fluid is 
the office of two oval glandular bodies, called 
the testes or testicles ; they are suspended 
in a portion of the common integument, 
termed the scrotum, by means of the sper- 
matic cord and cremaster muscle. 

The scrotum is composed of the common 
integument, sub-cellular tissue, and elastis 
niii-scle, (the fibres of the latter run in a lon- 
gitndinal direction, from the cellular sub- 
stance of the sheath, to the base of the 
penis), and lastly the tunica vaginalis, 
which is a prolongation of the peritoneum. 

The testicle has a peritoneal covering, 
termed tunica vaginalis testes, and also 
another distinct tunic termed tunica albu- 
ginea. The substance of the testicle is ex- 
tremely vascular, and the ultimate branches 
of its spermatic arteries are collected into 
small bundles of fine convoluted vessels, 
separated from one another by septulEB, or 
membranous partitions. From these the 
vasa seminifera, or beginnings of excretory 
ducts, take their origin, and gradually unife 
to form a smaller number of canals of 
larger diameter, but exceedingly tortuous in 
their course. The testicle is also .supplied 
with nerves and absorbents, secretory and 
excretory vessels. 

.SPERMATIC CORD.* 

The spermatic cord, the substance by 
means of which the testicle is connected with 
the abdomen, and by means of which it is 
suspended within its scrotal cavity, is com- 
posed in the following manner: l.?t. It has 
four coverings ; there is immediately under- 
neath the skin the faschia superficialis ; next, 
the cremaster muscle ; thirdly, the tunica 

* rLTiivall. 



vaginalis; and lastly, the tunica vaginalis 
reflexa. Within the cavity formed by the 
vaginal tunic, it is that the intestine protrudes 
in inguinal and scrotal hernia ; the hernial 
coverings, consequently, exclusive of the sac, 
will be the fasciiia and cremaster muscle. 

2ndiy. The constituent parts of the cord 
itself, are : a. The arteries, which are two 
in number; the artery of the cord, a small 
branch of the external iliac, which ramifies 
and expands itself upon the cord ; and the 
spermatic artery, which, as soon as it 
reaches the internal ring, enters the inguinal 
canal, runs down the posterior part of the 
cord, growing tortuous as it descends, ser- 
pentines along the superior border of the 
testes, between it and the epididymis, winds 
round the anterior end of the gland, and 
lastly reaches the convex border, where it 
becomes extremely convoluted, and whereto 
its branches are principally distributed. In 
its descent it detaches small unimportant 
twigs to the adjacent parts ; and, as it ap- 
proaches the testicle, becomes surrounded 
by an assemblage of venous vessels, b. 
The veins accompany their corresponding 
arteries, and they indeed may be said to 
make up the principal bulk of the cord, 
for they are not only numerous, but large 
and flcxuous, and, as they approach the 
testicle, form a sort of plexus, which has got 
the name of corpus pamjnniforme : they 
return their blood into the posterior vena 
cava. c. The nkkves, w^hich are derived 
from the hypogastric plexus, also accom- 
pany the spermatic artery : they are small, 
but sufTiciently numerous. Thoitgh the 
testicle does not possess any very great sen- 
sibility in health, we may vouch for its 
being acutely sensitive in a state of disease. 
d. Absorbents exist, both large and numer- 
ous, in the cord. They are readily found 

(122) 



ANATOMY ANIl PI1VS:(;I.V(;V OF THK HORSE. 



123 



alongside of ihc vciuuis fninks; and not' 
infrequently may be tilled by introducing 
mercury into the spermatic artery, r. The 
VAS DEFKRKxs, tlioiigti u Constituent of the 
cord, takes at first a solitary course, remote 
from (he blood vessels. The duct issues 
from the summit of the head of the epidi- 
dymis, beginning in a series of eoinolu- 
tions gradually unwinding as it proceeds; 
it takes an of)li(|ue course nearly as high as 
the external ring, "where it joins the blood ■ 
vessels, and continues to accompany theui 
posteriorly througii the inguinal canal: at i 

the internal rinsr it leaves them, turn.s i 

. 1 

inward and ascends into the pelvis, where 

we fmd it creeping along the side of (he 
bladder infolded in ])eriloneum to get to the , 
cervix, crossiiisr under its course first the I 
umbilical artery and then the ureter; at 
length it terminates by rather a contracted 
orifice within the mouth of the duct of the 
vesicula semiiialis, just behind a little emi- 
nence in the urethra — the capnt ^a/inag'iiiix, 
about an inch posteriorly to the cervix of. 
the bladder. Within the inguinal passage [ 
the duct is accompanied by the artery of 
Ihe vas dcfcrciis,n long slender branch of the 
epigastric. Its canal, fiexuous until the 
<luet has joined the cord, but straight in its 
4-ubsequent course, is not uniform through- 
out in caliber ; the area of its tortuous part j 
is large, but as it becomes straight it grows 
contracted: having entered the pelvis, ii 
gradually enlarges again, and acquires un- 
usual volume in running along the side of tiie ' 
l)kidder; and the canal of the enlarged por- 
tion presents a reticulated structure, v.hich 
gives its exterior an irregular, tuberculated 
appearance : the most contracted part is 
tliat in union with the duct of the vesicula j 
semi'.iaiis, which is a comparatively small 
cvlindrical conduit. The parietes of the 
duct are so remarkably thick and tirm to ; 
the feel, that we distinguish it at once by 
the fingers from the other parts of the 1 
cord: they consist of two tunics; the ex- 
ternal one (in which its main thickness con- 
sists) is white, fibrous, and ai)proaches in 
appearance to cartilage ; the internal one is 
tiiin and fine in texture, rnuco-membranous 



in its nature, and here and there incloses a 
reticulated structure. The different consti- 
tuent parts of the cord are connected alto- 
gether by cellular substance, destitute of 
any fat ; and from the circumstance of the 
parts in general being more bulliy below the 
ring, the cord increases in breadth and 
thickness as it approaches the testicle. 

THE EPIDIDYMIS. 

Tlie epididymis is extended along the su- 
perior border of the testicle, upon which it 
rests, and to which it is connected by the 
tunica vaginalis refiexa. Its ends are bulky 
in comparison to its middle : that receiving 
the vasa efierentia, the smaller one, is the 
vajnit or g-lobus minor; the other, giving 
rise to the vas deferens, is tlie globus major, 
the part fan-iers call the nut. The interior 
of this appendage to the testicle exhibits a 
structure entirely vascular. The vasa ef- 
ferentia unite and re-unite until they form 
a single duct, of whose numberless and 
very remarkable convolutions the globus 
major is entirely constituted : thes-e tortu- 
osities (v.hich, when squeezed, freely emit 
semen) will admit of being unwound for a 
considerable extent, so as to li:ive the 
length of the duct calculated with very 
tolerable exactness from beginning to end, 
which has been found to amount to several 
yards. It is small at its formation, but grows 
imperceptibly larger in making its manifold 
windings and turnings, until at length it 
assumes the size of the vas deferens, m 
which it ends. Its various convolutions are 
connected together by cellular membrane, 
and are interspersed with a sparing supply 
of blood vessels. 

The course of the srincii is this: It is 
secreted by the capillary coils of the sper- 
matic artery, from which it is received by 
tiie tubili seminiferi : these tubes carry it 
into the rete, and the rete discharges it 
through the vasa eflercntia into the epididy- 
mis, from which it is conducted by the 
vas deferens into the urethra. 

Formation and Descent. — It is a singu- 
lar fact, that the organs whose structures 
wc have heen investigating, are originally 



124 



ANATOMY AND PHYSIOLOGY OF 



formed in a situation remote from that in 
which they are destined to carry on their 
functions ; " the colt has no testicles," is 
the common observation of the unim- 
formed on these matters ; and we know 
ourselves that the purse is without them, 
but we know, in addition, that they exist 
ready-formed within the abdomen, and that 
they will descend at a certain period of age 
into the proper receptacle, the scrotum. 
During the fcetal state we find the testicles 
more or less developed, tinged with a blush 
of red, lodged beneath the psoas muscles, 
in contact with the inferior borders of the 
kidneys, covered and retained in their situ- 
ations by peritoneum, and concealed by the 
intestines around them. Here they receive 
their arteries from the contiguous trunk — 
the posterior aorta ; the vasa deferentia 
run forward to them, and the cremasters 
likewise turn forward instead of backward; 
there being at this time no such thing as a 
spermatic cord. Thus placed, the testicle 
may be regarded as one of the glands of 
the abdomen ; indoed it has considerable 
similarity to the kidney — receiving its ves- 

souree, and 
a long duct backward into the 
cavity of the pelvis ; nor does there appear 
any conclusive reason why it should not 
perform the same office in that situation 
that it does in the scrotum, and particu- 
larly since it is known that in birds the tes- 
ticles remain within the abdomen during 
life. From the part where the blood ves- 
sels enter, we find growing a whitish sub- 
stance, extending backward, diminishing 
in breadth as it recedes, passing through 
the ring where the hilus of the cremaster 
may be traced upon it, and whence it is 
prolonged into the scrotum, growing nar- 
rower and narrower until it vanishes; this 
fiubstance, regarded by some simply as a 
ligament, was considered by Mr. Hunter 
as the gubernaculum or pilot, by means of 
which the testicle is directed in its passage 
from the abdomen into the scrotum. Quit- 
ting the spot where it has been formed and 
matured, the testicle gradually retroccdes, 
guided Vjy the gubernaculum, until it ar- 



sels from the same contiguous 

spending 



rives on the internal ring, which, at this 
time (like every other part of the parietes) 
is closed by peritoneum ; this temporary 
obstruction it overcomes by drawing the 
membrane down along with it through the 
ring, and carrying the pouch made thereby 
down into the scrotum ; the gubernaculum 
at the time undergoing a complete in- 
version. This accounts for the production 
of the tunica vaginalis, and explains how 
that membrane comes to be doubled or re- 
flected; the testicle, receiving originally (as 
an abdominal viscus) one close adherent 
peritoneal tunic, and acquiring another 
which forms a loose covering as it passes 
through the ring, must necessarily have 
two; and since both are derived from one 
and the same membrane, it follows that 
one must be a continuation of the other. 
These elongations of membrane, though 
everywhere in contact, are prevented from 
adhering together by a continual exhala- 
tion of the natural serous secretion. Any 
interval that might subsist between them, 
in course, communicates with the cavity of 
the abdomen, through the ring, a part that 
remains open through life : this, however, 
is not the case with man — in his body the 
communication is cut oif, after the testicles 
have descended, by a natural contraction 
and obliteration both of the ring and the 
inguinal passage. In many instances, one, 
in some few, both of the testicles, are 
known to have remained within the belly 
through life. As we are unacquainted with 
the immediate cause of their descent, so 
we are unable to give any rational explana- 
tion of this phenomenon. I have under- 
stood, that in many of these cases the 
glands have been found to be but imper- 
fectly developed : this, however, is not with- 
out exception. 

Period of Descent. — Most animals have 
their testicles within the scrotum at the 
period of birth. In the human fcetus they 
begin to move about the seventh month ; 
about the eighth they reach the groins ; and 
before birth they arrive in the scrotum. 
In the horse, they pass through the ring 
about the sixth or seventh month before 



THE HORSE. 



125 



birth, and are found within the scrotum at 
the period of parturition. In some cases, 
one testicle will not make its appearance 
for some time after the other ; and as the 
operation for castration is seldom long de- 
layed, this will account for the rig-s (as 
horses having but one testicle are called) 
with which we meet every now and then. 
Again, instances are not wanling in which 
one testicle has descended to tiie ring and 
there remained through life.* 

PENIS. 

The penis is composed of the two corpora 
cavernosa : head, or glans penis : corpus 
musculosum urethra, and the plexus veno- 
sus. The corporo cavernosa make up the 
bulk of tlie organ, they extend from the 
pelvis to the glans penis ; at the ischial arch 
they arc invested with fibres of the erectors 
penis, and are strengthened and confined to 
Ihc pubes by the suspensory ligaments. It 
is supplied with blood from a branch of 
the cbtnra+or artery by means of the inter- 
nal pudic artery. Its nerves are termed 
pudic. so also are the veins. 

The g-lans is composed of a soft spongy 
tissue, highly elastic and distensible, and 
remarkable as the seat of the plexus venosus 
penis: the latter structure presents itself in 
the form of a venous conglomeration, and 
in the erect state of the organ constitutes 
its chief bulk. 

URETHRA. 

The urethra is a muco-membranous canal 

* In a communication I have been favored with from 
Mr. Brcttargh (whicli I liave inserted in the second vol- 
ume of The Veterinarian), is contained the following 
information on this subject : " Colts are foaled with their 
testicles in the scrotum, wliich remain there (in ordinary 
eases) until the fifth or sixth month, when they are taken 
up between the internal and external abdominal rinj^s, 
and there remain until tlie cleventli, twelfth or thirteenth 
montli, all dejicudini; ii\>on tlie dejjree of kee)), as in some 
that arc well fed the testicles can at all times l)e found in 
the scrotum. Were the testicles drawn up into the abdo- 
men, they would be too large to pass tluxjugb the inter- 
nal abdominal ring at the time they are wanted to prepare 
for secretion ; wliich is occasionally the case, and at once 
accotmts for our meeting witli horses that are said to have 
but one stone. I have seen one instance where both were 
ir-inting in t!i£ scitjtura at four years old." 



averaging in length, in the unerected state 
forty-eight inches; it extends from the ante- 
rior part of the glans penis to the neck of 
the bladder ; its use is to afford a passage 
for the urine and seminal fluid. 

rE:«ALE ORGANS OF GENERATION. 

The vulva or pudendum comprises the 
prominence and fissure, commencing imme- 
diately beneath the anus, and extending 
downwards some four or five inches. The 
fissm*e is longest and most conspicuous in 
breeding mares. The space between the 
anus and vulva is termed perineum. The 
prominences on each side of Ihe vulva are 
called labia pudendia. They owe their 
bulk principally to muscular and fatty sub- 
stance, and cellular tissue. 

The coinmissures are the parts uniting the 
labia above and below. The superior or 
upper commissure is extended to a sharp 
angle, and joins the perineum; the lower 
portion is rounded off, and is bounded by a 
hollow, at the bottom of whicii is lodged 
the 

Clitoris. — Tills is brought into view im- 
mediately after staling: it bears a close 
comparison to the head of the male penis, 
and. Like the latter, is susceptible of sensual 
enjoyment. To the clitoris belong a pair 
of muscles named erectors clitordis. They 
lake their origin from the porineum. Their 
office is to erect that body, and ])rotrude it 
into the vagina in the act of coition. 

T/ic inlcnial pniis are the vagina, uterus, 
Fallopian tubes, fimbriae, and ovaria. Tiie 
vagina is a musculo-membranous canal, of 
large dimensions, extending from the vulva 
to the uterus or womb. 

It is situated within the pelvis, having 
the bladder below and the rectum above it, 
to both of which it has cellular attach- 
ments, in addition to the reciprocal connec- 
tion with the peritoneum. To the rectum 
it is closely and firmly attached by cellular 
membrane. 

The figure of the vagina, when it is dis- 
tended, is that of an oblong cylinder; but 
in the collapsed state, its sides are in con- 
tact, and it will vary its form according to 



12G 



ANATOMY AND PHYSIOLOGY OF 



the full or empty condition of the. bladder. 
The largest part of the canal is the poste- 
rior ; there it exceeds the dimensions of the 
bladder. 

The length of the canal is about eighteen 
inches. Its course is horizontal, aixl ratlier 
shows an inclination to the curve of the 
rectum. 

The vagina, at its commencement from 
the vulva, is much thicker in its walls than 
elsewhere ; in composition it is partly mus- 
cular and partly membranous. The orifice 
of it is clothed in that strong, red, circular, 
fleshy band, which forms the sphincter 
vagina; and the adjoining part of the canal 
is also encircled by some considerable fleshy 
covering, and thickly coated with muscular 
fibres. Farther forward than this the vagina 
is composed of membrane. 

The Blambrane of the Vag-iiia. — The part 
of which it is constituted is one of the 
mucus class, and one that possesses consid- 
erable density, extensibility, and resistance. 
Its exterior surface is rough. Its interior 
is smooth, and has a pale pinkish cast; 
unless the mare be under the venereal oes- 
trum, and then its redness is heightened, 
and its secretion augmented. In the ordin- 
ary state, this membrane is thrown into 
folds, larger in breeding mares than in others, 
technically called rugrr. 

Considerably in advance of the clitoris is 
an opening leading from the lower part of 
the canal, large enough to admit with ease 
any one of the fingers : this is the orifice of 
tlie meatus urinarius, or outlet of the blad- 
der : it is guarded by a doubling of the 
vaginal membrane, which hangs over it, and 
serves the purpose of a valve. 

The large and consj)icuous protuberance 
at the bottom of the vagina, is the mouth 
of (he uterus. 

The uterus, or womb, is a iiollow mus- 
culo-meniliranous organ, united to the ante- 
rior part of the vagina, and is destined for 
the reception of thefa-tus. We distinguish 
the uterus by the body, horns, neck, and 
mt)uth. The body is the oblong or cylin- 
drical part, gi'ov.-ing out of the anterior ))or- 
tioH of the vajjina, in the centre of which 



it is terminated internally by the os-uteri, 
or mouth of the womb ; it gives origin, in 
front, to the horns. This part lies wholly 
within the pelvis, between the bladder and 
rectum, and is entirely covered by peri- 
toneum. 

The cornua, or horns, rise from the body 
of the uterus, and diverge towards the loins. 
Their length and size will be much greater 
in breeding mares than in others. In figure 
they are cylindrical ; they bend upward in 
their course, and terminate in round extrem- 
ities, to which are loosely appended the 
ovaries, or testicles, through the medium of 
the Fallopian tubes. 

The cervix, or neck, of the uterus is the 
rugose portion, protruded back.vard into the 
cavity of the vagina, which has a flower- 
like appearance, and can only be seen in a 
virgin uterus in the undistended state ; dur- 
ing gestation it undergoes a remarkable 
change. 

Independently of its union ^vith the 
vagina, the uterus is confined in its place 
by two broad portions of peritoneum, 
which attach it to the sides of the pelvis, 
named the lateral ligaments of the uterus. 
During the period of gestation, the uterus 
experiences considerable extension. The 
Fallopian tubes are two trumpet-shaped 
canals, having a remarkable serpentine 
course; running within the folds of the 
ligamenta lata, from the extremities of the 
horns to the ovaries. 

The tube commences by an aperture in 
the cornu, having an elevated whitish mar- 
gin, which is scarcely large enough to admit 
a small silver probe : from this it proceeds 
forward, folded in peritoneum, and ex- 
tremely convoluted, until it reaches the 
ovary, to which it becomes attached ; it 
then begins to enlarge in its diameter, 
grows less convoluted, and serpentines along 
the lower side of the ovary; it afterwards 
ends in a fring.-d doubling of membrane. 

The internal membrane of the tubes is 
simili'.r to that of the uterus. 

The ovari, or female testicles, are two 
egg-sliaped bodies, situated farther forward 
than ihe Fallopian tubes, within the cavity 



THE HORSE. 



127 



of llic abdomen: ihey receive close cov- 
erings, and are loosely attached tn ihe 
spine. 

These bodies are about the size of wal- 
nuts. They are not regular oviform ; they 
have deep fissures on their sides ; they 
bear a resemblance, at first view, to the 
testicles and llieir ducts in the male. 

Internally, the ovaries are composed of a 
whitish spongy substance, in which are, in 
some instances, found little vesicles, con- 
■ taining a yellowish glairy fluid, in others 
one or more dark yellow or brownish sub- 
stances, named corpora lutea : the vesicles 
are the ova, which, from impregnation, re- 
ceive further development ; the corpora 
lutea denote the parts from which vesicles 
have burst, and consequently only exist in 
the ovaries of those mares whose organs 
have been engaged in the generative pro- 
cess. Prior to the age of sexual intercourse, 
these bodies are small and white ; but, as 
soon as the season of copulation is at hand, 
they grow large, redden externally, and 
present many yellow spots or streaks 
through their substance. 

Munimec, though unconnected wath the 
uterus, anomatically speaking, are in func- 
tion concurring to the same important end. 
The mammae, vulgarly called udder, are 
two flattened oval-shaped bodies, depend- 
ing, between the thighs, from the posterior 
and inferior part of the belly. In quadru- 
peds, with but few exceptions, this is the 
situation of the mammas. 

In virgin mares the udder is so small 
that there hardly appears to be any. In 
mares who have had foals, the udder re- 
mains prominent or pendulous, and has a 
flabby feel 



Toward the latter part of gestation, this 
part swells, and becomes distinctly visible. 
Within a few days of foaling, the udder 
grows turgid wdth mUli ; it does not, how- 
ever, acquire its full distention until the 
foal has drawn it for a few days, from 
which time it maintains its volume, witii 
little variation, during the period of suck- 
ling. Soon after the foal begins to forsake 
the teat, the secretion of milk diminishes, 
and is followed by a contraction of the 
bag, "which goes on gradually, until it has 
resumed nearly, or quite, its former flat- 
ness. 

The interior of the mamma; has a light 
yellow'ish aspect, and evidently possesses a 
lobulated structure, which is held together 
by a fine cellular tissue, interspersed wdth 
granules of fat. It is constituted of glan- 
dular masses, irregular in magnitude and 
form, and loosely connected one with 
another, each of which masses is composed 
of a number of lobules, closely compacted 
and united together. These insulated lob- 
ulous portions receive small arteries, from 
which the milk is secreted. The former, 
by repeatedly conjoining one with another, 
become at length several demonstrable 
canals, radiating from every part, and dilat- 
ing to hold the milk. 

When the udder becomes charged with 
milk, it flows into the teat and distends it. 
Suction is apparently an operation purely 
mechanical. The teat is seized and closely 
compressed by the lips of the foal ; and the 
imbibing effort which follows has a ten- 
dency to produce a vacuum, or raise the 
valve at the upper part of the teat, and the 
milk passes from the reservoirs into the 
mouth. 



PHYSIOLOGICAL CONSIDERATIONS. 



0.\ THE REPRODUCTION OF ORGANIZED 
BEINGS.* 

" If the changes which living beings un- 
dergo during the period of tiieir existence, 
and the termination of that existence by 
the separation of their elements at a period 
more or less remote from their first combina- 
tion, be regarded as distinguishing them in 
a striking and evident manner from the 
masses of inert matter which surround them, 
still more is their difference manifested in 
the series of processes which constitute the 
function of Reproduction. A very unneces- 
sary degree of mystery has been spread 
around the exercise of this function, not 
only by general inquirers, but by scientific 
physiologists. It has been regarded as a 
process never to be comprehended by man, 
of which the nature and the laws are alike 
inscrutable. A fair comparison of it, how- 
ever, with other functions, will show that it 
is not in reality less comprehensible or more 
recondite than any one of them; — that our 
acquaintance with each depends upon the 
facility with which it may be submitted to 
investigation ; — and that, if properly in- 
quired into by an extensive survey of the 
animated world, the real character of the 
process, its conditions, and its mode of oper- 
ation, may be understood as completely as 
those of any other vital phenomenon. 

" It may be considered as a fundamental 
truth of Physiological Science, that every 
living organism lias had its origin in a pre- 
existing organism. The doctrine of 'spon- 
taneous generation,' or the supposed origina- 
tion of organized structures de novo out of 
assemblages of inorganic particles, although 
at different times sustained with a consider- 

* Carpenter's Physiology. 



able show of argument, based on a specious 
array of facts, cannot now be said to have 
any claim whatever to be received as even 
a possible hypothesis ; all the facts on which 
it claimed to rest having either been them- 
selves disproved, or having been found satis- 
factory explicable on the general principle 
omne vivum ex ovo. Thus, the appearance 
of Animalcules in infusions of decaying 
organic matter, the springing-up of Fungi 
in spots to which it would not have been 
supposed that their germs could have been 
conveyed, the occurrence of Entozoa in the 
bodies of various animals into which it 
seemed almost beyond possibility that their 
eggs could have been introduced, with 
other facts of a like nature, may now be 
accounted for, without any violation of 
probability, by our increased knowledge of 
the mode in which these organisms are pro- 
pagated. Thus, it is now well ascertained 
that the germs of Fungi and of many kinds 
of Animalcules are diffused through the 
atmosphere, and are conveyed by its move- 
ments in every direction ; and that, if to de- 
composing substances of a kind that would 
otherwise have been most abundantly peo- 
pled by these organisms, such air only be 
allowed to have access as has been deprived 
of its organic germs by filtration (so to 
speak) through a red-hot tube or strong 
sulphuric acid, no living organisms will 
make their appearance in them ; whilst in 
a few hours after the exposure of the very 
same substances to ordinary atmospheric 
air, it has been found to be crowded with 
life.* And when it is borne in mind, in the 
case of the Entozoa, that the members of 



* See the experiments of Schulze, in the " Edinb. New 
Phil. Journal," 1837, p. 165. 

(128) 



ANATOMY AND PIIYSIOI.OGY OF THE HORSE. 



129 



(his class are remarkable for the immense 
iminber of eggs which most of them pro- 
duce, for the metamorphoses which many 
of thrtii are known to undergo, and for the 
varieties of form under which there is reason 
to suspect that the same germs may de- 
velop themselves, it becomes obvious that 
no adequate proof has yet been afforded 
that they have been, in any particular case, 
ofherwi.-;e than the products of a pre-existing 



living organism. 



This, again, is the con- 



clusion to which all the most general doc- 
trines of Physiology necessarily conduct us. 
For it is most certain that we know noth- 
ing of Vital Force, save as manifested 
through organized structures; whilst, on the 
other hand, the combination of inorganic 
matter into organized structures is one of 
the most characteristic operations of vital 
force ; hence it is scarcely conceivable that 
any operation of physical forces upon inor- 
ganic matter should evolve a living organ- 
ism. Nor is such a conception more feasi- 
ble, if it be admitted that vital force stands 
in such a relation to the physical forces, 
that we may regard the former as a mani- 
festation of the latter, when acting through 
organized structures ; since no vital force 
can be manifested (according to this view), 
and no organization can take place, except 
througli a pre-existing organism. 

" It may be further considered as an es- 
tablished physiological truth, that, when 
placed under circumstances favorable to 
its complete evolution, every germ will de- 
velop itself into the likeness of its parent; 
drawing into itself, and appropriating by 
its own assimilative and formative opera- 
tions, the nutrient materials supplied to it ; 
and repeating the entire series of phases 
through which its parent may have passed, 
however multiform these may be.* Now 
the germs of all tribes of plants and 
animals whatever bear an extremely close 
relation to each other in their earliest con- 
dition ; so that there is no appreciable dis- 

* Tliu apparent exceptions to this rule, wliieli liave liccn 
lirou;;lit to;;et!icr under the collective tcnn, " Alternation of 
Generations," will lie presently considered, and ■will be 
shown to be only exceptional when misinterpreted. 
17 



tinction amongst them, which would enable 
it to be determined whether a particular 
molecule is the germ of a Conferva or of 
an Oak, of a Zoophyte or of a Man. But 
let each be placed in the conditions it re- 
quires ; and a gradual evolution of the 
germ into a complex fabric will take place, 
the more general characters of the new or- 
ganism preceding the more special, as 
already explained. These conditions are 
not different in kind from those which are 
essential to the process of nutrition in the 
adult; for they consist, on the one hand, in 
a due supply of aliment in the condition 
in which it can be appropriated ; and, on 
the other hand, in the operation of certain 
external agencies, especially heat, which 
seems to supply the force requisite for the 
developmental process. Now, although we 
may not be able to discern any such osten- 
sible differences in the germs of different 
orders of living beings as can enable us to 
discriminate them from each other, yet, see- 
ing so marked a diversity in their operations 
under circumstances essentially the same, 
we cannot do otherwise than attribute to 
them distinct properties ; and it will be con- 
venient to adopt the phrase germinal capa- 
city as a comprehensive expression of that 
peculiar endowment, in virtue of which 
each geni. Jevelopes itself into a structure 
of its own specific type, when the requisite 
forces are brought to bear upon it, and the 
requisite materials are supplied to it.* 
Thus, then, every act of development 
may be considered as due to the force sup- 
plied by heat or some other physical agency, 
which, operating through the organic germ, 
exerts itself as formative power ; whilst the 
mode in which it takes eilect is dependent 

« This term is preferred to that of "germ-power " sug- 
jrested by Mr. Paget, because the latter seems to imply 
that the force of development exists in the germ itself. 
Now, if this were true, not only must the whole formative 
power of the adult have been possessed by its first cell- 
germ, but the whole formative power of all the beings 
simultaneously belonging to any one race, must have been 
concentrated in the first cell-gei in of their iiriginal proge- 
nitor. This seems a ralmlh ail <ilisiiriliiin of any such 
doctrine ; and we are driven back on the .issumpiioii 
(which all observation confirms), that the force of develop- 
ment is derived from external agencies. 



130 



ANATOMY AND ri[VrtIOLOt;V OF 



upon the properties or endowments of the 
substances througli which it acts, namely, 
the germ on the one hand, the alimentary 
materials on the other, — just as an electric 
current, transmitted through the diHerent 
nerves of sense, produces the sensory im- 
pressions which are characteristic of each 
respectively; or, as the same current trans- 
mitted through one form of inorganic 
matter produces light and iieat, through 
another, chemical change, or tlu'ough an- 
other, magnetism. 

" In the development of any living being, 
therefore, from its primordial germ, we have 
three sets of conditions to study — namely, 
first, the ))hysical forces which are in opera- 
tion; seco)ul, the properties of the germ, 
which these forces call into activity; and 
tMrd, the properties of the alimentary mate- 
rials which are incorporated in the organism 
during its development. There is evidence 
that each of these may have a considerable 
inlluence on the result; but in the higher 
organisms it would seem that the second is 
more dominant than it is in the lower. For 
among many of the lower tribes, both of 
plants and animals, there is reason to be- 
lieve that the range of departure from the 
characters of its parent, which the organism 
may present, is considerably greater than 
that of the higher ; and that this is chiefly 
due to the external conditions under which 
it has been developed. The forms of a 
number of species of the lower Fungi, for 
example, appear to be in a great part de- 
pendent on the nature of their aliment ; so 
among the Entozoa, there seems strong 
reason to believe that those of the Cystic 
order are only Cestoidea, that are prevented 
by the circumstances under which they exist 
from attaining their full development; and 
the |)roduc'iion of a fertile 'queen' or of an 
imperfect 'worker,' among the hive-bees, 
appears to be entirely determined by the 
food v.itii which the larva is snppiied. No 
such variations have been observed among 
the higher classes; in wliicli it would seem 
as if the form attained by each germ is 
more rigidly determined by its own endow- 
ments ; a modilication in the other con- 



ditions, which in the lower tribes would 
considerably affect the result, being in them 
unproductive of any corresponding change. 
For, if such modification be considerable, 
the organism is unable to adapt itself to it, 
and consequently either perishes or is imper- 
fectly developed ; whilst, if it be less potent, 
it produces no obvious effect. Thus, a de- 
ficiency of food in the growing state of the 
higher animal will necessarily prevent the 
attaiimient of the full size ; but it will not 
exert that influence on the relative develop- 
ment of different parts that it does among 
plants, in which it favors the production of 
flowers and fruit in place of leaves, or that 
it seems to exercise in several parallel cases 
among animals. So, again, a deficiency of 
heat may slightly retard the development of 
the chick ; but, if the egg be allowed to re- 
main long without the requisite warmth, 
the embryo dies, instead of passing into a 
state of inactivity, like that of reptiles or 
insects. The extent, indeed, to which these 
external conditions may affect the develop- 
ment of the inferior organisms, must not be 
in the least judged of by that to which 
their operation is restricted in the higher ; 
and it is probable that we have yet much to 
learn on the subject. At present, it may 
be stated as a problem for determination, 
whether, from a being of superior organiza- 
zation, loiccr forms of living structure, 
capable of maintaining an independent 
existence, and of propagating their kind, 
can ever originate, by an imperfect action 
of its formative powers. Various morbid 
growths, such as cancer cells, to which the 
higher organisms are liable, have been 
looked upon in this light ; these have cer- 
tainly a powerful vitality of their own, 
which enables them to increase and multi- 
ply at the expense of the organism which 
they infest; and they have also an energetic 
reproductive power, by which they can pro- 
pagate their kind, so as to transmit the 
disease to other organisms, or to remote 
parts of the same organism ; but such 
growths are not independent ; they cannot 
maintain their own existence, when de- 
tached from the organism in which they are 



TH1-: HORSE. 



131 



devclopt'd ; and they have not, therefore, 
the attribute of a separate indiindualitif. 
Various phenomena hereafter to be detailed, 
however, respecting the ' gemmiparous' 
production of living beings, when taken in 
connection with that just cited, seem to ren- 
der it by no means impossible that the in- 
dividualization may be more complete in 
other casefs, so that independent beings of a 
lower type maij possibly originate in a per- 
verted condition of the formative operations 
in the higher. But no satisfactory evidence 
has ever been aflbrded by experience, that 
such 'equivocal generation' has actually 
taken place; and its possibilily is here 
alluded to only as a contingency which it is 
light to keep in view. That no higher type 
has ever originated through an advance in 
developmental power, may be safely as- 
serted ; for, although various instances have 
been brought forward to justify the asser- 
tion that such is possible, yet these instances 
entirely fail to establish the analogy that is 
sought to be drawn from them." 

* Tims, the autlioi- of the " Vestiges of the Natural 
History of Creation " refers to the various modifications 
which have taken place in our cultivated I'hints and 
Domesticated Animals, in proof that such elevation is 
possible ; quite overlooking the fact that these external iu- 
(iucnces merely niodifff the development, without elevating 
it, and that these races, if left to themselves, speedily revert 
to their common specific type. And he adduces the 
phenomena of metamorphosis — the transformation of 
tlie worm-like larva into an insect, and of a lish-likc 
tadjiole into a frog — as giving some analogical sanction 
to the same doctrine; totally overlooking the fact, that 
these transfonnatioTis are only part of the ordinary develop- 
mental process, by which the complete f.irm of the species 
is evolved, insteail of being transitions from the jierfcctcd 
typo of one class to the perfected tyjic of one above it. 
So, again, he quotes the tninsfomiatiou of the worker- 
grub of the hive-bee into the fertile queen, as an example 
of a. similar advance; without regarding the circumstance 
that t'le woi'ker is physicatlii higher (according to hunutn 
ideas, at le.ist) than the queen, whose instincts appear 
limited to the peiformance of her sexual functions ; and 
that the utmost wliicli the fact is capable of ]iroving, is, 
that the same germ may be developed into two different 
forms, according to the circumstances of its early growih. 
It must always he borne in mind that the character of a 
species, to be complete, slioidd include all its fonus, per- 
fect and imperfect, moililied and unmodified ; since in this 
mode alone can that "capacity for variatiim " he deter- 
mined, which is so remarkable a I'eatuie in many cases, 
-ami is that which specially distinguishes the races of plants 
and animals that have been subjected to human iiilhicnic. | 



" The development power which each germ 
possesses, under the conditions just now 
detailed, is manifested, iiot merely in the 
tirst evolution of the germ into its com- 
plete specific type, but also in the main- 
tenance of its perfect form, and, within 
certain limits, by the reproduction of i)art.s 
that have been destroyed by injury or dis- 
ease. This reproduction, as Mr. Paget has 
pointed out,* dift'ers from the ordinary pro- 
cess of nutrition in this, — that ' in grave 
injuries and diseases, the parts that might 
serve as models for the new materials to be 
assimilated to, or as tissue-germs to develop 
new structures, are lost or spoiled ; and yet 
the eftt!cts of injury and disease are re- 
covered from, and the right specific form 
and composition are retained ; ' — and, 
again, ' that the reproduced parts are 
formed, not according to any )5resent model, 
but according to the appropriate specific 
form, and often with a more strikingly evi- 
dent design towards that form, as an end 
or purpose, than we can discern in the nat- 
ural con.struction of the body.' In the re- 
production of the leg of a fuLl-growa 
Salamander after amputation, which was 
observed to take place by Spallanzani, it is 
clear that, whilst the process was from the 
first of a nature essentially similar to that 
by which its original development took 
place, it tended to produce, not the leg of 
a larva, but that of an adult animal. Hence 
it is obvious that, through the whole of life, 
the formative processes are so directed as to 
maintain the pejfection of the organism, 
by keeping it up, so far as possible, to the 
model or archetvjje that is proper to the 
epoch of its life which it has attained. 
The amount of this regenerating power, 
however, varies greatly in different classes 
of organized beings, and at difl'erent stages 
of the existence of the same being ; and, as 
Mr. Paget has pointed out,| it seems t© 

In no instance has tliis variation tended to confusC the 
limits of well-ascertained species ; ii has merely increased 
our acquaintance witli the number of diversified forms intc 
which the same germ may dcvdope Itself. 

* " Lectures on Heproductiun and JJepair." 

' Loc cit. 



132 



AKATOMY AND PHYSIOLOGY OF 



bear an inverse ratio to tlie degree of devel- 
opment which has previously takrji place 
in each case. Thus, in the Hijdfa and 
other Zoophytes, it would appear (as in 
Plants) to be almost unlimited ; I'wr the de- 
velopment process in them is checked at 
such an early period, that both the form of 
the organism and the structure of its tissues 
retain the most simple type ; and by the 
subdivision of one individual, no fewer 
than fifty were produced by Trembly. In 
this, as probably in all the cases in which 
new individuals have been obtained by 
artificial subdivision, there is some natural 
tendency to their production by the vege- 
tative process of gemmation ; but this does 
not always manifest itself. It is a curious 
fact, that the first attempt at regeneration, 
in some of these cases, is not always com- 
plete ; but that successive efforts are made, 
each of which approximates more and 
more closely to the perfect type. This was 
well seen in one of Sir J. G. Dalyell's ex- 
periments ; for he observed that, having 
cloven the stem of a Tubularia (a Hydroid 
Zoophyte), after the natural fall of its head, 
an imperfect head Vv^as at first produced, 
which soon fell off and was succeeded by 
another more fully formed; this in its turn 
was succeeded by another ; and so on, until 
the fifth head was produced, which was as 
complete as the original. 

" As a general statement of the amount 
of this regenerating power, which exists in 
most of the different classes of animals, 
has been already given, it is unnecessary 
here to do more than allude to some of 
those facts which most strongly bear out 
the doctrine just laid down. Next to 
Zoophytes, there are no animals in which 
the regenerative power is known to be so 
strong as it is in the lower Articulata (as 
the Cestoid Entozoa, and the inferior An- 
nelida), and in the Planaria, which may 
perhaps be regard;'d as rather approximat- 
ing to the Molluscous type; and here, again, 
we see that a low gi'ade of gen(>ral devel- 
opment is favorable to its exercise, and that 
the spontaneous multiplication which occa- 
sionally lakes place in these animals by 



fission or gemmation, is only another form 
of the same process. In the higher forms 
of both these sub-kingdoms, as wc; no 
longer meet with multiplication by gemma- 
tion, so do we find that the re|Darative power 
is much more limited ; the only manifesta- 
tion of it among the fully-formed Arrack- 
nida and Crustacea being the reproduction 
of limbs, and the power of cfl'ecting even 
this being usually deficient in perfect In- 
sects. The inquiries of Mr. Newport, 
however, upon the reproductive powers of 
Myriapods and Insects, in ditTerent stages 
of their development,* confirm the general 
principle already stated ; for he has ascer- 
tained that in their larval condition, Insects 
can usually reproduce limbs orantenn^ ; and 
that Myriapods, whose highest development 
scarcely carries them beyond the larvte of 
perfect Insects, can regenerate limbs or an- 
tennsE, up to the time of their last moult, 
when, their normal development being com- 
pleted, their regenerative power seems en- 
tirely expended. The Phasmida; and some 
other insects of the order Orlhoptera retain a 
similar degree of this power in their perfect 
state; butthese are remarkable for the similar- 
ity of their larval and imago states, the latter 
being attained, as in Arachnida, by a direct 
course of development, without anything 
that can be called a ' metamorphosis.' Lit- 
tle is known of the regenerative power in 
the higher Mollusca ; but it has been 
affirmed that the head of the Snail may 
be reproduced after being cut off', provided 
the cephalic ganglion be not injured, and 
an ndeiiuate amount of heat be supplied. 
In Vertebrata, again, it is observable that 
the greatest reparative power is found 
among Batrachian Reptiles, whose devel- 
opment is altogether lower, and whose life 
is altogether more vegetative, than that of 
probably any other group in this sub-king- 
dom. In Fishes, it has been found that 
portions of the fins which have been lost 
by disease or accident are the only parts 
that arc reproduced. But in the Sala- 
mander, entire new legs, with perfect bones, 
nerves, muscles, etc., are reproduced after 

* " riiiloiiOijliifal TmusiitLiuua," 1844. 



THE HORSE. 



133 



loss or severe injury of th 
bers ; and in the Triton a perfect eye has 
been formed to replace one which had been 
removed. In the true Lizards, an imper- 
fect reproduction of the tail takes place, 
when a part of it has been broken off; but 
the newly-developed portion contains no 
perfect vertebrfp, its centre being occupied 
by a cartilaginous column, like that of the 
lowc.'^t Fishes. In the warm-blooded Ver- 
tebrata generally, as in Wan, the power of 
true reprodviction after loss or injury seems 
limited, as Mi'. Paget has pointed out,* to 
three classes of parts, namely : (1.) ' Those 
which are formed entirely by nutritive rep- 
etition, like the blood and epcthelia, tlieir 
germs being continually generated de novo 
in the ordinary condition of the body ; (2.) 
Those which are of lowest organization, 
and (which seems of more importance) of 
lowest chemical character, as the gelatinous 
tissues, the areolar and tendinous, and the 
bones ; (3.) Those which are inserted in 
other tissues, not as essential to their struc- 
tm-e, but as accessories, as connecting or 
incorporating them with the other struc- 
tures of vegetative or animal life, such as 
nerve-fibi-es and blood-vessels. With these 
exceptions, injuries or losses are capable of 
no more than repaii', in its more limited 
sense ; i. c, in the place of what is lost, 
some lowly organized tissue is formed, 
which fills up the breach, and suffices for 
the maintenance of a less perfect life.' 
Yet, restricted as this power is, its opera- 
tions are frequently most remarkable ; and 
are in no instance, perhaps, more strikingly 
displayed, than in the re-formation of a 
whole bone, when the original one has been 
destroyed by disease. The new bony mat- 
ter is thrown out, sometimes within, and 
sometimes around, the dead shaft ; and 
when the latter has been removed, the new 
structm-e gradually assumes the regular 
form, and all the attachments of museles, 
ligaments, etc., become as complete as be- 
fore. A much greater variety and com- 
plexity of actions are involved in this 

* " Lc(.:u;-i.s o:i licpi-oduction niul IJcpaii'." 



process, than in the reproduction of whole 
organs in Ihe simpler animals ; though 
its effects do not appear so striking. It 
would seem that in some individuals this 
regenerating power is retained to a greater 
degree than it is by the class at large ; * and 
here again we find, that in the early period 
of development the power is more strongly 
exerted than in the adult condition. The 
most remarkable proof of its persistence even 
in Man, has been collected by Prof. Simp- 
son ; who has brought together numerous 
cases in which, after ' spontaneous amputa- 
tion of the limbs of a fcstus in utero,' occur- 
ring at an early period of gestation, there 
has obviously been an imperfect effort at 
the re-formation of the amputated part 
from the stump.f By the knowledge of 
these facts and principles, we seem justi- 
fied in the surmise, that the occurrence 
of supernumerary or multiple parts is 
not always due (as usually supposed) to 
the ' fusion ' of two germs, but that it 
may result from the subdivision of one ; 

* One of the most curious and well-autlienticateil in- 
stances of this kind is related by Mr. AVIiitc, in his work 
on the " Regeneration of Animal and Vegetable Sub- 
stances," 1785, p. 16. "Some years ago, I delivered a 
lady of rank of a fine boy, who had two thumbs upon one 
hand, or rather, a thumb double from the first joint, the 
other one less than the other, each part having a perfect 
nail. When he was about three years old, I was desired 
to take off the lesser one, which I did ; but to my great 
astonishment it grew again, and along with it the nail. 
The fiimily afterwards went to reside in London, wliere 
his father showed it to th.at excellent operator, William 
Bronifield, Esq., surgeon to the Queen's household ; who 
said, he supposed Mr. White, being afraid of damaging 
the joint, had not taken it wholly out, but he would dis- 
sect it out entirely, ami then it would not return. He ac- 
cordingly executed tlie plan be had described, with great 
dexterity, and turned the ball fairly out of the socket; 
notwithstanding this, it grew again, and a fresh nail was 
formed, and the thnml) remained in this state." The 
Author h.as been himself assured by a most intelligent 
Surgeon, that ho was cognizant of a case in wliich 
the whole of one ramus of the lower jaw bad been 
lost liy disease in a young girl, yet the jaw had been com- 
pletely regenerated, and teetli were developed and occu- 
jiled their normal situations in it. 

t These cases were brought by Prof Simpson before 
the Physiological Section of the British As.sociation, at 
Its meeting in Kdinburgh, August, 18.")0. The Author, 
having had the opportunity of examining Prof. Simpson's 
preparations, as well as two living examples, is perfectly 
satisfied as to the fact. 



134 



AN"ATO:.IY AND PHYSIOLOGY OF 



for, if it be supposed that this subdivi- 
sion has taken place when the develop- 
mental process has advanced no further 
than in a Hydra or a Planaria, it seems by 
no means impossible that each part might, 
as in those creatures, advance in its devel- 
ojiment up to the attainment of its com- 
plete form. 

" There are many tribes, both of Plants 
and Animals, in which multiplication is 
effected not only art ifi dally but sponta- 
neovsly, by the separation of parts, which, 
though developed from the same germ in 
perfect contiiuiity with each other, are capa- 
ble of maintaining an independent exist- 
ence, and which, when thus separated, take 
rank as distinct individuals. This process, 
which is obviously to be regarded, no less 
than the preceding, as a peculiar manifes- 
tation of the ordinary operations of Nu- 
trition, may take place in either of four 
different modes — 1. In the lowest Cellular 
Plants, and the simplest Protozoa, every 
component cell of the aggregate mass that 
springs from a single germ, being capable 
of existing independently of the rest, may 
be regarded as a distinct individual ; and 
thus every act of growth which consists in 
the multiplication of cells, makes a corre- 
sponding augmentation in the number of 
individuals. 2. In many organisms of a 
somewhat higher type, in which the fabric 
of each complete individual is made up of 
several component parts, we find the new 
growths to be complete repetitions of that 
from which they are put forth ; and thus 
Ihe composite organism presents the sem- 
blance of a collection of individuals united 
together, so that nothing is needed but the 
severance of the connection, to resolve it 
into a number of separate individuals, each 
perfect in itself. The most characteristic 
example of this is presented by the Hydra, 
which is continually multiplying itself after 
this fashion; for the buds or 'gemmae' 
which it throws off are not merely struc- 
turally but functionally complete (being 
capable, of seizing and digesting their own 
Jircy), previously to their detachment from 
the parent. 3. In by fur the larger propor- 



tion of cases, on the other hand, the 
'gemma' does not possess the complete 
structure of the parent, at the time of its 
detachment, but is endowed with the ca- 
pacity for developing whatever may be 
deficient. Thus, the bud of a Phanero- 
gamic Plant possesses no roots, and its 
capacity for independent existence depends 
upon its power of evolving those, organs. 
On the other hand, the 'zoospore' of an 
Ulva or a Conferva is nothing else than a 
young cell, from which the entire organism 
is to be evolved after it has been set free ; 
and, even in the ■ bulbels ' of the Mar- 
chantia, the advance is very little greater. 
The ' bulbels ' of certain Phanerogamic 
plants, however, bear more resemblance to 
ordinary buds. 4. In the preceding cases, 
the organism which is developed by this 
process resembles that from which it has 
been put forth; but there are many cases 
in which the offset differs in a marked de- 
gree from the stock, and evolves itself into 
such a different form that the two would 
not be supposed to have any mutual rela- 
tion, if their affinity were not pro^^^ed by a 
knowledge of their history. Sometimes 
we find that the new individual thus bud- 
ded off is in every respect as complete as 
that from which it proceeded, though de- 
veloped upon a different type ; but in other 
instances it is made up of little else than 
a generaiive apparatus, provided with loco- 
motive instruments to carry it to a distance, 
its nutritive apparatus being very imperfect. 
Of the first, we have an example in the 
development of MedusBE; from the Hydroid 
Polypes ; and of the second in the peculiar 
subdivision of certain Annelida, hereafier 
to be described. Now it is obvious that, in 
this process, no agency is brought into 
play Hiat differs in any essential mode from 
that which is concerned in the ordinary nu- 
tritive operation. The multiplication of 
individuals is performed exactly after the 
same fashion as the extension of the parent 
organism ; and the very same parts may 
be regarded as organs belonging to it, or as 
new individuals, according to their stage of 
development, and the relation of depen- 



THE HORSE. 



1 '^ t 
loo 



dence which tliey still hold to it. The es- 
sence of this operation is (he multiplication 
. of cells by continual sulnlicision. 

"We have now, on the other hand, to in- 
quire into the nature of the true Generative 
process, by which the original germ is en- 
dowed with its developmental capacity ; 
and this we shall find to be of a character 
precisely the opposite of the preceding. 
For, under whatever circumstances the 
generative process is performed, it appears 
essentially to consist in the re-union of the 
contents of ttco cells* of which the germ, 
which is the real commencement of a 
' new generation,' is the result. This pro- 
cess is performed under the three following 
conditions: 1. All the cells of the entire 
aggregate, produced by the previous subdi- 
vision, may be capable of thus uniting with 
each other indiscriminately ; there being no 
indication of any sexual distinction. Tliis 
is what we see in the simplest Cellular 
plants. 2. All the component cells of each 
organism may, in like manner, pair with 
other cells, to produce fertile germs ; but 
there are differences in the shares which 
they respectively take in the process, which 
indicate that their endowments are not pre- 
cisely similar, and that a sexual distinction 
exists between them, notwithstanding that 
this is not indicated by any obvious struc- 
tural character. This condition is seen in 
the Zygnema and its allies. 3. The gen- 
erative power is restricted to certain cells, 
w'hich are set apart from the rest of the 
fabric, and destined to this purpose alone ; 
and the endowments of the two sets are so 
far different, that the one furnishes the 
germ, wlulst the other supplies the fertiliz- 
ing influence ; whence the one set have 
been appropriately designated 'germ-cells ' 
and the other ' sperm-cells.' Such 'is the 
case in aU the higher Plants among which 
a true generative apparatus has been dis- 
covered ; and also throughout the Animal 
Idngdoni. 

* 111 veiyrare insf.iiccs, it is the re-union of tlio two 
p.iits of the contents of the same cell, which hail pre- 
viously tended to scp.nrate from each other, as if in tlie 
process of subdivision. 



" Thus, then, in the entire process in 
which a new being originates, possessing 
like structure and endowments with its 
parent, two distinct classes of actions par- 
ticipate, — namely, the act of Generation, 
by which the (ierm is produced ; and the 
act of Development, by which that germ is 
evolved into the complete organism. 'I'he 
former is an operation altogether suig-cncris ; 
the latter is only a peculiar modification of 
the Nutritive function ; yet it may give 
origin, as we have seen, to new individuals, 
by the se]>aration (natural or artificial) of 
the parts which are capable of existing as 
such. Now, between these two operations 
there would seem to be a kind of antago- 
nism. Whilst every act of Development 
tends to diminish the ' germinal capacity,* 
the act of Generation renews it; and thu- 
the tree, which has continued to exte d 
itself by budding until its vital energy 
is well-nigh spent, may develop flow era 
and mature seeds from which a vigoi ous 
progeny shall spring up. But the multipli- 
cation of individuals does not directly de- 
pend upon the act of generation alone ; it 
may be accomplished by the detachment 
of gemmcs, whose production is a sim 
act of development ; and the individuals 
thus produced are sometimes similar, some- 
times dissimilar, to the beings from which 
they sprang. W^hen they are dissimilar, 
however, the original type is always repro- 
duced by an intenening act of generation ; 
and the immediate products of the true g-en- 
erative act always resemble one another. 
Hence the phrase, ' alternation of genera- 
tions,' can only be legitimately employed 
when the term generation is used to desig- 
nate a succession of individuals, by what- 
ever process they have originated ; an ap- 
plication of it which cannot but lead to a 
complete obliteration of the essential dis- 
tinction which the attemjjt has been here 
made to draw between the generative act 
and the act of gemmation. For when it is 
said that ' generation a produces genera- 
tion n, whicii is dissimilar to itself, whil.st 
generation b produces generation c, which 
is dissimilar to itself, but which returns to 



136 



ANATOMY AND PHYSIOLOGY OF 



the form of generation a,' it is entirely left 
out of consideration that generation a pro- 
duces (the so-called) generation b by a 
process of gemmalioii; whilst the process 
by which generation b produces generation 
c is one of tnie generation. So generation 
c developes d by gemmation, which resem- 
bles li ; and d, by a true generative act, 
produces e, which resembles a and c. This 
distinction, although it may at first sight 
appear merely verbal, will yet be found of 
fundamental importance in the appreciation 
of the true relations of these processes, and 
of their resulting products. So, in the 
Author's opinion, the application of the 
term ' generation ' to the e?iHre product of 
the development of any germ originating 



in a generative act, whether that product 
consist of a single individual, or of a suc- 
cession, will be found much more appropri- 
ate, and more conducive to the end in view, 
than the indiscriminate application of it to 
each succession, whether produced by gem- 
mation or by sexual re-union. It is of 
great importance to the due comprehension 
of certain phenomena of Reproduction, 
which will come under consideration in the 
Animal kingdom, that the relations of the 
products of these two processes should be 
rightly apjireciated ; and this appreciation 
of them will, it is believed, be best gained 
by a careful inquiry into the phenomena 
of Reproduction in the Vegetable king- 
dom." 



EXAMINATIONS RESUMED. 



GLANT3ULAR APPAR-iTUS. 

Q. Describe the structure of a glandular body. — A. 
It consists of a collection of tubes, more or less convo- 
luted, united by cellular substance into masses of a 
rounded form, constituting a lobule ; each lobule has 
a separate investment of membrane ; and the whole 
aggregate of lobules is furnished with a general mem- 
branous envelope or capsule. Each gland jjreseiits a 
com])lex arrangement of numerous arteries, veins, 
ner\ cs, and lymphatics, and most of them are provided 
with an excretory duct, which conducts the secretion 
prepared in the gland. 

Q. \\'hat glands are su])posed to be destitute of a 
secretory duct ? — A. The pineal gland, thjToid, thy- 
mus, and renal ca])sules. 

Q. What function do most of the glands perform ? — 
A. Their function is two-fold, namely, the se])aration 
of some material from the circulating fluid, which 
would otherwise prove injurious to the system, and the 
elaboration of a product destmed to renovate the tis- 
sues. 

OF TIIE ABDOMEN. 

Q. IIow is the cavity of the abdomen bounded .' — 
A. Anteriorly, by the diaphragm ; posteriorly, by the 
pelvis; su])eriorly, by a portion of the vertebra; infe- 
riorly and laterally, by abdominal muscles. 

Q. Into how many regions is the abdomen divided ? 
— .-I. Into nine, as follows: right and left hypochon- 
driac; right and left lumbar; right and left iliac ; epi- 
gastric, umbilical, and hipogastric. 

PERITONEUJI. 

Q. M'hy is the peritoneum called " serous mem- 



brane?" — A. In consequence of the serous or waterv 
fluid with which its surface is constantly moistened. 

Q. What is the structure of serous meml)ranes ? — 
A. The same as that of the areolar tissue, having a 
very smooth and glistening inner sin-face, which is* 
covered witli a layer of cells ; constituthig a distinct 
tissue, termed epithelium. This is in contact with the 
primary mumhrane, thus isolating it from the tissues 
beneath. Sub-adjacent to this is a layer of condensed 
areolar tissue, which constitutes the chief thickness of 
the serous membrane, and confers u])on it its strengtii 
and elasticity ; this gradually jjasses into that base 
variety, by which the membrane is attached to the part 
it lines, and which is commonly known as the sub- 
serous tissue. A fibrous tissue enters into the compo- 
sition of the membrane itself, and its filaments ititer- 
lace in a beautiful network, wliich confers u])on it 
equal elasticity in every direction. 

Q. What is the purjiose of this membrane? — A. 
To facilitate the movements of the contained organs, 
by forming smooth surfaces wliich shall fj'cely glide 
over each other. 

STOMACH. 

Q. What effect does the gastric fluid have upon the 
food ? — A. It is supposed to have the projierty of dis- 
solvinj the albuminous and gelatinous constituents of 
the food. 

Q. What is the real solvent of the gastric fluid? — 
.1. Either hydrochloric, acetic, or lactic acid. 

Q. Is not the solvent action of the gastric fluid aided 
by some mechanical means ? — A. Yes. By the move- 
ments of the walls of the stomach, which are produced 
by the successive contractions and relaxations of their 



THE HORSE. 



137 



muscular fibres, the contents of the stomach are thus 
kept in a state of constant agitation, wliicli is considered 
favorable to their chemical solution. 

Q. Does absor]ition of nutritious matter lake place 
in the stomach? — A. Yes. A portion of the nutri- 
tious matter dissolved by the gastric fluid is at once 
absorbed into tlie blood-vessels of the stomach, and 
never passes into the intestinal tube, nor into the special 
lacteal system of vessels. 

Q. What term is apphed to the food after its reduc- 
tion, in the stomach, to a pulpy mass .' — A. Cliynie. 

Q. Gas is frequently evolved in the stomach and 
intestines during digestion: how do you accomit for 
this ? — A. It is owing to a disturbed or piorbid condi- 
tion of that process, and by no means a necessary at- 
tendant upon healthy digestion. 

Q. Does violent exercise immediately after a feed 
tend to retard the formation of chyme P — A. It does. 
The circumstances most favorable to perfect digestion 
are, a short period of rest, followed by gentle exercise. 

Q. Does any portion of the food ever pass unchanged 
through the pylorus along with the chyme .•' — A. Yes. 
AVhole oats are frequently found in the horse's excre- 
ment. 

INTESTINES. 

Q. The aliment now being converted into chyme, 
and having passed the pylorus, what becomes of it ? 
— A. It enters the duodenum. 

Q. Having entered the duodenum, with what does 
the chyme mingle ? — A. The biliary and pancreatic 
secretions. 

Q. AVhat effect do they have on the gastric secretion 
and the chyme ? — A. The biUary and pancreatic secre- 
tions are supposed to contain an excess of alkali ; this 
neutrahzes the acid of the gastric juice, so that there is 
no further solution of albuminous compounds, but the 
conversion of starch into sugar, which was interrupted 
in the stomach, now recommences. 

Q. What are the uses of the bile ? — A. The chief, 
uses of the bile appear to be those of a chemical agent 
promoting the decomposition of the chyme, and also 
stimulating the secretion of mucus, and the peristaltic 
action of the intestines. 

Q. What effect has the pancreatic juice on chyme or 
the elements of digestion ? — A. It forms an emulsion 
with oil and fat. 

Q. The ch)Tne, having been acted on by the preced- 
ing secretions, what name is then given to it.' — A. 
Chyle. 

Q. Describe the properties of chyle ? — A. If chyle 
be taken from the thoracic duct of an animal a few 
hours after it has taken food, it has very much the 
appearance of cream, being a thick fluid of an opaque 
white color, without smell, and having a slightly acid 
taste, accompanied by a perceptible sweetness. It 
restores the blue color of Utmus, previously reddened 
by acetic acid, and appears, therefore, to contain a ]ire- 
])onderance of alkali. When subjected to microscopic 
examination, chyle is found to contain a multitude of 
IS 



globules, of smaller diameter than those of the blood, 
and corresponding in size and appearance to those of 
milk. In about ten minutes after it is removed from 
the thoracic duct, it coagulates into a stiff jelly, which 
in the course of twenty-four hours sejiaratcs into two 
parts, providing a firm and contracted coagulum, sur- 
roimded by a transparent colorless fluid. 

Q. What are the principal ingredients of chyle? — 
A. A large proportion of albumen, a smaller one of 
fibrui ; a fatty .s-ubstance or emulsion, which gives to 
chyle the appearance of millv ; and several salts, such 
as carbonate of potassa, miuiate of potassa, and pro- 
phospate of u-on. 

Q. What change does the chyle undergo in its pas- 
sage along the various vessels ? — A. Its resemblance 
to blood increases in each of the successive stages of its 
progress towards the heart and lungs. 

<^. How are the chemical changes, and the contents 
of the intestines propelled through the tract of the 
aUmentary canal? — A. By the peristaltic action of the 
muscular coat of the same. 

Q. What becomes of the chyle after it has been ])rc- 
pared in the duodenum and fii-st intestines? — .4. It 
is received by absorption into the lacteals, and by them 
conveyed to the thoracic duct, which transmits it to 
large veins in the \icinity of the heart. (See distribu- 
tion of lymphatics.) 

Q. What do you understand by the " absorbent sys- 
tem?" — A. The absorbent system of vessels consists 
of two principal di\isions, wliich may be compared to 
two sets of roots proceeding from a common trunk ; 
one of these commences upon the walls of the intes- 
tines, and is termed the " lacteal " system ; whilst 
the other takes its origin in various parts of the sub- 
stance of the organism at large, especially in the skm 
and subcutaneous textures, and is known as the " lym- 
phatic " system. 

Q. AVhere do the lacteals most numerously abound ? 

— A. In the small intestines, below the point at which 
the liver and pancreas discharge their secretion.s. 

Q. Where do the lacteals commence? — A. Near 
the free extremities of the villi of the intestines. 

Q. In what way do they commence? — A. It was 
formerly su])poscd that they commenced by orifices 
upon the internal surface of the intestine ; but Carpen- 
ter, and other physiologists, contend that the lacteal 
vessels form loops by anastomosis with each other, so 
that they have no free extremity. 

Q. AMiat are the functions of the large intestines ? 

— A. Thev are engaged in the conveyance and expul- 
sion of feculent matter, and tliere are certain change.^ 
which take place m their contents, in aid of the object 
of nutrition, the exact nature of which has never been 
clearly determined. According to the best authority, it 
appears that some imjjortant changes are effected in 
that enlarged portion of the canal, termed circum, and 
which has, Iiy some, been regarded as a kind of sup- 
plemcntarv stomach, in which fresli chyme is formed, 
and fresh nutriment extracted from the materials that 
have passed through the small intestines. The large 



138 



ANATOJir AND PHYSIOLOGY OF THE HORSE. 



intestines also extract nutriment from their contents, 
nhich is proved by the fact that nutritious matter in- 
jected into them has been kno-nn to support life for a 
sertam time. 

.SPLEE.\. 

Q. AVhat is the function of the spleen? — A. It 
serves as a kind of diverticuhmi, to reheve the vessels 
of the digestive viscera when they arc compressed by 
undue aecumniulatioii of the contents of their cavities, 
or when they are conjjjested by obstruction to the flow 
of blood, through the liver or heart. It may also be 
considered as a lymphatic gland, for, in some instances 
ill wbicfc animals have been allowed to survive longest 
after removal of the spleen, the lymphatic glands of 
the \icinity have been found greatly enlarged and clus- 
tered together, so as nearly to equal the original spleen 
in volume ; hence, in such case we infer that its func- 
tion must be similar to that of the cnL-u-ged lymphatic 
glands. 

LIVER. 

Q. What comprises the prmcipal bulk of the liver ? 
— A. It is made up of a vast number of minute lobules 
of irregulai- form, but about the average size of a mil- 
let seed ; and each of them contains the elements of 
which the entire organ is composed, viz., a jjlexus of 
Mhary ducts connected with their main trunks, and a 
mass oi biltarj- cells ; each of which are connected in 
like niamicr with the three blood-vessels which miite 
to the circulation of this organ. 

Q. What are the vessels of the liver ? — A. The 
Repatic artery, vena portae, and hepatic veins, to which 
may be added the excretory ducts and absorbents. 

Q. Of what use is the hepatic artery '} — -A. It is the 
nutrient artery of the hver. 

Q. Of what use is the vena portCD? — A. It acts both 
as a vein and artery : as a vein, it receives the blood 
from most of abdominal viscera ; as an ai-tery, it rami- 
fies tlirough the liver for the secretion of bile. 

Q. What is the use of the hepatic veins ? — ^l. They 
return blood lo the vena cava. 

Q. What is the function of the liver P — A. It is an 
organ of excretion, designed to remove from the cireu- 
bting Huid tliat portion of the products of disintegra- 
tion, of which the principal component of the biliary. 
is the largest. 



Q. Into what substance is the greater ];art of the 
excrementitious matter converted ? — A. Biline. 

KIDNEYS. 

Q. Wh at is the embrj'otic condition of the kidneys ? 
A. The kidneys are preceded in the embn'o by a sub- 
stance first noticed by Wolff, and called after him the 
Wolffian bodies, or false kidneys, which originally ex- 
tend along the spine from the heart to the end of the 
intestines ; but they aftenvards become shorter, and 
after a time diminish by absorption, and wholly dis- 
appear. 

Q. What is the function of the kidneys ? — A. Their 
princi]!al function is to se])arate from the blood certain 
matters which would be injurious to it if retained. 

Q. What does the secretory surface of the kidneys 
consist of? — A. It is composed of epitliehal cells 
which hue the tubuU urinifera, which draw the peculiar 
elements of the miliary excretion from the vascular 
plexus which sm-rounds the exterior of the tubes, car- 
lying off the same to their terminations in the ureter. 

Q. What other an-angcmcnt is prorided within the 
kidneys for the elimination of the superfluous fluid of 
the blood? — A. A j)rocess of transudation takes place 
by the function of malpighian bodies, whose thin-walled 
capillaries allow the transudation of water to take 
place, under a certain pressure, into the tubuli minifera. 

SUPIl.\-RENAL CAPSULES. 
Q. What is the function of the supra-renal cap- 
sides'? — A. Their function has hitherto been involved 
in obscurity, and was sujjposed to be identical with 
other glands destitute of ducts or outlets ; but, lately, 
31. Ih'otcn Sequard has demonstrated that they play 
a very important part ui the nervous system of the 
horse. 

VASA DEFERENTU. 

Q. AVhat is the function of the vas deferens? — A. 
It is the excretory duct of the testicle, and conveys the 
semen to the vesiculte seminales. 

The author, instead of introducing examinations on 
the reproductive organs, has thought it best to substi- 
tute the opinions of that eminent jihjisologist, Dr. 
Carpenter ; and therefore the reader's attention is now 
directed to " Physiological coiisiderations on the re- 
production of organized beings."— \>a.ge 128. 



HEMARKS AND EXAMINATIONS ON THE EYE. 



The parts which compose tlie eye are 
divided into external and internal. The 
externa] parts are : First, the eyelashes, or 
cilia, which, in the horse, can scarcely be 
reckoned more than one, there being very 
few hairs in the under eyelid. SecontUy, 
the eyelids, or palpebral, upper and under : 
where they join outwardly, it is termed the 
external canthus, and inwardly toward the 
nose, the internal canthus : they cover and 
defend the eyes. The cartilaginous margin 
or rim of the eyelid, from which the eye- 
lashes proceed, is named tarsus. In the 
tarsus and internal surface of the eyelid 
there are small glands, which secrete a fluid, 
to prevent friction of the eye and its lids, 
and facilitate motion. Thirdly, the lachry- 
mal gland, which is placed on the upper part 
of the eyelid toward the external canthus ; 
from this gland the tears are secreted, and 
conveyed to the inner surface of the upper 
eyelid by several minute ducts, or canals, 
named lachrymal ducts. There is another 
small body, having a glandular appearance, 
in the inner corner of the eye ; on each side 
of which there are small oriiices which are 
called puncta lachrymalia : these are the 
mouths or openings of two small canals, 
which, joining together, form a membranous 
tube ; and this, passing through a small open- 
ing in the bone, extends to the lower part 
of the nostril, where its termination may be 
distinctly seen in the horse. As the lachry- 
mal gland is constantly forming tears, it 
must be obvious that some contrivance is 
necessary to convey them off, and prevent 
them flowing over the cheek: this purpose 
is answered by the canal just described. 

When any irritating matter is applied to 
the eye, the tears arc formed too abundantly 
to be carried off in this way*, they then 
flow over the cheek, hi the human eve, 



the puncta lachrymalia terminate inasmaH 
sac, from which the lachrynial duct proceeds:: 
this is not the case in the horse. In the 
inner corner of the horse's eye is placed a 
body connnonly termed the haw, no resem- 
blance to which is to be found in the hu- 
man eye. The horse has the power, by 
means of the muscles of the eye, to bring 
the haw completely over its surface ; it 
serves, therefore, as a second eyelid, and 
effectually wipes off any dust, hay, or seeds, 
or other matter which may have fallen upon 
the eye. The conjunctivial membrane or 
tunica conjunctiva, lines the inner surface 
of the eyelids, and covers the white part of 
the globe of the eye. This membrane has 
immerous blood-vessels, which are conspicu- 
ous when it is inflamed. The bulb or globe 
of the eye is composed of several coats and 
humors. The transparent cornea, whicli, 
in the horse, forms the front jjart of the eye, 
comprehends a larger part of the globe 
than in the human subject ; on removing 
this cornea, a fluid, which is named the 
aqueous humor, escapes, and the iris ap- 
pears. The iris is a muscular curtain, 
having a hole in the centre, whiclj is termed 
the pupil. This divides the fore part of the 
eye into two parts, named chambers, which 
are occupied by the aqueous humor. The 
pupil is of a dark bluish cast ; is of an oval, 
or rather of an oblong, form. The iris regu- 
lates the quantity of light that is required 
to pass through the pupil. For this purpose, 
it is composed of two sets of muscular 
fibres: by means of one the pupil is en- 
larged, and by the other it is diminished. 
Thus, if the pupil is first examined in the 
stable, where tliere is a moderate light, and 
immediately after in the sunshine, it will be 
found quite altered; being so small, in a 
strong light, as to be nearly closed. On re- 



140 



ANATOMY AND PHYSIOLOGY OP 



moving (he iris, the second humor, or crys- 
talline len.s, appears: this is retained in its 
situation by a transparent membrane, named 
its capsule, between which and the lens is a 
minute quantity of fluid. The third humor 
of the eye is the vitreous. This humor is not 
contained in one general sac, but in numer- 
ous minute and perfectly transparent cells, 
and resembles pure water : this humor 
serves to produce a small degree of refrac- 
tion in the rays of light, and occupies and 
distends all the posterior part of the globe 
of t he eye. The next coat to the conjunctivial 
is the sclerotica, or white of the eye, a 
strong, thick membrane, which extends 
from the transparent cornea to the optic 
nerve. The next coat to the sclerotic is the 
choroid. This is a delicate and very vascu- 
lar membrane. In the human eye it appears 
of a black color, and it is this which causes 
the pupil of the human eye to appear black ; 
but the choroid coat of the horse's eye is 
variegated in color ; in some parts black, in 
others blue, and in others gi-een. The next 
coat is the retina : this is a delicate expan- 
sion of the optic nerve over the choroid 
coat, which it accompanies to the margin 
of the crystalline lens, and there terminates. 
The use of the retina is to receive certain 
impressions made by the light reflected from 
objects, so as to produce in the mind an 
idea of their figure and color; the optic 
nerve being the medium of communication 
between the retina and brain. From the 
above explanation of the mechanism of the 
eye, it will readily appear that many cir- 



cumstances may occur to render vision im- 
perfect, or to destroy it altogether. If the 
transparent cornea, for example, became 
white, light could not pass through it, and 
the animal would be blind, however perfect 
the other parts of the eye might be. The 
cornea may be either too convex or too flat; 
in the former case, causing the animal to be 
near-sighted ; in the latter, producing an in- 
distinctness of vision with respect to objects 
that are near. The iris may, in consequence 
of disease, become fixed, or lose its power 
of motion ; in which case, the pupil would 
be always of the same size, and the animal 
would not have the power of adapting it 
to the various distances or objects ; or, as 
sometimes happens, the pupil may become 
quite closed, by which light would be per- 
fectly excluded from the retina. Supposing 
the cornea and iris to be healthy, the crys- 
talline lens, or its capsule, may become 
opaque, and thereby cause total blindness. 
But in this part, as in the cornea, we meet 
with different degrees of opacity : some- 
times it is very slight, the pupil appearing 
of a lighter color, and unusually large : in 
this state, the pupil is said to look dull or 
muddy, which causes the horse to start ; 
but when the opacity is complete, it consti- 
tutes the disease termed cataract. There 
is another disease, to which the reader's at- 
tention is called ; it is named gutta serena, 
or amaurosis. This disease is known by 
the pupil being unusually large or open, 
and by its continuing so when the eye is 
exposed to a strong light. 



EXAMINATIONS OF THE OKGANS OF SIGHT AND THEIR APPENDAGES. 



Q. AVhere are the eyes located? — A. Within the 
orbits. 

Q. By what foraminoe is each orbit perforated? — A. 
Ly the optic foramen. 

Q. From whence is the lining membrane of the orbit 
derived? — ^1. From the dura mater ami periosteum. 

Q. Enumerate the aj)peiKlaf;es of the eye. — A. The 
eyelids, eyelashes, rnuseles of the eyelids, tarsal carti- 
lnf,'es, meibomian ;,'lands, tunica conjunctiva, membrana 
nictitans, lachrvmal gland, puncta laehiymaha, lachry- 
mal sac, ductus ad nasnm, and the muscles of the eve- 
ball. 



EYELIDS. 

Q. AVhat parts do the eyelids occu])y ? — A. The cir- 
cumference of the orbits and front of the eyeball. 

Q. What are the eyelids conijiosed of? — .-L In com- 
position they are cuticular, muscular, cartilaginous, and 
membranous ; also glandular, vascular, and nervous. 

Q. What muscle enters into the composition of the 
eye? — A. The orbicularis palpebrarum. 

Q. How are the lids separated ? — A. By a transverse 
fissure, bounded by the angles or eanthi of the eye. 

Q. What is attached to the sujierior or temjjoral 
angle? — A. The taa-sal ligament. 



EXPLANATION OF FIGUEE XIV. 



HIXD EXTKEMITIES. 

to'. Tensor vaglnop. 

It'. Rectus. 

()'. Vastus extcmus. 

5'. Flexor metatarsi. 

r'. r. Gastrocnemius internus. 

s'. " externus. 

i\ Flexor pedis accessorius. ' 

«'. Insertion of the gastrocnemius. 

»'. Flexor metatarsi. 

x'. Extensor pedis. 

y. y'. Extensors. 

u. V. Tendo perforans and perforatus. 

K'. K'. Abductors tibialis. 

J\ J'. Triceps. 

V. r. Adductors. 

«,-. Hoof. 

5, 5. Saphena vein. 

8. Bifurcation of the suspensoiy ligament. 
»'. (Off-hind leg.) Plantains. 
z. Suspensory ligament. 

FORE EXTREMITIES. 

J". Pectoralis magnus. 
to", n". Triceps extensor brachii. 
o". Pectoralis transversahs. 
p". p". Flexor metacarpi extemus. 
g". " " medius. 

t". " " internus. 

s". Extensor metacarpi magnus. 

w". (At the upper part of the figure.) Levator humeri. 

u". u". u". u". V. (Beneath the olccrn.non and carpus.) Flexors perforans and per- 
foratus. 
x". Extensor pedis. 
y". y. Extensor suffraginis. 
z". Suspensory ligament. 
if. The hoof. 
4. Subcutaneous thoracic vein. 

6. lladial vein. 

8. Bifurcation of the suspenson' UganiPnt. 



THE HORSE. 



141 



Q. What is fixed to the inferior angle ? — A. The 
tendon of the orbicularis. 

Q. From whence is the loose portion of skin, enter- 
ing into the com|)osition of the upper lid, derived ? — ^-i. 
It is a prolongation of the slun covering the forehead. 

Q. From whence is that of the lower lid derived? — 
A. From the integuments of the face. 

Q. How are the internal surfaces of the Uds shaped ? 
— .4. Into concarities which adapt them to the convex- 
ity of the globe of the eye. 

Q. By what membrane are the Uds lined ? — A. By 
the eonjunctivial. 

T.UIS.U. CAKTILACES. 

Q. What are the tai'sal cartilages? — .1. They enter 
into the substance of the borders of the Uds, imparting 
to them both firmness and elasticity. 

Q. Describe the tarsal cartilages? — .-1. The superior 
cartilage is broader and more convex than the inferior ; 
they correspond in shape and size to their respective 
lids ; they are convex outwardly and concave inwardly, 
and are inserted into the rims of the orbits. 

Q. What is the texture of the tarsus? — A. Their 
texture is fibro-cartilaginous. 

MEIBOMLIN GLA>'DS. 

Q. Describe the meibomian glands ? — A. They have 
the appearance of white folhcular bodies, vertically 
ranged in parallel lines ; they vary both in calibre and 
length, and are in the u])per rather than tlie lower lid. 

(J. What is the function of the meibomian glands ? — 
A. To secrete a fluid wliich guards against friction 
betM'een the eye and its appendages. 

Tf.MCA COXJl"NCTIV.\. 

Q. What is the situation of the tunica conjunctiva ? 
• — .-1. It is the lining membrane of the eyelids, mem- 
brana nictitans, caruncula lachrymalis, puncta lachry- 
maUa, and is reflected to the globe of the eye. 

Q. Describe the eonjunctivial surface ? — A. The adhe- 
rent one is rough, lax, and flocculent ; the outer surface 
is smooth, glossv', and humid with secretion. 

(J. What are the peculiarities in the organization of 
the conj unctiva ? — A. It is a continuous membrane, yet 
■\-aries in texture, as follows : 1st. That portion wWch 
gives a covering to the conjunctiva ])clpebrahs is 
highly organized with blood-vessels, and is often tinged 
a dee]) red color. 2d. The conjunctiva sclerotica is not 
60 highly organized, yet has a few straggling vessels of 
larger calibre than those of the former, and its textm-e 
is more dense. 3d. The conjunctiva cornea? is thin 
and transparent, more of a horny textmv;, and has no 
appearance of vasculai-ity. 

M r.MBUAN A -MCTITAXS. 

Q. 'What is the common name for the above mem- 
brane ? — A. The haw. 

Q. AVhat is its structure ? — A. Cartilaginous. 

Q. What is its situation? — A. It is located behind 



the mferior canthus, between the e)-eball and side of 
the orbit. 

Q. AVhat is its figure ? — A. It apjiroaches that of an 
extended triangle, of which the short side is turned 
forwards, and tlie lengthened angle backwards. 

Q. Describe the anterior part? — A. It is thin and 
elastic, and bounded by a crescentic edge, terminating 
in two salient angles ; it increases in substance, but 
grows narrow posteriorly, and there ends in an obtuse 
conical point, which appears in the adipose tissue at the 
bottom of the orbit. 

Q. What is the form of its surfaces ? — -4 . Inwardly 
concave ; outwardly convex. 

Q. What is the body of the nictitating membrane 
clothed with ? — A. ]!y a portion of eonjunctivial mem- 
brane. 

Q. A\n-iat is the function of the membrana nictitans ? 
— P. To ])rotect the eyeball, in the removal of foreign 
bodies from its surface. 

LACIIKYMAI APPAR.\TUS. 

Q. What parts compose the lachm.yral apparatus? — 
.4. The lachrymal gland, eai-uncula lachrymalis, lachry- 
mal puncta and conduits, lachrymal sac, and ductus ad 
nasum. 

LACHETM.U. GLAND. 

Q. Where is the lachrj-mal gland situated? — A. In 
a depression, beneath the process of the orbital arch. 

Q. What are its coverings, and with what is it in 
contact ? — ^4. It is covered by the common aponeurotic 
Uning of the orbit ; it is in contact with the levator pal- 
pebra?, and is enveloped in fat and cellular membrane. 

Q. AVhat is its form ? — .4. It is irregular, slightly 
convex superiorly; incUning to the concave inferiorily. 
It is a conglomerate gland, constituted of many lobules. 

Q. Have the lobules any further organization ? — A. 
Yes, they are composed of minute granules. 

Q. AA'hat vessels do the granules receive and what 
s])rings from them ? ■ — .4. They receive the terminating 
ramifications of the supplying arteries, and from them 
spring the radicles of the excretory ducts. 

Q. AA'hat do the radicles terminate in, and where is 
their outlet? — A. The radicles unite vrith one another 
into a set of tubes, which open upon the eonjunctivial 
fining of the upper lid in the source of seven risible 
orifices near its sujierior angle; this is their outlet. 

Q. AVhat is the I'unction of the lachrymal gland ? — 
A. To secrete the tears. 

Q. AA'hat becomes of the su])erfluous tears? — .4. 
They cither fall over the lower Uds, or pass into the 
lachrymal sac ; from thence, by the ductus, to their out- 
lets within the nostrils, at their inferior j)arts. 

CARU.NXfLA LACIir.V.MALIS. 

Q. AA'hat is the caruncula lachr\-maUs ? — .4. It is a 
small emmence, lodged v.itliin tJie inferior canthus, be- 
tween the eyeball and Uds. 

Q. AA'hat is its use? — .4. It secretes a light yellow 
unctuous matter, with which the fine hairs on its surface 



142 



ANATOMY AND PHYSIOLOGY OF 



being coated it detains any small foreign bodies that 
may lloat in the lachrymal secretion ; it also directs 
tlie latter fluid into the puncta. 

LACHRYMAL PCWCTA AND CONDUITS. 

Q. What are the jjuncta lachrymaha ? — A. Two small 
orifices situated on the inward margins of the two lids — 
superior and inferior — near the racUx of the caruncle. 

Q. What do the j)uncta terminate in ? — A. The 
lachrymal conduits. 

Q. What is their situation? — A. Witliin the sub- 
stance of the eyelids. 

Q. How are conduits formed ? — A. A minute carti- 
laginous circle surrounds them, and they are lined by 
conjunctinal membrane. 

Q. What do the conduits terminate m ? — A. The 
lachrymal sac. 

LACHRYMAL S.\C. 

Q. Where is the lachrymal sac situated ? — A. With- 
in tlie deprestion which leads into the channel of the 
lachrymal bone, behind and below the small eminence 
upon the orbital ridge of that bone. 

y. Describe lire sac and its connections ? — A. It is 
an oblong membranous bag ; its front is crossed by 
fibres of the orbicularis ; it has also a coimection with 
the tendon of that muscle. The posterior jjai-t of the 
sac adheres firmly to the lachrjinal bone. It is com- 
j;osed of a dense, white, fibrous membrane, furnished 
with a fining from the conjimctivia. 

Q. By what is this sac perforated? — -A. By the 
lachrymal conduits. 

Q. What does it open into ? — A. Into the ductus ad 
nasum. 

Q. What is the fimction of tliis sac? — A. It is a 
reservoir into which the tears flow from the lachrymal 
conduits, and from thence pass into the ductus ad 
nasum. 

DUCTUS AD NASU.M. 

Q. What is the ductus ad nasum? — .4. It is a long 
membranous canal, commencing at the contracted ])or- 
tion of the lachrymal sac, and running with the groove 
through the lachrymal bone ; then along a canal in the 
superior maxillary bone, between it and the anterior 
turbinated bone ; terminating at the inner and inferior 
])art of the nostril. 

Q. What is the organization of the ductus? — A. It 
appears to be a continuation of the membrane com- 
])osing the lachrjiiial sac, which is strengthened by a 
fibrous sheath ; its internal surface is ])robal)ly mucous, 
which ])rotects it from the action of the tears, or 
lachrymi'.l secretion. 

(J. Describe the course of the tears, or lachrjinal 
secretion? — A. They are secreted by the lachrymal 
gland, and are poiu-ed by its excretory ducts over the 
surface of the eyeball ; the puncta lachrymalia absorb 
fhem ; they are then conveyed by the lachrymal ducts 
to the lachrymal sac ; and tlrrough the ductus ad nasum 
])ass into the nostril. 



THE EYEBALL AND ITS COATS. 

Q. What is the form of the globe of the e^'c ? - - .4. 
Nearly of a spherical figure. 

Q. Of what is the globe of the eye composed? — A. 
Of membranes, or coats, filled with humors or fiuids, 
wliich preserve its form. 

Q. How many coats has the eye? — A. Five: the 
sclerotic, choroid, retina, cornea, and iris. 

Q. Does not the tunica conjunctivia enter into the 
composition of the membranes of the eye? — A. Yes; 
it may be considered as common to both. 

Q. Where does it adhere most closely ? — A. Over 
the cornea. 

SCLEROTIC COAT. 

Q. What is the use of the sclerotica ? — A. It bounds 
the form of the eye, protects and supports the parts 
within. 

Q. Vriiat are its perceivable boundaries ? — A. It ex- 
tends fi-om the optic nerve to the cornea. 

■Q. What is inserted into it posteriorly ? — A. The 
fleshy part of the retractor muscle. 

Q. What is inserted into its anterior margins? — A. 
The tendons of the four recti. 

COKSEA. 

Q. What is the coraea ? — A. The transparent, ante- 
rior pai-t of the globe of the eye. 

Q. How does its form compai-c with the sclerotica ? — 
A. It is more convex. 

Q. What covers its convex surface ? — A. The con- 
j uncti\ia. 

Q. What is its structure? — A. Laminated. 

IKIS. 

Q. AATiat is the iris ? —A . It is a circular membrane, 
with an irregular central cavity, in the anterior chamber 
of the eye. 

Q. What is its central perforation called? — A. The 
pupil. 

Q. How is the periphery of the pupil bounded ? — A. 
By several dark, colored, glandular bodies, termed cor- 
pora nigra. 

Q. What is the use of the iris? — .4. By contracting 
it excludes all superfluous rays of light, and Ijy expand- 
ing admits through the jjupil all that pass through the 
cornea. 

Q. What is the structure of the iris? — A. It is a 
fibrous membrane, di\isable into two layers, provided 
with blood-vessels and nerves. 

CHOROID COAT. 

Q. What is the choroid ccat ? — A. It is a dark- 
colored membrane of delicate tcxtm'c, located immedi- 
atelv beneath the sclerotica. 

Q. AVhat are its boundaries? — A. It extends from 
around the termination of the optic nerve as far for- 
ward as the edge of the cornea, and ends in the ciHary 
circle. 



THE HORSE. 



143 



Q. ITow is the choroitl coal connected with the 
sclerotica ? — A. By cellular membrane. 

Q. What is remarkable at its outer edge? — A. It is 
throWTi into folds, called ciUary circle and processes. 

Q. AVhat is the color of the choroides ? — A. Extern- 
ally, its whole surface is black ; internally, the anterior 
parts are black, and the posterior half is of a brilUant 
variegated green. 

Q. What is the black part termed ? — A. Pigmentum 
nigrum. 

Q. AVhat name is given to the variegated part ? — A. 
Tajietum lucidum. 

Q. What difl'ercnce do we observe in the ])igment of 
the choroid surfaces? — A. The inner layer is thicker 
and more consistent than that found on the outer 
surface. 

EETiy.4. 

Q. AAHiat is the retina ? — A. It is the third or inner- 
most tunic of the eye. It cannot, however, be con- 
sidered as a tunic, for it pervades the interior of the 
globular exjiansion without contracting any adhesions 
until it has reached the corpus ciliare. 

Q. How is the retina formed ? — A. The optic nerve, 
ha\-ing reached the inner and inferior part of the globe 
of the eye, enters the sclerotic and choroid coats, and 
in its passage through them its diameter contracts; 
having arrived at the imier part of the globe, the nerve 
forms an eminence, from the circumference of which 
issues radiating fibres which form the retina. 

Q. How is the retina sustained in this state of globu- 
lar expansion? — ^-1. By the humors of the eye, which 
keep it in contact with the choroides. 

Q. The retina having radiated on the interior of the 
globe, where is it inserted ? — A. Into the corpus ciliare. 

nUlIOES OF THE EYE. 

Q. Of how many humors does the eye consist, and 
what are their names? — -A. Of three; they are called 
aqueous, crystalline, and vitreous humors. 



Q. AVhat parts of the eye do they occupv ? — A. 
They occupy in succession the spaces termed anterior, 
middle, and posterior chambers of the eye. 

AQUEOUS HUMOR. 

Q. AA'hat is the use of the aqueous humor? — ^-1. It 
transmits the rays of light, and aids the free motions of 
the iiis. 

Q. AVhat are its boundaries ? — ^-1. It fills the interval 
between the cornea and crystalhne lens. 

Q. Describe the aqueous hmnor. — ^-1. It is a bright 
Umpid fluid, and in properties bears some resemblance 
to the vitreous. 

Q. AVhat is the composition of both these humors ? 
— A. They are composed of albumen, gelatine, and 
muriate of soda, held in solution by an aqueous men- 
struum. 

Q. How is this fluid secreted ? — A. By secretion from 
the transparent walls of its capsule. 

CRYSTALLINE LENS. 

Q. AVhat is the use of the crystalline lens ? — A. It 
concentrates the rays of light, so as to make a distinct 
image in the posterior chamber. 

Q. AVhere is the crjstalline lens situated? — A. Be- 
tween the aqueous and vitreous humors. 

Q. By what is the crystalhne lens enclosed? — A. 
By a tunic, called tunica crystallina. 

VITREOUS HUMOR. 

Q. AVhat is the vitreous humor, and where is it situ- 
ated? — A. It is the most bulky humor of the eye ; of 
a jelly-like consistence, yet quite transparent, and occu- 
pies that portion of the eyeball posterior to the crj-stal- 
line lens. 

Q. AVTiat is the use of the vitreous humor ? — A. It 
supports the form of the eye, and maintains the other 
humors in their proper positions. 



RESPIRATORY SYSTEM. 



PHYSIOLOGICAL CONSIDERATIONS. 

Respiration and Structure of the Lungs. — 
The organs of respiration are the larynx, 
the upper opening of which is named glottis, 
the trachea or windpipe, bronchiEe and the 
lungs. 

The air is displaced out of the lungs by 
the action of the muscles of respiration ; 
and, when these relax, the lungs expand to 
a certain calibre by their elasticity. This 
may be exemplified by means of a sponge, 
which may be compressed into a small bulk 
by the hand, but, upon opening the same, 
the sponge returns to its natural size, and 
all its cavities become filled with air. The 
purification of the blood in the lungs is of 
vital importance, and indispensably neces- 
sary to the due performance of all the func- 
tions. When the lungs, and muscles con- 
nected with them, are in a physiological 
state, the horse is said to be in good wind — 
a very desirable state for an animal to be 
in, whose usefulness depends on his being 
capable of a long continuance of quick 
motion. The trachea, or windpipe, after 
dividing into bronchiee again subdivides into 
innumerable other branches, the extremities 
of which compose an infinite quantity of 
small cells, which, with the ramifications of 
the veins, arteries, nerves, lymphatics, and 
the connecting cellular membrane, make up 
the whole mass or substance of the lungs. 
The internal surface of the windpipe, bron- 
chia and air-cell, is lined with a membrane, 
which secretes a mucous fluid: when, in con- 
sequence of an obstructed .surface, this fluid 
becomes abundant, it is expelled by the 
nostrils. The whole is invested with a 
thin, transparent membrane, named pleura : 
the same membrane lines the internal sur- 
face of the ribs and diaphragm, and, by a 



duplicature of its folds, forms a separation 
between the lobes of the lungs. 



RESPIRATORY SYSTEM. 

The function of respiration is the conver- 
sion of venous into arterial blood. This 
arterialization of the venous blood is a pro- 
cess highly essential to the well-being of 
all animals ; more important is it than the 
assimulation of aliment ; for a horse may 
live several days without food, yet cannot 
exist many minutes unless his blood be 
arterialized. 

In considering the function of respiration, 
our attention is first turned to the mechani- 
cal means by which the air is alternately 
admitted and discharged from the lungs. 
The mechanical act of respiration is divisi- 
ble into two periods, that of inspiration, 
during which air is drawn into the lungs so 
as to increase its volume and distend its 
parenchyma and expiration, during which 
process the aii- which had been so received 
is expelled. 

Inspiration is accompanied by enlarge- 
ment of the capacity of the thorax in its 
various dimensions. This is eflected by the 
action of different sets of muscles, operated 
on by the nervous system. The principal 
muscle of inspiration is the diaphragm. 

Among the secondary muscles employed 
in inspiration are those which articulate the 
ribs, viz., the intercostales. Each rib is 
capable of a small degree of motion on the 
extremity by which it is articulated with 
the vertebrag. This motion is chiefly for- 
ward and backward ; the intercostal muscles 
favor this motion, as they are disposed in 
two layers, each passing obliquely, but with 
opposite inclinations, from one to the adja- 
cent rib. There are two ways in which the 

(144) 



ANATOMY AND PHYSIOLOGY OF THE UORSB. 



145 



chest may be dilated : first, by the dia- 
phragm ; and secondly, by the intercostales, 
which elevate the ribs. In natural respira- 
tion, the horse breathes chiefly through the 
aid of the diaphragm. Should the respira- 
tion become quickened, the intercostales are 
employed, and, when the respiration is labo- 
rious, 1 he auxillray muscles of the abdomen, 
back, and sides, are brought into use. 

The glottis is opened during inspiration 
by Ihe muscles of the larynx. 

The expulsion of the air from the lungs 
constitutes expiration. This takes place 
as soon as the air which has been ex- 
pired has parted with its oxygen, and re- 
ceived in return a certain quantity of car- 
bonic acid gas and vapor. In regard to the 
elasticity of the lungs, it is now demon- 
strated that they possess no inherent power 
of elasticity other than that common with 
all membranous textures. Hence, if an 
opening be made in the sides of the chest, 
the lobes on this side collapse inconsequence 
of the pressure of air from without. 

We have next to inquire what changes 
have, in the meanwhile, been effected in the 
blood by the action of the air to which it 
has been subjected in the lungs. A visible 
alteration, in the fu'st place, is produced in 
its color, which, from being of a dark pm-- 
ple, nearly approaching to black, when it 
arrives at the air-cells by the pulmonary 
arteries, has acquired the bright, intensely 
scarlet hue of arterial blood, when brought 
back to the heart by the pulmonary veins. 
In other respects, however, its sensible 
qualities do not appear to have undergone 
any material change. Judging from the 
changes produced on the air which has 
been in contact with if, we are warranted in 
the inference that it has parted with a 
certain quantify of carbonic acid and of 
water, and that it has in return acquired a 
certain proportion of oxygen. Since it has 
been found that the quantify of oxygen 
absorbed is greater than that which enters 
into fhc composition of the carbonic acid 
evolved, it is obvious that at least the excess 
of oxygen is directly absorbed by the blood ; 

19 



ana this absorption constitutes, no doubt, 
an essential part of its arterializafion. 

It has been much disputed whether the 
combination which seems to be effected be- 
tween the oxygen of the air and the carbon 
furnished by the blood, occurs during the 
act of respiration, and takes place in the 
au--cells of the lungs, or whether it takes 
place in f h^ course of circulation. On the 
first hypothesis, the chemical process would 
be very analogous to the simple combustion 
of charcoal, which may be conceived to be 
contained in the venous blood in a free 
state, exceedingly divided, and ready fo 
combine with the oxygen of the air, and 
imparting to that venous blood its charac- 
teristic dark color ; while arterial blood, from 
which the carbon had been eliminated, 
would exhibit the red color natural to blood. 
On the second hypothesis, we must suppose 
that the whole of the oxygen, which disap- 
pears from the air respired, is absorbed by 
the blood in the pulmonary capillaries, and 
passes en with it into the systemic circu- 
lation. The blood becoming venous in the 
course of the circulation, by the different 
processes to which it is subjected for sup- 
plying the organs with the materials re- 
quired in the exercise of their respective 
functions, the proportion of carbon which it 
contains is increased, both by the abstrac- 
tion of the other elements, and by fhe addi- 
tion of nutritive materials prepared by the 
organs of digestion. The oxygen, which 
had been absorbed by the blood in fhe lungs, 
now combines with the redundant carbon, 
and forms with it either oxide of carbon, 
or carbonic acid, which is exhaled dm'ing a 
subsequent exposure fo the air in the lungs. 
Many facts tend strongly fo confirm our 
belief in the latter of these hypotheses. 



The larynx is fhe organ producing the 
voice of fhe animal. 

Situation. — It is joined fo fhc fop of fho 
frachea (or windpipe), and is placed in fhe 
throat, between the posterior and broadest 

* I'ercivaU's IlippopathoUigy. 



r4G 



ANATOIIY AND PHYSIOLOGY OF 



parts of the branches of the lower jaw ; 
having the pharynx and uppermost part of 
1heo?iophagtis situated above it; the supe- 
rior portions of the sterno-hyoidei and thy- 
roidei below it; the tongue, with its muscles, 
and the os byoidf'.s, in front of it; and the 
trachea issuing from below and behind it. 

Attachment. — The larynx is retained in 
its place by its connection ^v:ith the os 
hyoides and pharynx ; by its muscles ; and 
by its coalition with the trachea. 

Conformation. — The larynx has so com- 
])lete a fleshy covering, that it is not until 
it is divested of its muscles (which have 
been heretofore described) that it is dis- 
covered to be composed of five pieces of 
cartilage, so joined together as to be move- 
able on one another, and open both supe- 
riorly and inferiorly, to admit of the passage 
cif air into and out of the trachea. These 
cartilages have received the names of thyroid, 
cricoid (two), nrytenoid, and ejng-lottis. 

The thyroid or shield-like cartilage, by 
much the largest of the five, forms the 
sni)erior, anterior, and lateral parts of the 
larynx. It consists of two broad lateral 
portions, continuous and prominent at the 
upper and anterior part of the neck, the 
prominence corresponding to which in 
liuman anatomy has received the name of 
pom II m Adami. Below this point of union 
the divisions recede from each other, leaving 
a triangular space between them, which is 
occupied by a ligament denominated the 
ligamcntiim crico-thyroideum. The four 
projecting corners from the posterior parts 
of the thyroid cartilage are named its 
cornna: the two superior are joined by cap- 
illar articulations to the body of the os 
iryoides ; the two inferior are connected by 
very short capsular ligaments to the cricoid 
cartilages ; the union of all which parts re- 
ceiv(v^ additional strengtii from expansions 
of membrane. At the roots of the superior 
cornua are two foramina, that give passage 
to nerves, of considerable importance, to 
the interior of the larynx. This cartilage 
not only constitutes by far the most exten- 
sive [jart of the larynx, but, as its name in- 



dicates, incloses and shields from external 
injury all the others. 

The cricoid or ring-like cartilage is placed 
below the thyroid. In front it appears like 
part of the trachea ; but it broadens so 
much behind, that it overlaps the first ring 
of the windpipe, somewhat after the form 
of a helmet. Upon its broad or posterior 
part are four surfaces of articulation : the 
two upper receive the binder extremities of 
the arytenoid cartilages, the two lower are 
adapted to the inferior cornua of the thyroid 
cartilage : they are all furnished with cap- 
sular ligaments and synovial membranes. 
Furthennore, it is attached by ligamentous 
expansions to those parts, and likewise to 
the first ring of the trachea. 

The two arytenoid, or eioer-shaped car- 
tilages, triangular in their figure, lie over 
the upper and back part of the trachea, 
leaving an apertvu-e between them leading 
into that canal, denominated, from its prox- 
imity to the tongue, the glottis. Their 
inward parts are everted, and form a tri- 
angular prominent border, over which is 
spread the membrane of the glottis : their 
outward surfaces are marked by concavities 
in which are lodged the arytenoid muscles. 
Posteriorly, they repose upon the cricoid 
cartilage, and are connected with them by 
capsular articulations: in front, they have a 
membranous connection with the cartUage 
next to be noticed. 

The epiglottis, so named from being 
raised over the glottis, and occasionally 
covering it like the lid of a pot, is well 
adapted, from its heart-like shape, to the 
rima glottidis ; whose margin is completed 
by two narrow slips of cartilage proceeding 
from the base of the lid to the arytenoid. 
By some, these slips of cartilage have been 
separately considered : but in my opinion 
improperly so ; for they are, in reality, 
nothing more than prolongations or appen- 
dices of the epiglottis. The surface of thiri 
cartilage presented to the interior of the 
larynx is smooth and concave, and covered 
by an extension of membrane from the 
glottis ; that part opposed to the tongue is 



THE UORSE. 



U7 



unevenly convex, and is tied to that organ, ' opposite to the body and transverse proces- 
as well as to the os hyoides, by a doubling' ses of the atlas; takes its course along the 
of membrane infolding some muscular ' anterior and inferior part of the neck, inclin- 
fibres: to thismusculo-membranous Ligature, I ing to the near side, between the sterno- 



whieh assists in retaining the cartilage in 
its ole\ated position, the name oi fr<enum 
epig-lotlirlis is properly given. The fi-a;ni;m 
receives co-operation in this function from 
strong elastic ligaments connecting the base 
of the epiglottis to the thyroid and arytenoid 
cartilages. 

If we detach the epiglottis, or raise it 
forcibly in order to obtain a more complete 



myloidei muscles (which by their approx- 
imation conceal the lower portion of it), 
and enters the chest between the two first 
ribs; wherein, under the curvature of the 
posterior aorta, it divides into two parts the 
bronchial tubes. 

Slructure. — From fifty to sixty annular 
pieces of cartilage enter into the com- 
position of the windpipe; altogether con- 



\-ievv of the rima glottidis, the latter will be | stituting a structure so remarkable, for the 
found to be stretched into an oblong quad- j inequality or . asperity of its exterior, that 

the ancients, in order to at once distinguish 
it from all other vessels, called it the aspcra 
arteria. No entire or undivided tubular 



substance could have partaken of the various 
motions of the head and neck, without 
having suffered more or less distortion, and 
consequent deformity and diminution of 
caliber, of some part of its canal, which 



rilateral figure, whose width gradually 
diminishes from the middle towards either 
extremity, and bears a ratio of about one 
to six when compared to its length. The 
sides turned forward are formed by the 
arytenoid cartilages ; those directed back- 
ward by two prominent folds of membrane 
(which envelop the th\TO-arytenoid luus- 
cles), commonly described as the rocal lig-a- would have been attended with frequent iii- 
ments, from their being concerned in the i terruptions to the free passage of the air, 
formation and intonation of the voice. \ dangerous, and even fatal, to the respiratory 
Immediately over them are slit-like aper- ; functions ; whereas, constructed as it is, 
tm-es, opening into membranous sacs, each j with the aid of its muscular power, no at- 
large enough to contain a walnut ; these ' titude into which the animal may naturally 
are the ventricles of the larynx, whose use j put himself will impede the freedom of pas- 
is also connected wdth the production and ' sage through it. The cartilages, or, as they 



modulation of the voice. 

The membrane lining the cavity of the 
larynx is one of great susceptibihty ; on 
which account it is kept continually moist 
by a mucus, oozing from numerous lacuna 
— the excretory orifices of small subjacent 
follicles whose situation is denoted by the 
little round eminences upon its surface. 
This is the common seat of that species 
of catarrh which is acxjompanied by cough. 

OF THE TRACHEA. 

The ti-achea, or windpipe, is a cartilagin- 
ous tube extending aloiu^ the neck, from 
the iaryjix to the lungs, for the passage of 
air. In horses of ordinary size, it is from 
twenty-five to tiiirty inches in Icngtli. 

Course. — The trachea commences from 
the inferior border of the cricoid cartilage. 



are commonly described, the rings of the 
windpipe, have all a close resemblance to 
one another : if there be any disparity be- 
tw^een them worthy of notice, it consists in 
those that form the superior part of the pipe 
being somewhat larger and broader than 
those nearest to the bronchial tubes.* A 
ring is not uniform in its breadth, in conse- 
quence of having waving or scolloped bor- 
ders ; the advantage of which is, that a sort 
of dove-tailed connection is cfiected whieii 
materially contributes to the compactness 
and strength of the entire structure. Its 
front and sides measure, in the broadest 
places, half an inch in breadth, and nearly a 

* Now and then we find, at the upper part of the tube, 
two or three or more of these rinjis accreted to-jether : it 
cives rise to sonic proniinenee there:il)(iuts ■ generally, and 
may often be detected by taction iu the living animal. 



148 



ANATOMY AND PHYSIOLOGY OF 



quarter of an inch in thickness — evidently 
made so substantial to resist external in- 
jury; whereas its posterior or unexposed 
parts grow suddenly thin and yielding, and 
taper to the extremities; which, instead of 
meeting and uniting, pass one over the 
other, and thus form a shield of defence 
behind, while they admit of a certain dila- 
tation and contraction of the internal 
dimensions of the tube. These attenuated 
ends arc joined together by a ligamentous 
expansion, mingled with a quantity of cel- 
lular membrane. The rings are likewise 
attached to one another by narrow ligamen- 
tary bands, strong and elastic ; which, after 
they have been drawn apart in certain posi- 
tions of the head and neck, have the power 
to approximate them ; when the pipe is re- 
moved from the body, and suspended by 
the uppermost ring, these ligaments coun- 
teract the tendency its weight has to sepa- 
rate the rings, and still maintain them in 
apposition. The lowermost ten or twelve 
pieces of cartilage appear on examination 
but ill to deserve the name of rings ; indeed, 
they are little more than semi-annular, the 
deficiences in them behind being made 
good by intermediate moveable pieces of 
cartilage. These pieces, whose breadth in- 
creases as we descend, are let into the 
vacuities in such manner as to overlap the 
terminations of the segments, and they are 
confined and concealed by the same sort of 
ligamentary and cellular investment as was 
before noticed. 

Muscle. — Where the outward extremity 
of the ring suddenly turns inward, and de- 
generates into a thin flexible flap on either 
side, a band of muscular fibres is fixed and 
stretched across the canal, dividing it into 
two unequal semi-elliptical passages. The 
anterior one is the proper air channel; the 
posterior or smaller one is filled with a fine 
reticular membrane, connecting the band to 
the posterior part of the ring, and preventing 
it in aclion, from encroaching upon the main 
conduit. This self-acting band appears to 
me to have been added to the tube to enable 
it to enlarge its caliber — not to diminish it, 
as a superficial view of these parts might 



lead one to imagine ; for, in consequence of 
the passage being naturally elliptical, and 
the muscle being extended across its long 
diameter, the contraction of its sides will 
give the tube a circular figure, by increasing 
the curvature of the ring anteriorly, and 
thereby, in effect, will expand and not con- 
tract the caliber of the canal. I would say, 
then, that the trachea was made muscular 
in order that it might have the power of in- 
creasing its capacity for the passage of air, 
whenever the lungs Avere called into extra- 
ordinary action : in addition to which, I 
think that this band may, in some degree, 
counteract any tendency certain positions of 
the head and neck have to alter its shape 
and diminish its circumference. This 
opinion is con-oborated by the circumstance, 
that the muscle grows slender and pale as 
wc approach the lower end of the pipe, 
where the canal itself is nearly circular, and 
where it is placed in the least moveable 
part of the neck.* 

Membrane. — The ti-achea is lined by a 
soft, pale red membrane, which anteriorly 
has a close adhesion to the rings them- 
selves, and presents a smooth, pohshed in- 
ternal surface ; but which, posteriorly, is 
loosely attached to the muscular band, and 
puckered into fourteen or fifteen longitu- 
dinal jilica: or folds, that extend with regu- 
larity from one end of the tube to the 
other. These folds were evidently made to 
allow of the contraction and elongation of 
this muscular band ; for I cannot myself 
assign any reason why they should exist in 
its relaxed state, unless this fulness of 
membrane be given to admit of enlarge- 
ment of the caliber of the tube during the 
contractions of that muscle ; if this be 
plausible, I may adduce the corrugation of 
the membrane as another proof that the 
caliber of the trachea is susceptible of aug- 
mentation. This membrane is continuous 
with that which clothes the rima glottidis ; 

* In tliis opinion, says Mi-. I'ercivall, I find I am at 
variance with Girard. Tlie Frcni'i fimf't'ssor as<'i'il)es to 
it the power of ronlrartinr/ the mUlier of the trachea. " Cetto 
conelie, bien evidemment mii.sculense, pent rctivri r Ir ral- 
ibrc do hi trachee, en rnpportant les cxtremites des seg- 
mcns."^ — Anat. let., p. 146 et 147, torn. ii. 



THE HORSE. 



149 



but it is paler than it, and not near so sensi- 
tive. Its arterial ramifications, also less 
abundant than upon the glottis, exhale a 
vapor from its surface ; independently of 
which, it is kept continually lubricated by 
mucus, furnished from its numerous lacuna, 
to defend it from anything acriminous that 
may be contained in the breath. 

Bronchial Tubes. — The trachea having 
entered the thorax, bifurcates into the t\vo 
brondiial tubes. Of them, the right is the 
more capacious canal, on account of having 
communication wWh the larger division of 
the lungs ; the left the longer one, in conse- 
quence of having to cross under the pos- 
terior aorta, in its course to the left division 
of the lungs. The last cartilage of the 
main pipe has a spear-lilce or angular pro- 
jection extending down between the bron- 
chial tubes, filling up that space which 
would otherwise be left open from the di- 
vergent manner in which they branch off: 
it i.^ quite loosely attached, in order that 
the branches may accommodate themselves 
to Ihe motions of the neighboring parts. 
The bronchial tubes vary in structure from 
the trunlc that gives origin to them: instead 
of their rings being formed of entire pieces 
of cartilage, they are constituted of several 
sej)arate pieces, makingup so many segments 
of the circle, overlapping one another, and 
united together and invested by an elastic 
cellular substance: they also differ in hav- 
ing no muscular band,another factcoiuiected 
with the physiology of that part. The bron- 
chial tubes, in penetrating the substance of 
the lungs, subdivide — the right into three 
principal branches, the left into two ; from 
which spring inimmerable others, that grow 
smaller and smaller, until the ramifications 
become so reduced that they are no longer 
traceable by the naked eye. In the larger 
branches, we may dissect out five and even 
six segments of cartilage, held together by 
a thin but dense and elastic cellular sub- 
stance ; in the smaller divisions, only two 
are found, and they are diminished in size ; 
and, in the smallest visible ramifications of 
all, cartilage is altogether wanting, though, 
in many places, marks of the rings may be 



traced upon the continuation of the lining 
membrane, which in these intimate parts 
compose the entire parietes of the tube. 
In the larger branches this membrane 
(which is continuous throughout the bron- 
chial system) assumes a plicated disposi- 
sition — apparently, to admit the more 
readily of expansion. 

THYROID GLANDS. 

Two egg-shaped, apparently glandular 
bodies, attached just below the larynx to 
the sides of the trachea, and united in front 
of that tube by an intervening portion of 
the same substance, which, by way of dis- 
tinction, is by some called the isthmus. 
They are enveloped and attached in their 
situation by cellular membrane ; are larger 
and more vascular in the young than in 
the old subject; and exhibit a spongy tex- 
ture, when cut into, which I am at present 
ignorant of the precise nature of. They 
are well supplied with blood-vessels, and 
have many small nerves going to them. 
Their physiology still remains obscure. 

OF THE LUNfiS AXD PLEURA. 

The lungs are the essential organs of res- 
piration: the pleura is but the membrane 
by which they are invested. 

PLEURA. 

The pleura is a fine, semi-transparent 
membrane, lining the cavity of the chest, 
and giving a covering to the lungs. By 
that portion of it which is called the medi- 
astinum, the cavity is divided into the right 
and left sides of the thorax. 

General Conformation. — If the lungs be 
exposed, by breaking off one or \\\o of the 
ribs, we shall perceive that their surface, as 
well as that of the cavity itself, is every- 
where smooth, polished, and humid. This 
is owing to the extensive investment of the 
pleura, the- surface of which is now pre- 
sented ; so that, in reality, without break- 
ing the surface, nothing but pleura can be 
touched ; although, from its extreme tenuity 
and pcllucidity, the viscera appear, on a 
superficial view, to present their own bare 



150 



ANATOMY AND PHYSIOLOGY OP 



exterior. Its other side, on the contrary, is 
rough, having jiumerous cellular flocculent 
appendages, Ijy wliich it is united to the 
parts it invests ; and so close and firm are 
these adhesions, that to cleanly detach it, 
in the recent subject, is a very difficult and 
tedious dissection. 

The pleura is a rejlecfed membrane ; by 
which is meant, one that not only lines the 
cavity in which the viscera lie enclosed, but 
by duplicature, or what in anatomical lan- 
guage is called reflection, gives a partial or 
complete covering to the contained organs 
themselves. It is evident, therefore, that 
such a membrane admits of division into 
two portions — a lining or parietal, and a 
reflected portion ; and these, with regard to 
the pleura, have, for the sake of more de- 
finite description, received the names of 
pleura costalis and pleura pidmonalis. They 
are both, however, continuous at all points, 
are precisely similar in structure and func- 
tion, and, in fact, are still but one and the 
same pleura. 

Mediastinum. — There is yet a third por- 
tion of th's membrane to which a distinct 
appellation has been given, and that is the 
mediastinvm, the membranous partition be- 
tween the cavities or sides of the thorax ; 
it differs from both the others in being com- 
posed of two layers, which are derived from 
the two pleura; of the opposite sides. 
If we conceive Ihe pleurae of the two sides 
of the thorax to be perfect sacs or bags, 
with flattened sides turned inwardly, and 
closely applied and united together, in such 
a manner that the double membrane formed 
by their union extends through the middle 
of the chest, from the dorsal vertebrce to 
the sternum, we shall at once have a toler- 
ably correct idea of the formation as well 
as situation of the mediastinum. 

Structure. — The pleura, from the nature 
of its secretion, is one of those included 
in the list of serous membranes to which it 
has been demonstrated also to be similar in 
its intimate organization. Like them, it 
presents a shining secreting surface, of a 
whitish asjicct, and considerable transpa- 
rency, and is composed of little else than 



condensed cellular substance, whose texture 
is penetrated by blood-vessels, absorbents, 
and nerves : by long maceration in water, 
indeed, it may be entirely resolved into cel- 
lular substance. In most parts it is ex- 
tremely thin, and by no means tough ; but 
it is not so in all, for that portion which 
faces the diaphragm is much denser and 
stronger than the pulmonary or costal di- 
vision of it. 

Organization. — The arteries of the 
pleura, which come from the adjacent parts, 
are in the natural state exceeding small, ad- 
mitting only the colorless parts of the blood 
— a circumstance that accounts for its pel- 
lucidity ; under inflammation, however, 
they contain red blood, and such is the ex- 
planation of that arborescent vascularity 
upon the sides of the thorax in horses that 
die of pnuemonia ; than which state noth- 
ing can better demonstrate the comparative 
number and distribution of these blood-ves- 
sels. The majority of them terminate in 
exhalent orifices, from which is continually 
poured, upon the contiguous surfaces of the 
smooth interior of the membrane, a serous 
fluid, in the form of steam or vapor, which 
may at any time be rendered visible by 
opening the chest of an animal recently 
dead. The absorbents of this membrane 
are very numerous; and, though their ex- 
treme exility prevents us from demonstrat- 
ing them in a state of health, yet may they 
often be seen in considerable numbers in 
horses that die of dropsy of the chest ; we 
have also abundant proofs of their exist- 
ence from various phenomena that occur 
in the diseases of the part. We know, for 
instance, that these vessels take up the 
serous fluid effused in hydrothorax, for they 
have been found full of it after death; and it 
is a fact that no longer admits of doubt, that 
blood, extra vasated into the chest, is absorbed 
by the mouths of these minute vessels. 

The nerves of the pleura are too small 
to be traced by dissection ; but, though it 
is not possessed of much sensibility in a 
healthy state, we know, at least we presume 
from analogy, that it is highly sensitive in 
the diseased; for few diseases are more 



EXPLANATION OF FIGURE XV. 



NO. 1. — FORE EXTREMITIES. 

LATERAL \TE\V OF TIFE OFF-FORE LIMli. 

k. Humero cubital. — Flexor brachii. 

71. Triceps externus. 

o. PectoraKs transversalis. 

P". Flexor metacarin externus. 

s". Extensor metacariii magnus. 

V. Extensor metacarpi obliquus. 

u'. Levator humeri. 

X. X. Extensor pedis. 

y. y. Extensor suffraginis. 

S,: The hoof. 

NO. 2. 

(VIIW AS ABOVE.) 

Ic". Humero cubital, or flexor brachii. 

m". n". Two of the triceps extensor brachii. 

p". Flexor metacarpi externus. 

s. Extensor " magnus. 

f. " " obliquus. 

u. Levator humeri. 

«'. u. Flexor tendons. 

x". Extensor pedis. 

y". y. Extensor suffraginis. 

8. Perforatus et perforans. 

4. Subcutaneous thoracic vein. 





NO. 3. 




(THE SAME VIEW.) 


r. 


m". n". Triceps extensor brachii. 


p\ 


Flexor metacarpi externus. 


9- 


Extensor suffraginis. 


S. 


Extensor metacarpi magnus. 


w. 


Flexor tendons. 


x". 


Extensor jicdis. 


z. 


Suspensoiy ligaments. 


4. 


Subcutaneous thoracic vein. 




NO. 4. 




OSSEOUS STRUCTLTIE, 


34. 


Os humeri. 


/• 


(Js ulnaris. 


35. 


Os Radialis. 


9- 


Trapezium. 


36. 


Ossa car])i. 



EXPLANATION OF riGtTEE XV. CONTINUED. 

37. Metacarpi magnum. 
X. " parvum . 

38. Ossa sesamoidea. 

39. Os suf&aginis. 

40. Os corona'. 

41. Os pedis. 

NO. 5. 

INSIDE VIEW OF THE OFF-FORE LEG. 

o". Pectoralis transversus. 

»•". Flexor metacarpi internus. 

5". Flexor metacarpi medius. 

s". Extensor metacarpi magniis. 

t". Extensor metacarpi obliquus. 

m". v". Flexor tendons. 

X. Extensor pedis. 

u". Suspensory ligament. 

C. Radial vein. 

8. Bifurcation of the suspensory ligament. 

2. Splent bone. 

&. Inferior border of the hoof. 



THE HORSE. 



151 



acutely painful in the human subject than 
pleurisy, and we have every reason to be- 
lieve tiiat horses sutler much from the same 
malady. 

Secretion. — It has been observed that 
the exhalents of the pleura secrete a serous 
fluid, which is emitted, in the form of an 
exhalation or vapor, into the cavity of the 
thorax ; and that it may be rendered visible 
at any time, if an animal, recently dead, 
be opened while yet warm ; or if an o]>en- 
ing be made into the chest of a live animal. 
In either case, a whitish steam will be per- 
ceived to issue from the interior of llie 
cavity. This vapor, shortly after death, be- 
comes condensed and converted into a 
liquid; which accounts for the contiguous 
surfaces of the pleura being moist, and for 
a collection of more or less fluid, resem- 
bling water, existing in the most depending 
parts of the cavity. In consequence of 
every part of the membrane being bedewed 
in this manner, the lung itself may be said 
to be in an insulated state ; for the pleura 
costalis does not, philosophically speaking, 
touch the pleiu-a pulmonalis, nor is the lat- 
ter ill actual contact with the mediastinum : 
all friction, therefore, in the motions of these 
parts, is by this interfluent secretion effec- 
tually prevented. In this, then, consists 
the chief use of the pleura, viz., to furnish 
a secretion for the purposes of lubrication 
and facility of motion, which it further 
promotes by its extreme glibness of surface. 
It is said also to answer the purpose of 
lig'aments to the contained organs, thereby 
confining and sh'cngthening them. The use 
of the mediastinum is to divide the chest 
into two compartments. 

LU.XGS. 

The lungs (by butchers called the lig-lils) 
are two spongy bodies formed for the pur- 
pose of respiration. 

Situation and Relation. — They arc con- 
tained in the lateral regions or sides of the 
thoracic cavity ; separated from each other 
by the mediastinum and heart, which occupy 
the middle region. Prior to any opening 
being made into the thorax, the lungs con- 



tinue to fill up ever}' vacuity : no sooner, 
however, is a perforation made into the 
thoracic cavity than they shrink in volume, 
and become in appearance too small for the 
spaces they occupy. This arises from their 
being during life — or rather during the 
unopened state of the thorax — in a con- 
stant state of inflation vriXh atmospheric 
air, which preserves them expanded ; and 
they suffer collapse of substance the instant 
air is admitted, in consequence of the pres- 
sure of the atmosphere upon them, from 
which they were protected before by the 
parietes of the thorax. 

Division. — The lungs are two in num- 
ber, the right and the left lung; parti- 
tioned from each other by the mediasti- 
num. A further division of these organs 
has been made into lobes. That on the 
right side, the larger of the two, consists of 
three lobes ; the left, only of two. These 
lobes, which are nothing more than partial 
divisions of the lung by fissures of variable 
extent through its substance, serve to adapt 
them more accurately to the thoracic cavi- 
ties, and, at the same time, render them 
fitter for the purposes of expansion and 
contraction. 

Volume. — The lungs of the horse, when 
inflated, are of great bulk ; * and the right 
is the larger of the two : in consequence of 
the heart being inclined to the left side, less 
space is given for the left lung. 

Attachment. — The lungs are attached, 
superiorly, to the spine (which attachment 
is sometimes called their roots) by blood- 
vessels, the divisions of the trachea, and the 
mediastinal portions of the pleura: every- 
where else, in a healthy subject, they are 
free and unconnected. 

Figure. — In form, the lungs of the horse 
are very like those of the human subject ; 
and the latter have been compared to the 
foot of an ox, to which the injected lung of 
the fostus l)ear3 indeed much resemblance ; 
for, though the two lungs are nut symmetri- 
cal, yet, both together, they put on this 
shape, which is the counterpart of tliat of 

* I consider, in comparison wiih the body, tliat tlicy 
exceed in magnitude those of tlic human subject. 



152 



ANATOMY AXD PHYSIOLOGY OF 



the cavity they occupy. With regard to 
their general figure, however, the lungs may 
be said to be conical : being broad and con- 
cave posteriorly, where they are opposed to 
the convex surface of the diaphragm ; nar- 
row and somewhat pointed anteriorly, where 
they are received into the blind pouches of 
the pleura, in the space between the two 
first ribs. 

Color. — In color, these organs vary some- 
what, depending upon the age of the ani- 
mal, and upon the quantity and distribution 
of the blood they contain. In the young 
subject, they are of a lighter and more uni- 
form shade than in the adult. In perfect 
health they assume a pink hue ; which, as 
age advances, becomes mottled with purple 
and grayish patches. Sometimes, in the 
dead subject, they are found of the color of 
the darkest venous blood, which arises from 
an inordinate congestion of that fluid within 
the pulmonary veins. 

Structure. — The lungs are composed of 
the branches of arteries and veins, and of 
the ramifications of the trachea ; all which 
vessels are connected together by an abun- 
dant intervening cellular substance, knov/n 
by the name of parenchijma. Beneath the 
curve made within the chest by the poste- 
rior aorta, the trachea divides into the two 
bronchial tubes, of which the right is the 
larger, but the shorter; the left the longer, 
in consequence of having to pass under the 
aorta in order to reach the left lung. Having 
entered the substance of the lung, the right 
tube divides into four others ; the left only 
into three ; which difTerence arises from the 
riglit lung possessing an additional lobe. 
These branches may be traced for a consid- 
erable extent within the parenchyma, giv- 
ing off in their passage numerous other 
smaller tubes of similar sti'ucture ; but, as 
we prosecute our dissection of them, w"e 
shall find that, in growing smaller, they par- 
take less and less of the nature of cartilage, 
and that the extreme ramifications are not 
only entirely membranous in their composi- 
tion, but of so fine a texture as to be per- 
fectly transparent. It will be remembered 
here, that, in speaking of the trachea, a 



membranous lining to it was described of 
the mucous kind, which, it was observed, 
thence passed into the bronchial vessels : 
now, it is of the continuation of this mem- 
brane in an attenuated state that the minute 
air-tubes appear entirely to consist; at the 
extremity of every one of wliich the mem- 
brane is prolonged into a kind of blind bag, 
or cul-de-sac, to which the name of air-cell 
has been given. 

From the arborescent ramification and 
peculiar mode of termination of the bron- 
chical tubes, some anatomists have com- 
pared them, and the cells at their extremities, 
to a bunch of grapes — supposing the stalks 
to represent the ramifications of the former, 
and the grapes connected with them the 
air-cells; others have described them as 
having resemblance to a honeycomb : and 
so far as the knife, with the aid of glasses, 
can develope their intimate structure, the 
first is an apt comparison, insomuch as it 
relates to the disposition of their cells ; 
the last, insomuch as it conveys an 
idea of their ready inter-communication. 
For, though they do not communicate 
but through the ramifications of the bron- 
chial tubes, this is a medium of inter- 
course at once so general and free, that 
numbers of them are inflated at the same 
time by impelling air into any one of the 
larger branches. With the parenchymatous 
substance, however, they have no commu- 
nication whatever.* 

The blood-vessels that enter into the com- 
position of the lungs are denominated the 
pulmonary. The pulmonary artery, having 
taken its origin from the right ventricle of the 
lieart, winds upward to the root of the left 
lung, and there divides into the riglii and 
left pulmonary arteries, which divisions 

* If tlie sulistancc of tlio kings be larerated or vent 
asunder, tlic surface will be Ibunil to present a luhuhiled 
aspeet. Introduec a blo\v-]iipe into one of these lolmli, 
and all the other lobules — tlie cnlire lung — maybe in- 
flated from this one \ sliowinj; the free communication cx- 
istin};- between them. The same may be eilected by in- 
jecting iniicksilver. You may do tlie same with the inter- 
stitial substance ; but in tliis case you do not KU tlie loliules. 
In fine, the lungs with their cells resemble a sponge; only 
that the connecting tissue has no communication with the 
sponge. 



THF HORSE. 



153 



enter their correspondent lungs. Tlie rami- 
fications of these vessels (which differ from 
other arteries in having no anastomotic 
communications one with another) accom- 
pany those of the bronchial tubes, and, 
like them, divide and subdivide, grow 
smaller and augment in number, as they 
approach the air-cells ; upon the internal * 
surfaces of which they become capillary, 
and assume a texture of correspondent 
thinness and pellucidity with the cells them- 
selves. Through these minute vessels every 
particle of blood is impelled every time it 
is circulated over the system, as was stated 
when on the blood : a remarkable change 
of color is thereby effected in it, and we 
have now an opportunity of seeing in what 
manner this fluid is exposed to the intluence 
of atntospherie air for the purpose. It is 
evident that no immediate contact can hap- 
pen between the air and the blood, for the 
thin, transparent side of the vessel, if not 
that of the air-cell likewise, must ever be 
interposed ; so that, whatever this influence 
be, it must take efiect through one or other 
or both of these membranes. We might 
conceive, indeed, that such minute vessels 
could not transmit through them such a 
body of fluid as the blood ; but, when we 
look at the volume of the lungs, and con- 
sider the incalculable number of air-cells 
they must contain, the globular surface of 
every one of which is furnished with an ex- 
pansion of pulmonary vessels, we shall feel 
more surprise and admiration at the extreme 
division and diffusion of this fluid in order 
to receive the necessary change, than that 
.such a prodigious number of capillaries 
should be equal, iji their united caliber, to 
the pulmonary artery itself. 

From the extremities of the arteries, upon 
the surface of the air-cells, arise the pul- 
monary veins. These, by repeated union 
with one another, form themselves, first, into 
visible branches, which subsequently become 
branches of larger size, until at length they 
end in eight pulmonary venous trunks, 
whicii proceed to, and by four openings ter- 

• Some say, " upuu tlic externul surfaces." 
20 



minate in, the left auricle of the heart. The 
ramiiications of these veins, unlike tlie 
generality of others, are not more numerous 
than those of their correspondent arteries : 
and tlie reason for this is obvious; for, here, 
one set of vessels are not more subject to 
compression than the other, nor does the 
heart (which is so proximate to them) re- 
quire any such aid as an additional number 
of veins affords to carry on the circulation. 
The pulmonary veins have only to convey 
the blood back to the heart, after it has 
received its due change within the capil- 
laries upon the air-cells. 

Organization. — Besides the pulmonary 
blood-vessels, there are two others, named 
bronchial arteries. They come off, by one 
trunk, from the posterior aorta, and each 
of them enters a division of the lungs, in 
the substance of which it branches forth, 
an.d takes the course of the bronchial tubes. 
These tubes they supply, as well as the coats 
of the pulmonary vessels, and the paren- 
chyma of the lungs, with blood : in fact, 
they may be regarded as the nutrient ves- 
sels of these organs. It has been, however, 
and still remains, a subject of dispute, 
whether these vessels do exclusively nourish 
the substance of the lungs or not ; some 
say that they do ; while others assert that 
they are assisted in this function by the pul- 
monary artery, with some of the branches 
of which they anastomose. The latter 
opinion certainly docs not appear to be sup- 
ported by facts of much weight; on the 
contrary, the blood which the pulmonary 
arteries contain is dark-colored, and unfit 
for the nutriment of any organ ; and as for 
anastomosis, we have no demonstrative 
proof of its existence. The bronchial veins 
end in one trunk, which returns the blood 
into the vena azygos. 

The nerves of the lungs are derived prin- 
cipally from a large plexus within the chest, 
constituted of the par vagnm and sympa- 
thetic. They enter the pulmonary structure 
in company with the bronchial tubes and 
blood-vessels, and continue their course 
with them, to be dispersed upon the bron- 
chial membrane and parietes of the air-cells. 



151 



ANATOMY AND PHYSIOLOGY OF THE HORSE. 



The absorbents of the lungs are large and j 
numerous, particularly the deep-seated : and 
of the superficial, we may often succeed in 
injecting considerable numbers, by intro- 
ducing a quicksilver-pipe under the pleura 
pulmonalis. They all pass through the 
absorbent glands situated around the roots 
of the bronchial tubes. 

Parenchyma. — The connecting medium 
of the various constituent parts of these 
organs, or, as it is termed, their parenchyma, 
appears to consist of little else than cellular 
tissue, without any intermixture of adipose 
matter : it admits of the free diffusion of 
any fluid that may be extravasated into it 
■ — of air that may have escaped from the 
air-cells, or of serous fluid poured out when 
the lungs become anasarcous ; but, as was 
observed before, there is no intercommuni- 
cation between it and the cells or vessels, as 
long as the organs preserve their integrity 
of structure. 

Specific Gravity. — The lungs, when 
heakhy, are exceeding light in comparison 
to their volume ; so that, if they be immersed 
in water, unlike most other parts, they wiU 
float upon the siuface, — a fact familiar to 
every one who has seen the liver and lights 
of an animal thrown into a pail of water 
to be washed : indeed, the name of lights 
itself seem to have been given to them from 
this very property. If the fcetal lungs, how- 
ever, be so treated, they will instantly sink 
to the bottom of the vessel : and this ex- 
perimental result at once shows why those 
of an animal that has once breathed should 
swim ; for, in the one instance they contain 



air, in the other they are wholly free from 
it. They are not to be regarded as respi- 
ratory organs in the foetus. It is evident, 
therefore, that the lungs owe their property 
of lightness to the air they contain ; and, as 
a further proof of it, if that air be by any 
means absorbed or pressed from them, and 
their bulk chminished by collapse of the 
air-cells, like other viscera, they will prove 
heavier than an equal volume of water : 
hence it is that the lungs of a horse that 
has died of hydrothorax, even though they 
be' sound, are of a greater specific gravity 
than those of one in health. It occasionally 
happens, however, that these viscera evince, 
in this particular, the properties of airless 
lung, while their natural volume and general 
appearance remain the same : there must be 
present interstitial deposition. 

BRONCHIAL GLANDS. 

Small, oval-shaped, glandular-looking 
bodies, situated about the roots of the lungs, 
adhering more particularly to the bottom 
of the trachea and the bronchial tubes. 
They exhibit a dirty French gray hue, inter- 
spersed with dark blueish spots, and are 
about the volume (though this varies much) 
of a tick-bean. For a long time the nature 
of these bodies remained obscure : of late, 
skilful injections have clearly shown them 
to be absorbent glands. They possess then- 
capsules, and, when cut open, exhibit a cel- 
lular structure. They contain a dark fluid, 
which will soil anything it touches ; whose 
principal ingi'edient chemists have found to 
be carbon. 



CIRCULATORY SYSTEM. 



PRELIMINARY REMARKS (oN THE BLOOD, 

ETC.). 

The appearance of blood is familiar to 
most persons. It contains the elements for 
building up and nourishing the whole ani- 
mal structure. On examining blood with a 
microscope, it is found full of little red glo- 
bules, which vary in their size and shape in 
different animals, and are more numerous 
ill warm than in cold-blooded animals; 
probably this arises from the fact that the 
latter absorb less oxygen. If the blood of 
one animal be ti-ansfused into another, it 
will frequently cause death. 

When blood stands for a time after being 
drawn, it separates into two parts. One is 
called serum, and resembles the white of an 
egg ; the other is the clot or crassamentum, 
and forms the red coagulum, or jelly-like 
substance : this is accompanied by whitish, 
tough threads, called fibrine. AVhen blood 
has been drawn from a horse, and it as- 
sumes a cupped or hollow form, if serum, 
or buffy coat, remain on its surface, it de- 
notes an impoverished state ; bat if the 
whole, when coagulated, be of one uniform 
mass, it indicates a healthy state of this 
lluid. The blood of a young horse gen- 
erally coagulates into a firm mass, while 
that of an old or debilitated one is gen- 
erally less dense, and more easily divided or 
broken down. The power that propels the 
blood into the different ramifications of the 
animal, is a mechanico-vital power, and is 
accomplished through the medium of the 
heart and lungs; the former is a powerful 
muscular organ contained in the chest. 
From certain parts of it arteries arise ; in 
others the veins terminate ; and it is princi- 
pally by its alternate contractions and ex- 
pansions, aided as already stated, tiiat the 
circulation of the blood is carried on. The 



heart is invested with a membranous sac, 
called pericardium, which adheres to the 
tendinous centre of the diaphragm, and to 
the great vessels at the base of the heart. 
The heart is lubricated by a serous fluid 
within the pericardium, which guards 
against friction. In dropsical affections, 
the quantity of this fluid is considerably in- 
creased, and constitutes a disease called hy- 
drops pericardii. The heart is divided into 
four cavities, viz., two auricles, named from 
their resemblance to an ear, and two ventri- 
cles, forming the body. The left ventricle 
is smaller than the right; but its sides are 
much thicker and stronger : it is from this 
part that the grand trunk of the arteries 
proceeds, called the great aorta. The right 
cavity, or ventricle, is the receptacle for the 
blood that is brought back by the veins 
after going the rounds of the circulation.; 
which, like an inverted tree, become larger 
and less numerous as they approach the 
heart, where they terminate in the right 
auricle. The auricle on the left side of 
the heart receives the blood that has been 
distributed through the lungs for ])uriiica- 
cation. Where the veins terminate in auri- 
cles, there are valves placed. The coronary 
vein, which enters the right auricle, has its 
mouth protected by a valve called semi- 
lunar, or half-moon shape, which opens only 
toward the heart, and prevents the blood 
taking a retrograde course. The different 
tubes coming from and entering into the 
heart are also provided with valves to pre- 
vent the blood' from returning. For exam- 
ple, the blood proceeds out of the heart, 
along the aorta; the valve opens forward oj 
upward, the blood also moves upward, and 
pushes the valve asunder, and passes 
through ; the pressure from above effec- 
tuallv closes the passage. The valves of 



156 



AXATOMV AND PHYSIOLOGY OF 



the heart are composed of elastic cartilage, 
which enables them to work with ease. In 
some diseases, however, they become ossi- 
fied. This, of course, is fatal. The heart 
and its appendages are also subject to other 
diseases, called dilatation, softening, hard- 
ening, etc. Now, the blood, having been 
brought from all parts of the system by 
the veins, enters into the vena cava ante- 
rior and posterior, which empty them- 
selves into the right auricle ; and this, 
when distended with blood, contracts, and 
forces its contents into the right ventricle, 
which, contracting in its turn, propels the : 
blood into the pulmonary arteries, whose 



luimerous ramifications bring it in con- 
tact with the air-cells of the lungs. It 
then assumes a crimson color, and is then 
adapted to build up and supply the waste. 
Having passed through the vessels of the 
lungs, it continues on, and passes into 
the left auricle: this also contracts, and 
forces the blood through a valve into the 
left ventricle. This ventricle then con- 
tracts in its turn, and the blood passes 
through another valve into the great aorta, 
from which it is distributed into the whole 
arterial structure : after going the rounds of 
the circulation, it is again retmuied to the 
heart by the veins. 



EXAMINATIONS ON THE NATURE AND PROPERTIES OF BLOOD. 



Q. What are the properties of blood? — A. In 
lieahh, it is a smooth homogenous fluid, of unctuous 
adhesive consistence, of a slightly sahne taste, and of a 
B])ecific gravity somewhat exceeding that of water. It 
exhales a vapor wliich has a pecuhar odor ; this, how- 
ever, differs in various animals. 

Q. Does the blood always preserve the same den- 
sity ? * — A. No. Its density is Hable to great variations, 
under the states of rest, labor, disease, and health. 

Q. What do you understand by the " crassamenium" 
of the blood? — A. It is supposed to consist chiefly 
of fibrin. 

Q. How is it colored ? — ^1. It owes its peculiai- color 
to what is termed the red globules, which are entangled 
in it during its coagulation. 

Q. How can this be demonstrated? — A. By long 
continued ablution in water, the red particles are liber- 
ated ; and we have remaining a white, solid, and elas- 
tic substance, which has all the properties of fibrine, 
and is almost exactly similar to the basis of muscle. 

Q. By what name was fibrine formerly known ? A. 

Coagulable lymjih. 

Q. What is the form of the red globules of the 
blood? — A. The Abbe de la Torre, who examined 
them under microscopes of considerable power, states 
that the}' obtained the appearance of flattened amuilar 
Ixidies, with a depression, sometimes perforation, in the 



* Dr. B. Habington is of opinin.i th:vt tlie blood, whilst circulating 
in the vespels. consists of two l)ar:sonIy — a fluid which hi- culls //>/;/«? 
5angu/H(A, and red globules; and he is iTiduced to Ik-Ucto, from his 
experiments, that fibrin and serum do not exist as such in the circu- 
lating fluid, but that the lifjuor sanguinis, when removed from the 
Vessels, and no longer subjected to the laws of liie, has then, and not 
before, the property of separating into fibrin and serum. Mrd. Chi- 
turg. Traii.snrf. vol. XVI. pt. 2. Lond. 1?31, and art. Blood (morbid 
eondiliona of the), in Cyclop, of Anat and Physiol. Lond. 1836. 



centre, but tliey differ in size and shape in various 
animals. 

Q. By what means is the blood colored? — A. By 
means of iron and oxygen. 

Q. Describe the projierties of the serum ? — A. It is 
the yellow fluid part that is left after the separation of 
the crassamentum ; it is of a saline taste, and homoge- 
nous, adhesive consistence. 

Q. What effect has a temperature of 160° on it ? — 
^4. The whole is converted into a firm white mass, per- 
fectly analagous to the white of an egg wliich has been 
hardened by boihng. 

Q. Can any hquor be extracted from the serum after 
having been coagulated by heat? — A. Yes. If the 
coagulum be cut into slices, and subjected to gentle 
pressure, an opaque liquor drains fi-om it, which is called 
the serosity. 

PERICARDinu. 

Q. By what is the heart surrounded? — A. The 
pericardium. 

Q. What is the structure of this? — A. It is a fibro- 
serous membranous bag, composed of two coats ; one 
fibrous, the other serous ; these are united by cellular 
tissue. 

Q. What are its connections ? — A. It is attached to 
the sternum, pleura, diaj)hragm, and to the roots of 
the large blood-vessels at the base of the heart. 

Q. A\'hat is the function of the serous surface of the 
pericardium? — A. To secrete the liquor pericardii. 

Q. What is the use of this liquor? — A. It serves to 
protect its own siu-face, and that of the heart, from 
friction. 

Q. AVhat office does the pericardium perform ? — ^4. 
It sustains the heart in its proper situation. 



THE HORSE. 



157 



IlKAUT. 

Q. What is the form of the heart P — ^-1. Its form is 
conoid, yet someAvhat flattened on the anterior surface 
and roundi'd on the other. 

Q. Where is the heart situated? — A. Witliin the 
thorax, in .the region of the fourth, fifth, and sixth 
dorsal vcrtebrse ; bounded on the sides by the lungs 
and walls of the thorax ; posteriorly, by the dia- 
jjhragm; inferiorly and anteriorly, liy the sternum. 

Q. How is the body of heart divided? — A. Into a 
base and apex. 

Q. What are the divisions internally? — A. It is 
divided into four cavities, viz : two auricles, or anterior 
cavities ; two ventricles, or posterior cavities. 

Q. What communications exist between the cavities 
of the heart? — .1. ]5etween the two auricles there is 
no communication, nor between the two ventricles ; 
but the right auricle opens into the right ventricle, and 
a similar ojiening exists between the left aiu'icle and 
ventricle. 

Q. IIow do veterinarians describe the relative i^itua- 
tiou of the cavities of the heart ? — ^1. The amides are 
described as anterior and posterior, because the right 
auricle forms the ujiper and fore part, and the left is 
in a posterior direction ; the ventricles being located 
under their respective auricles ; thus we have the ante- 
rior and |)OsterTor ventricles. 

Q. How is the exterior surface of the heart ])ro- 
tected ? — By a dujilicature of the pericardium. 

Q. What is the function of the auricles? — A. To 
receive the blood from the various vessels and transmit 
it to the ventricles. 

Q. What is the function of the ventricles? — A. 
One pro])els the blood to the lungs, for purification; 
the other distributes it through the arterial ramifi- 
cations. 

Q. Name the venous vessels which terminate in the 
right auricle. — .1. Three venous vessels terminate in 
it, viz : the vena cava, anterior and posterior, and the 
coronary vein ; the vena azygos forms a junction with 



the anterior cava, just as the latter pierces the walls of 
the amides. 

Q. How are the auricles divided ? — ^4. By the sep- 
tum auricularam. 

Q. Describe the internal mechanism of the right 
ventricle? — A. It has within it numerous fleshy pil- 
lars, longitudinally distributed; also, three fleshy 
prominences, termed carnae columnse, from which sev- 
eral tendinous cords proceed to the edges of those 
membranous and fibrous jjroductions ; these close the 
auriculo-ventricular ojicning; the apparatus alto- 
gether forms valvula tricupsis. Other cords, similar to 
the cord;p tendin.T, jiass between the outer wall and 
the septum. 

Q. M^here is the origin of the right ])ulmonary ar- 
tery? — A. It emerges from the upper and back part 
of the ventricle. 

Q. How is the mouth of this artery ju'otected ? — A. 
By three semilunar valves, which present little pouches 
within its cavity ; these valves consist of doubhngs of 
the Uning membrane of the parts. 

Q. Describe the left ventricle? — A. Its cavity is 
smaller than that of the right, and its wall is thicker. 
Its musculi jjectinati appear mostly upon the septum, 
within the a])ex and imder the valves ; it has two, in- 
stead of tlirec, carnal columns' ; they are more buUcy, 
and project more into the carity than those of the 
right. 

Q. From whence does the aorta arise? — A. From 
the up])er and fore part of the left ventricle. 

Q. What is remarkable about the mouth of the 
aorta? — A. It has three semilunar valves, similar to 
those at the origin of the judmonary artery. 

Q. By what are the ventricles divided ? — A. They 
are divided by a fleshy partition called septum ventric- 
ulorum. 

Q. How is the circulation of the blood efifected ? — 
A. By the alternate contraction of the auricles and 
ventricles, called the dyastole and systole of the heart. 

Q. By what vessels is the heart itself suppUed with 
blood ? — A. By the coronary arteries. 



ARTERIAL SYSTEM. 



DISTRIBUTION OF ARTERIES. 

The blood is propelled by the heart 
through the great aorta, which rises out of 
the base of the left ventricle, in the space 
between the left auricle and the pulmonary 
artery. The branches furnished by the 
main trunk are the coronary arteries. The 
right coronary artery emerges from between 
the pulmonary and right auricle, winds round 
the fissure separating that cavity from the 
right ventricle, and turns down under the 
termination of the vena cava; and distri- 
butes ramifications in its course, which 
penetrate the substance of the parietes, 
and end in spiral branches. The left coro- 
nary artery, in passing out between the 
pulmonary artery and left aui-icle, sends 
oft" a large branch, which encircles the 
other auricle ; it then takes its course down- 
ward, and ends in spiral ramifications. 

ANTERIOR AORTA. 

This is a shorter division of the main 
trunk. The course of this vessel is under 
the windpipe ; it gives origin to those large 
arteries which are distributed over the 
breast, head, neck, brain, and anterior ex- 
tremities. It divides, at a short distance 
from the heart, into the right and left ar- 
teria innominata ; the right is considerably 
longer than the left, and measures nearly as 
much again in circumference ; it forms the 
trunk from which the two carotid arteries 
spring; the left terminates in the following 
vessels : * 

1. The dorsal artery. 2. Posterior cervi- 
cal. 8. Vertebral. 4. Internal pectoral. 
5. External pectoral. 6. Inferior cervical. 

*■ Tlic vertebral artery, forming tlie basilar, gives oil" 
the posterior cerebellal, anterior cercbellal, posterior cere- 
bral, and the circular arteriosus 



7. Axillary. Each of these arteries ramify 
and anastomose with others, and are dis- 
tributed to muscular and adipose substance. 
From the axillary artery spring all the ar- 
teries of the fore extremity. This vessel 
can only be seen by detaching, the shoulder 
from the body. It arises within the chest, 
from the arteria innominata ; gains exit by 
making a sudden turn around the first rib, 
rather below its middle, crossing the lower 
border of the scalenus in the turn; it is 
first directed outward in this flexure, and 
then backward, and at length reaches the 
inner part of the head of the humerus, 
where it makes another turn backward, and 
afterwards takes the name of the brachial 
artery. Its branches are — 1. The external 
thoracic. 2. The internal thoracic, which 
runs to the point of tlie shoulder, and gives 
its branches to the levator humeri and 
shoulder joint. 3. The dorsalis scapula? 
ascends, in a flexuous manner, to the 
shoulder joint, crossing the insertion of the 
subscapularis. It runs for a short distance 
along the ribs. 4. The subscapularis, a 
large artery, which also arises from the 
upper part of the trunk, but near to its ter- 
mination. It passes along the ribs, screened 
from view by the edges of the subscapu- 
laris and teres major, to both of which 
muscles it detaches several small branches, 
and ends near the lower angle of the bone ; 
it also gives oft' several branches to the 
triceps and panniculus. 5. The humeral. 

The humeral artery descends from the 
inner and back part of Ihe head of the os 
humeri, in an oblique direction on the body 
of the bone, where it divides into the ulnar, 
spiral, and radial arteries. On its inner 
side, it has the .spiral and ulnar nerves ; in 
front, the radial nerve ; and behind, the 

(158) 



4XAT0MY A>,D PIlVS:uLYGY OF THE HORSE. 



159 



humeral veins ; and it is covered inter- 
nally by the large pectoral muscle, to which 
it sends some small branches. But its prin- 
cipal branches are — 1. One near its origin, 
which crosses the bone to get to the flexor 
brachii, and sends twigs to the shoulder- 
joint. 2. A posterior branch, arising a lit- 
tle lower down, which enters the muscle 
called triceps. 3. Near its termination, 
another branch to the flexor brachii. Where 
the artery divides, it is covered by the hu- 
meral plexus of veins, and by the absorbent 
glands of the arm. 

The vlnar artery consists of a common 
root, from which spring three or four ves- 
sels of considerable size, running in waving 
lines upon the inner side of the lower end 
of the humerus. The upper one is dii'ected 
to the ulnar, splitting before it reaches the 
bone, and pending one branch upward upon 
the elbow, and another downward to the 
heads of the flexors ; to which muscles 
the other branches of this vessel are dis- 
tributed. 

The spiral artery, the outermost division, 
turns round the os humeri, passing under 
the flexor brachii, and sending a recurrent 
branch to it, to arrive at the front of the 
radius, where it splits into several branches, 
of which — 1. Some run into the elbow 
joint. 2. Others, larger and more numer- 
ous, penetrate the heads of the extensors. 
3. Two long, slender ones descend upon the 
radius, and give branches, in their course, 
to the extensor muscles as low as the knee, 
and there end in ramifications about and 
into the joint, joining with others coming 
from the radial. 

Tlie radial artery, the principal division 
humeral, continues its descent along the 
radius, about the middle of the arm ; the 
nerve accompanies it first on its outer side, 
and subsequently behind it. A short way 
above the knee, it splits into the metacarpal 
arteries. 

The small metacarpal artery descends, 
within a cellular sheath, along the inner and 
back part of tlie knee. It continues its 
descent along the mctacarj^al vein (which 
runs to its inner side), till it gets below the 



knee, and then transmits its divisions down 
the front of the suspensary ligament ; be- 
tween it and the canon bone, it sends off 
branches over the front of the knee, the 
canon, and suspensary ligament. 

The large metacarpal artery, a continua- 
tion of the radial trunk, continues its course 
down the leg, by the side of the tendo per- 
foratus, passing under the posterior annular 
ligament, approaches the fetlock just above 
the joint, and then splits into three vessels ; 
from the middle division three recurrent ar- 
teries are given out ; the side divisions be- 
come the plantar arteries. From the arch 
below come off" two other branches, which 
descend into the joint. The plantar arte- 
ries, external and internal, in the fore ex- 
tremity, result from the fork of the meta- 
carpal ; in the hind, from that of the 
metatarsal. (Their general distribution is 
the same, both in the hind and fore feet.) 
They descend the fetlock upon the sides of 
the sessamoids, in company with the veins 
which run in front of them, and with 
the plantar nerves which proceed behind 
them ; the artery then passes down to, 
and into, the substance of what is called 
the " fatty frog ; " it next passes the inner 
and upper exti-emity of the coffin bone, and 
afterwards to the foramen of the posterior 
concavity of the bone. The branches of 
the plantar artery are many and important. 
After detaching some smaU ramifications 
inwardly to the fetlock, posteriorly to the 
flexor tendons, and anteriorly to the ex- 
tensor tendon, it then sends ofl' — 1. The 
perpendicular artery. 2. The transverse 
artery. 3. The artery of the frog. 4. The 
lateral laminal artery. 5. The circulus ar- 
teriosus. From the latter arise two prin- 
cipal sets of vessels — 1. The anterior 
laminated arteries. 2. The inferior com- 
municating arteries, " thirteen, and some- 
times fourteen, in immber." 3. The circum- 
flex artery. Then, again, from this vessel 
spring the solar arteries, which may be so 
named from their radiated arrangement. 
These latter are destined for the supply of 
the sole, upon which they run in radii at 
equal distances, whose common centre is the 



160 



ANATOMY AND PHYSIOLOGY OF 



toe of the frog, where they end in commu- 
nications with the arteries of that body. 

THE CAROTID ARTERY. 

The right arteria innominata, having de- 
tached seven important branches, which 
vary but little in their mode of origin, 
general course, and distribution, from the 
several arteries into which the left division 
resolves itself, become the common carotid 
— a large vessel emerging through the up- 
per opening of the chest ; it divides, as it 
quits the chest, into two branches, called 
the right and left carotids. These arteries 
ascend, and having reached the top of the 
larynx, the carotid of either side branches 
into three divisions — the external and inter- 
nal carotids, and the ramus anastomoticus : 
here, though the trunk itself becomes deeply 
lodged in soft parts, its situation is well in- 
dicated by the larynx, with which it is in 
contact. This vessel detaches — 1. Several 
unimportant muscular branches in its pro- 
gress up the neck. 2. The thyroideal 
artery, which furnishes the laryngeal, a 
small artery that perforates the ligament 
uniting the cartilages of the throat. 

The external carotid artery is the large 
division, which may be regarded as the con- 
tinuation of the carotid itself. This artery 
is imbedded in glandular substance, sur- 
rounded by venous and nervous trunks, and 
protected by bony prominences and muscles. 
The first branch of the external carotid is 
the submaxillary artery ; it comes ofl" behind 
the horn of the ox hyoides, just as the 
carotid makes its second curve, and ranks 
next in size to the trunk itself. After reach- 
ing the lower jaw (about one-third of its 
length downwards), it arrives upon tlie face; 
here it becomes subcutaneous, ending m an 
equal division, called the facial and inferior 
labial arteries. Its branches are, the ascend- 
ing laryngeal, pharyngeal : smaller branches 
go to parotid gland, and a large branch, 
called the lingual. The latter detaches a 
few twigs into the submaxillary space ; it 
then brandies into two arteries, the ranine 
and the sublingual. The ranine, apparently 
a continuation of the lingual, passes along 



the under part of the tongue, and transmits 
branches to the interior, and continues of 
large size even to the tip of the organ, 
wherever its extreme ramifications are ex- 
pended. The sublingual artery winds along 
the under and outer border of the tongue, 
preserving a more superficial course than 
the former. It supplies the subling^ial 
gland, and distributes branches over the 
membrane of the tongue. The submental 
artery leaves the submaxillary, follows the 
course of the branch of the jaw, and de- 
taches twigs to muscles ; it then transmits 
its ramifications into the gums internally. 
The anterior masseter branches pass on the 
external side of the jaw. 

The inferior labial artery courses the side 
of the jaw, invested in the cellular and 
fleshy substance belonging to the buccinator. 
It gives ofT slender ramifications to the in- 
vesting cellular substance,, also the buc- 
cinator arteries ; the buccal twigs bifurcate, 
sending their divisions respectively to the 
upper and under lips ; these form the supe- 
rior and inferior coronary arteries of the lips. 

The facial artery ascends upon the side 
of the face, crosses the buccinator, then, 
having run as high as the bony ridge from 
whence the masseter arises, it detaches a 
large branch, and then expands upon the 
upper and fore part of the face ; its termi- 
nating ramifications are in the cellular sub- 
stance and skin covering the fore part of 
the face. 

The posterior auricular gives branches to 
the parotid gland, and to the different mus- 
cles of the ears. 

The temporal artery, the anterior auricular, 
and the internal maxiUary, may be con- 
sidered as the terminating branches of the 
external carotid. The internal maxillary 
gives off deep temporal branches, long 
slender twigs, to the soft palate, to the car, 
and to the articulation of the jaw; the facial 
artery also gives off the inferior maxillary, 
the supra-orbitar, the ocular, the infra- 
orbitar, and the palate maxillary. The 
second and smallest division of the carotid 
is the 



EXPLANATION OP FIGURE XVI. 



XO. 1. 

FRONT A>D SIDE VIEW OF THE NEAR-HIND LEG. 



g. Ligaments of the patella. 

/". Triceps. 

m'. Tensor vagina?. 

«'. Rectus. 

o'. Vastus extenius. 

q". y'. Extensor suffraginls. 

X. X. Extensor pedis. 

7. Sheath and penis. 

8. Bifiu-cation of the suspensory ligament. 
^■. The hoof. 

NO. 2. — OSSEOUS STRUCTURE. 

22. Femur. 

23. Patella. 

24. Tibia. 
e. Fibula. 

25. Os calcis. 
2G. Astragahis. 

27. Inferior tarsus. 

28. Metacai-pi magnum. 
*. " parvum. 

29. Sessamoids. 

30. Os suffraginis. 

31. Os coronte. 

32. Os pedis. 

NO. 3. 

OtJTSrDE VIEW OF THE NEAK-HIND LEr7. 

K. Abductors. 

J". Triceps. 

m'. Tensor vagina?. 

vt'. Rectus. 

o". Vastus externus. 

?•'. Gastrocnemius externus. 

V. s'. Plantaris. 

«'. Gastrocnemius externus. 

!)'. 7('. Flexor pedis. 

X. Extensor pedis. 

y. y. Peroneus. 

u. V. Flexor tendons. 

i{. The hoof. 

8. Bifiircation of suspensory ligament. 

No. 4 is nearly the same as No. 3, and therefore needs no further description. 
z. Suspensory ligament. 



EXPLANATION OF FIGURE XVI. CONTINUED. 
XO. 5. 



fc'. Abductor tibialis. 

5. Glans penis. 

r. Gastrocnemius externus. 

t. Flexor pedis accessorius. 

tt'. Insertion of the gastrocuemlus. 

x'. X. q. Extensor pedis. 

8. IJifurcation of the suspensory ligament. 
&,: The hoof. 

9. Flexor metatarsi. 
5. The saphena vein. 

z. Suspensory ligament. 



THE HOESE. 



161 



RAMUS ANARTOMOTICUS. 

It leaves the trunk of the carotid, joins 
the vertebral, and from it arises the occipital 
artery, which gives off twigs to be dispersed 
upon the dura mater, temporal muscle, and 
muscles of the occiput. 

INTERNAL CAROTID. 

This vessel, whose calibre is not more 
than half that of the external carotid, 
ascends to the base of the skull : at its en- 
trance into the skull, a vessel comes off 
named the arteria communicans : after 
having given ofl' this vessel, the internal 
carotid pierces the dura mater, takes its 
course up near the optic nerve, and branches 
into four divisions, which supply the cere- 
brum with blood. 

The remaining vessels of the brain are 
derived from the vertebral artery, which 
gives off posterior arteries to the dura mater, 
and ramifications to the medulla oblongata. 

The basilar artery sends off branches to 
the cerebellum. 

tut; posterior aorta. 

Considerably longer and larger than the 
anterior is the main trunk, from which are 
derived the artery of the abdomen, pelvis, 
and posterior extremities, in addition to the 
posterior intercostals, and some few of the 
thoracic arteries. It commences opposite 
the fourth dorsal vertebrse : from its orisjin 
it courses first upward, and then backward, 
having the pulmonary artery on its left, the 
termination of the windpipe on its right, 
then takes a course along the spine, inclin- 
ing to the left side. From the inferior part 
of the curvatttre of the aorta arise the right 
and left bronchial arteries: these vessels 
penetrate the lungs in company with the 
bronchia, to the branches of which they 
cling in the course of their ramifications 
within the substance of the lungs. 

The esophageal also spring from the con- 
cavity of the arch near to the former, and 
proceed backward to the esophagus, where 
it divides into an inferior and superior arterv. 
The intercostal, the remaining branches, 
come off in pairs from the sides of the ves- 

21 



sel, to supply all those intercostal spaces 
posteriorly to the last. These arteries run 
along the lower borders of the ribs, and end 
about the inferior parts of the chest and 
abdomen. They furnish, near their origin, 
small branches, which enter the vertebral 
canal. Having detached these small ves- 
sels, the posterior aorta continues its pas- 
sage into the abdomen. In making its 
exit from the chest, it gives off the phrenic 
or diaphragmatic arteries. 

Within the abdomen, the aorta continues 
to be firmly fixed to the spine, by its several 
cellular attachments, as far as the lumbar 
vertebra, under the body of which it branches 
into four large arterial trunks. Prior to this 
division, the abdominal aorta gives off the 
ccEliac artery, which is nothing more than 
the common root of the splenic, gastric, and 
hepatic — arteries that in some instances 
have separate origins. 

The splenic artery, after passing between 
the stomach and spleen, ends in the left 
gastric artery. In its course it gives off 
several branches to the pancreas, called pan- 
creatic arteries. 

The gastric artery, the smallest of the 
cceliac divisions, runs forward to the small 
curvature of the stomach, between the layers 
of the omentum, branching, before it reaches 
this organ, into two vessels, called inferior 
and superior gastric, which finally ramify 
upon the upper and under sm-face of the 
stomach. 

The hepatic artery, the largest of the 
cceliac division, proceeds before the pancreas 
to the right side of the cavity, and passes 
over the pyloric end of the stomach, and 
gives off smaU branches to the pancreas. 
Near the pylorus, it sends a branch to the 
duodenum, which, as soon as it reaches the 
intestine, divides : one division — the duo- 
denal — retrogrades along the gut, and ends 
in anastomosis, with branches coming from 
the anterior mesenteric; the other — the 
right gastric — crosses the gut, proceeds to 
the great curvature of the stomach, where 
it inosculates with the left gastric. The 
hepatic artery itself is continued forAvard to 
the porta of the liver, where it divides 



162 



AXATOMY AND PHYSIOLOGY OF 



into the right and left hepatic ; the right, — 
the larger and shorter one, — after giving off 
a considerable branch to the portio media, 
turns back to reach the right lobe ; the left, 
after giving off a branch or two to the mid- 
dle portion, penetrates the left lobe. 

The anterior, or great mesenteric, is the 
next vessel to tiie coeliac, and arises from 
the under part of the posterior aorta. From 
its origin, it passes downward within the 
layers of the mesentery, detaching some 
small twigs to the pancreas ; it then sepa- 
rates into larger vessels (commonly from 
eight to twelve in number), from wlrich are 
derived a branch that runs to the duode- 
num ; several other branches encircle and 
ramify on and around the intestines. 

The renal or enmlgent arteries leave the 
aorta at right angles just below the preced- 
ing vessel ; they each pass into the respect- 
ive kidneys, and therein divide into branches 
that penetrate the glandular substance. 

The spermatic arteries, right and left, 
originate from the under part of the aorta.; 
they pass out of the abdomen, at the ab- 
dominal ring, to the testicles. In the female, 
they pass to the ovaries, fallopian tubes, 
and horns of the uterus. 

The posterior aorta also gives off the 
small mesenteric, and five or six pairs of 
lumbar arteries. Under the last lumbar 
vertebrce, the aorta gives off tvvo pau-s of 
arterial trunks, called the external and inter- 
nal iliacs. 

The internal iliacs give off a branch 
called the artery of the bulb, and afterwards 
branches into three divisions — the obtura- 
tor, gluteal, and lateral sacral arteries. 

The artery of the bulb passes to the bulb 
of the penis, where it terminates. In the 
female, this artery sends its terminating 
branches to the vagina. It gives off the 
foetal umbilical artery. In leaving the pel- 
vis, the prostatic artery, which detaches 
twigs to the vesiculae seminales, also distri- 
butes its ultimate ramifications to the pros- 
tate gland. It also gives off divers branches, 
anal and perineal, to the posterior portion 
of the rectum, anus, and parts comprising 
the perineum. 



The obturator artery is the lowest of the 
divisions of the internal iliac. Its branches 
are the arteria innominati, and ramifications 
to the obturator muscles and ligaments. Its 
divisions are the ischiatic, which distributes 
its branches to the triceps ; next, the pubic : 
the internal pubic artery gives two sets of 
branches, which pass to the penis. 

The gluteal artery is destined principally 
to supply the gluteal muscles. 

The lateral sacral artery, having reached 
the coccyx, divides into two branches. It 
furnishes the sacro-spinal branches, five 
or six in number, and the perineal artery. 
It soon divides into several ramifications, 
of which many run into the gluteal mus- 
cles ; others descend on the back of the 
thigh, and others are distributed to the anal 
muscles, and to the skin and cellular sub- 
stance of the perineum. The lateral sacral 
also fiu-nishes the lateral coccygeal, and 
the inferior coccygeal. 

The external iliac artery, right and left, 
results from a branch of the posterior aorta, 
which takes place under the body of the 
last of the lumbar vertebra?, and jiasses 
into muscles, forming the inside of the 
thighs. The vessel gives off the circumflex 
artery of the ileum, the artery of the cord, 
and the arteria profunda: the latter, having 
reached the posterior quarters, it sends its 
ramifications into the biceps. Before this 
vessel dips into the substance of the thigh, 
it gives rise to a large branch called the 
epigastic •artery. 

The epigastric artery, in passing the mar- 
gin of the internal ring, forms a branch 
which divides into several small arteries; of 
these a twig runs to the groin, and ramifies 
among the adipose membrane and absorbent 
glands ; then, next, a slender branch to the 
cremaster, and subcutaneous tAvig to the 
thigh, and, lastly, the external pudic artery. 

The femoral artery. — Regarding the pro- 
funda femoris as a limb of the external 
iliac, we descend to the femoral artery, the 
subsequent continuation of the same trunk. 
This artery proceeds in an oblique direction 
down the haunch, preserving nearly the line 
of its middle ; opposite to the bead of the 



THE HORSE. 



163 



tibia, it branches into the anterior and pos- 
terior tibial arteries ; the anterior tibial gives 
off the inguinal artery, also three or four 
branches to the sartorius, and one to the 
side and front of the stifle. Its posterior 
branches arc a large artery to the gracilis 
(which detaches twigs to the long and short 
heads of the triceps), also one to the biceps. 
At the back of the stifle come off the pop- 
liteal branches, four or five in number, 
taking opposite directions, which are des- 
tined for the supply of the joint ; one runs 
down upon the posterior tibial muscles ; 
another — the recurrent branches — climbs 
the back of the os femoris, and anastomoses 
^\^th the descending ramifications of the 
profunda femoris. 

The tibial arteries are a continuation of 
the femoral trunk, which branch off into 
tibial arteries at the head of tibia. 

The posterior tibial arlenj^ the smaller of 
the two, passes along the posterior deep 
region of the thigh, to the hock, where it 



ends in bifurcation. Its branches are, one 
that runs into the flexor pedis ; another to the 
upper and back part of the tibia ; and small 
twigs to both the flexors. There are several 
terminating branches, some ramifying sub- 
cutaneously, others continuing down the leg 
internally over the tendon of the flexor 
pedis, and ending at the lower i)art of the 
canon in divers smaU ramifications. 

The anterior tibial artery, after leaving 
the trunlv, passes down the fore ]oart of the 
thigh to the hock and metatarsal bone, 
where it becomes the metatarsal artery. 

The metatarsal artery pursues its course 
downwards to about two-thirds the length 
of the leg ; it then gains the posterior part 
of the latter ; a little above the fetlock, it 
divides into three vessels : one forms an arc, 
(as in the fore extremity), from which come, 
off the recurrents, and they anastomose 
with the posterior tibial artery ; the lateral 
divisions become the plantar arteries. 



164 



ANATOMY AND PHYSIOLOGY OF 



Aorta 



Anterior Aorta 



Left Arteria 
Innominata 



{Posterior Cerebellal. 
Anterior Cerebellal. 
Posterior Cerebral. 
Circular Arteriosus. 



REMARKS ON THE DISTRIBUTION OF ARTERIES. 

The preceding is a brief sketch of the arterial structure, and the professional man 
will perceive that we have not named the whole of the arteries ; therefore, in order to 
supjily this deficiency, the author here introduces a table of the arteries, constructed by 
Mr. Percivall. 

TABLE OF THE ARTERIES. 

Anterior Aorta. 

Posterior Aorta. 

Right Ai'teria Innominata. 

( Left Arteria Innominata. 

fDorsal. 

Posterior Cervical. 

Vertebral, forming the Basilar. 

Internal Pectoral. 

External Pectoral. 

Inferior Cervical. 

Axillary. 

^External Thoracic. 
Internal Thoracic. 
Axillary < Dorsalis Scapulae. 
Subscapular. 
Humeral. 
r Ulnar. 

Humeral ^ ^^^^^ _ _ c q^^y[ Metacarpal, 
l^ \ Large ditto. 

T IV T i. 1 i External Plantar. 

Large Metacarpal j j^^^^^.^^^^ ^.^^^_ 

f Perpendicular. 
Transverse. 
Plantar < Artery of the Frog. 
Lateral Laminal. 
Circulus Arteriosus. 

<( Solar. 

The Right Arteria Innominata sends off branches correspondent to those on the left 

side; and, in addition, the 

Right Carotid \ External Carotid. 
Left ditto. > Ramus Anastomoticus. 
) Internal Carotid. 
' Ascending Pharyngeal. 



Ant. Laminal. 

Inf 

Circumflex. 



Communicating. 



Common Carotid 



Submaxillary. 



External Carotid <( Parotideal. 

Int. Pterygoid. 
Post. Masseter. 
Post. Auricular. 
Temporal. 
Ant. Auricular. 
Int. Maxillary. 



Pterygoid. 
Lingual. . . . 

Inferior Labial. 



Facial. 



Ranine. 

Sublingual. 

Buccinator. 

Angular Oral. 
r Masseter. 
J Buccal. 
] Slip. Labial, 
l^ False NasaL 



Deep Temporal. 

Palatine. 

Inf. Maxillary. 

Supra-Orbitar. 

Ocular. 

Infra- Orbitar. 

Palato Maxillary. 



THE HORSE. 



165 



!( Dura Matral. 
Occipital. < Temporal. 
( Nuchal. 
['Arteria Conimunicans. 
Anterior Dura Matral. 
Internal Carotid < Anterior Cerebral. . . -^ Ophthalmic 
Middle Cerebral. 
(^Lateral Cerebral. 



Posterior Aorta 



Thoracic Division. 
Abdominal ditto. 



Right Bronchial. 



Thoracic Division < 



Abdominal 
Division 



Cselic <^ 



Splenic 
Gastric 



Hepatic 



Bronchial . ^eft ditto. 

_r^ , , , Superior CEsophaa;eaL 

CEsophageal. [ i^knox ditto. 

Intercostals. 
Phrenic. 

Pancreatic Branches. 

Splenic Branches, 

Left Gastric. 

Superior Gastric. 

Inferior ditto. 

Pancreatic Branches. 

Duodenal. 



Right Gastric. 



Right and Left Hepatic 
Duodenal Branches. 
Small Mesenteric. 
Coecal Branches. 
Anterior Colic Branches. 
Right Renal. ) External BrancheB. 
Left ditto. \ Capsular Renal. 
Spermatic ■{ Right and Left. 

Posterior Mesenteric j -p , . 

^ Lumbars — five or sLx pairs. 



Anterior Mesentric 



Renal 



Artery of the Bulb 



Bifurcation of ihe Posterior Aorta into External and Internal Iliac ArterieB. 

Umbilical. 

Vesical Branches. 

Prostatic. 

Anal and Perineal Branches. 
Arteria Innominata. 
Foraminal Branches. 
Ischiatic. 



Internal 
Iliac 



Obdurator 



Pubic 
Int. Pubic 



Branches to the Crus Penis. 
Ditto Corpus Cavernosum. 
Ditto Dorsum Penis. 
Ditto Glans Penis. 
Cutaneous Branches. 



The Middle Sacral issues at the Bifurcation of tlie Trunk. 
f Circumflex of the Ileum. 
E t 1 Hi -! -'^^'■y °^ ^'^^ Cord. ( Branch to the Groin. 

j Arteria Profunda. -{ Epigastric. < Branch to the Ring. 
1 Femoral. < External Pudic. 



IGG 



ANATOMY AND PHYSIOLOGY OF 



Femoral 



Inguinal. 

Muscular Branches. 
Stifle Branches. 
Muscular Branches. 
Popliteal, -j Recurrent, 

Anterior Tibial . . . . 



Posterior Tibia . 



Recurrent Articular. 
Muscular Branches. 
Cutaneous Branches 
Metatarsal Branches, 
Metatarsal Artery. . 
' Muscular Branches. 
Medullary. 
Tarsal. 
Internal Metatarsal. -{ Recurrent. 



Recurrent. 
External Plantar. 
Internal Plantar. 



DISTRIBUTION OF VEINS IN 
THE HORSE. 

The two main venous trunks, the vena 
cava, anterior and posterior, correspond to 
the anterior and posterior aortse. 

THE ANTERIOR VENA CAVA 

Forms the main trunk of the veins, re- 
turning the blood from the head, neck, chest, 
and fore extremities. It is principally formed 
by the concurrent union of the jugular and 
axillary veins, and is situated at its forma- 
tion in the space between the two first ribs, 
about midway between the sternum and 
vertebra; ; it also receives the pectoral, ver- 
tebral, dorso-cervieal, and inferior cervical 
veins, and the vena azygos. 

THE JUGULAR VEIN. 

It passes behind the condyle of the lower 
jaw, under the parotid gland, and joins the 
external carotid artery, and continues its 
course down the neck with the latter. It 
now receives the auricular veins, anterior 
and posterior, and also internal. The next 
is the temporal, the third is the internal 
maxillary ; the latter in its course receives 
the blood of many small veins, — the palato- 
maxillary, infra and supra orbitar, ocular, 
inferior maxillary, and deep temporal ; the 
fourth branch, received by the jugular vein, 
is the parotideal, and the last branches from 
the masseter muscles. 

THE OCCIPITAL VEIN 

Descends from tlie head, along with the 



occipital artery. It brings blood from the 
occipital sinuses, receives veins from the 
posterior lobes of the cerebrum and cere- 
bellum ; also from the dura mater. 

The suhmaxillarjj vein is a large branch of . 
the jugular. It is formed upon the side of 
the face by the concurrence of the facial, 
labial, and varicose veins. It joins the 
trunk by the side of the trachea, just below 
the parotid gland. In its course it receives 
a number of veins; tiie principal are — the 
submental, sublingual, lingual, pharyngeal, 
and superior laryngeal veins. The facial 
vein results from an expansion of small 
veins upon the side of the face, one of 
which is the varicose from the masseter. 
The labial vein is formed by tiie union of 
a plexus of venous branches, coming prin- 
K'ipally from the angle of the mouth, joined 
by others both from the upper and lower 
lips. The varicose vein is buried in the 
masseter. 

The jugular trunk having received the 
submaxillary, proceeds down the neck, and 
terminates in the anterior vena cava, within 
the space between the two first ribs. Near 
the junction of the submaxillary the jugu- 
lar receives the small thyroideal, cutaneous, 
muscular, and tracheal veins. Near its 
termination it receives a branch of the 
superficial brachial, and plait or plat vein. 

The vertebral vein runs the same course 
as the artery, through the foramina, in the 
transverse processes of the cervical verte- 
bra?, with the exception of the last. This 



THE HORSE. 



167 



vein has communications witii the occipital 
sinus and posterior cerebral veins, medulla 
oblongata, and spinal marrow ; it also re- 
ceives vessels from the deep-seated mus- 
cles in the vicinity, and ends in the an- 
terior vena cava, just behind the first rib. 

The axiUari/ vein returns the blood dis- 
tributed by the axillary artery to the va- 
rious parts of the fore extremity ; there is a 
superficial and deep-seated set; the former 
run under the skin, the latter among the 
muscles. The plantar veins are an intri- 
cate network of small veins, and cover the 
foot with a venous netting. The veins 
of the sole pour their blood into the veins 
of the laminse; the latter increase in size 
towards the coronet, and gradually unravel 
themselves, so as to collect in a great many 
branches; these run upward, through the 
substance of the coronary ligament, and 
form the superficial coronary vein ; from 
them other branches proceed and join the 
deep coronarv, and afterwards unite in 
a single vein opposite the pastern joint. 

The veins of the frog, after ramifying in 
the form of network over that body, ascend 
into the heel, growing larger as they leave 
the foot ; they make a single branch at the 
pastern joint, then unite with the vein com- 
ing from the lamina;, thereby forming the 
plantar vein. The plantar vein ascends, 
unites wiih other vessels, and becomes 
metacarpal. 

The metacarpal veins, two in number, 
result from the union of the plantar ; these 
veins pui'sue their course up the leg, one on 
either side, to the back of the knee, where 
they end in anastomosis. The internal 
metacarpal vein preserves the line of the 
splint bone. These vessels receive in their 
course cutaneous veins from the front of 
the canon, and one or two descending 
veins from the back of the leg; it after- 
wards forms the deep-seated veins of the 
arm. 

The superficial brachial vein ascends 
along the inner side of the radius to the 
clbow-joint ; here it crosses over to the front 
of the biceps and pursues its "ascent upon 
that muscle toward the point of the shoul- 



der, and then passes inward to the jugular 
vein. In its course to the latter, it receives 
numerous cutaneous and muscular branches, 
communicates with the humeral vein, and 
anastomoses with other veins of the arm. 

The radial veins, two in number, arise 
from the junction of the metacarpal veins ' 
above the knee ; they take the course of 
the radial artery, and receive anastomosing 
vessels as they ascend from the ulnar and 
superficial veins. 

The ulnar veins (with one exception) 
end in the common trunk of the humeral 
vein. 

The humeral vein accompanies the ar- 
tery ; it receives small veins from the mus- 
cles. 

T7ie axillarij vein is the continuation of 
the humeral, augmented by the accession 
of the triceps vein. Its branches are, the 
subscapular vein, and dorsalis scapular; 
the latter terminates about midway be- 
tween the chest and shoulder. The re- 
maining branches of this vein are the 
humeral thoracic, and the external thoracic ; 
it also receives other small veins, which 
contribute more or less to its volume. 

The pectoral vein runs the coiuse of the 
pectoral artery. It originates in branches 
from the abdominal parietes, continues to 
receive accessory vessels in its course, and 
ascends along the inner and lower border 
of the first rib. 

The dorso-cervical vein consists of two 
divisions, ramifying with the dorsal and 
posterior cervical arteries; it receives the 
anterior intercostal vein. 

The inferior cervical vein runs down the 
lower part of the neck in company with the 
artery; the principal branches are mttscular, 
though some come from the skin and ab- 
sorbent glands in the vicinity. 

The vena azygos ends just as the trunk 
opens into the auricle ; it returns the 
blood from the lower intercostal veins. 

THE POSTERIOU VENA CAVA. 

This is the corresponding venous trunk 
to the posterior aorta, returning the blood 
from the parietes of the abdomen and pel- 



ns 



ANATOMY AND PHYSIOLOGY OP 



vis, the urinary and genital organs, and the 
posterior extremities. It takes its course 
under the bodies of the lumbar vertebras, 
runs along the great fissure of the liver, 
perforates the cordiform tendon, and pur- 
sues its way directly across the cavity of 
the chest to the lower part of the right auri- 
cle : in its passage it is joined by tlie lum- 
bar spermatic, renal, hepatic, and diaphragm- 
atic veins. 

The common iliac veins are formed under 
the sacro-iliac, symphysis, by the union of 
the external and internal Uiacs ; they re- 
ceive a vein from the psose and iliacus, cir- 
cumfTex vein of the ileiim, middle sacral, 
and azygos. 

The ischiatic vein, situated upon the side 
of the pelvic cavity, midway between the 
external iliac and lateral sacral veins ; ex- 
ternal and internal branches unite to form 
it. The internal comprise veins coming 
from the bladder, anus, pei-ineum, and, in 
the male, from the bulb and prostate ; in 
the female, from the vulva and body of the 
vagina. The external come principally 
from th* gluteal and obtiuator muscles. 

The lateral sacral vein comes from the 
tail, formed by coccygeal veins ; it runs 
forweird to the sacrum, and receives in 
its course the perineal and sacro-spinal 
branches. 

The external iliac vein takes the same 
course as the artery ; as it departs from the 
belly, this vessel receives 

The inguinal vein (coming from the 
groin), also a superficial or sub-cutaneous 
abdominal vein,, luiown as the milk vein in 
cattle. 

The femoral vein is the continuation of 
the iliac trunk below the brim of the pelvis ; 
and is the main channel into which the 
deep-seated veins of the hind extremity 



pour their blood. We commence the de- 
scription, as in the fore extremities, at the 
leg. 

The large vietatarsal vein ascends the 
canon by the side of the flexor tendons, 
and passes over the front and inner part of 
the hock ; it sends out branches, from which 
result the 

Anterior tibial veins, which run between 
the tibia and fibula to the back and lower 
part of the os femoris, and then are joined 
by the posterior tibial vein, and all three 
unite to form the femoral. 

The posterior tibial vein is a continua- 
tion of the small metatarsal vein, and cor- 
responds in size to the small luetacarpal 
It runs in company with the posterior tib- 
ial artery, receiving various muscular 
branches in its course, also the medullary 
vein of the tibia. 

The femoral vein results from the two 
last-named vessels ; runs behind the femoral 
artery, and ends in the external iliac vein. 
It receives muscular veins, as well as veins 
from the stifle joint, and the medullary vein 
of the OS femoris ; also, about two-thirds of 
its length upwards, it is joined by the sapb- 
ena vein. 

77(6 vena saphena major results from the 
large metatarsal vein ; at the hock it anas- 
tomoses with the anterior tibial vein ; it 
also receives cutaneous and muscular 
branches in its course. 

The vena saphena minor springs from the 
small metatarsal vein ; it runs up the back 
of the hock, over the root of the os calcis, 
and ultimately reaches the femoral vein. 

The vena poHa circulates the blood 
through the liver, and is principally formed 
by the union of the splenic and mesenteric 
veins. 



'IBE HOKbE. 



169 



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ANATOMY AND PHX9IOL0GY OF 



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EXPLANATION OP FIGURE XVII. 





OSSEOUS STRl 


1. 


Frontal bones. 


3. 


Occipital. 


4. 


Temporal. 


8. 


Superior maxillaris. 


10. 


Inferior " 


11. 


Cer\ical vertebrae. 


14. 


The sacrum. 


16. 


The false ribs. 


18. 


The sternum. 


10. 


The ileum. 


20. 


The ischium. 


21. 


Pubis. 


22. 


Femur. 


23. 


Patella. 


24. 


Tibia. 


e. 


Fibula. 


25. 


Os caleis. 


26. 


Tarsal bones. 


27. 


The inferior tarsal bones. 


28. 


Metatarsi magnum 


29. 


Sessanioiilcs. 


30. 


Os suffraginis. 


31. 


Os corona; 


32. 


Os ])eclis. 


33. 


Scapula. 


34. 


Os humeri 


35. 


Radius. 


/• 


Os ulnaris. 


36. 


The carpal bones. 


37. 


Mctacarpi niagnmn. 


38. 


Sessamoids. 


39. 


Os corona^. 


40. 


Os suffraguiis. 


41. 


Os pedis. 


d. 


Dorsal spines. 



MUSCULAR STRUCTURE. 

THE HEAD. 

a. Orbicularis palpebrarum. 

c. Dilator naris lateralis. 

e. Orbicularis oris. 

_/". Xasalis longus. 

Ii. IJuccinator. 

j. Depressor labiL 

I: Masseter. 

10. Region of the parotid gland. 

o. Adducens vel depriment amem. 



EXPLANATION OF 1-IGURE XVII. CONTINUED. 
THE NECK. 

h". C'L>i-\ical ligament. Ligamentum colK. 

c". Trachelo subscapularis [scalenus]. 

s. Splenius. 

r. i. Tendon of the splenius and complcxus major. 

11. Levator humeri. 

SUPEKIOR TART OF TIIE SHOULDER AND BACK. 

i"'. Latissinius dorsi. 
u". Trapezius. 

SIIOULDEll AND FORE E.\TEEMITIES. 

g. h". Sjiinatus muscles. 

I". 7h'. n'. Triceps extensor brachii. 

s". x". Extensors nietacarpi. 

p". q". Flexors externus ct intenius. 

II. 11. II. It. Flexors perforans et perforatus. 

8. The ])astern. 

«,-. «,-. Hoofs. 

ABDOMIN.VL REGION. 

c'. Abdominis transvcrsalis. 
■1. Subcutaneous tlioracic vein. 

POSTERIOR EXTREMITIES, 



e'. 


Erector coccygis. 


.</'• 


Comjn-cssor coccygis. 


t'. 


Glutei. 


J', 


. Triceps. 


7c'. 


Biceps abductor. 


v. 


Abductor tibialis internus. 


r'. 


r. s'. Gastrocnemii. 


V. 


Peroneus. 


a'- 


Extensor metatarsi intenius. 


u. 


Insertion of the gastrocnemius. 


V. 


Flexor perforans et perforatus. 


X. 


y. Fleshy belly of tlie extensors. 


8. 


The pastern. 


«,•• 


Sf. Hoofs. 



THE HORSE. 



171 



THE BRAIN AND ITS APPEN- 
DAGES. 

The cerebrum, cerebellum, and medulla 
oblongata, and medulla spinalis are invested 
with three membranes : the dura mater, pia 
mater, and tunica arachnoides. Of these 
the exterior is the dura mater ; which^ 
though called a membrane, is of a dense, 
tough, and inelastic texture. It is so firmly 
adherent, by means of numerous little 
prominences, to the sutures of the cranium, 
that it is difficult to separate them ; this 
membrane is to the internal cranium what 
the pericraninm is externally. The inner 
surface of the dura mater is lubricated by 
a fluid furnished by its own blood-ves- 
sels. 

The pia mater is that membrane which 
closely envelopes the substance of the 
brain, and dips down between its convolu- 
tions, and adheres to its surface by num- 
berless minute blood-vessels. It differs in 
its appearance and texture from the dura 
mater; presenting a smooth surface exte- 
riorly, but a rough and villous one next to 
the brain, and being composed of a beauti- 
ful network of blood-vessels united together 
by a delicate cellular tissue. 

The third membrane has been compared 
to a spider's web, in allusion to which the 
name of vwmbrana aravlinoides has been 
given to it. 

The arteries which supply the brain with 
blood are the two vertebrals, besides two 
other branches called the internal carotids. 
Its bk)od is returned from the sinuses of 
the dura mater by the vertebral and jugular 
veins. 

It is on the supply of the vertebral ar- 
teries, however, that the brain mainly de- 
pends for its supply, for, if ligatures are 
placed on these arteries, the animal dies; 
whereas, both the carotids may be tied 
without occasioning any apparent ill effects. 
If our memory servos us, Dr. J. C. Warren, 
of this city, has performed the latter 
operation on the human subject with suc- 
cess. 

In raising the bony covering of the brain, 



we meet with two processes, called the 
falx, or longitudinal process, and the ten- 
torium, or transverse process. The former 
resembles the blade of a scythe, hence its 
name. These processes are formed from 
duplicatures of the dura mater; the first 
descends for a short distance between the 
lobes of the cerebrum. It takes its rise 
from the crista galii, and terminates on the 
OS occipitis. 

The tentorium is extended from the inner 
plate of the os occipitis along the sides 
of the cranium to its base, whence it may 
be traced to the sphenoid bone, and is 
lost in the common covering of the dura 
mater. It is composed of two laminee : one 
is continuous with the faLx : the other forms 
that portion of the membrane which covers 
the cerebellum. The tentorium is equally 
divided by the falx into two lateral por- 
tions. 

The sinuses. — The superior, or longitu- 
dinal sinus, runs within the duplication of 
the falx, along its superior border. 

The tioo lateral sinuses are formed within 
the duplicature of that part of the tento- 
rium which is attached to the temporal and 
occipital bones ; one extending to the right, 
and the other to the left. They receive 
veins both from the cerebrum and cerebel- 
lum. 

The cavernous sinuses, so named from the 
cavernous appearance of their interior ; 
they receive some important nervous trunks 
in their passage from the brain, and for 
lodging the terminations of the internal 
carotid arteries. They commonly commu- 
nicate \vith the sub-occipital sinus ; these 
arc also of membranous formation, and are 
found upon the cuneiform process of the os 
occipitis, running longitudinally to ihe fora- 
men magnum, 
the cerebellum 
cerebrum. 

Cerebrum. — The largest portion of the 
cerebral mass, and that whicii presents it- 
self to our view in raising the skull, is the 
cerebrum. It is equally divided by a longi- 
tudinal tissure along its middle, into which 
the falx cerebri descends : and its divisions. 



Thoy receive veins from 
and posterior parts of the 



172 



ANATOMY AND PHYSIOLOGY OP 



which are symmetrical, both internally and 
externally, are denominated hemispheres. 

Cerebellum. — The cerebellum is at once 
distinguished from the cerebrum by its 
being only one-sixth the size of the latter. 
Its figure is irregular : it has two oval ends, 
and its lateral dimensions exceed its longi- 
tudinal. It is divided into three oblong 
lobes — a middle and two lateral. 

BIcdnlla oblongata, the smallest division 
of the cerebral mass. It rests on the cunei- 
form process of the occipital bone, and is 
continued upward and backward to the 
foramen magnum. 

The upper surface of the medulla oblong- 
ata forms, with the tuber annulare, the 
floor of the fourth ventricle. 

PUuatary gland, a red body, of an egg 
form, seated upon the sella tursica, within 
a fold of the dura mater. It has a mem- 
branous capsule, surrounded by cellular ad- 
hesions, by which it is firmly retained in its 
place. 

Medulla spinali.'^. — The spinal marrow 
is that extended portion of braiu-like sub- 
stance whicii is continued from the poste- 
rior part of the medulla oblongata through 
the entire length of the spinal canal. It is 
inclosed in the same membranes that en- 
velop the brain ; but, in addition to them, 
the superior ligament of the spine serves as 
a covering and defence to it below. To 
this, and to the periosteum lining the 
canal, its proper theca is loosely attached 
by cellular, adipose, and gelatinous matter. 
Its dura mater is derived from that which 
covers the brain: in being continued through 
the foramen magnum, the membrane is 
contracted into a cylindrical sheath which 
loosely encases the marrow, and is generally 
described under the denomination of theca 
vertebralis. The arachnoid membrane and 
pia mater have the same relation to the 
marrow that the same membranes have to 
the brain, of which they may be considered 
prolongations. 

ORIOIX AND DISTHIBUTION OI" THK NKRVES. 

The nerves, being symmetrical in number 
and distribution on either side of the bodv, 



take their origin in pairs, and these pairs 
are numbered, and so distinguished from 
one another, according to the order in 
which they arise. There are forty-six pairs 
of nerves ; ten, coming from the brain, are 
distinguished as the cerebral nerves; thirty- 
six, from the spinal marrow, denominated 
tlie spinal nerves. 

CEREBRAL NERVES. 

First pair, or olfactory nerves, arise from 
the corpora striata along the posterior bor- 
ders of which bodies the medullary band.s 
or roots of them may be traced as high up 
as the middle lobes of the cerebrum. These 
are the largest of the cerebral nerves, are 
bulbous at their origin, pulpy in texture, and 
exhibit, when cut into, comparatively to 
their size, large cavities, which are walled 
in by a layer of medullary matter, enclosed 
within a thinner one of cortical substance. 

Second pair, or optic nerves, arise from 
the thalamia nervorum. They leave the 
cranium through the optic foramen, and 
pass to enter the globe of the eye, within 
the interior of which it expands, and forms 
the retina. In its whole course, it is en- 
closed within a sheath prolonged from the 
dura mater. 

Third pair, or molorcs oculorum, take 
their origin by several filaments, from the 
inward parts of the crura cerebri. The 
trunk of the nerve first runs obliquely out- 
ward, across the back of the crus, then 
turns downward and enters the cavernous 
siiuis, on through the foramen lacerum-or- 
bitale. In entering the cavity, the nerve 
divides into two branches. The smaller 
is generally received by the levater oculi. 
The larger branch subdivides into several 
others ; the longest of these runs round the 
eyeball, and penetrates the oblique muscle. 
Two or three others run to the abductor 
and depressor muscles. 

Fourth ])air of pathetic. — These take a 
filamentous origin, and pass the border of 
the tentorium, entering the cavernous sinus, 
from thence to the orbit. Its destination 
is the superior oblique muscle of the eye. 

FiftJi pair, or par trigemini. — These av3 



THE HORSE. 



173 



the largest nerves of the brain. They take 
their origin by filaments from the crura cere- 
belli, and pierce the dm-a mater. Each 
nerve appears to form a ganglion ; from 
this ganglion we say that three nerves de- 
part. One is called the ophthalmic; the 
second, the anterior maxillary ; the third is 
the posterior maxillary nerve. The oph- 
thalmic nerve is the smallest of the three 
divisions ; as it emerges from the orbit, it 
divides into three branches, called the 
lachrymal, the super-orbitar, and the lateral 
nasal branch. 

Tlic second division, or anterior maxiUarii 
nerve, leaves the cranium tlirough the hole 
called foramen rotundum, of the sphenoid 
bone, and takes its passage through the 
mferior orbital canal, whence it emerges, 
covered by the levator labii superioris, 
upon the face : \\ere it splits into several 
large branches, denominated the facial 
nerves. But prior to its entering this canal 
it detaches several important branches to 
the ej-elid, lachrymal duct ; also several 
long filaments, which descend on the tube- 
rosity of the anterior maxilla, peneti-ate the 
bone, and furnish twigs to the antrum, and 
the two superior molar tcetli. The largest 
branch is the spheno-palatine, or lateral 
nasal nerve, to which the foramen spheno- 
palatine gives passage into the nose, 
wherein it divides into two sets of fila- 
ments. One of these is spread over the 
lateral parietes of the nasal cavity; the 
other ramifies over the sinuses, and sends 
a filament to the lower border of the sei> 
tum. A branch also goes to the velum 
palati, and another branch accompanies the 
palatine blood-vessels, and ramifies over the 
soft palate. 

The facial branches of this division ter- 
minate on tlie front and sides of the face, 
and receive communicatjing filaments from 
the anterior facial branch of (he portio 
dur.i, and with them form a plexus. 

The third division, the posterior maxillary 
nerve, gives off a branch which runs up in 
front of the parotid gland, and joins the 
portio dura; also branches called the buc- 
cal nerve, pterygoideus, and gustatory. The 



latter descends by the side of the tongue, 
penetrates that organ about its middle, and 
vanishes in its tip. It also sends ramifica- 
tions to the roots of the incisive teeth, and 
to the under lip. 

Sixth pair, or abducenles^ ailse by means 
of filaments from the medulla oblongata.; 
this nerve gives off two or three filaments 
to the retractor ocuU ; but its principal des- 
tination is to the abductor, along the fasci- 
cula of which, its ramifications are equally 
distributed. 

Seventh pair, or auditory nerves. — This 
pair includes two separate ner\'es on either 
side ; one, from its remarkable softness, is 
denominated the portio mollis; the other, 
in contradistinction, the portio dura. The 
portio mollis enters the organs of hearing, 
and is distributed to the labyrinth. 

The portio dura arises from the medulla 
oblongata, and passes to the internal part 
of the ear, the tympanum, and eustachian 
tube. It is also distributed to the temples, 
eyelids, nose, lips, cheek, and neck. 

Eig-hlh pair, or par vag-iim. — At its 
commencement it consists of two separate 
portions ; the first called the glosso-pharyn- 
geal nerve, and the second the true par va- 
gum. They arise from the corpora olivaria, 
and make their exit through the base of the 
cranium. The glosso-pharyngeus gives off 
branches, which join the portio dura, to the 
constrictors of the pharynx, and form 
branches which ramify in the base of the 
tongue. 

The proper par vagum, having disnnited 
Ijom the glosso-pharyngeal nerve, proceeds 
downwards to join the carotid artery, and 
takes its coiu'se along the neck to the chest. 
Its filaments are — 1. To the cervical gan- 
glion. 2. The pharyjigeal branch, whose 
filaments ])ass to the esophagus and larynx. 
3. Two slender branches to the carotid ar- 
tery, which form a jilexus. 4. The laryngeal 
branch. 

At the back part of the neck the par 
vagum inclines upwards, and ;s found 
above the carotid artery ; it then passes 
between the two first ribs into the chest 
Having entered the thoracic cavity-, it rxms 



174 



ANATOMY AND PHYSIOLOGY OF 



within the superior mediastinum ; the right 
nerve adheres to the trachea, crosses above 
the root of the right lung, alongside of the 
oesophagus and gains the under side of 
that tube before it leaves the chest. On the 
left side the nerve accompanies the anterior 
aorta, and crosses the root of the posterior 
aorta, and also reaches the oesophagus. Its 
branches within the chest are filaments to 
the tracheal and cardiac plexuses ; also, a 
branch called the recuiTcnt nerve ; branches 
to tiie pulmonary plexus, and also two 
cords that branch out and penetrate the 
walls of the auricles. The recun-ent nerve 
of tlic left side originates from the par 
vagum, by the side of the anterior aorta, 
and coils round the root of the posterior 
aorta. 

The recurrent nerve, so denominated from 
its retrograde course, passes upwardly and 
outwardly, and is found between the caro- 
tid artery and the trachea ; having reached 
the top of the latter, it spreads into fine ter- 
minating branches, several of which run to 
the muscles of the larynx and thyroid carti- 
lage, and end in ramifications upon the 
membrane of the glottis. Its branches are 
filaments to the pulmonary plexus, cardiac 
plexus, posterior cervical ganglion, and 
branches to the oesojjliagus and trachea. 

TJie par vagum runs to the stomach. 
The left nerve sends filaments to the heart, 
and others along the small curvature, which 
communicates with the ramifications of the 
right nerve ; the other crosses to the left 
side, and joins the great semilunar ganglion. 
The right nerve, as soon as it reaches the 
heart, dividas into numerous branches, 
which join the left, and spread their ramifi- 
cations upon the under part of the heart; 
some run to the pylorus, and others join the 
hepatic ])lcxus. 

Accessor// nerves to the eighth. — These 
nerves are considered as accessory to the 
eighth, in consequence of their being found 
in close connection in issuing from tiie 
cranium; it originates in the vertebral canal, 
by the union of several filaments. In its 
course into the cranium it receives many 
other line threads, and in that cavity joins 



the par vagum. Beneath the atlas, the 
accessory nerve divides ; the front division 
runs downward, and penetrates the belly, 
h-ansmitting side twigs in its course. The 
posterior division turns round the transverse 
process of the atlas to the scapula, near 
which it is lost in muscular substance. 
The branches of the accessory pass to the 
par vagum, anterior cervical ganglion, and 
communicate with the sub-occipital nerve. 

Ninth pair, or liiig-iialcs, arise behind the 
eighth pair, from the corpora olivaria; it is 
found in company with the par vagum, near 
the coronoid process. The nerve passes 
down the lower jaw, between the muscles 
forming the root of the tongue, and ends in 
the tip of the latter. It sends branches to 
the lingual muscles and to the hyo-glossus 
longus. 

Tenth pair, or sub-occipital nerves. — They 
arise from the medulla oblongata, and be- 
ginning of the spinal marrow; they pass 
out through a hole in the fore part of the 
body of the atlas. It then branches into a 
superior and inferior division. The superior 
is distributed to the extensor muscles of the 
head and neck. The inferior branch goes 
to the trachea, lymphatic glands, and mus- 
cles of the neck. 

CERVICAL NERVES. 

These consist of seven pairs, originating 
from the cervical portion of the spinal mar- 
row. Each nerve, as soon as it issues from 
the spinal canal, forms two nervous fila- 
ments, one superior, the other inferior. 

The first cervical nerve makes its exit be- 
tween the first and second cervical vertebrse. 
It sends branches to difierent muscles, and 
communicates with the 

Second cervical nerve, which makes its 
appearance between the second and third 
vertebras. Its superior filament sends 
branches to the muscles of the neck, and 
levator humeri, communicates with the ac- 
cessory nerve, and 

Third cervical. — This also sends branches 
and twigs to the difierent muscles of the 
neck, and communicates with the fourth. 

The fourth, Jifth, siath, and seventh pairs 



THE HORSE. 



175 



pass from the spine, between their respec- 
tive vertebrae, and send branches to the 
phrenic nerve, and ramifications to the mus- 
cles, sympathetic nerve, and unite with the 
dorsal. 

THE DIAPHRAGMATIC OR PHRENIC NERVE. 

This is formed by branches from several 
of the cervical nerves. It takes its course 
down along the inferior border of the scale- 
nus muscle. It terminates by numerous 
ramifications on the tendinous parts of the 
diaphragm. 

DORSAL NERVES. 

These consist of eighteen pairs. They 
pass from the vertebral canal in the same 
manner as the cervical, having superior and 
inferior branches. The inferior branches 
follow the course of the intercostal blood- 
vessels, and are called intercostal nerves. 
The superior branches are distributed to 
the back and loins. 

LUMBAR NERVES, 

Consist of five pairs (corresponding to 
the number of the lumbar vertebrse). 

The first nerve ends in ramifications near 
the stifle, and gives off branches to the last 
dorsal nerve, to the sympathetic, and to the 
second lumbar nerve. 

Tlie second nerve has communication 
with the first nerve, and sympathetic ; also 
the crural. It sends one division to the fore 
part of the haunch, where it becomes sub- 
cutaneous, and ramifies over the stifle. The 
other division crosses the ilio-lumbar artery, 
just below its origin, and takes nearly a 
similar course to the inward part of the 
haunch, and then ramifies upon the skin; in 
its way it detaches a considerable branch, 
called the spermaticus externus, which passes 
through the abdominal ring, and sends 
twigs, in the male, to the scrotum and tes- 
ticle ; in the female, filaments go from it to 
the uterus, udder, and external labia. 

The third nerve contributes to form the 
crural and obturator. It sends small 
branches to the sympathetic, psoas, and 
obturator nerves. 



The fourth nerve sends a branch to the 
sympathetic, contributes to the production 
of the crural ; and also sends a branch to 
the obturator. 

The fifth nerve communicates with the 
sympathetic, crural, and sciatic plexus. 

SACRAL NERVES, 

Consist of five pairs ; a superior and in- 
ferior fascicula. The superior make their 
exit through holes upon the upper part of 
the sacrum, and are there buried under a 
thick mass of muscle, and become cutane- 
ous upon the outer part of the hauncli. 

The inferior fascicula. — The first nerve 
largely contributes to the origin of the 
sciatic plexus, and sends a branch to the 
gluteal nerve ; also to the sympathetic and 
second lumbar nerves. The second nerve 
communicates Avitli tlie third and sympa- 
thetic, and sends branches to the surround- 
ing muscles and sciatic plexus. The third 
and fourth have similar connections. The 
fifth passes into the coccygeal muscles. 

COCCYGEAL NERVES. 

These issue from the spine, in the same 
manner as the last described. They com- 
municate with one another, ai'e distributed 
to muscles in the vicinity, and end in fila- 
mentous ramifications at the end of the tail. 

NERVES OF THE FORE EXTREMITY. 

The fore extremity receives its nerves 
from the axillary, or humeral plexus, and 
this plexus is formed by the union of por- 
tions of the sixth and seventh cervical 
nerves, and a division of the first dorsal 
nerve. 

The external thoracic nerves, sLx or seven 
in number, arise from the humeral plexus, 
and are distributed to the pectoral, triceps, 
and other muscles ; they finally ramify into 
the skin. 

Tlie scapjilar nerves are called anterior, 
posterior, and sub-scapular. The former 
sends its ultimate filaments to the triceps. 

The posterior scapular nerve sends 
branches to the sub-scapularis, triceps, teres 



ITff 



ANATOSIY AND PHi'SIOLOGY OF 



minor, and shoulder joint, and ends in the 
insertion of the levator humeri. 

The subscapular nerves run upward be- 
tween the shoulder and chest, and enter the 
subscapularis. 

The spiral or exiernal cutaneous nerve is 
furnished by the axillai-y plexus ; arises be- 
hind the humeral artery, and passes between 
the OS humeri and the head of the triceps, 
through the extensors, to the external flexors 
of the canon. It gives off several branches 
to the triceps, ramifies on the fore and' out- 
ward part of the knee, and sends branches 
to the heads of the extensor muscles. 

The radial nerve descends with the 
humeral artery to the inward side of the 
elbow joint, and runs along the back part 
of the radius to the knee; passing under 
the annular ligament, it descends to the leg, 
and takes the name of the internal metacar- 
pal nerve. It gives off numerous twigs to 
the muscles, and finally becomes subcutane- 
ous. 

The ulnar nerve originates from the 
humeral plexus. It passes down the radius, 
under the annular ligament, to the tendo 
perforans, and there becomes the external 
metacarpal nerve. It gives off internal 
eutaneous and subcutaneous branches, rami- 
fies into cellular substance, penetrates the 
heads of the flexors, and finally disperses 
its ramifications in front of the leg. 

TIte metacarpal nerves continue down 
the leg, over the fetlock joint, where they 
become the plantar nerves \ these pursue 
their course behind their corresponding 
blood-vessels to the back part of the foot, 
which they penetrate to the inner side of 
ihxi lateral cartilages, 

Tlie plantar nerve detaches a branch from 
the fetlock to the lateral cartilage ; another 
passes to the fatty frog. The final branch 
enters a hole in the back and lower part of 
the coffin bone, in company with the plan- 
tar artery, and there divides and distributes 
its ultimate branches around the edges of 
the sole. 

NERVES OF THE UIND EXTREMITY. 

The crural nerve is derived partly from 



the second, third, fourth, and fifth lumbar 
nerves. It makes its appearance under the 
transverse process of the loins, and proceeds 
in a line \\ath the external iliac artery. It 
gives off filaments to the psoas magnus, 
iliacus, rectus, and vastus internus muscles. 
It also gives off cutaneous filaments ; one 
runs to the stifle, and ends in ramifications 
upon the fore part of the thigh. The other 
continues down the leg, and can be traced 
as low as the fetlock. 

The obturator nerve, contributed to by 
third and fourth lumbar nerves, sweeps 
round the brim of the pelvis, and detaches 
twigs to the obturator muscles. Its ultimate 
filaments are expended on the triceps and 
gracilis. 

The gluteal nerve, after leaving the cavity 
of the pelvis, accompanies the gluteal artery, 
and passes into the substance of the gluteal 
muscles. 

The sciatic nerve derives its origin from 
the sacral and last of the lumbar nerves j 
after leaving the cavity of the pelvis, passes 
between the hip joint and the tuberosity of 
the ischium, and plunges into the substance 
of the haunch. Here it divides into branches 
called the popliteal nerves. At the hock its 
principal branch separates into the external 
and internal metatarsal nerves ; the former 
runs over the flexor pedis to the os calcis. 
Their subsequent coui-se and ultimate dis- 
tribution are the same as those of the plan- 
tar nerves of the fore extremity. The second 
popliteal nerve passes between the beUies 
of the gastrocnemii, above the first, detach- 
ing twigs to them in its passage, and then 
spreads into many branches, which pene- 
trate the heads of the flexor muscles of the 
foot, and send filaments into the stifle joint. 

SYMPATHETIC NERVE. 

This nerve derives its name from the uni- 
versal influence which it has on the nervous 
system. It communicates with the head, 
neck, chest, pelvis, and abdomen, by its fre- 
quent intercourse and connection with their 
respective nerves. It is supposed by some 
writers to be a ner\'ous system of itself. 
It has, at different distances, a great number 



THE HORSE. 



177 



of gangliform tubercles, from which ramifi- ' 
cations proceed forward, as well as filaments 
backward, to the ganglia of the nerves of 
the medulla spinalis. It is considered gen- 
erally as beginning from a branch of the 
fifth and sixth pair, given off at the base of 
the cranium. The ganglionic sti-uctures 
and the different plexuses are named from 
their form, location, and distribution ; hence 
we have the cervical ganglion, semilunar, 
sacral, etc. From the semilunar ganglion 
nervous filaments shoot in various direc- 
tions, which, from their being compared to 
the rays of the sun, are denominated the 
solar plexus. From the divergent filaments 
of the latter, the several smaller plexuses 
of the abdomen may be said to derive 
their formation, taking names according to 
the viscera they are particularly designed to 
furnish with nerves ; hence we have the 
splenic plexus, that sends filaments to the 



spleen, the hepatic plexus, mesenteric, aortic, 
hypogastric, and renal plexuses. The sym- 
pathetic nerve in the abdomen travels over 
the sides of the bodies of the lumbar verte- 
brcB, below the articulations of tlie ribs, and 
pursues its course into the pelvis. Here, 
also, it forms ganglia, which con-espond in 
number to those of the lumbar nerves : and 
from every ganglion come off two filaments: 
one which runs to the corresponding lumbar 
nerve ; the other crosses the aorta, and, by 
joining the aortic plexus, communicates 
with nerves coming from the sympathetic 
of the other side. 

From the loins, the sympathetic descends 
into the pelvis, and takes its course along 
the side of the sacrum, and forms five gan- 
glia, corresponding to the sacral nerves ; it 
finally terminates by forming a union with 
its fellow. 



EXAMIXATIOXS OX XEUROLOGY. 



Examinations on Xeurolog)-, which will include the 
names of parts not alluded to in the preceding 
summary of the nen'ous system. 

NERVES. 

Q. What are nei-ves? — A. Long, firm, and white 
chords, wliicli ramify after the manner of blood-vessels, 
and are distributed to all parts of the horse's body. 

Q. Where do they arise? — A. From the brain, 
metluUa oblongata, and medulla spinalis. 

Q. What communications have the different nerves 
with each other? — A. They anastomose : forming 
sometimes a plexus ; at others, a knot or gangUon, 
from which other branches arise. 

Q. What is the structure of nerv^es? — A. They 
consist of fasciculi, or bundles, of distinct longitudinal 
fibres, closely connected together by cellular substance. 

Q. What are the coverings of ner\-es? — A. Contin- 
uations of those which envelop the brain and spinal 
marrow, termed nemilema. 

Q. What is the structure of ganglions ? — ^1. They 
are formed by a close intermixtm'e of filaments. 

niUIS AXD ITS ME1IBR.1N-ES. 

Q. "Where is the brain situated? — A. It occupies 
the cranial cavity. 

Q. How is the brain dinded ? — • A. Into cerebrum, 
cerebellum, and medulla oblongata. 

Q. I!y what membranes is the bram enveloped? — 
A. By three membranes, or meninges : 1st, The dura 
mater ; 2d, Pia mater ; 3d, tunica arachnoides. 
^"' 23 



VVTIA M.iTEK. 

Q. "What is the situation of the dura mater'7 — A. 
It is the external covering of the brain. 

Q. How does it diticr from the other coverings of the 
brain ? — A. It is more dense, tough, and inelastic. 

Q. IIow is it retained within the cranium ? — ^-1. It 
is firmly adherent to the interior of the cranium, more 
l)articulai-ly to the depressions between the teeth of the 
cranial sutures. 

Q. How does the internal differ fi-om the external 
surface ? — A. It has a smooth, pohshed, and lubricated 
surface. 

Q. Is the dura mater supplied with neiTes? — A. 
Being composed of tendinous fibre, it is sujjposed to be 
destitute of nerves. 

Q. How are the processes of the dura mater 
formed ? — A. By duplicatures. 

Q. What are the use of the processes? — A. They 
steady and protect the various dirisions of the brain. 

Q. By what names are the processes known ? — A. 
The longitudinal process is called fals cerebri, and the 
transverse ditto is called tentorium. 

Q. What is the situation of the falx cerebri? — A. 
It forms a partition imder the anterior and superior 
parts of the cranial cavity extending from the crista 
gain to the occiput, and ends in continuity with the 
tentorium. 

Q. What is the situation of the tentorium cerebelh ? 
— A. It is extended, after the manner of an arch, from 
the cerebral plate of the occipitis along the sides of 



178 



ANATOMY AM) PHYSIOLOGY OF 



tlie cranium to its base; whence, greatly diminished in 
breadth it continues onward to the os sjAenoides. 

SDfUSES OF THE DURA MATEK. 
Q. What are the names of the principal sinuses of 
the dura mater? — A. The superior or longituduial 
sinus; two lateral, cavernous, and sub-occipital sinuses. 

riA JIATER. 

Q. What is the situation of the pia mater ? — A. It 
surrounds and closely invests the convolutions of the 
brain, and passes into the ventricles, furnishing them 
with an internal membrane. 

Q. What is the structure of the pia mater? — A. It 
presents a smooth exterior surface ; next the brain it 
is rough and villous, and is composed of a network of 
blood-vessels, which are united together by a dehcate 
cellular tissue. Being highly vascular, it is supposed 
that the Ijlood-vcssels of the brain ramify in it before 
entering the latter. 

ARACHNOID MEMBRANE. 

Q. Where is the tunica arachnoidea situated ? — A. 
It is a delicate and transparent membrane, spread 
uniformly over the surface of the brain. 

CEREBRUM. 

Q. Where is the cerebrum situated? — A. It occu- 
pies the superior part of the cranium. 

Q. What is its form, and how is it divided ? — A. It 
is oval, convex above and concave below, and is divided 
bv a longitudinal fissure along its middle, into which 
the falx cerebri descends. Its divisions are derom- 
inated hemispheres. 

Q. What is the appearance of the surface of the 
cerebrum ? — A. It is covered with eminences called 
convolutions. 

Q. Of what is the substance of the brain supposed to 
consist ? — .-1. Of two kinds of matter ; the external is 
called cortical or cineritious, and the internal is termed 
medullai-y. 

Q. What is the color of the cortical? — A. Red- 
dish-ash. 

Q. What is the color of the medullary portion ? — 
A. Of a milk-white hue. 

CORPUS CALLOSUM. 

Q. What is the situation of the corpus caUosum ? — 
A. It is an oblong white body, located at the bottom of 
the fissure which divides the two hemispheres of the 
brain. 

Q. What does the corpus callosum join on each 
side? — A. Its edges blend with the medullary sub- 
stance of the two hemispheres of the cerebrum. 

Q. What name is given to the medullary substance 
of both hemisiiheres, together with the corpus callosum, 
when the usual anatomical section is made? — A. By 
cutting off the hemispheres of the cerebrum nearly 
evsn with the corpus callosum, there is seen a large 



oval mass of medullary oubstance, called the centrum 
ovale. 

LATERAL VENTRICLES. 

Q. What are the lateral ventricles ? — A. Two cavi- 
ties situated beneath the corpus callosum and medullary 
arches of the cerebrum. 

Q. What di\ides the lateral ventricles from each 
other ? — A. The septum lucidum. 

Q. Name the parts which are generally considered as 
the contents of the lateral ventricles. — A. They are 
the corpora striata, the hippocampi, jjlexus choroides, 
fornix, and the thalami nervorum ojiticorum. 

Q. What is the situation and form of the corpora 
striata? — A. They are found on the lower and back 
parts of the ventricles, projecting into the centre of 
the cavities, where they expand as they approach the 
septum ; grow narrower and recede from each other 
above; below, they extend to the anterior cornua. 

raPPOCAMPI. 

Q. What is the situation of the hippocampi ? — A. 
They occupy the superior spaces of the ventricles in 
contact with the septum. 

Q. From whence do they originate ? — A. From the 
centres of the hemispheres. 

Q. What is their structure? — A. They consist of 
alternate lamina; of medullary and cortical matter. 

PLEXUS CHOROIDES. 

Q. What is the situation of the plexus choroides ? — 
A. They are situated in the channel between the 
corpus striatum and hippocampus. 

Q. Describe the appearance of the same ? — A. It is 
a soft vascular substance, consisting of a plexus of 
minute blood-vessels ; it makes its appearance from 
behind the fornix, and ends abruptly in a round bulbous 
mass. 

FORNIX. 

Q. Describe the fornix and its situation ? — A. The 
fornix is that part wliich receives the posterior border 
of the septum lucidum. It is extended after the 
manner of an arch, between the corpora stratia below 
and the heads of the hippocampi above, where it forms 
a junction with the corpus callosum. 

Q. Describe the processes or crura of the fornix ? — 
A. The two inferior crura spring from the corpus 
albicantium, at the base of the brain, and finally unite ; 
thus united, they appear within the ventricles and con- 
stitute the body of the fornix. The superior crura 
proceed from the upper end of the fornix, and descend 
into the superior cornua of the lateral ventricles, and 
end in sharp, pointed extremities. 

THALAMLA. 

Q. What is the situation of the thalamia nervorum 
opticorum? — A. They form the upper and back parts 
of the lateral ventricles. 

Q. Describe the thalamia. — ..-l. They have a wliite 



THE HORSE. 



179 



apjiearance, ponoiil in form, narrow and approximated 
infcriorly; broad sii|)eriorly ; they finally contract into 
medullary bands, the tractus o])tici, which turn round 
the crura cerebri to the base of the brain. 

Q. How are the thalami distinguished from the 
corpora striata? — .'1. They are more dense and firmer 
in composition. 

T.EXIA. 

Q. What is the situation of the t;enia? — A. They 
are located in the groove between the thalamus and 
corpus striatum, partly covered by the plexus choroides. 

COMMISUEES. 

Q. Xame the commisures of the brain. — ^4. 1st, 
commissm'a mollis; 2d, commisura inferior cerebri; 
3d, commisura superior cerebri. 

Q. How is the commisura mollis formed? — A. By 
contiguous parts of the thalami, which are united by 
cortical matter. 

Q. How is the commisura inferior cerebri formed ? 
— By a connection between the hemispheres of the 
brain. 

Q. "Where is the superior commissure located ? — A. 
Above the commissura mollis ; it has the a))i)earance of 
a short medullary chord. 



Q. What is the foramen? — -rl. It is a triangular 
depression under the arch of the fornix, into which the 
lateral ventricles open. 

VENTRICLES. 
ll!emar];s. — Ha\ing put the usual questions regarding 
the lateral ventricles, which may be numbered 1 and 
2, we now come to the third ventricle, which is not so 
well marked as in the human subject.] 

XniRD VENTRICLE. 

Q. How is the third ventricle formed? — A. By a 
mere fissure existing between the thalami. 

[Remarks. — The fourth ventricle, being located in 
the cerebellum, will be considered under this head.] 

IXFU.NDIBn.UM. 

Q. Where is the inftindibulum located ? — A. At the 
inferior part of the third ventricle. 

PINEAL GL.VXD. 

Q. VTbere is the pineal gland located ? — A. Be- 
tween the summits of the thalami, over the third 
ventricle, and above and before the superior com- 
missure. 

Q. Describe the pineal gland. — A. It is a small 
conoid bod)-, of grayish color, marked by a sUght 
de])rcssion along its centre. 

Q. AVhat are its attachments? — A. It is attached 
by means of the pia mater to the thalamia and tuber- 
cula quadragemina. 

Q. What is the internal structure of the pineal 
gland ? — .4. It consists of cortical and granular 
matter. 



NATES AND TESTES. 

Q. Where are the nates and testes situated? — A. 
Above the third ventricle, beliind the pineal gland, and 
immediately over and within the third and fourth ven- 
tricles. 

Q. How do the nates differ from the testes? — A. 
The former are larger than the latter, and are separated 
by a groove from the testes, and by a deep perpendicular 
fissui'e from each other. 

Q. AVhat is their form? — A. Semi-oval. 

Q. What is their composition ? — A. They are com- 
posed of cineritous and medullary matter. 

CEREBELLUM. 

Q. AVhat is the situation of the cerebellum ? — A. In 
the inferior and posterior parts of the cranium. 

Q. How does the cerebellum compare in size with 
the cerebrum? — A. The former is only about one- 
sixth the volume of the latter. 

Q. Describe the appearance of the cerebellum ? — A. 
Its surface is lobular and convoluted ; its form is 
irregular, haring two oval ends placed transversely, 
united in the centre by a broad vermiform belt ; its 
lateral dimensions exceed its longitudinal. 

Q. How is the cerebellum divided? — A. Into three 
lobes, a central and two lateral. 

Q. How does the composition of the cerebellum 
diflfer from that of the cerebrum ? — A. In the former 
the cortical substance exceeds the medullary, and, 
instead of forming the bulk of the outer parts, as is 
the case in the cerebrum, it pervades the inner. 

FOLTtTH VENTRICLE. 

Q. What is the situation of the fourth ventricle ? — 
A. It is situated between the cerebellum, tuber aimu- 
lare, and medulla oblongata. 

Q. Where is the choroid plexus of the cerebellum 
situated? — A. Within and across the posterior part 
of the fourth ventricle, between the cerebellum and 
medulla oblongata. 

Q. How is the choroid plexus of the cerebellum dis- 
tributed? — A. It is distributed into three divisions: 
one hes in the middle of the calamus ; the two latter 
are found within fissures in the cerebellum, occupying 
the spaces between it and the tuber annulare. 

BASE OF TIIE BRAIN. 

Q. How is the base or posterior part of the cerebrum 
divided? — A. It is di\ided into six lobes. 

Q. Describe their dirisions. — A. There are two 
anterior or inferior, resting upon the wings of the 
ethmoid bone; two middle, upon those of the sphenoid; 
and two sujjerior or posterior, lodged in the fossa of the 
squamous portions of the temporal bones. 

Q. What name is given to two broad, smooth promi- 
nences which appear over the middle lobes at the base 
of the brain ? — A. These are the corpora striata. 

Q. What nerves originate from this vicinity? — A. 
The olfactory nerves. 



180 ANATOMY AND PHYSIOLOGY OF THE HORSfc. 

Q. What lobes rest on the wings of the sphenoid \ Q. AVhat is the situation of the crura cerebelli ? — A- 
bone ? — A. The crura cerebri. I They are located higher up and in a more outward 

Q. From whence do they arise ? — A. From the in- 1 direction tluin the crura cerebri, 
ferior and middle lobes of the cerebrum, and are con- ' Q. Describe the crura cerebelli. — A. They are two 
tinued into an ovoid ])rntuberance above them, named cylindroid, medidlary chords, which join the lateral 
tuber annulare. lobes of the cerebellum to the tuber annulare. 

Q. A\''hat is observable between the crura cerebri ? Q. '\\''hat does the tuber annulare rest upon ? — A. 
— A. A small hemis])herical medullary eminence. On the cuneiform process of the posterior occipital 
called cor])us albicantium. bone. 

Q. AVherc are the tractuso]itici situated ? — A. They Q. Where are the foruminae ca?ca situated? — A. 
wind obliipiely downwai-d around the crui-a. : Above and below the tuber. 

y. Where do they proceed from.' — A. From the Q. 'What is their appearance? — A. They are 
terminations of the ihalamia. , described as little, round depressions, or blind holes. 



EXPLANATION OF FIGURE XVIII. 

[PROM BlAI^E■s " OUTUNES."] 



THE HEAD. 

A. The skull, face, and upper jaw, in one jiiece. 
7?. Lower jaw. 

0. Incisor teeth. 
h. Tushes. '*' 

c. Molares, or grindcr.s. 

d. I'eak formed by the extremities of the nasal bones. 

c. Zvftomalic spine, to the bottom of which the masseter takes its origin. 

/. Orbit. 

(/. Cavity above the orbital arch. 

■/(. Pole.' 

('. Zygomatic arch. 

j,j. iStyloid jirocesses for the attaelunent of the muscles. 

k. Joint formed by the upper and loi\er jaws. 

1. Meatus auditorius, or opening to the uiternal ear. 

THE NECK. 

C, C. Mai'ks the extent of the cervical vcrtebne. 

D. Dentata. 
1)1. .\tlas. 

II. Wingf uf the atlas. 

0, Lar^e superior spine of the dentata. 
p. Body of the dentata. 

(/. Inferior spine of the dentata. 

s, s, s, ,1, .1. Su])erior spines of the fi\e remaining cervical vertebrae. 

)•, r, i; r, r. Oblique ju'ocesses of the five last cervical vertebra!. 

II, n, It, II, II. Transverse jirocesses of the same bones. 

i, t, I, t, I. Inferior spines of the five last cervical veteljrcp. 

THE 'nioR.\x. 

V, V. Caviniform jiro. -ss of the sternum. 

w, IV, «', ic, ic, w, w. C'ostae or true ribs. 

V< V' y< V^ l/i .'/• .'/> .'/i 2/i .'/• Kibs as distinguished from the costir. 

X, re, .r, a-, a; x, x, x, x. Cartilages by means of whidi the ribs are attaclied to the sieriuim. 

z, z, z, z, z, z, z. Heads of the ribs. 

1, 1, 1, 1, 1. Superior sjiines of the first five dorsal vertebne, tlie fifth being generally the longest sniue in the 

body. 

2, 2, 2, 2, 2, 2, 2, 2. Superior spines from the sixth to the thirteenth, towards which the)- slope downward; 

the thirteenth is generally the most u]night spine in the dorsal region. 

3, 3, 3, 3, 3. Last five of the superior of the back spines, which have an inclination forward. 

THE LOINS, OR LUMBAR KEGION. 

4, 4, 4, 4. 4, 4. Superior spines of the lumbar region, thicker than the dorsal spines, and having a decided in- 

cliniuion forward. 
o, o, o, 5. Projecting transverse processes of the loins. 

THi; SACRUM. 

6, G, G, G, 6. Superior spuies of the sacrimi leaning decidedly backward, thus leavmg a large sjiace between the 
points of the last lumbar and the first sacral spine, at which place occms tlie great hinge of the back. 
8, 8, 8, 8. Bodies of the sacral vertebne. 



', '< ', ', ', ', ', ', I 



. Coccygeal bones. 



^.'o 



Tin; TAIL. 



THE PliLVLS. 



E. Ossa innominata, consisting of three bones ujion each side. 

(/. Ilium. 

6. Pubis. 

c. Ischium : the three bones unite at the cavity which receives the head of the thigh lione. 

9, 9. 'J'he inferior spines of the ilium. 

10. Su])erior spine, wliich partly covers the first sacral spine. 
c, (.'. Ischiatic spines. 



EXPLANATION OK FIGURE XVIII. CONTINUKD. 
THE TIIICII AXD STIFLE JOINT. 

/', F. Femurs. 

d. Hound head of the bone. 

e. Short neck of t)io femur. 
/'. Great trochanter. 

</. Small external trochanter. 

h. Small internal trochanter. 

»', I. Sulcus whence the gastrocnemii muscles originate. 

J, J. Posterior condyles of the femur. 

k, /,-. Anterior trochlea o\er which the ])atella glides. 

(J, G. Patellas : the inferarticidar cartilages of the stifle joint, as well as the cartilages tipping the dorsal 

lumbar sacral spines, and the su])erior margin of the blade bone or scapula, are necessarily omitted in 

this delmeation, wliich is admirably drawn from a macerated skeleton. 

THE TIBI.A .\XD FinUL.\, OU LEG BOXES, .VXD THE HOCK JOINT. 

// //. 'I'ibias. 

/, /. Heads of the bones. 

m, VI. Fibulas. 

»i, n. Inferior head of the tibia. 

/, /. llock joirif. 

0, 0. Astragalus. 

J), p. Calfis forming the point of the hock. 

THE rOSTERIOR SHAXK BOXES. 

A', K. Canons, metatarsals, or shank bones. 
},, L. Sjilint bones. 

THE BOXES OF THE PASTERXS, AXD FEET, OF THE POSTERIOB LIMBS. 



M, M. Sessamoids. 
h, N. Large pastern bone. 
O, 0. Smaller jiastern bone. 
p, ]>■ I'edal bones. 



BOXES OF THE AXTERIOR EXTREMITY. 



Q. Scapula or blade bone. 

(/. Su]>erior margin whence the cartilage has been removed. 

b. Spine of the sca])ula. 

c. Anterior fo.ssa of the scapula. 

d. Posterior fossa. 

e. Shallow cuji which receives the head of tlie humerus : the cartilage, which is situated aromid the margin 

of this cu]), and wliich serves to deepen it, has been destrojed by maceration. 
/. Tuberosity terminating the spine of the scapula, whence the flc.\or brachii originates. 
Jl. Humerus or arm bone. 
</. Head of the bone. 

//. Smooth cartilaginous and synovial pulley over which the tendon of the flexor brachii plays. 
1. l'"xternal trochanter of the humerus. 
,/. Inferior liead of the liumerus. 
k. Pit into which the ulna is received. 
S, 8. Ulna, the top of which is termed the olecranon. 
T, T. ]{adius. 
I. Head of the bone. 
VI. Inferior liead of the !)one. 

U, U. Carpus or knee joint, consisting of two rows of bones. 
n. Trapezium, which gives security to the great liexors, and attachment to several of the lessor flexors of the 

fore leg. 
.V, v. Canon or shank bone. 

o, 0. Head of the bone receiving the lower row of the bones of the knee. 
W, W. S])lint bones. 
]). Inferior head of the canon bone. 
X, X. Sessamoid bones. 
Y, y. Large pastern bone. 
/, Z. Small jjastern bones. 
J'. Pedal or cofhn bone. 



DISTRIBUTION OF THE LYMPHATICS. 



' Mr. Percivall remarks, in his lectures, ] 
that " no English veterinarian has, up to 
the present day (1820), been at the pains 
to demonstrate, practically, the particular 
distribution of the absorbing vessels of the 
horse. Professor Girard, whose ' Traite 
d' Anatomic Veterinaire ' does no less credit 
to the talent and industry of its author than 
honor to the veterinary school over which 
he presides, has presented us with an arti- 
cle on the ramification of the lymphatics, 
which I shall translate. 

" THE THORACIC DDCT. 

" The largest, longest, and most remark- 
able of the lymphatic vessels, in which 
terminate the majority of the lymphatics 
of the body, is situated \\'ithin the thorax, 
on the right side of the dorsal vertebrae, be- 
tween the aorta and vena azygos: it re- 
ceives the lymphatics from the posterior 
extremity', pelvis, parietes, and viscera of 
the abdomen, head, neck, v/ithers, and left 
anterior extremity. 

" It takes its origin under the loins, in a 
dilation or sinus situated at the root of the 
great mesenteric artery, and is named the 
receptaculum cliyli : it directs its course 
foru'ard, enters the thoracic cavity by the 
aortic perforation tlu'ough the diaphragm, 
extends along the bodies of the dorsal ver- 
tebra, until it arrives opposite the base of 
the heart, where it curves downward to 
cross over to the left side in its way to the 
anterior opeuuig of the thorax ; as it leaves 
the spine for this purpose, it runs over the 
trachea and esophagus ; having reached 
(he left side, it stretches forward to the 
beginning of the anterior vena cava, and 
terminates in the base of the left axillary 
vein. Not unijequently, it ends in the right 
axiUarj; in some instances, even in the be- 



ginning of the anterior cava. At its terrrii- 
nation, it dilates and forms a sinus, whose 
mouth opens into the vein, is guarded by a 
broad valve, so disposed as to prevent any 
reflux of blood into the duct.* It has also 
a ligamentous band around it, at this part, 
which confines it to the vein receiving its 
contents. 

"the RECEPTACnLUM CHYLI..^ 

"This reservoir forms the point of general 
confluence of all the lymphatics of the pos- 
terior limbs and abdomen, and from which 
originates the thoracic duct. It is main- 
tained by the aorta on one side, the vena 
cava posterior on the other, and is formed 
by the union of five or six large lymphatics, 
of which two or tliree .come from the en- 
trance of the pelvis, two or three others 
from the mesentery, a single one from the 
environs of the stomach and liver." 

The Professor here makes a classification 
of the lymphatics jof the bodjr. 

LYMPHATICS DISCHARGING THEIR CONTENTS 
iNTO THE ABDOMINAL PORTION OF THE 
THORACIC DUCT. 

" 1. Lymphadcs of the Posterior Extremi' 
ties. — These are distinguishable into the 
superficial and deep-seated. The first origi- 
nate from the skin and subcutaneous cel- 
lular tissue. They form divers ramifica- 
tions, which accompany the snjierficial 
veins ; of which the most remarkable at- 
tend the vena saphena major, frequently 
anastomosing with one another, and form- 
ing an anastomotic network. All these 
lymphatics run to the subcutancou.s ingui- 

* NetTTithstanding this valve, blood often gains admis- 
sion into the canal ; this is obsen'able in all cases of vio- 
lent death, or in which struggles and convulsions attend 
expiration. 

t Percivall's Lectures. 

(ISli 



182 



ANATOMY AND PHYSIOLOGY OF 



nal glands, which are lodged npon the 
superior and anterior part of the thigli. 

" The deep-seated lymphatics take their 
rise from the foot, ascend along with the 
plantar veins, continue upward among the 
muscles, in company with the deep-seated 
veins, corresponding in their principal di- 
visions to those vessels, and proceed to the 
inguinal glands. 

"All the lymphatics of the posterior 
limbs assemble at these glands, and here 
form a plexus, from which several large 
branches depart and traverse the iliac 
glands, clinging to the sides of the iliac 
vessels, and discharge their contents into 
the pelvic branch, contributing to the recop- 
taculum cliyli. 

" 2. Lymphatics of the Pelvis. — The 
vessels coming from (his cavity run in 
part 1o the inguinal glands, and in part 
to the internal pelvic glands. The su- 
perficial lymi)hatics about the pubes and 
Iho outlet of the pelvis run and join those 
of the extremities; those of the perineum 
and anus enter the cavity, and are accom- 
panied by those coming from the croup and 
tail, both proceeding to the glands within 
the interior of the pelvis. All the deep- 
seated lymphatics accomjiany the veins, 
make for the pelvic glands, form union with 
the others, and run and empty themselves 
into the main pelvic branch, wherein their 
lymph mixes with that coming from the in- 
guinal glands. 

" The lymphatics of the urinary and 
genital organs, included in the pelvic cavity, 
also traverse the glands lodged therein, and 
unite with those of the parietes of the pel- 
vis. Those of the scrotum enter Ihe in- 
guinal glands, as also do those belonging 
to the sheath and penis. The ramifications 
derived from the testicle and spermatic 
cord take the course of the veins, and pene- 
trate one or two of the lumbar glands 
lodged at the entrance of the pelvis. The 
lymphatics of the mammae, which are also 
divisible into superficial and deep-seated, 
run to the inguinal glands, and anastomose 
with the superficial set belonging to the in- 
ferior parietes of (he abdomen ; but, before 



they reach these last glands, they pervade 
those of the mammae. 

" 3. Lympliatics of the Parietes of the Ab- 
domen. — These vessels, in general but little 
developed, for the most part run to the in- 
guinal glands. The superficial set of the 
lower parietes accompany the cutaneous 
inguinal vein, anastomose with the lympha- 
tics of the scrotum and mammae, and tra- 
verse the glands in the groin : some of them 
direct their course forward, along with the 
cutaneous external thoracic veins of the 
thorax, unite with the superficial lymphatics 
of that part, and proceed to the axillary 
glands. The deep-seated vessels of the 
belly run in company with the epigastric 
vein, and go to the inguinal glands, or else 
they accompany the pectoral vein, and per- 
vade the glands in front of the thorax. 

" The superficial or subcutaneous lym- 
])hafics of tiic loins join either those of the 
croup or those of the flanks : the deep- 
seated, which spring from the peritoneum, 
muscles, or spinal canal, perforate one of 
the lumbar glands, and pass onward to ter- 
minate in the main pelvic branch. 

"4. Absorbents of the Mesentery. — The 
mesenteric branches, ordinarily two or 
three in number, the most considerable 
of which is constantly united to the great 
mesenteric artery, receive all the vessels 
continued from the mesenteric glands, as 
well as those coming from the mesentery 
and intestines. 

" The mesenteric absorbents, extremely 
numerous, are sustained between the layers 
of the mesentery, where they form a vascu- 
lar network ; many of them issue from the 
exhalent surface of the mesentery and in- 
testinal tube ; others take their rise from 
the interior of the intestines, from which 
they imbibe chyle. All these vessels con- 
verge towards the lymphatic reservoir, 
clinging in their passage around the mesen- 
teric veins ; some, however, taking a solitary 
course at a greater or less distance from any 
blood-vessel. Having arrived at the root of 
the mesentery, they pass through one or 
two, sometimes three, of the mesenteric 
glands, and afterwards join the principal 



TOE HORSE. 



183 



lumbar lymphatics. The absorbents of the 
colon and caecum caput coll run to the 
glands set at intervals along the intestinal 
tube, whence they proceed to the rccepta- 
culum chyli. 

" 0. Lymphatics of the Liver, Stomach, 
Spleen, and Omentum. — The hepatic trunk 
comprises the lymphatics issuing from the 
above viscera. This branch of the recepta- 
culum chyli not uncommonly consists of 
two divisions, and receives in addition to the 
above-mentioned vessels many ramifications 
from the crura of the diaphragm. 

" The lymphatics of the pancreas, like 
the above, also run with the divisions of 
its veins, and join either those of the liver 
or those of the spleen : some proceed di- 
rectly to the common hepatic trunk. 

" II. KAiMIFICATIONS TERMINATING IN THE 
THORACIC PORTION OF THE MAIN COMMON 
DUCT. 

"1. Lymphatics of the Parietes of the 
Thorax. — The superficial absorbents of 
the chest take their rise either from the sur- 
face of the skin or else from the subcuta- 
neous muscles ; they form several large 
branches which accompany the thoracic 
cutaneous vein, unite with the superficial 
lymphatics coming from the anterior parie- 
tes of the abdomen, and proceed to the 
axillary glands. 

" The deep-seated set take divers direc- 
tions, and pass through the different sets of 
glands. The pectoral, which anastomose 
""ita ramifications from the abdomen, fol- 
low the pectoral vein, and reach one or two 
glands at the entrance of the chest. The 
intercostal spring from the pleura and in- 
tercostal muscles, accompany the intercos- 
tal veins, pervade the internal dorsal glands, 
and terminate by several branches in the 
thoracic duct. 

" The lymphatics of the fleshy part of 
the diaphragm unite, some with the poste- 
rior intercostal, others with pectoral ; those 
coming from the crura run to the dorsal 
glands, where they anastomose with the 
intercostal : those from the cordiform ten- 
don anastomose with the deep hepatic, run 



forward between the layers of mediasti- 
num, nearly to the heart, and enter the car- 
diac glands. 

" 2. Lymphatics of the Thoracic Viscera. 
— The absorbents of the different organs 
contained within the thorax traverse one or 
several of the bronchial or cardiac glands, 
and afterwards form divers branches, which 
end in the thoracic duct. The pulmonary 
lymphatics, very numerous, are distin- 
guished into superficial and deep-seated. 
The first take their rise from the surface of 
the lungs, creep along under their envelop- 
ing membrane, and make for one or more 
of the bronchial glands. The deep set, 
which originate from the air-cells and from 
the parenchymatous tissue, follow the di- 
visions of the pulmonary veins, run to the 
roots of the bronchise ; there unite with 
the superficial, and perforate one or two of 
the bronchial glands. 

" The cardiac lymphatics derive their 
origin either from the surfaces (both exte- 
rior and interior) of the heart, or from the 
muscular substance of the organ ; they 
mount upon the curvature of the posterior 
aorta, and disappear in the cardiac glands. 

" The lymphatics of the superior part of 
the mediastinum, ai.d oi the cesophagus, 
join, some the intercostal, and others the 
bronchial ; those coming from the anterior 
part of this membranous partition, from 
the thymus, trachea, and oesophagus, unite, 
either with the pectoral, or close with the 
cardiac and anterior intercostal. 

" 3. Lymphatics of the Head. — The 
lymphatics of the head form two planes, 
a superficial and a deep one. The super- 
ficial pursue the course of tiie cutaneous 
veins, and run in part to the sublingual 
and gutteral glands. The deep vessels, 
which come from the nostrils, fauces, palate, 
etc., also run to the gutteral and sublingual, 
in which they unite with the superficial. 
From these two groups of glands, through 
which pass the lymphatics of the head, de- 
part several large branches, two or three of 
which descend upon the anterior face of the 
trachea; others follow the course of the 
deep-seated and cutaneous veins, unite with 



ISi 



ANATOMY AND PHYSIOLOGY OF THE HORSE. 



those of the neck, and descend to the front 
of the chest. Almost all these vessels ter- 
minate in the thoracic duct ; some few 
alone, on the right side, ending in the right 
axillary trunk. 

" 4. Lijmphatics of the Left Fore Extrem- 
iljj. — The lymphatics of this member present 
the same disposition as those of the poste- 
rior limbs, and are divided into superficial 
and deep-seated. The former, consisting 
of diverse rainifications, accompany the 
superficial veins ; the more considerable of 
them forming a plexus, which accompanies 
the cutaneous (superficial brachial) vein 
of the limb. The deep vessels originate 
from the foot, muscles, and bones, pursue 
the divisions of the deep veins, and plunge 



into the axillary glands, wherein they unite 
with the superficial, and whence they ex- 
tend to the thoracic duct. 

" The Right terminating- Trunk of the 
Lymphatics. — This very short lymphatic 
canal is obliquely situated at the entrance 
of the thorax, upon the transverse process of 
the last vertebra; of the neck, extending in 
a direction from above downward, and from 
without inward, and tenninating most; com- 
monly in the right axillary vein ; though, in 
some instances, it joins the thoracic duct. 
This trunk is formed by the lymphatics 
coming from the right axillary glands, and 
some from the right lung, and right side of 
the neck and trachea." 

(See Appendix.) 



EXAMINATIONS ON THE. PHYSIOLOGY OF THE LY5IPHATICS. 



Q. WTiat is the character of the fluid found in the 
^Ttiphatics? — A. It resembles dilute, liquor sanguinis, 
or the liquid portion of the blood in -srhlch the cor- 
puscles float. 

Q. AVhat finally becomes of the lymphatic fluid ? — 
A. It was formerly supposed that the lymphatic fluid 
was elimmated from the system; but Carpenter and 
other physiologists now contend that this is not the 
case ; that the same is poured into the common recep- 
ticle with the nutrient materials newly imbibed fi'om 
the food, whence both are propelled together into the 
general current of the circulation ; and thus, instead of 
being eliminated, the Ijinphatic fluid is employed in the 
formation of new tissues. 

Q. From whence is the IjTnphatic fluid derived ? — 
-4. 1st, from the residual fluid, which, having escaped 
from the blood-vessels into the tissues, has furnished the 



latter with the materials of their nutrition, and is now 
to be returned to the current of the circulation. 2d, 
from the particles of the solid fralneMS'Oik which have 
lost their \'ital powers, and are therefore unfit to be 
retained as components of the H^^^g system; they 
therefore reenter the circulation, to be agam sabmftted 
to the assimulatlng process, so that nothing shall be 
lost. 

Q. By what process do fluids enter the cutaneous 
IjTnphatics ? — A. By a process of imbibation. 

Q. What fluid is more readily absorbed than some 
others? — ^. Milli. 

Q. What authority have you for this ? — A. Schoeger, 
in the course of liis experiments, found that the lympha- 
tics of a hmb, long immersed in milk, became tinged 
with it, M'hile none of it could be detected in blood 
draira &om the veins. 



§lmnx^ d '^tmluxd €tt\\mMts. 



84 



(185) 



A GLOSSARY OF VETERINARY TECHNICALITIES. 



Abdomen. — The posterior part of the body of the horse. 

AhJomiiuiIis. — Pertaining to the abdomen. 

Abdoiiiiintl Regions. — The divisions of the exterior of 
the abdomen. 

Abductor. — Muscles arc named oWucfoc.s- wliitli draw- 
parts from tlie a.xis of the body, or given centres. 

Abnormal. — Unnatural, irregular. 

Accelerator. — A nniscic of the penis. 

Acetabulum. — A name given to the cavity in which the 
head of the thigh bone articulates. 

Achillis Tendo. — The tendon of the nuiscle inserted 
into the heel of man. 

Acuniinated. — I'oiuted, like a needle. 

Adductor. — Muscles which draw (larts tow ard the axis 
of the body. 

AdijHise. — Fatty matter. 

Adventitious. — Accidental. 

Afferent. — A term used to designate tlie structures 
which convey fluids to difterent parts. 

.U(F. — Wings. 

Albumen. — An element which constitutes the chief part 
of the white of an egg. 

Allmentari/ Canal. — Tlie passage which commences in 
the a'sopluigus and ends in the anus. 

Alveolus. — The bony sockets of the teeth. 

Anal. — Kelating to the anus. 

Anatomi/. — To cut, with a view of displaying the struc- 
ture, relations, and uses of parts. 

Animus. — The principle of vitality. 

Annular. — A ring-like ligament, found at the posterior 
part of the knee of the horse. 

Antniioulst. — A term applied to counteracting muscles 
or tendons. 

Anterior. — A term applied to what may be situated 
before another part of the same kind. 

Anii. — A prefix, signifying against. 

Antilabium. — Against the lips. 

Antrum. — Cavity in bones. 

Anus. — The posterior extremity of the rectum. 

Aorta. — The largest artery of the body. 

Aortic. — Pertaining to the aorta. 

Apex. — The pointed end of an organ. 

Aponeurosis. — A tendinous expansion of fibre. 

Arachnoid. — A membrane of the brain. 

Arch of the Colon. — Transverse portion of that intestine. 

Areola. — The spaces between fibres com|)Osing an 
organ. 

Arterial. — A property belonging to arteries. 

Arlenalization. — The change which occurs in venous 
blood when brought in contact with air in tli« lungs. 

Arleri/. — The name of blood-vcs?ols whirli distriliutc 
arterial blood. 



Articular. — Belonging, or relating, to joints. 

Articulation. — {From articulus.) A joint. 

A.i/terili/. — A roughness. 

Astraijalus. — The bone beneath the os caleis. 

Alias. — The anterior bone of the neck. 

Attollens. — A name given to muscles which lift, or raise, 
the parts. 

Amlitonj. — Muscles and parts connected with the ear. 

Auricular. — Kelating to the ear. 

Auricles. — The anterior cavities of the heart. 

Axilla. — The part between the superior region of the 
arm and the chest. 

B. 

Biceps. — (From, bis — twice, and ca]mt — ahead; two 
heads.) The term is ajiplicd to muscles, having two 
distinct heads, or origins. 

Bifurcate. — (Bifurcas ; from bis, twice, and furca, a 
fork). A blood-vessel or muscle is said to bifurcate when 
it divides into two branches. 

Biliary. -litihithig to the bile. 

Brachial. — Of, or 'belonging, to the .inn. 

Bronclike. — Bifurcations of the windpipe. 

Bronchial. — Kelatiiig to the bronchia". 

Buccal. — (From bucca, the cheek.) Belonging to the 
cheek. 

Buccinator. — A muscle of the cheek. 

Bulb. — A dilated portion of the tube at the base of the 
jienis. 

Bursa'. — Sacs, or bags. 

Bur.i(e Mucosce. — Sacs found in the region of joints. 

Bur^l. — Kelating to bursa;. 

C. 

I Cacum — The blind gut. 

Circ<il. — Pertaining to the caecum. 

Caleis Os. — The prominent bone of the hock. 

Cancilli. — Cellular structure of bones. 

Canine Teeth. — The eyetccth, ciispidati. 

Caullius. — The angle of the eve. 

Capillary. — Hair-like vessels which are found between 
the arterial and venous vessels. 

Capsule. — A membranous sac. 

Capsular. — A term applied to ligaments whii-li surround 
articulations. 

Caput. — The head. 

Cardia. — The heart. 

Cardiac. — Pertaining to the heart. 

Carotid. — The name of the jirincipal arteries of the 
neck. 

Carfins. — The bones of the knee. 

Caruncle. — A small lleshy excrescence. 

Caruncuhr fxn-ri/malis. — Small flcsjiy bodies fonnd in 
the angle of the eye. 

(197) 



188 



GLOSSARY OF VETERINARY TECHNICALITIES. 



Cauila. — The tail. 

Cava. — The largest vein in the body of the horse. 

Cavity. — A hollow part; the abdominal cavity, for 
example. 

Cellular. — Composed of cells. 

Centrum Ovale. — The appearance of tlie brain, when a 
horizontal section is made on a level witli the corpus cal- 
losum. 

Centrum Tendinosum. — Tendinous centre of the dia- 
phragm. 

Cej>hul!c. — Pertaining to the head. 

Cenhellum. — Inferior lube of the brain. 

Cerebrum. — Superior lobe of the brain. 

Cerebral. — Relating to the brain. 

Cerebro-siiinal. — Pertaining to both tlie brain and spinal 
cord. 

Cervical. — Pertaining to the neck. 

Cervix. — The neck or contracted portion of an organ. 

Choree Teiullna. — Part of the internal structure of the 
heart. 

Choroid. — The inner tunic of the eye. 

Cht/le. — A fluid found in the thoracic duct and lacteals. 

Chijme. — A name given to the food after it has passed 
the pylorus. 

Cilia. — The eyelids, hair of the same, etc. 

Cineritious. — A term applied to that part of the brain 
wliich is of an ash color. 

Clrculus. — A ring. 

Clitoris. — A part of the pudendum of tlie mare corres- 
ponding to the glans penis of the horse. 

Cocci/T. — The bones of tlic tail. 

Cochlea. — Tlie spiral cavity of the car. 

Cacum. — (Sometimes spelt caicum.) The blind gut. 

Cccliac. — Prolongation of tlie solar plexus, an artery 
and vein of the abdomen. 

Colon. — The largest and most dilated portion of the 
intestines. 

Culumnce Carme. — A muscular arrangement within the 
cavity of the heart. , 

Commisure. — A suture, junction, or joint. 

Comjilcxus. — To embrace or surround. 

Concha. — External cavity of the car. 

Conduit. — A canal. 

Condi/le. — An irregular process or enlargement. 

Coiuli/lold. — A tubercle, wart-like. 

Coni/lobate. — Pall-sliape. 

Coni/lomcratc. — An assemblage of glands. 

Conjunetivia. — L.xternal coat of tlic eyeball, and inter- 
nal lining of the eyelids. 

Conoid. — Cone-like. 

Constrictor. — Muscles tliat arc-bound together arc tlius 
named. The ofTice is to close an outlet. 

Contlnuiti/. — Identity of parts, having direct connection. 

Convolute. — Rolled up. 

Coracoid. — Like a crow's beak; a process of tlie 
scapula. 

Cornea. — Anterior coat of tlie eve. 

Cornu. — A horn. 

Corona. — A crown, tlie superior paitcrn is tlius named: 
OS coron;c. 

Coronal Suture. — The uniting medium between tlie 
frontal and parietal bones. 

Coronary. — Arteries and veins, jirojjer to the lieart, arc 
thus named 



Coronotd. — Processes of bones are thus named when 
they form an eminence. 

Corpora. — A term applied to numerous prominences in 
the brain and elsewhere. 

Corpus. — A body. 

Corpora Striata. — Striped eminences in the brain. 

Corpuscle. — A minute body. 

Corrurjator. — A muscle wiiich wrinkles the surrounding 
parts. 

Cortical. — Resembling bark. 

Costa. — A rib. 

Costal. — Pertaining to the region of the ribs. 

Costalis Pleura. — That portion of tlie plem'a which 
lines tlio interior of the cliest. 

Cotyloid. — Cuji-sliaped. 

Cranium. — The skull. 

Crassanientum. — The clot, or red globules, of the blood. 

Crcmaster. — A muscle of the testicle. 

Crest of the Ilmm. — The anterior, superior parts of the 
pelvis. 

Cricoid. — Ring-like. 

Crista. — A ci'cst. 

Ciurial. — In the form of a cross. 
V Crural. — Belonging to the thigli. 

Crystalloid. — Resembling a crystal. 

Cuboides. — One of tlie bones of the knee, which resem- 
liles a cube, or die. 

Cuncifornie. — A bone of the knee, in form resembling a 
wedge. 

Cuspidata. — The tushes of the horse arc thus named. 

Cutaneous. — Belonging to the skin. 

Cuticle. — The scarf skin. 

Cyst. — A bladder or sac. 
D. 

Dartos. — A name given to the muscle which cormgatcs 
the scrotum. 

Deferens. — The excretory canal of the testes. 

Dentatus. — A tootb-like process on the second cervical 
vertebra. 

Lkntes Incisors. — The twelve front teeth of the Iiorse. 

Dentes Molurcs. — The twenty-four grinders. 

Depressor. — A muscle is so named when it depresses 
the part on which it acts. 

Diaphragm. — The muscle which separates the thora.>c 
from the abdomen. 

Diastole. — Periodic dilation of the heart. 

Dilator. — A name given to muscles whicli dilate certaia 
parts. 

Dlploe. — The cellular structure, which separates bony 
tablets. 

Diverticulum. — A blind tube, diverging from the course 
of a larger one. 

Dorsal. — Pertaining to the back. 

Ducts. — Orifices of various canals. 

Ductus. — A canal for conveying fluids. 

Duplicate. — Doubled. 

Dupllcature. — Reflection of a membrane upon itself. 

Dura Mater. — The outermost tunie of the brain. 

K. 

Effivent. — Vessels are thns nnincil whicli con^■ey fluids 
from gland-'. 

Ehrator. — A muscle is so called when it lifis or elevates 
tiic parts to which it is attached. 



GLOSSARY OP VETERINARY TECHNICALITIES. 



189 



Enc'phalon. — The brain. 

Ensiform. — Sword-like. 

Ephlidijmis. — An .ippendage to the testicle. 

Epigastrium. — Ec^'ion of the stomach. 

Epii/lolti.i. — Canilajje at the root of the tongue. 

Epi;)h;/sis. — A union of bones by means of cartilage. 

Ejiithelium. — A transparent membrane covering various 
internal parts. 

Erector. — A name given to certain muscles, which raise 
or erect the parts. 

Eroded. — Rough and jagged. 

Esopliayus. — The gullet. 

EtJimoid. — Sieve-like. 

Bxilo-Motarij. — The trae spinal neiTes. 

Excretorif. — Vessels and ducts are thus named ivhicli 
discharge fluids. 

Erpiration. — The act of expelling air from the Umgs. 

Extensor. — To stretch out; a name given to several 
muscles and tendons. 

Extremity. — The end. 

F. 

Facial. — Belonging to the face. 

Falciform. — Scythe-shaped. 

Fall. — The scythe process of the dura mater. 

Fascia. — The tendinous expansion of muscles. 

Fascicular. — Fibres arranged in bnndles. 

Fauces. — Posterior part of the mouth. 

Femoral. — Of, or belonging to, the thigh. 

Fenestra. — Part of the internal car. 

Fibre. — A thread or filament. 

Fib7'ous. — Composed of fibres. 

Fibula. — A small bone attached to the lateral part of 
the tibia of the horse. 

Filament. — A minute fibre. 

Filijerm. — Thread-like. 

Fimbria. — A fringe. 

Fissui-c. — A crack or groove. 

Flarus. — Yellow. 

Flexor. — A name given to numerous muscles and ten- 
dons which bend the limbs. 

Foliatus. — Leaf-form. 

Follicle. — A minute sac or bag. 

Foramen. — An opeuing. 

Fornix. — Arch or vault; one of the structures of the 
brain. 

Fossa. — A sliallow cavity or depression. 

Frainum. — A ligament which restrains motion. 

Frontal. — Belonging to the anterior part of tlie cranium. 

Function. — Any action by which vital phenomena are 
produced. 

Fundus. — The base or bottom. 

Funis. — The umbilical cord. 



Ganglion. — A knot or enlarp^ment in the course of a 
nerve. 

Gastric. — Pertaining to the stomach. 

Gastric Juice. — A secretion, peculiar to the walls of the 
stomach. 

Gastrocnemii. — The tendinous portion of muscles in- 
serted into the os calcis, or point of the hock, arc tlius 
named. 

Gemini. — Twins: two organs precisely alike are thus 
earned. 



Gestation. — Pregnancy. 

Gland. — An organ of seeretion. 

Glandula. — A small gland. 

Glandular. — Kesembling a gland. 

Glenoid. — The name of articulating cavities. 

Glissons Capsule. — The fibrous envelope of the liver. 

Globate. — Globe-like. 

Globulis. — Ucd particles of the blood. 

Globuline. — Albuminous constituent of the blood. 

Glomerate. — Congregated. 

Glossa. — The tongue. 

Glottis. — Upper opening into the windpipe. 

Gluteal. — Belonging to the haunch. 

Gracilis. — A muscle on the inner part of the thigh. 

Granule. — A small grain. 

Gutteral. — Belonging to the throat. 

H. 

Hepatic. — Belonging to the llvei:. 

Hiatus. — An aperture or foramen. 

Hippo. — A horse ; a prefix. 

Hipjwcampus. — Two eminences in the lateral ventricles 
of the brain. 

Homo. — A prefix designating similarity. 

Humerus. — The bone beneath the shoulder blade. 

Hi/o. — Names compounded with this prefix relate to 
muscles situated near the root of the tongue. 

Hi/oidcs. — Bone at the root of the tongue. 

Ili/pocliondrium. — A region of the abdomen. 

Hiipoqastric. — Eclating to the h\-pogastric region of tlus 
abdomen. 

I, J. 

Peo. — A prefijc, the ilerim or bone of the pelvis. 

Ileum. — A portion of the intestinal tube. 

Iliac. — Eegionof the flanks. 

Incisors. — The twelve front teeth, or nippers, of ths 
horse arc thus named. 

Incus. — A bone of the ear. 

Infra. — Under ; a prefix to t-iic name of several muscles. 

Infra. — Without. 

Infundibulum. — A fimnel or dnct. 

Inguinal. — Pertaining to the groin. 

Inguinal Ligament. — Pouparts ligament. 

Innominatum. — Without a name. 

Innominatum Os. — Union of the ileum, ischium, and 
pubie bones. 

Inosculation. — Union of the extremities of vessels. 

Insertion. — Attachment of a muscle or tendon to t;« 
part which it moves. 

Integuments. — The skin and sub-ti.ssuts. 

Interai-ticular. — Between the joints. 

Interosseous. — JIusclcs and ligaments situated betweea 
bones arc thus named. 

Interseptum. — The nvuki. 

Interstitial. — A term applied to substances ticer.pyinj 
the spaces between contiguous pans. 

Interspinales. — Between the spines of bones. 

Intertransrersales. — Muscles located bet%veen the trans- 
verse processes of bones. 

Intervertebral.— Thu articular cartilages between the 
vertebra; are thus named. 

Intestinal Canal. — 'The interior of the duodenum, jeju- 
num, ileum, coecum, colon, and rectum, comj)diOi the ia- 
iestinal cauaL 



190 



GLOSSARY OF VETEniNARY TECHNICALITIES. 



Intra. — AVitliin. 
Intestines. — The bowels. 

Ini'ertehrata. — Animals without internal bony structure. 
Ischium. — A part of the bones of the pelvis. 
Isthmus. — A naiTow passage. 

Jejunum. — A terra applied to that portion of the intes- 
tine which is generally found empty. 
Jiirjular. — Belonging to the neck. 



Lahorium. — Kclating to the lips. 

Lahia. — ThcWfi^. 

Lachrymn. — A tear. 

Laclirijinal. — Structures concerned in the secretion and 
transmission of tears. 

iMiiculs. — Absorbent vessels of the lymphatics. 

Lactiferous. — Vessels conveying milk. 

Lacuna:. — Ducts issuing from small glands. 

Lamella. — Thin plates. 

Lamina. — A scries of plates. 

Laminntfd. — Leaf-like. 

iMrn/nr/cat. — Relating to the larv-nx. 

Larynx.. — The superior part of the -winilpipe. 

Lata. — Broad. 

Lateral. — Pertaining to tlie side. 

Latissimu.'i. — A term applied to a muscle in consequence 
of its great breadth. 

Lens. — A crystalline body; a lentil. 

Lenticular. — Shaped like the lens. 

Levator. — A tcriu apjilied to muscles whicli raise the 
parts to which they are attached. 

Ligament. — A tendinous cord. 

Linea. — A white line ; thread-like. 

Linea Aspera. — A rough projection. 

Linea Sanilnnares, or scmi-circularis. — Lines on each 
Bide of the linea allia, formed by the termination of the 
fibres of the abdominal muscles. 

Linea Transrersali.'!. — Lines crossing the recti muscles 
of the abdomen. 

Linijnul. — Pertaining to the tongue. 

Lintjualis. — A muscle of the tongue. 

Liquor Sanguinis. — The fluid element of the blood. 

L(Aie. — A division of an organ. 

Lobus. — A lobe. 

Local. — Confined to a part. 

Loins. — The postei'ior jiart of the back. 

Longissimus. — The longest. 

Longus. — Long, lengthy. 

Lumbar. — Belonging to the loins. 

Lujnbrici. — Worms. 

Luna. — The moon. 

Lunare. — A bone of the knee. 

Lymph. — A fluid found in tlie lynijihatics. 

Ljmphiitic. — Of ilic nature of lymph. 

M. 
Major. — The greater. 
Malar. — Belonging to the cheek. 
itiillens. — A liammer or mallet. 
Malphigian Ilmlics. — Dark points of the kidneys. 
Mamma. — The udiler. 
Mammary. — Belonging to the udder. 
Massetcr. — A muscle of the jaw. 
Mastoid. — Processes of bones presenting the form of a 
nipple arc thus named. 



Hater. — A mother. 

Maxilla. — Bone of the jaw. 

Maxillary. — Pertaining to the jaw. 

Meatus. — A passage. 

Meatus Auditorius. — The internal auditory passage of 
the ear. 

Meatus Urinarius. — The orifice of the urethra. 

Median. — Central, the central line. 

Mediastinum. — The partition which divides the thorax. 

Medulla. — The medullary substance of the brain is thus 
named. It signifies marrow or jiith. 

Medulla Spinalis. — The spinal marrow. 

Membranes. — Tissues. 

Membranous. — Having the texture of membranes. 

Meninges. — Membranes of the brain. 

Meningial. — Relating to the membranes of the brain. 

Mesenteric. — Pertaining to tlie mesentery. 

Mesentery. — Membranes uniting the intestine*. 

Mesian Line. — The middle line. 

Meso. — Words compounded of meso signify the middle. 

Metacaiyal. — Relating to the knee of the horse. 

Metacarpus. — The bones of the knee. 

Molar. — The grinders. 

Motor. ^- To move ; the nerves of voluntary motion are 
thus named. 

3Iucus. — Animal mucilage. 

Mucous. — A term applied to the mucous tissues. 

Muscular. — Belonging to a muscle. 

Muscle. — Flesh; a bundle of muscular filjres. 

Mylo. — Names compounded of this word relate to 
muscles located in the region of the root of the tongue. 

Myology. — A description of the muscles. 

N. 
JSares. — The anterior cavity of the nostrils. 
Nasal. — Belonging to the nose. 
Navicular. — Boat-shaped. 
Aeuri/ema. — The sheath investing the nerves. 
Nidus. — Naked. 

Nucha. — A part of the superior region of the neck. 
Nucha Ligamentum, — A lig.amcnt of the spine. 
Nyinplue. — Intern.al l.abi.T of the vulva. 

O. 

Obliijue. — A term applied to muscles that have an 
obUi)uo direction. 

Obturator. — Name of muscles, foramin.'e, etc. 

Occipital. — Connected with the occiput or posterior 
part of the cranium. 

Occipito Atloid. — That which has reference to the occi- 
put and atlas. 

Occipito Frontalis. — A muscle which reaches from the 
occiput to tlic forehead. 

Ocular. — Belonging to the eye. 

Odontoid. — Tooth-like. 

(E.-:ophagus. — The gullet. 

Olecranon. — Point of the arm, formed l>y the ulna. 

Olfactory. — Relating to tlie sense of smell. 

Olivaris. — Resembling the olive. 

Omentum. — The caul. 

Omo. — Names compounded of this word signify raus- 
clcs which are attached to the scapula. 

Opaque. — Not transparent. 

Optic. — Relating to vision. 



GLOSSARY OF VETERINARY TECHNICALITIES. 



191 



OrhinJar. — Sphorical-cirfuhir. 

Orhknlaris Oris. — Muscle of the lips. 

Orliiriilaris PtiZ/itiraram. — JIusclc of tlie cvuliils. 

Odiiaifare. — The smallest bono of the internal ear. 

Orliit. — The hony socket of the eye. 

Oiiiitar. — Pertaining to the orbit. 

Orijan. — A part having a distinct ofBcc to purfurm. 

Orijanism. — Vital organization. 

Orijani:eil. — Possessed of organs; endowed with life. 

Orifice. — An aperture. 

Oriyin. — The fixed point or commencement of a niu.scle. 

Os. — A bone. 

Osseous. — Bony. 

Oiaria. — The female testes. 

Ovum. — An egg. 

P. 

Palatine. — Relating to the palate. 

Palate. — The roof of the mouth. 

Palate Os. — Bone of tlie palate. 

Palpebrcv. — The eyelids. 

Paries. — A wall. 

Parietes. — The walls of the abdomen and thora.x, etc. 

Parotid. — Name of the gland beneath the car. 

Parotid Duct. — Opening into the cheek from the parotid 
gland. 

Patella. — The stifle bone. 

Pectinated. — Shaped like the teeth of a comb. 

Peduncle. — A stalk. 

Pellicle. — A thin membrane. 

Pelvis. — The cavity formed by the innominata and 
sacrum. 

Penis. — The principal organ of generation in the male. 

Per/orans. — Perforating ; the name of part of the flexor 
tendons. 

Perforatus. — Perforated for the transmission of tlie 
preceding tendon. 

Peri. — Around; an envelope. 

Pericardium. — The sac containing the lieart. 

Pericranium. — The membrane investing the skull. 

Perineum. — The part between the anus and organs 
of generation. 

Periosteum. — Membrane investing bones." 

Peripheri/. — Tlie circumference. 

Peritoneum. — The serous membrane which lines the in- 
terior of the abdomen and is reflected on its contents. 

Peroneal. — Relating to the fibula. 

Petaloid. — Shaped like a petal. 

Pelrosum Os. — Rough portion of the temporal bone. 

Peter's Glands. — Clustered mucous glands of the in- 
testines. 

Pharijngial. — Relating to the pharynx. 

Pharynx. — Superior part of the gullet. 

Phrenic. — Belonging to the diaphragm. 

Pia Mater. — A thin membrane investing the brain. 

Pigmentum Nigrum, — Black pigment upon the choroid 
coat of the eye. 

Pilus. — Hair. 

Pineal. — Shaped like the fruit of the pine. 

Pisiform. — Shaped like a pea. 

Piluitari/ Membrane. — The schneiderian membrane of 
the nostrils. 

Placenta. — The afterbirth. 

Plantar. — Relating to the feet. 



Pleura. — The serous membrane which lines the cavity 
of the chest, and is reflected on the contents of the same. 

Plcrus. — A network of nerves or vessels. 

Piica. — A fold. 

Puns. — A bridge. 

Pons \'arolii. — A part of tlie brain. 

Popliteal. — JIuscles, nerves, and vessels in the region 
of the hock. 

Pores. — Extremities of the exhalcnts of the skin. 

Porta. — A door or gate. 

Portio. — A portion or branch. 

Posterior. — Behind. 

Posticus. — Situated behind. 

Pratcordin. — The anterior part of the chest. 

Prima: IVie. — First passages of the alimentary can.il. 

Process. — The projecting eminence on a bone. 

Profundus. — Deep-seated. 

Pronatus. — Muscles of the fore limbs. 

Prostate. — A gland near the neck of the male bladder. 

Pseudo. — False ; a term ajiplicd to spurious membranes. 

Psoa-. — The loins. 

Psoas. — Belonging to tlie loins. 

Pteri/goid. — Shapeil like a wing. 

Pubcs. — The junction of the pelvic hones at their in- 
ferior parts. 

Pubic. — Pertaining to the pubes. 

Pudendum. — The external parts of the female organs 
of generation. 

Pudic. — Belonging to the pudenda. 

Pulmonanj. — Belonging to the lungs. 

Puncta. — Lachrymalia. The tear-ducts within the eye- 
lids. 

Punctum. — A point. 

Pi/lorus. — The outlet of a horse's stomach. 

Pi/riforni. — Shaped like a pear. 



Quadratus. — Square in form or figure. 

R. 

Radial. — Belonging to the radius. 
I'adiatcd. — Diverging from the centre like the sun's rayj. 
Radicle.''. — Germs of tlie root,s. 
Radius. — Bone of the fore extremity. 
Rami/'//. — To branch out, or from. 
Ramose. — Branched. 
Ramus. — A branch. 
Ranine. — Vessels under the tongue. 
Rapic. — The central line of the scrotum. 
Rectum. — The posterior termination of the intestines. 
Rectus. — Straight. 

Recurrent. — Running in a backward direction. 
Reflection. — A duplicature. 
Regions. — Divisions of the body. 
Renal. — Belonging to the kidneys. 
Rele. — Net-work. 
Retiform . — Net like. 
Retina. — Expansion of the optic nerve. 
Retractor. — Muscles thus named draw backwards. 
Rctrahens. — Drawing back. 
Rima. — An opening or fissure. 

Rotator. — A name given to muscles that rotate or r> 
volvc a part. 
Rotundus. — Circular, round. 



192 



GLOSSARY OP VETERINARY TECHNICALITIES. 



Ruga. — A T\Tinkle. 
Rvrjose. — Wrinkled. 



S. 



Sac. — A bag or cyst. 

Saculateil. — Encysted. 

Sacral. — Belonging to tlie sacrara. 

Sagittal. — Arrow-shaped. 

Salivary. — Relating to tlie saliva 

Sanguis. — Blood. 

Saphena. — A vein of tlie hind extremities. 

Scaphoid. — Shaped like a boat. 

Scapula. — Shoulder blade. 

Scrotal. — Relating to the scrotum. 

Scrotum. — The sac in which the testicles are con- 
tained. 

Sebaceous. — Resembling suet. 

Secernent. — Secretory. 

Semen. — Secretion peculiar to the testes. 

Semi. — One-half. 

Septum. — A partition or division. 

Serrated. — Resembling the teeth of a saw. 

Serum. — The fluid portion of the blood. 

Sessamoid. — Like seeds. 

Sigmoid. — Flexure. 

Sineiu. — A tendon. 

Sinus. — A long cavity. 

Sperinatic. — Belonging to the testicles. 

Sphenoid. — Wcdge-Iike. 

Sphenoidal. — Belonging to sphenoid bone. 

Sphincter. — Circular muscles, wliich close an opening, 
are thus named. 

Spinal. — Belonging to the spine. 

Spinal Marrow. — Medulla spinalis. 

Spine. — The vertebral column. 

Spinus. — Thorn-like. 

Splanchic. — Belonging to the intestines. 

Squamous. — Resembling scales. 

Stapes. — A stiiTup ; bono of the ear. 

Sternal. — Belonging to the breast bone. 

Sternum. — Breast bone. 

Striated. — Markcil with long lines. 

Stijioid. — Shaped like a ix)inted pencil. 

Sub. — Under; beneath. 

Sulilimus. — This tenn is applied to a muscle when 
seated more superficially than another of the same kind. 

Sulilingual. — Beneath tlie tongue. 

Submaxilltin/. — Under the inferior ja^v. 

Subscapular. — Inner side of the shoulder blade. 

Super. — Above. 

Superjicial. — Upon or near the surface. 

Superior. — Tlie tipper part. 

Suture. — Junction or union. 

Sympathetic. — Associated in function. 

Symphysis. — A connection of bones by an inter>-ening 
substance. 

Synovia. — The lubricating fluid of joints, sometimes 
called joint-oil. 

Systole. — Contraction of the heart. 

T. 
Tabula. — An extended surface. 
Tarsus. — The hock. 
Tegumrntary. — Relating to the skin. 
Temporal. — Relating to the temporal regions of the 



Tendon. — The extremity of a muscle. 

Tendo Achillis. — The tendon of the gastrocncmii, in- 
serted into the hock or heel of man. 

Tensor. — A name given to muscles which stretch or ex- 
tend parts. 

Tentorium. — A membranous partition of the brain. 

Teres. — Round ; cylindrical. 

Testes. — The testicles. 

Thalami Nervorum Opticorum. — Supposed origin of 
the optic nen'cs. 

Tl>ala7nus. — A bed or origin of certain parts. 

T/ieca. — A sheath. 

Thoracic. — Belonging to the thorax or chest. 

Thoracic Duct. — The trunk of the absorbents. 

Tliorax. — The chest. 

Thyro. — Names compounded with this word belong 
to muscles which are attached to the thjToid cartilage. 

Thyroid. — Resembling a shield. 

Tibia. — The bone beneath the femur. 

Tibial. — Belonging to the tibia. 

Tinea. — The name of a fish ; the tench. 

Tissue. — An organized sti-ucture. 

Trachea. — The windpipe. 

Tracheal. — Pertaining to the windpipe. 

Trachelo. — Names compounded with this word belong 
to muscles located in the region of the neck. 

Transversalis. — Having a transverse direction. 

Transi-ersus. — Placed aci-oss. 

Trapezium. — A four-sided-fignre, bone of the horse's 
knee. 

Trapezoides. — A bone which in figure somewhat re- 
sembles the preceding ; it also enters into the composition 
of the horse's knee. 

Trapezius. — Four square ; a muscle placed over tbo 
region of the withers. 

Triangularis. — Triangular. 

Triceps. — Three-headed. 

Tricuspid. — Having three points ; a name applied to 
a valve in the right ventricle. 

Trijid. — Three-cleft. 

Trigastric. — Having three bellies. 

Trisplanchic Nerve. — The great sympathetic or gan- 
glionic ncn-e. 

Trochanter. — Eminences or tuberosities on the bones. 

Tuba. — A tube. 

Tuber. — A solid roundish substance. 

Tuberosity. — Protuberance or projection. 

Tubular. — Tube-like. 

Tunic. — A membranous covering. 

Turbinated. — Shaped like a sugar-loaf. 

Turgid. — Swollen. 

U. 

Clna. — Bone of the fore extrSmity, termed point of 
the elbow. 

Ulnar. — Pertaining to the ulna. 

Umbilicus. — Tlie n.avel. 

Unciform. — Shaped like a hook. 

Ureter. — A tubular connection between the kidneys 
.and bladder. 

Urinal. — Pertaining to the urine. 

Uterine. — Relating to the womb. 

Uterus. — The womb. 

Uvula. — A pendulous body, posterior to the soft palate. 



EXPLANATION OF FIGURE XIX. 



OSSEOUS STRUCTURE. 



1. 


Frontalis. 


2. 


rarietalis. 


3. 


Oceii)ital. 


5- 


Nasal. 


6. 


Lachmyral. 


8. 


Superior maxillaiy. 


9. 


Anterior " 


U). 


Inferior or lower jaw. 


11. 


Cervical vertebra>. 


16. 


True ribs. 


17. 


False ribs. 


18. 


Stenium. 


19. 


Ileum. 


22. 


Femur. 


23. 


Patella. 


24. 


Tibia. 


25. 


Os calcis. 


26. 


Astragalus. 


27. 


Tarsal bones. 


28. 


Metatarsi magnum. 


29. 


SessamoiJs. 


30. 


Os suffi'agiiiis. 


31. 


Os corona'. 


32. 


Os pedis. 


33. 


Scapula. 


34. 


Os humeri. 


35. 


Radius. 


36. 


Carpus. 


37. 


Metacarpi magnimi. 


39. 


Os suffraginis. 


40. 


Os corona?. 


41. 


Os pedis. 


D. 


Dorsal spines. 



MUSCULAR STRUCTURE, 

FOEWAKD PARTS. — THE HEAD. 

a. Orbicularis palpebrarum. 

b. Levator palpebra?. 

c. Dilator naris lateralis. 

d. " " anterior. 

e. Orbicularis oris. 

f. Nasalis longus. 

g. Levator labii superioris. 
i. Buccinator. 

J. Retractor labii inferioris. 

h. Massetcr. 

m. Attolentes ct abducens aurem. 

1. Temporal vein. 

2. Facial vein. 

THE -NECK, 
c". Traclielo subscapularis. — Scalenus. 
6. Rhomboidcus longus. 



EXPLANATION or FICLUE XIX. CONTINUED. 

f. Splenius. 

0. Abdiicens vel (leprinicns aurcm. 

r. i. Tencloii of the splenius and complexus major. 

!'. Stcrno maxillaris. 

X. Subscapulo hyoideus. 

TnK SIIOULDEE, .INTERIOR MUSCLES, AKD FOKL EXTREMITir?. 

a. Trapezius. 

6'. Teres. 

e". Pectoralis transvcrsus. 

f. Antea spinatus. 

</". Postea spinatus. 

I", r. Triceps extensor brachii. 

o". Pectoralis mafjnus. 

r". Flexor metacarpi internus. 

s". s". Extensor metacarpi niagnus. 

t. t. Extensor metacarpi obliquus. 

u. Tendons perforatus and perforans. 

u. (At the humeral region.) Levator humeri. 

x". x". Extensor tendons. 

8. The hoof. 

THE ABDOMEN AND POSTERIOR PARTS. — ABDOMINAL REGION, AND OF TlIE COSTA. 

a". Levatores co.itarum. 

o". ObUquus externus abdominis — (beneath the dotted line). 

D. Scrratus magnus. 



POSTERIOR PARTS. 

g". Ligaments of the patella. 

Ji. d. e. Glutei. 

k. Extensor metatarsi internus. 

m. Tensor vaginte. 

m". Rectus. 

u". Vastus externus. 

n. Gastrocnemius internus. 

V. Flexor pedis. 

u. Flexors perforatus and perforans. 

x". x". Fleshy belly of the extensor. 

X. X. Extensor tendons, 

y. Peroneiis. 

8. The hoof. 



GLOSSARY OP TETERINART TECHNICALITIES. 



193 



V. 

Vagina. — A sheath; the cavity between the pudenda 
and womb. 

Var/i/ial. — Pertaining to the vagina. 

Valvular. — Valve-like. 

Vas. — A vessel. 

Vas Deferens. — Excretory duct of the testicle. 

Vasa. — The plural of vas ; vessels. 

Vascular. — Highly organized with blood-vessels. 

Vascular Si/stem. — The heart and its vessels. 

Vastus. — Kelates to size; large, thick and fleshy mus- 
cles of the thigh. 

Vena. — A vein. 

Vena Cava. — The great vein. 

Vena Porta. — The largest vein of the liver. 

Venter. — The belly. 

Ventricles. — A term applied to the cavities of the brain 
and heart. 

VermifoiTn. — Shaped like a worm. 

Vertebr(E. — Bones of the spinal column. 

Ve.tical. — Formed like a bladder; pertaining to the 
bladder. 



Vesicles Graaffian. — Small bladders or cysts found in 
the ovaria (female testes). 

V^ia. — Way or passage. 

I'illous. — Velvet-like, applied to the villous coat of a 
horse's stomach. 

Viscera. — Internal organs. 

Visceral. — Relating to a viscus. 

Viscus. — An organ within the body. 

Vital. — Life-like. 

Vitreous. — Glassy ; transparent. 

Vivisection. — Surgical operations on living subjects. 

Vivus. — Living ; life-like. 

Vulva. — The pudendum. 

Z. 

Zoolorji/. — The science of animals. 
Zootherapeutics. — Relates to the cnratiTe action of med- 
icines. 

Zootomy. — Comparative anatomy. 
Zi/ijoma. — An arch or yoke. 
Zygomatic. — Belonging to the zygoma. 



25 



i 
J 



%i\€mxi fekfll»skal C^arl 



(196) 



A VETERINARY TOXICOLOGICAL CHART, 

CONTAINING THOSE AGENTS WHICH ARE KNOWN TO CAUSE DEATH IN THE HORSEJ 
WITH THE SYMPTOMS, ANTIDOTES, ACTION ON THE TISSUES, AND TESTS. 

BT W. J. T. MORTON, 

Lecturer on Veterinary^ Materia Medica, etc. ' 

"Poisons are substances which are capable of altering or destroying, in a majority of 
cases, some or all of the functions necessary to the support of the vital principle." — 
Fcedere. They are d rived both from the organic and inorganic kingdoms ; and their 
action is either local or remote. Local action is referrable to, 1st, Chemical Decomposi- 
tion ; 2d, Lnitation and Inflammation; 3d, Nervous Impression. Remote action is 
effected by, 1st. Absorption ; 2d, Sympathy. Animal Poisons rank first iii potency; next 
to these, the Mineral ; and lastly, the Vegetable. Aerial poisons are, perhaps, the most 
insidious. 

The manner in which poisons are introduced into the System varies. The Alimen- 
tary Tube, the Skin, the Cu-cula*ion, and the Lungs, are the media. 1st, They may be 
taken into the Stomach inadvertently with the food, or they may be maliciously or acci- 
dentally administered. They may also be thrown up as Enemata. 2d, They may be 
placed underneath the Skin ; or injected into the Circulation ; or they may be absorbed 
from Wounds. 8d, If gaseous, they may be inhaled, and enter the blood during it:; 
transit through the Lungs. They are generally arranged according to the effects which 
they produce upon the Ariimal Economy. The great end of Toxicological Science is 
to counteract their influence, which may be accomplished by chemically decomposing 
them, by their expulsion from the System, and by restoring the Function of the Organ 
of wliich they have caused derangement. As comparatively large quantities of the 
Poisons are required to destroy Life in the Horse, the niceties of chemical manipulation 
in the application of Tests are uncalled for. It will generally be sufficient to collect 
some of the contents of the Stomach and Intestii:es, add distilled Water to them, filter and 
to the Solution apply the Test or Re-agent. Sometimes they require the influence of 
heat; and, when the contents are not attainable, portions of the Alimentary Tube which 
have been most acted upon by the Agent are to be boiled in iistilled Wat-er,and similarly 
treated. 



I. — IRRITANT POISONS. 



Tliese produce their action upon some part of the Alimentary Canal, particularly the Stom- 
ach and Intestines ; and by absorption they are often carried to othvr Org-ans. The 
principal Symptoms are those of Irritation and Inflammation. 

A GENTS. { are the most powerful of all local irritants. 

Indications of their action are uneasiness, 
'"sulphuric Acid. I frequent pawing and shifting of the posi- 
tion, increased secretion of saliva, which is 
sometimes viscid and fetid, the mouth in- 
flamed, difficulty in swallowing from corro- 

,, , ,, . ... isionof the fining of the esophagus, acute 
Hydrochloric Acid. ° , r . 

gastric irritation extending to the intestines, 

Symptoms. — The liquid mineral acids i and giving rise to symptoms resembling a 

(197 > 



ACIDUM SULPHURICUM. 



ACIDU.M NITRICUM, 

Nitric Acid. 
ACIDUM HYDROCHLORICUM. 



ins 



TOXICOLOGICAL CHART. 



most violent attack of colic ; pain on pres- 
sure being applied over the abdomen ; fre- 
quent attempts to dung and stale ; and, after 
the faeces have been voided, a discharge of 
mucus streaked with blood takes place : 
tenesmus, pulse quick and feeble, prostra- 
tion of strength, profuse persjjiration, cold- 
ness of the body, and death, after the ani- 
mal has endured excruciating agonies. 

In one case related to me, nitric acid was 
poured into the ear, and death took place 
from inflammation extending to the mem- 
branes of the brain. 

Treatment. — As the general symptoms 
of poisoning by the liquid mineral acids do 
not materially differ, neither will the general 
treatment. This will consist, 1st, In dilut- 
ing the agent by throwing into the stom- 
ach large quantities of water by means of 
Read's pump. 2d, In neutralizing it, by 
suspending in the water chalk, magnesia, or 
soap; or, in the absence of these, the plaster 
from the walls. 3d, In allaying the su- 
pervening inflammation by means of blood- 
letting, should the urgency of the symp- 
toms demand it ; and also by the adminis- 
tration of opium, and a free use of demul- 
cents. The subsequent nervous debility 
and prostration of strength are to be com- 
batted by the milder vegetable tonics, and 
a gradual return to liberal diet. 

Morbid Appearances. — The mouth, pha- 
rynx, and esophagus, present traces of the 
action of the peculiar acid. The stomach 
is distended with gas, and occasionally 
lined with its disorganized tissue, which is 
eroded in patches, and so deeply ulcerated 
as to form perforations. Intense inflam- 
mation often exists in this viscus, which 
extends throughout the whole of the intes- 
tinal tube, involving its peritoneal tunic ; 
this last circumstance has been thought to 
be distinctive between poisoning by acids 
and metallic compounds; this cannot, how- 
ever, be relied upon. The blood in the 
larger vessels sometimes forms a firm clot. 
These appearances will not be so marked 
when an acid has been given in small doses 
for some time, or if much diluted we may 



then expect to find the coats of the stom- 
ach and intestines thickened and contracted, 
the result of chronic inflammation, with 
here and there eroded spots, but not of any 
depth. 

Tests. — General. — Sour taste — neu- 
tralization by the alkalies — effervescing 
with the carbonates — reddening of litmus 
paper. 

Particular. — Sulphuric Acid. — The parts 
with which it comes in contact are first 
whitened, and then changed to a brownish 
color. By macerating them or the con- 
tents of the stomach in distilled water, fil- 
tering, and adding a solution of the nitrate 
of bari/tes, an insoluble precipitate, the sul- 
phate of bari/tes, is obtained. 

Nitric Acid. — The tissues changed of a 
yellow color, which is heightened by am- 
monia. The filtered solution boiled on 
copper filings in a test tube emits orange- 
colored fumes of nitrous acid. Potassa be- 
ing added to it, by evaporation a salt is ob- 
tained, which deflagrates ; or a piece of 
bibulous paper may be sattuated with the 
solution, dried, and inflamed. 

Hydrochloric Acid. — Tissues blanched. 
Its fumes are rendered more manifest by a 
rod dipped in ammonia being held in them. 
This test, however, we are rarely able to 
avail ourselves of. On the addition of 
nitrate of silver to the solution, it gives a 
white precipitate, the chtoride of silver. 

AGENT. 

AOIDUM OXALICUM. 

Oxalic Acid. 

Syinploms, — Instances are recorded of 
horses having been poisoned by this acid, 
but whether maliciously given, or adminis- 
tered by mistake for the sulphate of mag- 
nesia, I cannot say. The symptoms atten- 
dant on its action, when a concentrated 
solution is given, will not be dissimilar to 
those produced by the mineral acids. When 
diluted, however, it is said to cause death 
by palsying the heart and nervous system, 
or by inducing tetanus or narcotism ; but I 



TOXICOLOGICAL CHART. 



199 



am not aware that such action has been ob- 
served in the horse. 

Treatment. — Avoid large quantities of 
water, as it favors the absorption of the 
acid. Throw into the stomach a mL^ture 
of chalk, or of magnesia and water, partic- 
ularly the former ; or lime from the walls 
may be used ; either of which will form an 
insoluble salt. The alkalies are inadmissi- 
ble, because they form soluble salts. De- 
mulcents to be freely employed, and the 
remaining irritation to be allayed by opium- 

Morbid Appearances. — None recorded 
in the horse. In other animals the stom- 
ach has been found to contain black extra- 
vasated blood, its inner coat being of a 
cherry -red color; in some places the sur- 
face is brittle, and the subjacent stratum 
gelatinized. The intestines are usually in- 
flamed throughout. When its influence 
has been through the medium of the blood 
on remote parts, the heart has been found 
to have lost its contractility, and to contain 
arterial blood. 

Tests. — Acid reaction on litmus paper. 
A concentrated solution with ammonia 
forms a salt whose crystals radiate, the ox- 
alate of ammonia. 

Hydrochlorate of Lime throws down a 
white precipitate which is soluble in nitric 
acid, the oxalate of lime. 

Sulphate of Copper yields a blue or green- 
ish-white precipitate, the oxalate of copper. 

Nitrate of Silver causes a dense white 
precipitate ; also an oxalate which, when 
dried and heated, fulminates. 

AGENT. 

ACIDUM ARSENIOSUM. 

Arsenioiis Acid, 
White Arsenic. 



resembling 



Symptoms. — Intense pain 
acute enteritis; belly tympanitic, with a 
rumbling noise in the intestines ; the dejec- 
tions offensive, and mixed with mucus ; 
pulse quick and feeble, becoming scarcely 
perceptible at the jaw ; respiration labori- 
ous; surface of the body covered with an 
extremely cold, clammy sweat ; extremities 



cold; efforts to vomit; countenance anx- 
ious, and indicative of great torture ; mu- 
cous tissues injected ; mouth hot ; increased 
secretion of saliva, which is singularly fetid ; 
delirium from pain which has become con- 
tinuous; exhaustion; death. The action 
of this poison is not merely as a local irri- 
tant, it being often conveyed to remote 
parts through the medium of the circula- 
tion, thus causing death. Even as an 
external applicant it has been known to pro- 
duce much general derangement of the sys- 
tem, independent of its influence as an 
escharotic, which is powerful. On this 
account, when the methods usually resorted 
to have failed to demonstrate its existence 
in the contents of the stomach and intes- 
tines, Orfila has succeeded in detecting it 
in the organic tissues, particularly the liver. 

Treatment. — A free use of diluents, or 
of lime water; avoid blood-letting, as this 
promotes the absorption of the poison ; 
give large doses of the hydrated peroxide 
of iron precipitated by ammonia from a 
solution of the sulphate of iron, so as to 
form an insoluble arsenic of iron, which 
may be expelled by the action of active 
purgatives. The subsequent inflammation 
is to be combatted by the ordinary antiphlo- 
gistic remedies; while the debility which 
supervenes, and which is often great, is best 
counteracted by the vegetable tonics and 
judicious dieting. 

Morbid Appearances. — The stomach and 
intestines, especially the latter, highly in- 
flamed and ulcerated in patches. The 
csDcum and colon present the most marked 
action, the villous coat being black from an 
eftusion of altered blood, and the peritoneal 
tunic involved. Congestion of blood in the 
lungs, liver, and kidneys; redness of ihe 
lining membrane of the windpipe, extend- 
ing to the air-passages generally; conjunc- 
tival membrane highly injected, and the 
blood in a fluid state throughout the body. 
Ecchymosis in the heart. 

Tests. — 1st, by Reduction. — The sus- 
pected powder, being dried, is to be mixed 
with twice its weight of newly-burnt and 
pulverized charcoal, and introduced into a 



200 



TOXICOLOGICAL CHART. 



test-tube : tlie heat of a spirit lamp is now 
to be ajiplied; first to the upper part of the 
mixture, and afterwards steadily to the bot- 
tom of the tube, when, if arsenious acid is 
present, the metal arsenicum will be sub- 
limed, and, encoating the tube, form a ring 
of a polished-steel lustre, the inner surface 
of which is crystalline. The little watery 
vapor, which will be condensed within the 
tube before the metallic crust begins to ap- 
pear, is to be removed by a roll of bibulous 
paper. 

2c?, by Liquid Rc-agenls. — The contents 
of the stomach, or such parts of thatviscus 
as have been acted upon, being boiled in 
distilled water, the solution is to be filtered. 
The ammoniacal sulphate of copper added to 
this gives an apple-green precipitate, the ar- 
senite of copper. TIte ammoniacal nitrate of 
silrer, a lemon-yellow precipitate, ciianging 
io a dark brown on exposure to light, the 
arscnilc of silver. Sulphuretted Hydrogen, 
— generated by the action of dittrte suphu- 
ric acid on suphuret of iron, in a flask, hav- 
ing an emerging tube bent at a double right 
angle, — passed up through the solution for 
ten or fifteen minutes, gives a sulphur yel- 
low precipitate, the sniphuret of arsenicum. 
Water impregnated with this gas affords 
the like compound. The solution for this 
test must be perfectly neuti-al. This pre- 
cipitate may be afterwards subjected to re- 
fluction. 

3(/, by Nascent Hydrogen. — This is ef- 
fected in Marsh's tube. The fluid con- 
tents of the stomach, or the filtered solution 
before spoken of, being introduced into it, 
zinc and sulphuric acid are added, and the 
arseniuretted hydrogen as it escapes from 
the jet inflamed, when water and metallic 
arsenic will be condensed upon the glass 
disc held above it. The former will be dis- 
sipated by the heat, and around the latter 
a ring of arsenious acid may be seen. In 
the absence of a Marsh's tube, a common 
two-ounce wide-mouthed vial, with a cork 
jw'rforated by a piece of glass tube or oven 
1obacco-|}ipe, may with care be made lo an- 
swer all the purpose. 



AGENT. 

HYDRARGYRI BICHLORIDUM. 

Bicidoride of Mercury, 
Corrosive Suhlimate. 

Symptoms. — The effects which follow 
the administration of large doses of this 
salt, resemble those which supervene when 
the mineral acids have been given, except 
that, generally, super-purgation is present, 
and the fcccal matter is profuse and highly 
offensive. Its solubility renders it more 
energetic than arsenioiis acid, although it is 
not so frequently had recourse to for poi- 
soning. 

The protochloride of mercury, calomel, 
when incautiously given, has also caused 
death, by inducing inflammation of the mu- 
cous lining of the intestines, accompanied 
with violent purging and tenesmus. 

Treatment. — The white of eggs suspend- 
ed in water, the albumen of which renders 
the bichloride of mercury insoluble ; or large 
quantities of wheat-flour, or milk. Lon 
filings have also been advocated, which, 
reviving the metallic mercury, may be ex- 
pelled by purgatives ; a free use of dUutents. 
The treatment of the salivation, which 
sometimes supervenes, consists in exposure 
to cool air, tlie exhibition of saline purga- 
livcs, and nourishing diet. 

Morbid Appearances. — These would 
closely resemble the effects produced by the 
above agent, the mucous lining of the ali- 
mentary canal being intensely inflamed 
throughout, its texture destroyed, and in 
parts corroded. The disorganized tissue 
often contains the poison, which it yields 
by analysis. 

Tests. — Lime-icater, ^^•hich throws down 
an orange yellow precipitate, the hydrated 
binoxide of mercury. 

Iodide of Potassium, which gives a beau- 
tiful scarlet compound, the Mniodide of 
mercury. 

Protochloride of Tin, which first affords 
a whitish precipitate, the protochloride of 
mercury ; and, on adding more of the test 
a grayish-black powder is formed, which 



TOXICOLOGICAL CHART. 



201 



consists of minutely divided metallic mer- 
cury. 

Sulphur elted Hydrogen, which gives a 
blackisli compound, a sulpJiurcl of mercury. 

To these may be added the test by re- 
duction, the reducing agent being the pro- 
tochloridc of tin, assisted by beat. 

Albumen is not now relied on as a re- 



agent. 



A GENT. 

ANTIMCNU POTASSIO-TARTRAS. 

Potassio-Taiirate of Antimony, 

Emetic Tartar. 



this precipitate by hydrogen at once dissi- 
pates all doubt. 

AGENT. 

SALTS OF COPPER. 



salts of copper are 
poisons to the horse. 



Symptoms. — Violent gastric irritation; 
nausea ; efforts to vomit ; profuse perspira- 
tion; catharsis, accompanied with colicky 
pains and much flatus ; increased secretion 
of urine ; the heart's action at first much 
quickened, and afterwards scarcely percep- 
tible ; labored respiration ; injection of the 
mucous tissues ; extreme distress ; death. 

Treatment. — The yellow bark, or any 
other astringent vegetable that contains 
tannin, to be administered both in powder 
and decoction ; a free use of dilutents, olea- 
ginous purges, and opium, should then be 
had recourse to for the purpose of allaying 
the irritation. 

Morbid Appearances. — The stomach 
highly inflamed, and eroded patches on the 
mucous coat, which are of a deeper color 
than the surrounding parts ; intestines red- 
dened, encoated with slimy mucus, and 
thickened; lungs gorged with blood; and 
general inflammation of the whole system 
consequent on its absorption. 

Tests. — Caustic Potass and Lime-tvater, 
which precipitates the oxide of antimony- 
The carbonate of potass acts \\'ith still 
greater delicacy. 

Hydrochloric and Sulphuric Acids also 
aflbrd the like precipitate. A strong infu- 
sion of the gall-nut gives a dirty, yellowish 
white precipitate, the gallate of antimony. 

Sulphuretted Hydrogen throws down an 
orange-red precipitate, the red sulphuret of 
antimony, which is so peculiar as to be al- 
ways distinguished ; and the reduction of 

26 



Symptoms. — The 
rarely employed as 
Large doses of the sulphate improperly 
given have sometimes caused much intes- 
tinal irritation, followed by colicky pains 
and diarrhoea ; and, in one instance, death 
from gastro-enteritis. Doubtless inordinate 
quantities would always destroy life, when 
symptoms similar to those caused by any 
other erodent would be manifested, it being 
a local imtant. The same, perhaps, may 
be said of the impure acetate of copper. 

In the neighborhood of works for smelt- 
ing of copper, horses are frequently attacked 
with diseases of the joints, indicated by 
swelling, bursal distension, exostosis, and, 
ultimately, anchylosis, arising cither from 
the state of the herbage or the impregnation 
of the air by the vapors disengaged. 

Treatment. — Give a solution of the fer- 
rocyanide of potassium, or of soap. Albu- 
men is also an antidote, and metallic iron, 
which latter precipitates the copper. This 
is to be expelled by oleaginous purgatives. 
Tepid water rendered slightly alkaline may 
also be freely given; and opium, to aUay 
irritation. A free use of demulcents, as 
grael, infusion of linseed, etc., is indicated. 

For the local affection, punctm-e the bur- 
sal distention, and, after the evacuation of 
the cyst, apply an elastic bandage, giving 
gentle compression. Remove the animal 
to another locality. 

Morbid Appearances. — Stomach ulcer- 
ated where the agent has adhered, and gen- 
eral inflammation of its mucous lining 
and that of the intestines, with here and 
there spots of erosion. In the instance ad- 
verted to of the sulphate of copper causing 
death, there was an engorgement of the 
blood-vessels of the lungs. 

Copper is with extreme difficulty detected 
in any of the secretions. It, however, has 
been found in the organic tissues, particu- 



202 



TOXICOLOGICAL CHART. 



larly the liver after incineration, und also in 
the blood. 

Tests. — Water of Ammonia affords an 
azure-colored precipitate, or a violet -colored 
solution, the ammoniuret of copper. 

Ferrocyanide of Potassium causes a 
brown precipitate, the ferrocyanide of cop- 
per. 

Sulphuretted Hydrogen throws down a 
blaclvish compound, the sulphuret of copper. 

A piece of polished iron introduced into 
the solution is soon covered with metallic 
sapper. 

AGENT. 

SALTS OF LEAD. 

Symptoms. — Of these, like the above, 
comparatively large quantities are required 
to cause death. Violent spasms, tremors, 
obstinate constiiTation of the bowels, fol- 
lowed by paralysis, partial or complete, are 
the usual indications. 

In the neighborhood of lead works ani- 
mals are often thus affected, when, in addi- 
tion to these symptoms, there is a depraved 
appetite present : the stomach after death 
being found filled to repletion with strange 
and incongruous substances. 

Treatment. — Solutions of the svilphate 
of magnesia or soda, combined with croton 
or linseed oil ; afterwards allaying the irri- 
tation by means of opium. 

Tlie phospliate of soda has also been ex- 
tolled as an antidote. 

The treatment for tlie paralysis which 
remains consists in judicious dieting and 
exercise. 

Morbid Appearances. — The lining mem- 
brane of the stomach and intestines is 
sometimes inflamed, sometimes blanched; 
the caliber of the latter is diminished, and 
its coats corrugated; the muscular tissue 
throughout the body has lost its power of 
contractility ; the buccal membrane is pale, 
and the blood of a brighter color than nat- 
ural. 

Tests. — Chromate of Potass throws down 
a yellow precipitate, the chromate of lead. 



Iodide of Potassium likewise gives a yel- 
low pi'ccipitate, the iodide of lead. 

Sulphuretted Hydrogen causes a black 
precipitate, the sulphuret of lead. 

A rod of Zinc introduced into it causes 
a deposition of metallic lead in a crystalline 
form. 

The alkaline carbonates and sulphates, 
although they give white precipitates with 
lead, have been objected to as tests. 

AGENT. 

POTASSiE NITRAS. 

Nitrate of Potash, 

Nitre. 

Symptoms. — Much uneasiness ; cholicky 
pains ; pulse feeble, quick, and irregular ; 
respiration accelerated; mouth hot; mu- 
cous lining of the eyelids and nostrils 
highly injected ; increased secretion of 
urine; frequent voiding of fteces. If the 
quantity given is very great, the abdominal 
pains are more intense ; the breathing more 
labored; the pulse quicker; ineffectual ef- 
forts to stale are made ; the extremities are 
cold ; and the prostration of strength is 
extreme. If not, after manifesting much 
uneasiness, the fseces are frequently voided ; 
diuresis supei-venes ; and relief is obtained. 

Treatment. — A free use of demulcents; 
oleaginous purgatives ; hot rugs to the ab- 
domen, and over the loins ; opiate enemata ; 
if necessary, the abstraction of blood ; with 
hand-rabbing, and bandages to the extremi- 
ties. Possibly a mustard cataplasm or a 
sheepskin over the loins will be of service. 
Such counter irritants as are likely to be 
caiTied to the kidneys are to be avoided. 

Morbid Appearances. — The villous coat 
of the stomach highly inflamed and studded 
with dark spots resembling ccchymosis, 
varying in size and running into patches ; 
they are easily scraped off, and contain a 
deposit of serum. The cuticular coat is 
also inflamed, but not so highly, and its 
texture is much weakened ; the small intes- 
tines are pervaded with an inflammatory 



TOXICOLOOICAL CHART. 



203 



blusli ; llie lungs and heart are congested, 
and the venous blood is of a brighter color 
than usual. Constriction and inflamma- 
tion of the neck of the bladder have also 
been observed. 

Tests. — From the fluid contents of the 
alimentary tube, or from the urine, the salt 
may be obtained by evaporation and crystal- 
lization. It is known by deflagrating when 
thrown on a piece of ignited charcoal) of 
which it animates the combustion ; and by 
yielding nitric acid when distilled with sul- 
phm-ic acid. Heat also disengages oxygen 
from it. 

Chloride of Platinum added to its solu- 
tion gives a yellow precipitate. 

AGENT. 

CAXTHARIS. 

llie Blistering Fbj. 

Symptoms. — Much uneasiness ; intesti- 
nal irritation; frequent attempts to stale; 
strangury ; bloody urine ; accelerated pulse 
and respiration ; continual pain, with much 
constitutional disturbance. These symp- 
toms increase in urgency, until death closes 
the scene. 

Treatment. — Expulsion of the agent 
from out of the alimentary tube by brisk 
purgatives ; oil is objectionable, on account 
of the solubity of the active principle of 
the cantharides in it. A free use of dilu- 
ents ; opium may be given, and oleaginous 
and demiilcent injections thrown into the 
bladder. Sheepskins over the loins ; hot 
rags over the abdomen. 

3Iorbid Appearances. — The mucous lin- 
ing of the alimentary canal throughout in 
a high state of diffused inflammation ; but 
the urinary organs are principally affected: 
the blood-vessels of the kidneys, bladder, 
and urethra, are much engorged, and the 



lining membrane of the latter has in some 
places a sphaceletic appearance. 

Tests. — Washing of the contents of the 
stomach and alimentary tube will develop 
portions of the beautiful green case-wings 
of the fly, which appear not quickly to un- 
dergo decomposition ; Orfila having detected 
them in a body some months after death. 

AGENTS. 

BITE OF THE VIPER, 

STING OF THE HORNET, WASP, ETC 

Symptoms. — Subcutaneous inflamma- 
tion, indicated by swelling and increased 
heat, with eff'usion into the cellular tissue, 
which sometimes goes on to gangrene; 
pain ; constitutional excitement ; quickened 
and irregular pulse ; rigors. 

The bite of a viper has been knov/n to 
cause cerebral derangement and death, by 
its influence on the nervous system. 

Treatment. — Kemoval of the stings ; 
counter-irritants, as liniment of ammonia 
or turpentine, which, if sufficient, are to be 
followed by scarification, the use of emol- 
lients, and the general antiphlogistic reme- 
dies, such as bleeding, fomentations, and 
laxatives, with opium to allay the general 
irritation. The virus of the tooth of the 
viper may be extracted by cupping, or, 
which is preferable, let the part be excised, 
and the nitrate of silver freely applied 
afterwards. 

Moi'bid Appearances. — But few instances 
of death are recorded. If it takes place, it 
is probably the result of sympathetic and 
general excitement of the whole system; 
the usual indications, therefore, of increased 
nervous and vascular action may be ex- 
pected to be met with. 

Tests. — None. 



204 



TOXICOLOGICAL CHART 



II. — NARCOTIC POISONS. 



These produce Stupor, Delirium, and other affections of the Brain and Nervous System, 

followed by Death. 



AGENT. 

OPIUM. 

Opium. 

Symptoms. — The horse will bear large 
doses of this drug ; the quantity necessary 
to destroy life is consequently great. Sup- 
posed instances are recorded of its causing 
death when given in doses of a few drachms 
in order to check supcrpurgation ; also when 
the animal has been debilitated by disease, 
when symptoms of enteritis have shown 
themselves, accompanied with a torpitude 
of the bowels, and much suffering previous 
to death. Much larger quantities liave, 
however, often been given with impunity, 
and frequently with advantage. 

■Treatment. — Expulsion of the agent 
from out the alimentary tube by means of 
oleaginous pui'gatives, enemata, venesec- 
tion, and a free use of demulcents, with 
fomentations to the abdomen, and counter- 
irritants to the extremities. 

Should a state of stupor prevail, exercise 
may be given, and cold water dashed over 
the head. 

3Iorbid Appearances. — The mucous lin- 
ing of the stomach and intestines inflamed, 
and easily torn asunder, the inflammation 
being diffused. This has been thought to 
be a distinctive between the eflfects induced 
by mineral and vegetable poisons; but it 
cannot be relied upon, as repeated small 
doses of an erodent will induce the like 
appearances, only (here will be more thick- 
ening of the tunics. 

Tests. — Odor, which is cliaracteristic. 
To the suspected matter add distilled water 
acidulated with acetic acid; agitate for a 
few minutes, filter and evaporate to the con- 
i-istence of syi'up ; boil this in alcohol, and 
agaiu filter and evaporate ; dissolve the re- 
siduum in distilled water, and add to the 
solution acetate of lead, which leaves mor- 



phia in solution : this being heated with 
sulphuretted hydrogen, any remaining lead 
will be precipitated. On nitric acid being 
added to the morphia obtained by evapora- 
tion, it dissolves with efTervescence, and 
becomes of an orange-red color. Suspended 
in water and treated with a drop or two of 
the pcrmuriate of iron, it is also dissolved, 
and forms a greenish-blue solvition. 

AGENT. 

TAXUS BACCATA. 

The Teio. 

Symptoms. — Effects variable ; large quan- 
tities have sometimes failed to cause any 
injury, while at others comparatively small 
quantities have destroyed life. It would 
appear to be very insidious in its influence, 
as the animal generally drops down dead 
without indicating any previous suffering. 
In some instances slight convulsions have 
preceded death. The partially dried leaves 
appear to be more energetic than the green 
leaves, probably from greater quantities be- 
ing partaken of. 

Treatment. — Usually no opportunity is 
afforded for the employment of remedies. 
Should it, however, be the case that the 
leaves of yew are suspected to have been 
eaten, I am not aware of any method which 
could be adopted but that of endeavoring 
to expel them from the system as quickly 
as possible, which may be effected by active 
purgatives. The after-treatment wiU de- 
pend upon the symptoms which may pre- 
sent themselves. 

Morbid Appearances. — The alimentary 
tube distended with faecal matter in a semi- 
fluid state, and highly fetid gases. 

The mucous lining inflamed throughout, 
particularly of the larger intestines, with 
here and there patches of extravasated 
blood. 



TOXICOLOGICAL CHART. 



205 



In some few cases scarcely a trace of 
diseased action in the tissues could be 
found. 

Tests. — Portions of the vegetable in the 
stomach and intestines mixed with the in- 
gesta. 

Tlie active principle of the poison is 
unknown, hence the diiiiculty in the treat- 
ment. 

AGENT. 

ACIDUM UYDnOCYANICUM. 

I/)/d)-oci/(»iic Acid, 
Prussic Acid. 

Si/mptoms. — Its influence is sudden, and 
that of a powerful sedative to the system, 
and, when the quantity is not large, evanes- 
cent : otherwise it is followed by marked 
cerebral derangement, manifested by giddi- 
ness and coma ; the breathing becomes 
laborious; the nostrils expanded; the pulse 
quickened and lluttering; much debility is 
present, with loss of power : to these suc- 
ceed tetanic spasms ; the muscles become 
rigid ; the jaws locked, and the membrana 
nictitans is forced over the eye, which is 
prominent, and has a glassy appearance ; 
profuse perspiration covers the body, accom- 
panied by violent convulsions and intense 
suffering. These effects are succeeded by 
a remission for a time, during which the 
animal appears to bo in a state of partial 
insensibility ; but the exacerbations return 
again and again, and then the paroxysms 
become less and less powerful, until at 
length, all action disappearing, the animal 
is left in a state of exhaustion, the vital 
powers being much depressed. In what- 
e^jser way the agent is introduced into the 
system, the effects are similar. The most 
active form of the poison is that of vapor. 

When the dose is sufficiently large to 
cause death, it is unaccompanied with suf- 
fering. 

Treatmenl. — Cold affusions over the 
body ; the inhalation of dilute ammoniacal 
and chlorine gases, particularly the latter. 

The coma may be removed by blood- 
letting; and diffusible stimulants, such as 



ammonia, may be administered, combined 
with tonics to rouse the depressed vital 
powers. 

Of course this treatment will only be of 
service when the drug has been too fre- 
quently given, or administered in too large 
quantities. 

Morbid Appearances. — The inner tunic 
of the stomach and intestines slightly in- 
flamed ; the vessels of the lungs gorged 
with blood ; the parenchyma natural ; the 
lymphatics containing red blood ; the heart 
inflamed, and spots of ecchymosis on its 
lining membrane ; the vessels of the brain 
highly injected, particularly those of the 
medullary portion, in which organ the odor 
of the acid is easily recognized, as well as 
throughout the body, and particularly in the 
halitus from the blood. The eyes are glis- 
tening and prominent. 

Tests. — Render fluid the contents of the 
stomach, and distil an eighth part over, when 
the following tests will be available : Tlie 
odor, which resembles that of bitter al- 
monds, and imjjresses the throat and nos- 
trils with a peculiar acridity. 

Sulphate of Copper, the solution being 
rendered alkaline by potass, throws down a 
green precipitate, which becomes nearly 
white on adding a little liydrochloric acid, 
the cyanide of copper. 

Sulphate of the Protoxide of Iron, simi- 
larly employed, gives a greenish precipitate, 
which becomes of a deep blue color on the 
addition of sulphuric acid, the ferrocijanate 
of tlie protoxide of iron. 

Nitrate of Silver throws down a white 
precipitate, the cyanide of siher, which is 
soluble in nitric acid only at its boiling 
temperature, and which, wiien dried and 
heated in a tube, emits cyanogen gas, which 
burns with a rose-colored flame. 

A GENT. 

CARBONIC ACID. 

Symptoms. — Instances are known of 
horses having been suffocated diuing fires, 
arising from the disengagement of this gas, 
with, perhaps, some of the compounds of 



206 



TOXICOLOGICAL CHART. 



hydrogen. Its sources otherwise are abund- ' 
ant. In a state of dilution it causes coma ; 
"when ]mre, spasm of the glottis, and death ; 
by asphyxia. I 

Treatment. — Removal to the air; cold 
aflfusions over the body ; bloodletting ; dif- 
fusible siiniulants. 

Morbid Appearances. — Engorgement of 
the vessels of the lungs with black blood. 
The v-cssels of the brain and of the heart 
are in a similar state. The bronchi and 
trachea filled with frothy mucus. 

Tests. — The tests for carbonic acid gas 
are simple enough, but here they are inap- 
plicable. 

AGENT. 

SULPHURETTED HYDROGEN. 

Symptoms. — This gas, given off from 
cesspools and other places, has been at 
times the cause of death. It is rapidly ab- 



sorbed by the blood, and produces coma 
and tetanic convulsions. Sometimes death 
takes place from asphyxia. 

Treatment. — The same as the above; 
to which, perhaps, may be added the inha- 
lation of dilute chlorine. 

Morbid Appearances. — The muscles Imve 
lost their power of contractility. The 
blood-vessels are gorged with fluid black 
blood; the bronchial tubes inflamed, with 
increased secretion of mucus both in them 
and the trachea ; the odor from the body is 
highly offensive. 

Tests. — Carbonate of Lead on a piece 
of card paper, exposed to an atmosphere 
impregnated wdth this gas, is tm-ned black 
by the formation of the snlplmret of lead; 
but as the body when undergoing decom- 
position emits the same kind of gas, this 
test can only be accepted as a corrobora- 
tive proof. 



Ill — NARCOTICO-ACRID POISONS. 



Tliese cause Death, either by irritation or narcotism, and sometimes by both combined. 
Their influence is first local and then remote, impressing the Nervous System. They 
are principally derived from the Vegetable Kingdom. 



AGENT. 

NUX VOMICA ET STRYCHNIA. 

Vomic Nut and Strychnia. 

Symptoms. ■ — The vomic nut induces a 
quickened and irritable pulse, highly la- 
bored respiration, snortings, tetanic spasms, 
loss of muscular power, injection of the 
mucous tissues, extreme thirst, and death 
from asphyxia; previous to which there is 
intense suffering. The action of its alka- 
loid, strychnia, is more energetic. It is 
shown by tremors, followed by a quickness 
of the pulse and labored respiration, ex- 
treme irritability, loss of po\ver in the ex- 
Iremities, tetanic convulsions increasing in 
violence, the legs being thrust from the 
body, the muscles rigid, opisthotonus, pro- 
fuse perspiration, insensibility, and the 



pulse and resph-ation being scarcely percep- 
tible ; the paroxysm exists for a few min- 
utes only, and is followed by a remission 
of the symptoms, leaving the animal much 
exhausted and extremely irritable. The 
exacerbations, however, continue until death 
takes place from suffocation. 

Treatment. — From the tenacity with 
which the powder of the nut adheres to the 

' stomach and intestines, it is ^^^th difficulty 
dislodged. Its removal may be attempted 
by means of active purgatives, or antidotes 
may be tin-own in ; these consist of chlo- 
rine and of iodine, which form inert eom- 

: pounds with the active principle, sti-ychnia ; 

I bat, as the action of the alkaloid is on the 
spinal maiTowand the brain, little good can 

', be Ivopcd to be obtained when a dose suf- 

i ficiently large to destroy life has been given, 



TOXICOI.OGICAL CHART. 



207 



unless active measures bo iniincdiately 
adopted, ll" ihe dose be not sufiieiently 
liirfje for this purpose, there will be a suc- 
cession of paroxysms, leaving behind them 
mueli debility, which is to be counteracted 
by tonics and diffusible stimulants, with, 
perhaps, counter-iiTitants along the course 
of the spine, lest effusion should take 
place. 

Morbid Appearances. — Mucous lining of 
the alimentary tube inilamed, lungs gorged 
with blood, and the vascular system through- 
out the body in a state of congestion. The 
spinal canal much inflamed. Eft'usion of 
bloody serum into the theca vertebralis; 
motor division of the spinal cord more in- 
jected than the other, and the nerves taking 
their origin from it inflamed. The mem- 
branes of the brain have been found in- 
flamed, with effusion on the surface of the 
cerebellum, and a softening of the whole 
cortical portion of the bfain. Rigidity of 
the muscles of the body. Rapid decompo- 
sition, accomjianied with much foetor. 

Tests. — The powder of the nut has a 
greenish-gray color, an intensely bitter taste, 
and the odor of liquorice. Being collected, 
it is to be boiled in water acidulated with 
sulphuric acid, filtered, and the solution 
neutralized by carbonate of lime and evap- 
orated to dryness. The dry mass being 
acted upon by successive portions of alco- 
hol, these are to be evaporated to the con- 
sistence of sjTup, when the product will be 
fovmd to have an intensely bitter taste, and 
it becomes of a deep orange-red color with 
nitric acid, which color is desti-oyed by the 
protochloride of tin. Sometimes it de- 
posits crystals of strychnia on standing. 
These tests will also be available for the 
alkaloid ; to which may be added its spar- 
ing solubility in water, the alkaline reaction 
of its alcoholic solution, and its forming 
neutral and crystallizable salts with acids. 

AGENT. 

SEMEN CROTONI. 

Croton Seed. 
Symptoms. — This purgative, when in- 
cautiously administered, has produced death 



by inducing violent inllannnation of tiie 
intestinal canal, followed by superpurga- 
tion ; the alvine dejections being profuse, 
watery, and offensive. 

Treatment. — A free use of demulcents, 
with astringents, as catechu, opium, and 
chalk. Bloodletting ; opiate enemas. Hot 
rugs to the abdomen, counter irritants, etc. 

Morbid Appearances. — Violent inflam- 
mation of the intestines, particularly the 
caecum and colon, involving all the tunics, 
the mucous lining being easily torn. Fte- 
ces abundant and semi-fluid. Lungs in a 



state of congestion. 

Tests. — None definite. 

A GENT. 

DIGITALIS PURPUREA. 

J^u.C Glove. 

Symptoms. — Languor, gastric irritation, 
coldness of the body and extremities, pale- 
ness of the mucous tissues, cold and clam- 
my perspiration, quickened and feeble pulse, 
death. 

When it accumulates in the system, af- 
ter having been repeatedly given in compar- 
atively small doses, it produces loss of 
appetite, nausea, languor, a quick and irreg- 
ular pulse, followed by purgation, and the 
effects then gradually disappear. 

Treatment. — Expulsion of the agent by 
means of a solution of aloes, combined 
\\'ith linseed oil. The free use of demul- 
cents; diflusible stimulants; counter-irri- 
tants. 

Morbid Appearances. — Depending upon 
the condition and previous state of the 
animal. If much debUitated, inflammation 
of the mucous lining of the stomach and 
alimentary tube may be seen to exist. At 
other times no trace of its influence on any 
of the tissues can be detected, and it is then 
supposed to cause death by exhaustion of 
the nervous energy. 

Tests. — None definite. 

AGENT. 

VERATRUM ALBUM. 

White Hellebore. 
Symptoms. — Efforts to vomit, accclcr- 



208 



TOXICOLOGICAL CIIAllT. 



atcd pulse, uiitraiiquil respiration, intestinal 
irritation, which, if followed by purging, 
affords relief; if not, these symptoms be- 
come more urgent, the body is covered with 
perspiration, saliva is secreted in increased 
quantities, the legs become deathly cold, 
inflammation of the bowels supervenes, and 
death. 

Treatment. — A free use of demulcents. 
Milk has been strongly advocated ; on what 
grounds beyond that of its being a bland 
fluid, I am at a loss to conjecture. Olea- 
ginous purgatives ; counter-irritants. 

Morbid Appearances. — The villous coat 
of the stomach will be found inflamed; the 
intestines also in a high state of inflamma- 
tion, particularly the cascum and colon ; the 
heart pale and flabby ; and the lungs con- 
gested. 

Tests. — None definite. 

A GENT. 

NICOTIANA TABACUM. 

Tobacco. 

Symptoms. — Nausea, giddiness, coma, 
feeble and irritable pulse. Sometimes gen- 
eral excitement of the system, profuse per- 
spiration, labored respiration, pulse much 
quickened, partial insensibility. 

Treatment. — Expulsion of the agent by 
purgatives ; diffusible stimulants when coma 
exists ; demulcents. 



Morbid Appearances. — I am not ac- 
quainted with an instance of death having 
taken place, although this agent is fre- 
quently given as a vermifuge in very large 
quantities. 

Tests. — None definite. 

AGENT. 

JUNIPERUS SABINA. 

Savin. 

Symptoms. — This, like the preceding 
agent, is given as a vermifuge, and some- 
times incautiously. Gastric irritation is 
then evinced, the animal refuses food, and 
is languid ; this is followed by diuresis, and 
sometimes by purging ; the pulse becomes 
irregular and full, and the respiration hur- 
ried. 

Treatment. — Expulsion of the agent 
from out the alimentary canal by oleagi- 
nous purgatives ; demulcents. 

Morbid Appearances. — Esophagus and 
stomach inflamed, particularly the villous 
portion of the latter viscus, on which patches 
of extravasated blood are seen to exist ; the 
smaO intestines contain much mucus, and 
are slightly inflamed ; lungs congested ; 
larynx and trachea of a rusty yellow color ; 
glands at the root of the tongue much 
enlarged. 

Tests. — The partially digested vegeta- 
ble matter found in the alimentary tube, 
which may be distinguished by its odor. 



Under the head of Narcotico- Acrid Poisons, perhaps, should be placed the Atrota 
Belladonna, Deadly Nightshade, which, in large doses, induces singultus, a dilatation 
of the pupils, feeble and irritable pulse, and a relaxed state of the bowels. Also many 
of the umbelliferous order of plants, as Conium Maculatum, Common Hemlock, the 
influence of which is probably that of a Narcotic; Cicuta Virosa, Water Hemlock, 
which, to some animals proves an energetic Poison ; with a few of the natural family 
of the RanunculacsB, as the Aconitum Napellus, Monkshood, and Helleboris Niger, 
Black Hellebore, which cause death by irritation, producing gastro-enteritis, followed by 
delirium; likewise Delphinium Stapiivsagria, S«cesacrf ; Bryonia Alba, Wild-vine 
or Bryony, and Felis Foemina, Female Fern; of which latter very large quantities are 
rofiuired to cfl'ect any marked change in the animal system; and, indeed, it may be said 
of the Vegetable Poisons generally, that the Horse is enabled to resist the influence 



TOXICOLOGICAL CHART. 209 

of comparatively immense doses of them, which in all probability arises from the 
peculiar structure of his stomach. 

Wheat and Barley have been designated as poisons to this animal ; and occasionally 
they have proved to be so, by setting up acute gastritis. A very common sequela of 
poisoning by Wheat is inflammation of the laminae, the result of metastasis ; and of 
Barley, a depilation of the sldn. We are, however, in want of more correct information 
than at present we possess, before anything definite can be laid down under this head, 
as both wheat and barley, given in moderate quantities and with judgment, often prove 
beneficial. 

I am induced to pass the agents above enumerated thus cursorily over, my object 
having been to give a condensed and tabular view of such substances as are known to 
destroy life in the horse when incautiously or maliciously administered, and to elucidate 
a Thesis on Poisons which I had the honor to read before the Members of the Veteri- 
nary Medical Association in 1836 : at the same time, I hope that this attempt may 
prove of some use to the Student of Veterinary Medicine. — Morton. 

27 




v^^^ 



EXPLANATION OF FIGURE XX. 



TirK HEAD. ■ 

a. Orbicularis ])al])C'brarum. 

6. lA'vator palptlirtr. 

c. Dilator nan's lateralis. 

d. Dilator naris anterior. 

e. e. Orbicularis oris, the circular muscle of the mouth : the tetters are rather loo 

low to indicate the muscle. 

f. Nasalis longus. 

(j. Levator labii sii])erioris. 

k. Masscter. 

m. Attoleutes et abducens aurem. 

THE NECK. 
c". Trachelo subscajnilaris. — Scalenus. 
s. Splciiius. 

r. t. Tendon of the splenius and curaplexus major. 
H. Levator humeri. 

V. Sterno ma.\illaris. The jugular vein is here shown between the two preceding 
muscles. 



THE SnOlLDER .tND FORE EXTEEMIITES. 

e". Sterno Bcapularis. — Pectoralis transversus. 

y". Antea spinatus. 

g". Postca spinatus. 

}i. Teres major. 

mP. n'\ Triceps extensor brachii. 

I. Sca])ulo ulnaris. 

o". Pectoralis magnus. 

P". ?(". Flexor metacarpi extemus. 

r. " " intemus. 

r". Kueejoiut. 

s". 5. Extensor metacarpi magnus. 

t. Extensor metacarpi obliquus. 

?<'. w". V. Tendons perforans and perforatus. 

y". y". Extensor sufixaginis. 

z". z". Pastern joint. 

8. 8. Extensor tendons. 

6. Radial vein. 

g. Flexor pedis. 

k. Humero cubital. 



ABDOMIN.VL REGION. 

6. Litercostales. 

c. Transversalis abdominis extemus. 

d. " " intemus. 
JD. Serratus magnus. 

J- Pectoralis magnus. 

7. The sheath. 

4. Superficial thoracic vein. 



EXPLANATION OF FIGUKE XX. CONTINUED. 

POSTERIOR EXTREMETTES. 

s'. Erector coccygis. 

9. Compressor coccygis. 

h". i. The three glutei. 

J'. Triceps. 

K, k. Biceps abductor tibialis. 

5. Tibia. 

6. a;. X. g. Fleshy belly of the extensors. 
I. Plantaris. 

m. Tensor vaginse. 

n'. Rectus. 

0\ Vastus externus. 

r. Gastrocnemius internus. 

It. u. u. V. Gastrocnemii. 

y. Peroneus. 

y. X. X. 8. Extensor tendons. 

X. (Off leg.) Flexors perforans and perforatus. 



DICTIONARY OF VETERINARY SCIENCE : 



CONTAINI'- J 



MANY PRACTICAL OBSERVATIONS, 



OF uvea IMTOBTAKCB TO 



HUSBANDMEN AND HORSE OWNERS. 



eSUNPD EEOU VAEIOTJS SOURCES, WITH APDn"":^. 

(Sll) 



A DICTIONARY OP VETERINARY SCIENCE. 



Abdomen.^- That part of the animal 
usually denominated the belly- This cavity 
contains the intestines, or bowels, liver, 
spleen, pancreas, kidneys, etc, and is sepa- 
rated from the thorax, or chest, by the 
diaphragm. 

Abortion. — Our attention was called, a 
short time ago, to a mare, about eight years 
old, said to be laboring under colic. She 
had been driven very fast during the early 
part of the day ; and about noon, w^hen-Avc 
saw her in the stable, she seemed to mani- 
fest considerable uneasiness. The surface 
of the body was cold, pulse small and in- 
termittent. The genitals were considerably 
swollen, and a slight discharge from the 
vagina was observed. She had occasional 
uterine pains, whicli, however, were very 
feeble. 

We immediately gave the following dif- 
fusible stimulant: 

Powdered grains of paradise, 1 drachm. 

" bethroot (trillium purpureum) 4 drachm. 
Hot water, 1 quart. 

This was administered from a bottle. In 
a few minutes, the parturient process com- 
menced, and she shortly gave birth to a 
dead foetus. The mare Avas in her fifth 
parturient month. She was put on a gen- 
erous diet, and rapidly convalesced without 
any after treatment. 

Remarks. — Great care and gentleness 
should be exercised toward mares during 
pregnancy. Hard work in harness, over 
bad roads, is likely to produce abortion ; 
and mares that have once aborted are liable 
to a recurrence of the same, Light work 
and moderate exercise, however, are essen- 
tial to their general health. 

When the period of foaling draws nigh, 
the mare should be separated from her com- 
panions. Having foaled, she should be 



turned into a pasture, where there is a barn. 
Tlie foal may be weaned at sLx months ; if 
it should die, or be taken from tiie dam, 
humanity would suggest the propriety of a 
few -weeks' rest, to enable the mother to re- 
cover from the effects of parturition. 

JMlscarriage, slipping, or slinking foal or 
calf, icarjnng. — In mares, miscarriage is 
very generally caused by over-exertion dur- 
ing the latter period of gestation. It is not 
unfrequently brought about by accidents at 
grass, such as falling in a ditch or hole, and, 
struggling violently to extricate themselves. 
Kicks on the belly are by no means an un- 
common cause of miscarriage ; for which 
reason, a mare, when near her time, should 
be kept by herself: after foaling she will 
require a few weeks' rest, in order to re- 
cover from the effects of parturition ; and, 
when first brought into work again, the 
services required of her should be very 
slight. Exposure to wet and cold will oc- 
casion miscarriage ; also, high feeding and 
want of proper exercise. Abortion is of 
more frequent occurrence in sheep than m 
mares, and is caused by fright, overdriving, 
and being worried by dogs, and by being 
kept in cold, damp situations, and on im- 
proper food. 

Cows are particularly liable to the ac- 
cident of warping, or slinking the calf. 
The common cause of abortion is improper 
feeding. The filthy, stagnant water they 
are often compelled to drink is likewise a 
serious cause, not only of abortion, but 
also of general derangement of the animal 
functions. Dr. White states that " a farm 
in Gloucestershire had been given \\\> three 
successive times in consequence of the loss 
the owners sustained by abortion in their 
cattle : at length the fourth proprietor, after 
suffering considerably in his live stock for 

(213) 



214 



A DICTIONARY. 



the first five years, suspected that the water 
of his ponds, which was extremely filthy, 
might be the cause of the mischief; he 
therefore dug three wells upon his farm, and, 
having fenced round the ponds to prevent 
his cattle from drinking there, caused them 
to be supplied with the well-water in stone 
troughs erected for the purpose ; and from 
this moment his live stock began to thrive, 
and the quality of the butter and cheese 
made on his farm was greatly improved. 
In order to show," says the same author, 
" that the accident of warping may arise 
from a vitiated state of the digestive organs, 
I vAU. here notice a few circumstances tend- 
ing to corroborate this opinion. In 1782, all 
the cows in possession of farmer D'Euruse, 
in Picardy, miscarried. The period at 
which they warped was about the fourth or 
fifth month. The accident was attributed 
to the excessive heat of the preceding sum- 
mer ; but, as the water they were in the 
habit of drinking was extremely bad, and 
they had been kept upon oat, wheat, and 
and rye straw, it appears to me more prob- 
able that the great quantity of straw they 
were obliged to eat, in order to obtain suf- 
ficient nourishment, and the injury sustained 
by the third stomach, in expressing the fluid 
parts of the masticated or ruminated mass, 
together with the large quantity of water 
they drank, while kept on this dry food, was 
the real cause of their miscarrying. 

" A farmer at Chareton, out of a dairy 
of twenty-eight cows, had sixteen slip their 
calves at different periods of gestation. 
The summer had been very dry, and, during 
the whole of this season, they had been 
pastured in a muddy place, which was 
flooded by the Seine. Here the cows were 
generally up to their knees in mud and 
water. In 1789, all the cows in a village 
near Mantes miscaiTied. All the land in 
tliis ]3lace was so stiff as to hold water for 
some time ; and, as a vast quantity of 
rain fell that year, the pastures were for a 
long time completely inundated, on which 
account the grass became bad : this shows 
that keeping cows on food that is deficient 
in nutrition, and difficult of digestion, is 



one of the principal causes of miscarriage." 
It is supposed that the sight of a slipped 
calf, the smell of putrid animal substance, 
is apt to produce warping. Some curious 
cases of abortion which are worthy of notice 
happened in the dairy of a French farmer. 
For thirty years his cows had been subject 
to abortion. His cow-house was large and 
well ventilated ; his cows were in apparent 
health ; they were fed like others in the vil- 
lage ; they drank the same water ; there 
was nothing different in the pasture; he 
had changed his servants many times in the 
course of thirty years ; he pulled down the 
barn or cow-house, and built another, on a 
different plan ; he even, agreeably to super- 
stition, took away the aborted calf through 
the window, that the curse of future abor- 
tion might not be entailed on the cow that 
passed over the same threshold. To make 
all sure, he had broken through the wall at 
the end of the cow-house, and opened a new 
door. But still the trouble continued. 
Several of his cows had died in the act of 
abortion, and he had replaced them by others : 
many had been sold, and their vacancies 
filled up. He was advised to make a thor- 
ough change. This had never occurred to 
him ; but at once he saw the propriety of 
the counsel. He sold every beast, and the 
pest was stayed, and never appeared in his 
new stock. This was owing, probably, to 
sympathetic influence ; and the result of 
such influence is as fatal as the direct con- 
tagion." (See Youatt.) 

The usual symptoms preceding abortion 
are a sudden filling of the udder, and a 
loose, flabby, and sometimes swollen ap- 
pearance of the genitals, which discharge a 
Utile red-colored fluid. The lancet and 
medicine have been resorted to with very 
little success. Both of them are decidedly in- 
jurious ; the animal should be put into some 
dry, sheltered place, by herself, and kept on 
boiled mashes and gruel for a few days. 

Absorbents. — Medicines which are giv- 
en in view of absorbing gas or neutralizing 
acidity in the digestive cavity. 

Absorbent Vessels. — (See Lacteals, 
part first.) 



A DICTIONARY. 



215 



Absinthium. — Common wormwood, used 
for the purpose of reducing swellings that 
have resulted from violence. Two ounces 
of wormwood are steeped in one quart of 
New England rum ; if a limb of the ani- 
mal is involved, the wormwood is then 
bound on with bandages, and the parts 
occasionally wetted with the fluid. 

Acacia. — Gum arabic, used as a demul- 
cent and lubricant. In poisoning, it is use- 
ful to sheathe the membranes of the stomach 
and alimentary canal, and wiU defend them 
from the action of drastic purges. 

Acacia Catechu. — Gum catechu. This 
is a powerful astringent : it is obtained from 
a tree that grows in Japan. 

Acetabulum. — The socket in which the 
head of the thigh bone is lodged. 

AcETATED Liquor of Ammonia. — This 
has been long known by the popular term 
of Mindererus' spirit, and is made by pour- 
ing any quantity of acetic acid, diluted with 
seven times its amount of water, upon car- 
bonate of ammonia, until all fermentation 
ceases, or until a neutral solution has been 
formed. It is useful in horse practice ; it 
gently invigorates, is diaphoretic, and some- 
times it proves mildly diuretic. It princi- 
pally shows its salutary effects in the com- 
mencement of the febrile stage, or at the 
close of lingering febrile diseases, particular- 
ly of influenza. In the more early stages of 
epidemic catarrh, it may also be exhibited : 
the dose is from four ounces to an almost 
unlimited quantity. The author used this 
preparation with remarkable success in the 
treatment of influenza, which prevailed, in 
Massachusetts, in the fall and winter of 
1855. The dose for horses and cattle is 
from three to four fluid omices. It is gen- 
erally given diluted with an equal quan- 
tity of water. 

Acids. — Are distinguished by their spur 
taste ; they readily combine with alkalies, 
producing effervescence. Those commonly 
used in veterinary practice are : sulphuric, 
nitric, hydrochloric, and acetic. They are all 
more or less corrosive, and decompose the 
vital tissues, by uniting with their serous, 
albuminous, and saline constituents. There- 



fore, when administered to the horse, they 
should be diluted with water. 

AcoNiTA. — Wolfsbane. — A powerful 
sedative ; it moderates the action of the 
heart, and produces depression of the vital 
energies. It is generally used in the form 
of tincture. Dose, from ten to fifteen drops. 

Action'. — The gait of a horse ; which de- 
pends on his powers and the mode of 
training. 

Action of Medicines.* — Every medi- 
cine is endowed with certain inherent char- 
acteristic actions, which distinguish it as 
decidedly as its physical and chemical pro- 
perties. Thus, some medicines act on the 
bowels, causing purgation ; others on the 
kidneys, stimulating the secretion of urine ; 
and others on the brain and nervous sys- 
tem, causing insensibility ; in fact, there 
is no part or organ of the body, except the 
spleen and pancreas, which is not influ- 
enced, and that often in several different 
ways, by some medicinal agent. It is im- 
possible, however, to explain why a medi- 
cine should act in one way rather than in 
another ; why, for example, aloes is purga- 
tive, and not diuretic, narcotic, or anaesthetic; 
or why chloroform is anaesthetic, and not 
vesicant, diuretic, or purgative. The stu- 
dent must therefore endeavor to conceive of 
these actions, or dynamical effects of medi- 
cines, in the same manner as he does of 
their more familiar properties of color, odor, 
taste, or density. 

Some medicines, as demulcents, caustics, 
and astringents, have merely a local or topi- 
cal action — soothing, irritating, corroding, 
or altering the animal tissues, but not ex- 
tending their influence beyond the part to 
which they are first applied. Others, either 
with or without such a local effect, have a 
remote or indirect action on organs at a 
distance from the part with which they are 
first brought in contact. Medicines which 
act thus remotely or indirectly are thought 
to produce their effects in either or both of 
the two following ways : (a) They are 
absorbed into the circulation, and carried 
by the blood to remote organs ; or (b), The 

♦ Finby Dun. 



21G 



A DICTIONARY. 



impression, which they produce on the parts 
with which they are first brought in contact, 
is transmitted along the nerves to other 
parts. The latter mode of operation is 
sometimes called action by sympathy. 

(a.) The great majority of medicines ap- 
pear to act in the former of these two ways, 
being taken up by the blood-vessels from 
the surface of the mucous membranes, skin, 
or other part to which they have been ap- 
plied. Thus, most medicines given by the 
mouth, after having, if solid, undergone 
solution in the acid gastric juice or alkaline 
bile, pass, by a process of endosmose, into 
the capillary veins which ramify on the sur- 
face of the stomach and intestines, enter 
the general circulation by the mesenteric 
and portal vessels, and are thus carried to 
all parts of the body, altering, it may be, 
the nutritive processes of various organs 
and tissues, and at length expelled through 
some of the excretory channels, as the skin, 
kidneys, or bowels. The rapidity with 
which most substances are thus absorbed, 
and make the round of the circulation, is 
almost incredible. Professor Hering, of the 
Veterinary College, Stuttgardt, found that 
yellow prussiate of potash injected into one 
of the jugular veins of a horse appeared in 
the other in twenty-five seconds, and was 
exhaled from the mucous and serous mem- 
branes in a few minutes ; and also that 
chloride of barium injected into the jugular 
vein of a dog reached the carotid artery in 
seven seconds. Dr. Blake observed that 
chloride of barii;m and niti-ate of barytes 
traversed the whole circulation of a dog in 
nine seconds, and that of a horse in twenty 
seconds ; and a similar rapidity of distri- 
bution doubtless obtains with substances 
which cannot easily be detected in the blood. 

(b.) The other hypothesis, regarding the 
action of medicines, is that they owe the 
development of their effects to the produc- 
tion of some nervous impression on the 
part to which they are first applied, and its 
subsequent transmission to remote organs 
by means of the nervous system. A recent 
modification of this theory, advanced by 
Messrs. Morgan and Addison, assumes that 



the nervous impression is produced, not 
upon the part with which the medicine is 
first brought in contact, but on the interior 
of the blood-vessels after partial absorption. 
Part of the evidence in support of these 
hypotheses is derived from the fact that 
some poisons operate with such extreme 
rapidity as to render it doubtful whether 
there could be time for their being absorbed 
and making the round of the circulation. 
Thus : anhydrous prussic acid, conia the 
alkaloid of hemlock, and aconita the alka- 
loid of aconite, when injected into the 
veins, applied to the cellular tissue, or given 
by the mouth, produce almost instantaneous 
eflfects, and death in a few seconds. It ap- 
pears, however, that the strongest evidence 
in favor of the theories under consideration 
consists in the effects of local injuries in 
producing constitutional disturbance. For 
example, a blow on the region of the 
stomach sometimes causes fatal swooning ; 
distention of the stomach often produces 
hiccough ; the presence of worms in the 
intestines sometimes induces epilepsy ; and 
a local injury frequently causes fever and 
constitutional chstnrbance of all the more 
important organs of the body. In such 
cases the connection between cause and 
effect obviously depends on the transmis- 
sion of nervous impressions only. And if 
topical causes are thus productive of remote 
efiects, it' is surely fair to infer that medi- 
cines and poisons may operate in a similar 
manner. 

In fine, although it would appear that 
most medicines are absorbed and actually 
conveyed to the parts on which they act, 
and that such absorption and actual con- 
tact are essential to their action, yet it is 
highly probable (though not yet positively 
ascertained) that some substances, espe- 
cially the more active poisons, astringents, 
and emetics, owe their effects to the pro- 
duction of a nervous impression, and its 
projjagation to remote organs. Nor is it at 
all improbable that, under different modify- 
ing influences, certain substances will oper- 
ate sometimes in one and sometimes in 
the other of these two ways. 



A DICTION'AUY. 



217 



Actual Cautery. — Red-hot iron. (See 

FlKING.) 

Acute. — A term applied to those diseases 
which are sudden in their attack and vio- 
lence, accompanied with great pain. 

Acute Lndigestiox in Cattle, called 
Hove, or Blown. — When cattle have be- 
come fatigued by driving or by long fasting, 
and suddenly find themselves with plenty 
of food before them, particularly such as 
requires little mastication, as chaff, bran, 
grains, etc., etc. ; and also at all times 
when they meet with food they have long 
been deprived of, as various artificial grasses, 
particularly red clover, they are apt to eat 
greedily, and omit to stop for the purposes 
of rumination ; by which means the rumen 
or paunch becomes so distended as to be 
incapable of expelling its contents. From 
this, fermentation begins to take place, and 
a large quantity of gas generates which in- 
creases the distention, until the stomach, 
by its pressure on the diaphragm, suflbcates 
the animal. 

The si/mptoms are uneasiness and distress, 
with quickened respiration ; sometimes there 
is a degree of phrensy present. When it is 
occasioned by green food, the evolution of 
gas is enormous, and the tympanitis gives 
a drum-like distention to the belly ; but 
when dry food, as chaff, bran, etc., etc., has 
been taken, the impacted matter does not 
distend so quickly, and the symptoms arc 
less acute; they resemble those of constipa- 
tion ; and sounding the side gives back a 
response as though a solid matter were hit 
against. It is thought to be more likely to 
occur in warm and wet weather than in any 
other ; and, if such be the case, it must arise 
from the state of the vegetable matter and 
the surrounding warmth both being favor- 
able to fermentation. 

The treatment will consist in attempting 
to lessen the distention by ef0C2/fl^f«^thc dis- 
tending gas, or otherwise trying to neutralize 
it. Purgatives have little or no effect. The 
evacuation of the gases is effected by the 
introduction of a probang, which is passed 
down the esophagus ; or it is brought 

about by puncturing the side, when the dis- 
ss 



tention is urgent, or the want of assistance 
renders it imperative to evacuate the gas 
immediately, to prevent suffocation ; a 
puncture is therefore at once made into it, 
which, among gi'aziers, is called pminching. 
When nothing better is at hand, this may 
be performed with a lancet, or even a pen- 
knife ; the wound made being kept open by 
the introduction of a piece of hollow elder 
or common wood; the place of puncture 
being midway between the ileum or haunch- 
bone and the last rib, a span below the 
transverse processes of the lumbar vertebrse 
on the left side, to which the first stomach 
or paunch inclines. A cattle trocar will, 
however, permit the gas to escape with cer- 
tainty and speed, and should always be 
used to make the puncture, in preference to 
any other instrument. As soon as the air 
is perfectly evacuated, and the paunch is 
observed to resume its office, the trocar 
may be removed ; the wound being care- 
fully closed by a pitch plaster, or other ad- 
hesive matter. It is necessary to observe, 
that this operation is so simple and safe, 
that, whenever a medical assistant cannot 
be obtained, no person should hesitate a 
moment about doing it himself. The do- 
mestic remedies for lessening the distention, 
by condensing the gas, have been various ; 
as oil of turpentine, and particularly am- 
monia, a strong solution of which in water 
has been found serviceable. The alkalies 
generally have long been used with variable 
success. Vinegar, in the Qitarterh/ Journal 
of AffricMlture, is strongly recommended ; 
but, as it is observed that the elastic fluids 
developed are not always alike, so the effects 
resulting from the most reputed agents have 
too often failed. Mx. Youatt recommends 
the introduction of chlorinated lime, given 
in doses of from "ij to 3iv suspended in 
water. 

But it is to a foreign veterinarian we are 
indebted for the best agent for neutralizing 
the gases given off when the rumen is dis- 
tended. M. Charlet has recommended the 
chloride of potash, which substance has a 
great affinity for the compounds of hydro- 
gen that usually form the major portion of 



218 



A DICTIONAKY. 



those which exist in the stomach. This I 
substance is to be given in doses of an 
ounce to a horse, half an ounce to a cow, 
and three drachms to a sheep. Occasion- 
ally, however, from the contents of the 
stomach being in a state of fermentation, 
no gas will escape, upon the probang or 
trochar being introduced. The chloride of 
potash is thea to be poured down the pro- 
bang or trochar, which ever may be used ; 
and this substance must not be mixed with 
either mucilage or aromatic bitters, but sul- 
phuric ether and cold water may be joined 
to it without injuring its effects. 

^THER NiTROsus. — Swect Spirit of 
nitre. Sweet spirit of nitre is stimulant, 
anti-spasmodic, diuretic, and diaphoretic. 
The dose is from one to two ounces, diluted 
with water. 

Age. — The age of a horse may be known 
by marks in the front teeth and tusks of 
the under jaw, until he is about eight years 
old, after which period it is a matter of 
guess-work ; yet those who are expert can 
tell very near the exact age. There are 
many circumstances which tend to show 
whether a horse be old or not. The num- 
ber of a horse's teeth is forty, — twenty-four 
grinders, and sixteen others, — by some of 
which his age may be known up to a certain 
period. Mares have only thirty-six teeth, 
as in them the tushes are usually wanting. 
A few days after birth, the colt puts forth 
two small front teeth in the upper and un- 
der jaws, and soon after two more : these 
are called nippers. The next four shortly 
afterwards make their appearance. The 
four corner teeth — as they are termed — 
come a few months after the last named. 
These twelve teeth, in the front of the 
mouth, are small and white, and continue 
without much alteration until the colt is 
about two years and a half old, when he 
begins to shed them. The two teeth that 
first make their appearance are the first that 
are lost, and are replaced by two others, 
called horse's teeth, considerably stronger 
and larger than those that have made way 
for them. Between the third and foiuih 
year the two teeth next the first fall out, 



and are in like manner replaced by horse's 
teeth. Between the foiu-th and fifth year, 
the corner teeth are changed ; the tushes 
make their appearance. About the fifth 
year, the horse is said to have a full mouth. 
After this period, up to the eighth year, the 
age of a horse can, with some degree of 
certainty, be Icnown by the cavities in the 
teeth, which at first are deep, but are gradu- 
ally, by the process of mastication, worn 
down, and about the eighth year disappear. 
After the fifth year, the above criterion of 
age may be corroborated by the grooves in 
the tushes of the male, which are inside ; 
they are two in number. At six, one of 
these cavities, viz., the one next the^ grinder, 
disappears ; at seven, the other is consider- 
ably diminished ; and at eight is almost, 
but not always, entirely gone. After this 
period, the tushes become more blunt and 
round. The marks in the upper teeth are 
by some considered indicative of the horse's 
age ; those in the two front teeth disappear- 
ing at eight, in the two next at ten, and in 
the corner teeth at twelve. The marks in 
the lower teeth will disappear about the 
eighth year. 

As a horse grows old, he generally turns 
more or less gray ; the cavities above the 
eyes become deeper ; the under lip falls ; 
the gums shrink away from the teeth, giving 
them the appearance of a greater length ; 
the back becomes hollow, or curved. 

Age of Neat Cattle is known by their 
horns. At the age of about two years, 
they shed their first fore teeth, which are re- 
placed by others, larger and more prominent; 
about five, the early teeth are all replaced 
by the permanent ones. As the animal ad- 
vances iir years, these teeth wear down, the 
enamel disappears, and they assume a black 
or brown appearance. When three years 
old, a change takes place in the structure 
of the horns ; after which period these ap- 
pendages, lilce the permanent teeth, preserve 
the same character. After the third year, 
the horns continue to grow as long as the 
animal lives, and the age is indicated by 
the rings, or prominences, which are easily 
distinguished on the horn, and by which the 



A DlCTIONAP.y. 



219 



age of the creature may be nearly ascer- 
lainod, by adding three years to the num- 
ber of rings. 

Airing, in the management of horses, 
implies exercising tliem in open air. 

Albumen. — That part of the white of an 
egg which coagulates into a solid mass 
when boiled ; it abounds in the bones, 
muscles, cartilage, hoof, hair, etc. 

Alcohol. — Rectified spirit. This is ex- 
tensively used in medicine for making tinc- 
tures. With an equal quantity of water it 
is termed A^ew England rum. Alcohol is a 
powerful irritant and caustic poison, to 
whatever part of the horse it is applied. If 
applied externally, it causes sweUing, pain, 
and irritation ; if given internally, it absorbs 
from the living parts the serous or watery 
portion, and condenses the fibrous struc- 
ture. Alcohol, diluted in any form, acts on 
the horse as a diuretic, causing tiie kidneys 
to secrete a large amount of urine, in con- 
sequence of which they become overworked, 
and finally diseased. It is used as a dift'u- 
sible stimulant. The best substitute is 
warm ginger tea. 

Aliment. — That which nourishes the 
system. 

Alimentary Canal. — The interior of 
the stomacii and intestines. 

Alkalies. — There are different sorts : 
soda, potash, and ammonia, are alkalies. 

Aloes. — Obtained from the aloe plant. 
The aloes now in use as a cathartic for 
horses, cattle, and sheep, are the Barbadoes. 
Pure Barbadoes aloes are of a dark brown 
color, present a rough appearance when 
broken, and have a rather pleasant aroma. 

Alteratives. — A class of medicines 
that act gradually and permanently upon 
the liorse, by increasing the tone and vigor 
of the secreting, excreting, and absorbing 
system, without diminishing or destroying 
their power. 

Althea. — Marsh mallows. Tliis plant 
is generally used in the formation of emol- 
lient drinks, as it contains a largo amount 
of mucilage. 



Alum. — A mineral astringent, used to 
destroy proud flesh. " Alum is a powerful 
astringent, whether administered internally 
or applied externally. It may be given to 
the horse in does of from 3ij to 3iv, and 
its employment has been attended with 
some benefit in obstinate cases of diabetes, 
also in diarrhoea, the primas viae having 
been previously emptied by means of lax- 
atives. It has likewise been found useful 
in dysentery and lead colic. For either of 
these diseases it may be advantageously 
conjoined wdth opium and aromatics." 
{Morton's Pharmacy.) 

Amaurosis, or Gutta Serena.* — This 
disease, known by the term glass eyes, 
from the peculiar glassy appearance the 
organs assume, is generally considered 
as dependent on a paralytic state of the 
optic nerves, or of their expansions, the 
retiuEB. By others, it is, liowever, thought 
to arise from the effects of inflammation, 
hy, which coagulable lymph is placed over 
the optic nerve, rendering the retina inac- 
cessible to the stimulus of light ; this can 
hardly be an occasional, and is certainly not 
riie usual, cause. The disease, however, is 
likely to arise from any irritation of the 
brain ; thus, it is found to follow staggers 
and the loss of large quantities of blood ; 
which last-mentioned cause especially af- 
fects the nervous system. The veterinarian 
should make himself familiar with the ap- 
pearances of this complaint, otherwise he 
may lie open to serious imposition. In 
amaurosis, a horse presents indications of 
blindness in his manner, though but little in 
his eyes; he seems cautious in stepping-; 
lifts his legs high, tmd moves his ears 
quickly, as though endeavoring to make up 
by sound the intelligence lost by the depri- 
vation of siglit: but, above all, a hand 
moved close to the eye occasions no wink- 
ing, unless held near enough for the motion 
to influence the air around, which an artful 
person might manage with ease. When 
this kind of eye is examined closely, the 
pupil will be found of one invariable .•<« 

* Blaine. 



220 



A DICTIONART. 



and unvarying hue ; it will not enlarge and 
diminish as in a healthy horse, when re- 
moved farther from, or nearer to, the light ; 
for the retina, ceasing to be influenced by 
the luminous ray, no longer controls the 
movements of the iris. It is, therefore, from 
the peculiarities in the manner of the horse, 
the invariable size of the pupil, and a green- 
ish glassy cast in such eyes, that these cases 
may be distinguished. As it has hitherto 
proved incm'able, we shall waste no time on 
its treatment. 

Ammonia. — This is a volatile alkali ; is 
rapidly absorbed by water ; and, by union 
with acids, forms several salts. The com- 
pounds of ammonia employed medicinally 
are: hydrochlorate of ammonia, sesqui-car- 
bonate, and solution of the acetate of 
ammonia. The aromatic spirit of ammonia 
is a valuable stimulant and anti-spasmodic 
in colic or hoven. For the preparation of 
the latter, Mr. Morton gives the following 
formula : • 

Take of spirit of ammonia, 8 fluid ounces ; volatile 
oil of lemons, 1 fluid drachm ; volatile oil of rosemary, 
14 fluid drachm. Dissolve the oil in the spirit hy 
agitation. 

Anasarca. — That form of dropsy that 
affects the Vvhole, or nearly the whole sys- 
tem, or, in other words, an effusion of serum 
into the meshes of the cellular tissue. 

Anasarca, CEdema, and Water Farcy.* 
— We need malie no distinction between 
these terms, particularly the two first. As 
generally accepted, oedema carries probably 
rather a more local definition with it ; thus, 
we say an oedematous swelling: but ana- 
sarca is more frequently used to designate 
an extensive dropsy of the cellular mem- 
brane. Both, however, have the same 
origin, and are accompanied by the same 
symptoms. It differs from ascites princi- 
pally in its external seat, which is some- 
times partial and sometimes general. It 
also appears under different fornij;, as it has 
different origins ; and its terminations are 
also under the influence of these circum- 
stances. A debility of the absorbent system 

* Blaine. 



is usually observed in the spring and au- 
tumn. There is, however, some general 
atony of the whole system, and the ffdema 
disappears as the constitution establishes 
itself. At other times anasarca and cedema 
appear as accompaniments or sequelEe to 
acute diseases that have disturbed the func- 
tions generally, in the which case the 
absorbents become irritated ; or to the 
cedema is added tumefied lymphatics. 

Anesthetics. — Agents which produce 
insensibility to external impressions and to 
pain. The author uses, for inhalation, three 
parts of sulphuric ether to one of chloroform. 
In allusion to the use of anesthetics, 
Mr. Morton writes : " AnsEslhetics are less 
used in surgical and other painful operations 
inthe lower animals than in man, on account 
of the larger quantities required, the diffi- 
culty of administration, and the undue pro- 
longation of the preliminary stage of 
excitement. They have been used in par- 
turition, and afford, as in the human subject, 
immunity from pain, but without apparent 
interference with the force or frequency of 
the involuntary contTactions of the uterus. 
They have further been used for relieving 
the irritability and pain of such diseases as 
peritonitis, pleurisy, and pneumonia ; for 
removing the spasms of tetanus, colic, and 
asthma ; and for alleviating, by local appli- 
cation, the irritability of severe wounds. 
For all such purposes their use might, with 
advantage, be much extended." 

Anastomosis. — The communication of 
blood-vessels with each other, or their open- 
ing one into the other, by which means, 
when the passage of blood through an 
artery or vein is prevented by ligature, com- 
pression, or any other cause, the circulation 
is still kept up by means of the anastom- 
osing vessels. 

Anatomy. — The science that teaches 
the structure of the animal economy. 

Analysis. — The resolution of compound 
bodies into their original or constituent prin- 
ciples. 

Anchylosis. — The loss of motion in a 
joint. There are two lands, called com- 



A DICTIONARY. 



221 



plete and incomplete. In the former, the 
joint has grown together so as to be immov- 
able ; in the latter, some motion remains, 
and the rigidity is owing to the contraction 
and thickening of the ligaments. Anchy- 
losis in the horse is not unfrequently a con- 
sequence of wounds or bruises ; the latter, 
causing an absorption of the fluids that 
nourish the joint, anchylosis is the result. 
In bad spavins and ringbones, there is fre- 
quently anchylosis of the hock and pastern 
joints. The author's attention has lately 
been called to a case of ringbone that had 
been operated upon by some person totally 
unacquainted with the nature of the disease. 
The operation was performed in the most 
cruel and barbarous manner. The operator 
having never studied the anatomy of the 
parts, it could not be otherv\dse expected. 
On an examination of the animal, ossific 
or bony deposits were found inside the hind 
legs, in the form of a spavin ; deposits also 
existed on the canon bones, and on the 
pasterns, thus proving that the disease was 
incurable ; the general health was impaired, 
the knees sprung, and the animal was pro- 
nounced by the owner to be worthless ; yet 
this specimen of inhumanity, the self-styled 
" doctor," had the audacity to state that he 
could perform a cure for the trifling sum of 
five dollars. The fact of his attempting to 
cure a constitutional disease by local means, 
under such unfavorable circumstances, 
shows that he was an ignoramus ; and the 
barbarous manner in whicli he performed 
the operation, shows that he was destitute 
of every particle of humanity. The author 
has digressed merely for the purpose of 
warning owners of domestic animals 
against trusting them, when diseased, in 
the hands of those who are unacquainted 
with their mechanism. 

Aneurism. — A tumor filled with blood, 
communicating with an artery. It usually 
occurs from rupture of one of the coats of 
the artery, and dilitation of the cellular coat: 
it is then denominated true aneurism. 
When an artery is wounded, and the blood 
escapes into the surrounding tissues, it is 
called false aneurism. 



The general mode of curing aneurism is 
by tying a ligature around the artery ; the 
coats of the artery become united, and part 
of the artery obliterated ; the circulation is 
carried on by anastomosing vessels. (See 
Anastomosis.) Some aneurisms have been 
known to undergo certain natural changes, 
by which they have been spontaneously 
cured, thus proving that the vital power is 
more efficient " than an evil system of med- 
ication." 

Anise Seed. — A mild carminative. It 
is much used in veterinary practice, and is 
one of the ingredients in cordial balls. 

Anodynes. — Medicines that relieve pain, 
procure sleep, and lessen the irritabiUty of 
the nervous system. 



ANTACIDS. 



•ALKALIES. 



Anthelmintics. — Medicines that are said 
to desti'oy worms, and are supposed to cause 
their expulsion from the animal. Many of 
the remedies recommended by some \\Titers 
would be more likely to lull the horse, in- 
stead of the former. The proper method 
of preventing the generation of worms in 
the alimentary canal, is to pay attention to 
feeding, watering, etc., and give cathartics. 

Antimony. — A mineral poison. It has 
been extensively used in veterinary practice. 
There are numerous preparations of anti- 
mony, but they are all more or less objec- 
tionable. Large quantities of this mineral 
have been used on horses ; yet, in some 
cases, where there is vital power enough in 
the animal to dispossess it from the system, 
no immediately unfavorable results were 
observed. Yet it is an agent of such diver- 
sified therapeutical powers, that the wisest 
of the faculty have never ventured to pre- 
scribe and fix limits to its action. (See 
Toxicological Chart.) 

Mr. Finlay Dun, of the Edinburgh college, 
has lately made a series of experiments 
with tartar emetic, on horses, and he speaks 
very highly of it as antiphlogistic. The 
dose for a horse is from one to four drachms, 
either in bolus or solution, repeated as oc- 
casion may require. 

Antidotes. — See Toxicological Chart. 



9,99. 



A DICTIONARY. 



Antiseptics. — Medicines that coiTect 
and prevent putridity. The best and most 
efRcient are charcoal, Peruvian bark, acetic 
acid, and bayberry bark. 

Anti-spasmodics. — Medicines that are 
employed in spasmodic and convulsive dis- 
orders. The most efficient are assafoetida, 
pennyroyal, or any of the mints. The most 
powerful in spasm, or lockjaw, are lobelia, 
warmth and moisture, castor, musk, gin- 
seng, and Indian hemp, or milk weed. 

Apoplexy. — A lesion of some of the 
vessels of the brain. 

Arm. — A term applied to the upper part 
of the fore leg. 

Aromatics. — Medicines that have a 
warm, pungent taste, and fragrant smell ; 
of this kind are cardamom seeds, cloves, 
and nutmegs, sweet flag, etc. 

Arsenic. — A destructive mineral poison. 
It has been used, in many diseases of the 
horse, without the slightest benefit. Dr. 
White states, " So various are its effects, 
that he has known a very small quantity to 
terminate fatally." 

Arteriotomy. — When blood is taken 
from an artery, the process is called arteri- 
otomy. The proper place for puncturing 
the temporal artery, is at the precise spot 
where this vessel leaves the parotid gland 
to curve upwards and forwards around the 
jaw, which is just below its condyle. The 
operation should be performed with a lan- 
cet. 

Arterio - Phlebotoaiy is sometimes re- 
sorted to for the abstracting blood from 
the roof of the mouth and the toe of the 
foot ; in such cases, however, a want of 
knowledge, as regards the anatomy of the 
parts, may occasion a serious ha'morrhage. 

Ascites. — Dropsy of the abdomen. 

AsTiiM.\. — Supposed to originate in the 
muscles of respiration. (See Cough, Roar- 
ing, etc.) 

Astringents. — Medicines that contract 
and condense muscular fibre. The princi- 
pal are kino, catechu, oak bark, nutgalls, 
and bayberry bark. 

Atmosphere. — The name given to an 
elastic invisible fluid which surrounds the 



globe ; it is composed of oxygen, nitrogen, 
and a small portion of carbonic acid gas. 
In stables that are not ventilated, the vapor 
arising from the dung and urine combine 
with it, and render it unfit for respiration. 

Atlas. — The first vertebra, or bone of 
the neck. 

Atrophy. — A v>-asting of the body. 

Auricles. — The two small cavities of 
the heart, 

Backgalled. — When accidents of this 
kind occur, the saddle or harness should be 
padded, or chambered, so as to remove 
pressure from the part ; sometimes they are 
diffi.cult to heal, owing to the presence of 
morbific matter in the system. 

Backraking. — This is a name given by 
farriers to the operation of introducing the 
hand into the fundament, and emptying the 
rectum of its contents. The use of injec- 
tions will, ere long, supersede this beastly 
practice. The most suitable injection to 
soften the faeces is warm soapsuds. 

Back Sinews. — The flexor tendons of 
the fore and hind legs are so named. They 
are frequently strained, or otherwise injured, 
by over exertion or accidents. 

Ball. — Bolus, or large pill. The mode 
of giving a ball is by drawing out the 
tongue to the right side, and liolding it in 
the left hand, while an assistant stands on 
the left side and holds the mouth open. 
The ball is to be held by the finger and 
thumb of the right hand, drawn into as 
small a compass as possible, and passed as 
far as the horse's throat. This must be 
done by a quick motion of the hand, which 
should be kept toward the roof of the 
mouth, as there is more room for it in that 
direction. 

Balsam. — A name applied to several 
resinous substances, such as balsam of tolu, 
Peruvian balsam, balsam copaiba, etc., 
Canada or fir balsam ; the medicinal prop- 
erties are stimulant and diuretic. 

Balsam Copaiba, or Capivi, is used for 
chronic cough ; the dose is about one ounce. 

Balsam of Sulphur. — A preparation 
made by boiling sulphur and olive oil to- 
gether, until united in the form of a dark- 



A DICTIONARY. 



colored tenacious mass. I'his has been 
mnch esteemed by old farriers in obstinate 
coughs. When mixed with a small propor- 
tion of oil of anise-seed, it has been thought 
more efRcacions, and is then named anis- 
ated balsam of sulphur. 

Bandage. — Strips of linen, cotton, or 
flannel, about three or four inches wide. 
They are serviceable in habitual swellings 
of the legs, or weakness of the fetlock joint. 
They are likewise used for the purpose of 
keeping on dressings, or assisting in uniting 
parts that are cut or lacerated ; they assist 
by pressure in expelling matter, or pre- 
venting the descent of ruptures, and as 
compresses for restraining bleeding or hem- 
on-hage. The mode of applying the bandage 
to the leg is as follows : the material, after 
being cut the proper width, must be rolled 
up, and the bandage fixed by taking two or 
three turns in the same place ; after which, 
the roller may be carried round spirally, 
taking care tliat every turn of the bandage 
overlaps about two-thirds of the preceding 
one. When the inequality of the parts 
cause the margin to slack, it must be re- 
versed, or folded over; that is, its upper 
margin must become the lower, etc. A 
bandage should be moderately tight, so as 
to support the parts without intercepting 
the circulation, and should be so applied as 
to press equally on every part. In band- 
aging a horse's leg, the roUer should be 
applied from the upper part of the hoof to 
the knee ; in every case it is advisable to 
bandage from joint to joint, thus leaving 
the joint at liberty. When it is found 
necessary to bandage a joint, the bandage 
should be put on in the form of a figure 8. 

Barb. — A general name for horses im- 
ported from Barbary. The barb, one of 
the most celebrated of the African races, is 
to be met with in Barbary, Tripoli, and 
Morocco ; he seldom exceeds more than four- 
teen hands and a half in height. The barb 
requires more excitement to call out his 
powers than the Arabian ; but, when suf- 
ficiently excited, his qualities of speed and 
endurance render him a powerful antagonist 
to the /Vrabian. 



Bark. — This name is generally applied 
to several different species of Peruvian 
bark, the yellow and the red. The active 
I principle of the yellow bark is an alkaloid 
principle, called quin^, combined with a 
peculiar acid, called kinic, or cinchonic, in 
the state of an acid salt ; besides these, it 
contains an oily and a yellow coloring mat- 
ter, tannin, Idnate of lime, and woody fibre. 
Their value in treating diseases of the horse 
consists in their tonic and astringent prop- 
erties. It should be given to the horse in 
the form of infusion ; one ounce of pow- 
dered bark to a quart of boiling water. It 
is also useful to restore indolent ulcers to a 
healthy state. The best tonic for a horse is 
hydrastis Canadensis (golden seal). 

Bar Shoe. — A particular kind of shoe, 
which is sometimes used to protect the frog 
from injury; also in corns. 

Bars of the Foot. — (See Foot, part 
fii-st.) 

Bars of the Mouth. — Transverse ridges 
on the roof of the mouth ; they are most 



conspicuous, or 



full. 



in a young 



hors 



When swollen, or fuller than usual, the 
horse is said to have the lampas. 

Basilicon. — A digestive ointment, com- 
posed of equal parts of olive oil, yellow 
beeswax, and common resin (or rosin). 
These are to be melted over a slow fire, 
and stirred until the mixture is quite cool. 

Bay. — A bay color, in horses, is so 
named from its resemblance to dried bay 
leaves. 

Biceps. — The biceps is a double-headed 
muscle, which senses to bend a limb. 

Bile, or Gall. — A bitter, greenish fluid, 
secreted by the liver for the purpose of as- 
sisting digestion. In the horse there is no 
gall bladder, or receptacle for the bile ; it 
passes directly into the duodenum, or first 
part of the small intestines, a few inches 
from the stomach. 

Bilious. — Diseases are called bilious 
when they depend on a morbid state of the 
liver. 

Bits. — There are various kinds of bits 
in use ; among them are the snaffle and 
curb. A snaffle may be either plain, or 



2-2i 



A DICTIONAKY. 



twisted, but the latter is apt to make the 
mouth callous ; it consists of two pieces, 
having a sort of hinge joint in the centre. 
When used for the purpose of breaking 
young colts, it should be made large, so as 
not to hurt the mouth. The form of the 
curb bit resembles somewhat the letter 11. 
The bridle is fastened to the side pieces, 
which act as levers of different powers, ac- 
cording to the distance from the cross-bar, 
to which the bridle is attached. The hu- 
mane man will never inflict unnecessary 
severity on the horse, and will avoid contin- 
ual strain on the reins or bridle, which, 
aside from the torture they inflict, tend to 
render the horse's mouth callous. The best 
form of bit, and the most simple, is the stiff, 
arched bit. The author has seen a very fme 
specimen of this article, manufactured by 
Messrs. Hannaford & Dsley, of this city. 
The centre piece is large and curved ; the 
checks are movable, and their upper ends 
curved outwards, which prevents their injur- 
ing the cheek bones. It is very important 
that a horse should be properly bitted; 
many docile horses are rendered stubborn 
and unmanageable, by having a bit that is 
too narrow. Many young horses are injured 
while they are teething, and the mouth is 
tender, by bearing too hard on the rein. 
The author would suggest a trial of an 
India rubber centre piece, in such cases. 

Bite of any Rabid Animal. — In most 
works on veterinary science, the writers re- 
commend excision, or cutting out the bitten 
part, and afterwards cauterizing with the 
firing iron ; but this method is very unsatis- 
factory, and only puts the animal to unne- 
cessary torment. The morbid matter from 
a rabid animal is generally taken up by the 
absorbents, sometimes in a few seconds, 
and the operation of cauterizing would then 
be of no avail. The treatment we recom- 
mend is, to dose the animal with a tea of 
lobelia ; half a pound of the herb and seed 
may be steeped in two quarts of scalding 
water, and given in doses of half a pint, at 
intervals of an hour. A large poultice of 
the same should be bound on the bitten 
part, and kept in contact with the parts by 



bandages, and the poultice renewed every 
six hours, until all signs of poisoning disap- 
pear. The animal should be kept on scalded 
shorts, in moderate quantities. 

Bladder. — The bladder is a musculo- 
membranous bag, situated, when empty, in 
the cavity of the pelvis. Its use is to con- 
tain the urine, which flows into it through 
the ureters, from the kidneys. It is divided 
into three parts, viz., the fundus or bottom, 
the body, and the neck. When full, the 
fundus of the bladder protrudes out of the 
pelvis, into the abdominal cavity ; it then 
receives a covering from the peritoneum. 
Its other coats are an internal mucous mem- 
brane, and an external muscular coat, formed 
of two distinct sets of fibres ; the one lon- 
gitudinal, and the other circular. The 
former are thickest about the fundus, the 
latter about the neck or cervix, — which, by 
this arrangement, is always kept closed, 
except during the time of voiding the urine. 
On opening horses that have died from 
accident, we sometimes find the bladder 
empty, and its muscular fibres so condensed 
that it appears like a solid mass of small 
dimensions ; such is the contractile power 
of its muscular coat, by which, with some 
assistance from the abdominal muscles and 
diaphragm, the urine is expelled. The 
author has opened several horses that have 
died from lockjaw, and found the bladder 
distended to its utmost capacity, containing 
about a gallon and a half of dark-colored 
fluid, resembling coffee-gi-ounds. In one 
case, the mvTscular fibres about the neck 
of the bladder were lacerated by the over- 
distention and spasm of the neck of that 
orEran. When horses are accustomed to 
drink too much water, without being al- 
lowed to stale often enough at work, the 
bladder becomes over-distended, and often 
paralysis, weakness, or local debility sets 
in, and the neck of the bladder becomes at 
length so relaxed as to be unable to offer 
sufficient resistance to the muscles that pro- 
pel the urine into the lurethra, so that it is 
constantly dribbling off as fast as it is 
secreted. This is termed incontinence of 
urine. 



A DICTIONARY. 



225 



Sometimes the irritability of ihc bladder,! 
in the latter case, depends on the acrimony 
of the urine; and, whenever ihis is the case, 
attention to feeding, watering, etc., will 
remove it. Diseases of the kidneys and 
bladder are accompanied with tenderness 
over the loins, and a remarkable stiffness of 
the hind legs. Whenever the bladder is 
distended with urine, recourse should be 
had to the catheter. 

Palsy, or paralysis, of the bladder, is 
sometimes dependent on functional de- 
rangements, as stomach staggers, or injuries 
to the brain and spinal marrow. 

Blasting. — When cattle or sheep are 
first turned into luxuriant pasture, after be- 
ing poorly fed, they fiequently gorge them- 
selves with food, which, fermenting in the 
rumen, or paunch, so distends it with gas 
that the animal is often in danger of suffo- 
cation. The symptoms are most distressing; 
and, unless relief be speedily afforded, death 
very commonly ensues. If the symptoms 
are very alarming, a flexible tube may be 
passed down the gullet : this will generally 
allow the gas to escape, and afford tempo- 
rary relief, until more efficient means are 
resorted to ; these will consist in arousing 
the stomach and digestive organs to action, 
by stimulants and carminatives, and coun- 
teracting the tendency to putrescence by 
doses of charcoal or soda. Some prac- 
titioners recommend puncturing the rumen, 
or paunch ; but there is always some dan- 
ger attending it, and, at best, it is only 
palliative, and the process of fermentation 
will proceed ; the gas may -escape, but the 
materials that furnished it still remain. 
Youatt states : " A cow had eaten a large 
quantity of food, and was hoven. A neigh- 
bor, who was supposed to know a great 
deal about cattle, made an incision into the 
paunch ; the gas escaped, a gi'eat portion 
of the food was removed with the hand, 
and the animal appeared to be considerably 
relieved, but rumination did not return : on 
the following day the animal was dull ; she 
refused her food, but was eager to drink. 
She became worse and worse, and on the 

29 



sixth day she died ;" thus proving i hat the 
remedy was worse than ihe disease. 

When animals are blasted in a moderate 
degree, the carminative drink, and decoction 
of lobelia, will prove effectual. In all cases 
of hove, it will be advisable to give injec- 
tions of warm water, to w^hich add a hand- 
ful of salt, and the same quantity of 
charcoal. As a means of preventing the 
blast, it may be remarked, that animals 
should never be turned into any nutritive 
pasture while the dew is on the ground, or 
after rain. 

Bleedixg. — The practice of abstracting 
blood has received the seal of antiquity, yet 
that is no argument in favor of its useful- 
ness ; and, in view of improving in the 
future, the author here introduces an article 
on the subject, by Professor Buchanan : 

" We affirm that bleeding is a barbarous 
and unscientific remedy, and deny that it is 
ever necessary. In this matter we take our 
stand upon the facts recognized by the high- 
est authorities in medical literature. We 
refer to the most recent and accurate re- 
searches in chemistry and pathology ; to the 
experimental investigations of Andral, Ma- 
gendie, Louis, Simon, and many others, 
which have settled, beyond all doubt, and 
placed among the permanent facts of medi- 
cal science, to be received by all medical 
schools of whatever therapeutic faith, the 
phenomena of the blood, when its composi- 
tion has been affected by hemorrhage, by 
bleeding, and by various other agencies. 

" It is indisputably established that bleed- 
ing produces a special change in the com- 
position of the blood. The change which 
it produces is not a removal of any cjfelc or 
morbid materials, — not a removal of any 
element which tends to create or aggravate 
disease, — but a removal of the most neces- 
sary and healthy portion, upon the presence 
of which we depend for the maintenance of 
health and vigor. Bleeding inevitably re- 
duces the red or globulous portion of the 
blood, because it removes or destroys a 
certain amount of the red globules, and the 
loss which it produces is readily supplied by 



226 



A DICnOXAKY. 



absorption of water and of comparatively 
crude materials, while the highly-organized 
globules are regenerated with great slow- 
ness and difficulty. 

" It is a well-established fact, that the red 
globules of the blood are essential to life, 
and that their abundance or scarcity is a 
criterion of the vital force and activity of 
the constitution. As the proportion of the 
red globules increases, the general vital 
power rises, and the activity or energy of all 
the organs increases ; while a diminution of 
their ratio enfeebles or disorders the various 
organs, and predisposes to nervous and 
tuberculous disorders, and to the whole 
range of adynamic and cachectic diseases. 
If Ihe ratio is diminished as much as one- 
seventh, general debility is the consequence, 
predisposing to disease and diminishing the 
])ower of recovery ; if as much as one-fourth 
or more, this reduction of vital power is 
incompatible with health, and inevitably 
results in some form of disorder. 

" Is it not, then, exquisitely absurd to 
adopt, as a remedy in disease, a measure 
which, even in the most vigorous health, 
tends directly, with rigorous precision, to 
destroy the vital powers and bring- on 
disease ? Yet this measure has been, and 
still is, sustained by many medical men, 
although clinical experience, as well as 
chemical science, has shown its injurious 
eflects, and thousands in America and 
Europe have been, and are now, demon- 
strating that all forms of disease may be 
better treated without bloodletting than 
with it. 

" We affirm that, in disease, the patho- 
genetic elements of the blood should be 
removed, instead of its healthful and neces- 
sary constituents. Nature has provided for 
the removal of all noxious materials, by 
numerous appropriate outlets, which dis- 
charge every thingthat is injurious to human 
health. It is the duty of the physician to 
aid nature by such medicines and means as 
will rouse the secretions and excretions, and 
thus insure the restoration of the blood to a 
perfectly healthy condition. When, for 
want of knowledge how to accomplish this. 



he destroys with unnatural violence a large 
portion of the vital blood itself, which is as 
necessary to the body as its solid tissues, he 
acts with as much scientific precision as the 
savage, who would treat a case of convul- 
sions, not by removing its causes, but by 
cutting out a portion of the convulsed 
muscles.'' 

It will be very difficult, however, to con- 
vince some of the " older heads," and the 
world in general, that bleeding can be dis- 
pensed with ; therefore the veterinarian must 
be prepared to please his employer, and do 
just as his superiors have done, — or else 
" loose caste " and practice. 

Blemishes. — They consist of broken 
knees, loss of hair, cracked heels, false quar- 
ters, splents, windgalls, spavins, etc. 

Blind, Moon. — A disease of the horse's 
eyes, which is supposed to be the forerunner 
of cataract, and often ends in total blindness. 
Blister Fly. — Cantharides, or Spanish 
fly. The object in applying a blister is to 
promote absortions and to combat deep- 
seated inflammations. 

Bloodroot. — Sangitinaria Canadensis, 
used to prevent the growth of fungus, or 
proud flesh ; a substitute for caustic. 
Blood Spavin. — Enlarged bitrsse. 
BoTS. — Short reddish worms, which are 
often found attached to the horse's stomach. 
Ml-. Clark says " that bots are not, properly 
speaking, worms, but the larvce of the gad- 
fly, which deposits its eggs on the horse's 
coat in such a manner as that they shall be 
received into his stomach, and then become 
bots. When the female fly has become im- 
pregnated, and the eggs are sufficiently ma- 
tured, she seeks among the horses a subject 
for her purpose, and, approaching it on the 
wing, she holds her body nearly upright in 
the air, and her tail, which is lengthened for 
the purpose, earned inwards and upwards. 
In this way she approaches the part where 
she designs to deposit the eggs ; and, sus- 
pending herself for a few seconds before it, 
suddenly darts upon it, and leaves the egg 
adhering to the hair by means of a gluti- 
nous liquor secreted with it. She then 
leaves the horse at a small distance, and pre- 



A DICTIONARY. 



pares the second egg ; and, poising herself 
before the part, deposits it in ihe same way ; 
the liquor di'ies, and the egg becomes firmly 
glued to the hair. This is repeated by va- 
rious flies, till four or five hundred eggs are 
sometimes deposited on one horse. They 
are usually deposited on the legs, side, and 
back of the shoulder, — those parts most ex- 
posed to be liclvcd by the animal : in lick- 
ing, the eggs adhere to the tongue, and are 
carried into the horse's stomach in the act 
of swallowing. The bots attach them- 
selves to the horse's stomach, and are some- 
times, though less frequently, found in the 
first intestine. The number varies consid- 
erably ; sometimes they are not half a dozen, 
at others they exceed a hundred. They 
are fixed by the small end to the inner coat 
of the stomach, to which they attach them- 
selves by means of two hooks. The slow- 
ness of their growth, and the purity of their 
food, which is supposed to be the chyle, 
must occasion what they receive in a given 
time to be proportionably small ; from 
which, perhaps, arises the extreme difficulty 
of destroving them by any medicine or poi- 
son thrown into the stomach." A large 
amount of opium, tobacco, and corrosive 
sublimate, sufTicient to destroy the horse, 
have from time to time been given ; and, on 
opening the stomach, these animals have 
been found uninjured. " The presence of 
bots in the horse's stomach is not easily 
ascertained, as it is certain that great num- 
bers have been found after death in the 
stomach, without appearing to have pro- 
duced any kind of inconvenience to the ani- 
mal while alive. It does not appear that 
any eflectual remedy has yet been discov- 
ered for bots." Mr. Blaine says, " that he 
has kept them alive for some days in olive 
oil, and in oil of turpentine, and that even 
the nitrous and sulphuric acids do not im- 
mediately destroy them. At a certain sea- 
son of the year, they detach themselves from 
the stomach, and pass off with the excre- 
ment." A run at grass is the most effec- 
tual remedy. 

Compound for Bots. — Persons desirous 



of treating a horse for bots, can use the fol- 
lowing : 

Powdered poplar bark, ... 4 ounces. 

" mandrake, . . . . 2 ounces. 

" balmony (snakehead), . . 4 ounces. 

" wormseed, . . . .2 ounces. 

" goklen seal, .... 1 ounce. 

" slippery elm, .... 4 ounces. 

Mix. Uinde into sixteen powders, and give one, night 
and morning, in the food. 

Regimen. — The animal should be kept 
on a geiierous diet ; green food or succulent 
and agreeable vegetables will effect a change 
and assist to detach the bots. If, however, 
such articles cannot be procured, let the 
horse have a mess of scalded shorts every 
night. 

Bow-legged. — Defective conformation 
of the legs. 

Box, Loose. — A loose box, as it is gen- 
erally called, is a place wherein a horse is 
turned without being fastened to the man- 
ger or rack : such a place is useful to turn a 
horse into when he is sick, or when the mare 
is about foaling. 

Brain. — The connection that exists be- 
tween the brain and stomach, by means of 
the eighth pair of nerves, or par vagum, is 
the cause of this important organ being 
often disturbed in its function. Thus it is 
that, when the stomach is loaded with food, 
its function becomes deranged, and the brain 
is affected sympathetically. A diseased 
action is then set up, and all the functions 
become more or less deranged. A horse in 
this case will become duU and languid, and 
sometimes labor under symptoms of apo- 
plexy. In consequence of this nervous 
communication between the stomach and 
brain, the latter organ is sometimes aflijcted 
by the imtation of bots in the st^macli. 
The best way to prevent apoplexy, staggers, 
etc., is, by attention to diet, exercise, etc. 

Dropsy of the brain does not often occm: 
to horses or cows ; but sheep appear to be 
more liable to the disease than other quad- 
rupeds. The symptoms of the disorder in 
horses are vai-Lable. " In one case there 
was a considerable degree of dulness and 
heaviness about the head : the pulse was 



228 



A DICTIONARY. 



not much affi-ctcd, but there was loss of ap- 
petite. The animal appeared as if suffering 
much pain in the head, generally keeping it 
lower tiian the manger. These symptoms 
were followed by delirium, convulsions, and 
death. In another case, when probably the 
water had accumulated very gradually in 
the ventricles of the brain, the horse ap- 
peared to be free from pain, except when 
the circulation was hurried by brisk motion, 
when he would fall down in violent spasms, 
the fit seldom lasting but a few minutes. 
This horse, being of scarcely any value, was 
destroyed, and, upon opening the brain, 
about six ounces of water escaped." Sir 
George Mackenzie has described two Jcinds 
of this disease which sometimes happen to 
sheep : " The first consists of an accumula- 
tion of water in the ventricles of the brain ; 
the other — which is most common — arises 
from animalculae, called hydatids. In this 
case, the water is contained in cysts, or bags, 
unconnected with the substance of the brain, 
on wliicli it acts fatally by pressure. Very 
soon after water has begun to collect, cither 
in the ventricles or cysts, the animal shows 
evident and decisive symptoms of the dis- 
ease. He starts, looks giddy and confused, 
as if at a loss what to do ; retires from the 
flock, and sometimes exhibits a very affect- 
ing spectacle of misery." 

Breaking. — The breaking of young 
horses is a matter of great importance, and 
should never be intrusted to any one of a 
cruel or harsh disposition, as, under such a 
master, the very best-tempered horse may 
be rendered vicious. They are often broken 
when much too young ; they are often found 
racing at tln-ee, and in constant work before 
they are four years old. This is one of the 
causes of contracted feet and lameness, that 
are continually presenting themselves to our 
notice. Farmers in general put their colts 
to worlv too young; and, although exercise 
may improve their growth and constitution, 
yet this advantage is more than counter- 
balanced by their being shod at a period 
when then- feet are tender. 

Bridle Hand. — The left is called the 



bridle hand, in contradistinction to the riglit, 
which is termed the loliip hand. 

Broken Wind. — The origin of broKen 
wind is supposed to be a morbid secretion 
from the membrane lining the windpijie, 
bronchial tubes, and ramifications; the air- 
cells are somewhat ruptured, and the air is 
entangled in the cellular substance, or com- 
mon connecting membrane. The bulk of 
the lungs is greatly increased, while their 
capacity for containing air is diminished. 
It is stated in Rees' Cyc/opcedia, under the 
head of broken v.dnd, " that, after opening 
more than ten broken-winded horses, their 
lungs were uniformly found emphysemat- 
ous. (See Emphysema.) This complaint 
is generally considered incurable ; but it 
may often be alleviated by constant atten- 
tion to diet." The animal should be fed on 
shorts, and green food if it can be procured, 
and boiled carrots. When used, his exer- 
cise should at first be moderate, and he 
should never be exercised immediately after 
feeding. If the horse shows any disposition 
to eat the litter, a muzzle must be provided. 

According to ]\Ii-. Richard Lawrence, 
"the most common appearance of the lungs 
in broken-winded horses is a general thick- 
ening of their substance, by which their 
elasticity is in a great measure destroyed, 
apd their weight specifically increased. At 
the same time, their cajmcity for receiving 
air is diminished." Dr. White writes, "that 
he has examined the lungs of broken-winded 
horses without observing this general tiiick- 
ening of their substance ; on the contrary, 
they have appeared superficially lighter and 
larger than in their natural state. Two 
horses were purchased for the purpose of 
making experiments, and so badly broken- 
winded as to be useless. In tlie first, the 
lungs were unusually large, and there was 
a considerable quantity of air in the cellular 
membrane ; but it was not ascertained 
whether the air had escaped from the air- 
cells, or had been generated within the 
common cellular membrane. The other 
I horse was kept about a month in a field 
where tliorc was no water and very little 



A DICTIONARY. 



22ft 



grass. When taken up, he appeared per- 
fectly free from the disorder. He was shot ; 
and, upon examining the lungs, they had 
not the slightest appearance of disease." 
This proved the superiority of nature's 
remedies over those of man. The same 
author relates that he purchased a broken- 
winded horse that was incapable of work- 
ing. By allowing him only a small quan- 
tity of hay, sprinkled -with water, giving 
mashes, mixed with a small quantity of 
oats, and only a small qviantity of water, 
taking care at the same time that he had 
regular and moderate exercise, his wind be- 
came gradually better, and he afterwards 
was perfectly free from the complaint. 

The author has examined the lungs of 
two horses which were said to be afflicted, 
for some time previous to death, with bro- 
ken wind, without detecting a loss of con- 
tinuity in their structure ; neither was their 
specific gi-avity diminished. 

BRoxcniA. — (See Windpipe.) 

BiioNCHOTOMY. — The operation of open- 
ing the windpipe for the purpose of produc- 
ing artificial respiration, or to remove any 
substances that may have lodged in the 
upper part of the larynx. 

Bl-rns are best treated by a mixture of 
equal portions of lime-water and linseed 
oil, the parts being frequently anointed with 
the mixture. 

BuRsj3 MucosjE. Mucous Bags, or Sacs. 
— These arc described as membranous sacs, 
contaiiiing a fluid similar to synovia, or 
joint oil, and interposed between tendons 
and the parts on which they move. In 
violent exertions these vascular membranes, 
which secrete and confine the synovia, are 
injured ; hence we have wdndgalls, bog- 
spavin, etc. 

BuTTERis. — An instrument used by 
horse-shoers for paring the horse's hoofs. 

CiEcuM. — The blind gut. So named 
because it is open at one end only. In the 
horse this part of the intestines is remark- 
ably large. 

Calf, Diseases of. — Many of tlie dis- 
eases of calves originate in a disordered 
state of the stomach, either from taking too 



much milk at a time, or from the milk not 
being sufficiently fresh, or being taken from 
a cow whose health is imj^aircd. When- 
ever the stomach is disordered, either by the 
quantity or quality of the milk, it causes a 
variety of disorders, such as scouring, want 
of appetite, costiveness, colic, yellows, con- 
vulsions, etc. 

Calkins. — A name given to the promi- 
nences on horses' shoes, which are turned 
downward fcr the purpose of preventing 
their slipping. 

Calving. — At the end of nine lunar 
months the period of the cow's gestation is 
complete ; but the parturition does not ex- 
actly take place at that time, — it is some- 
times earlier, at others later. " One hun- 
dred and sixteen cows had their time of 
calving registered : fourteen of them calved 
from the two hundred and forty-first day to 
the two hundred and sixty-sixth day, — 
that is, eight months and one day to eight 
months and twenty-six days ; three on the 
two hundred and seventieth day ; fifty-six 
from the two hundred and seventieth to the 
two hundred and eightieth day ; eighteen 
from the two hundred and eightieth (o the 
two hundred and ninetieth day ; twenty on 
the three hundredth day ; five on the three 
hundred and eighth day ; consequently there 
were sLxty-seven days between the two ex- 
tremes. Immediately before calving, the 
animal appears uneasy; the tail is elevated; 
she shifts about from place to place, and is 
frequently lying down and getting up again. 
The labor pains then come on, and, by the 
expulsive power of the w'omb, the feel us, 
with the membranes enveloping it, is pished 
forward. At first the membranes appear 
beyond the vagina or shape, in the form of 
a bladder of water : this soon bursts, the 
water is discharged, the head and fore feet 
of the calf are protruded (in natural labor) 
beyond the shape. The body next appears, 
and the delivery is com])lete. In a little 
time afterwards, some trifling pains take 
place, Yi'hich separates the afterbirth, or 
cleansings; and these being expelled, the 
process is finished. 

When the membrane breaks, and the 



230 



A DICTIONARY. 



fluid escapes early in calving, and before 
the mouth of the uterus is sufficiently ex- 
panded, the process is often slow, and it is 
a considerable time before any part of the 
calf makes its appearance. The practice 
of hurrying the process by introducing the 
hand, or di'iving the animal about when 
symptoms of calving appear, is very impro- 
per. It has been known in many instances 
to cause the animal's death. It sometimes 
appears that a wrong presentation takes 
place, and renders the calving impracticable 
without assistance. In such cases it is 
necessary to introduce the hand in order to 
ascertain the position of the calf, and change 
it when it is found unfavorable. When, 
for example, the head presents without the 
fore legs, which are bent under the breast, 
it cannot, in this position, be well drawn 
away without danger. In this case the calf 
should be gently pushed back in the uterus, 
placing the cow in the most favorable 
position, and taking the opportunity for so 
doing while there are no pains nor straining. 
When the calf is pushed back, the fore legs 
are to be carefully drawn downward, in a 
line with the head, and brought out into the 
vagina. The author has known several 
cases, where parturition was seemingly dif- 
ficult, of a resort to force in extracting the 
calf; but it should be recollected that nature 
is never to be interfered with in the process 
of delivery, or in any of her operations, 
tinless it is clearly ascertained that assist- 
ance is necessary. When much force is 
used in drawing the calf, and especially if 
the animal be rather fat, a disease of the 
\\omb is apt to follow, puerperal fever sets 
in, which often proves fatal. Great mis- 
chief is also done by endeavoring to extract 
the calf without regard to its position in the 
uterus : it is sometimes so placed that de- 
livery is not practicable until the position 
of the calf is shifted. When much force 
is used in drawing the calf, it sometimes 
happens that the womb falls out or is in- 
verted, and great care is required in putting 
it back, so that it may remain in its situa- 
tion. In doing so, there is an advantage 
derived from placing the cow in such a 



position that the hind parts may be higher 
than the fore. If any dust or straw remain 
about the womb, they should be carefully 
removed before the womb is put back. A ' 
linen cloth is then to be put under the 
womb, which is to be held by two assistants. 
The cow should be made to rise, that being 
the most favorable position, and the opera- 
tor is then to gi-asp the body of the womb 
with both hands, and gently return it. 
When so returned, one hand is to be im- 
mediately withdrawn, while the other re- 
mains to prevent that part from falling 
down again. The hand at liberty is then 
to grasp another portion of the womb, which 
is to be pushed into the body like the former, 
and retained with one hand. This is to be 
repeated until the whole of the womb is 
put back ; if the womb does not contract, 
friction with a brush around the belly and 
back may excite the muscles to contraction: 
should this fail, the animal may have an 
astringent and aromatic di'ink, made by in- 
fusing three ounces of ground poplar bark 
in about three pints of hot water; when 
cool, administer with a horn or bottle, taking 
care, while pouring down the oesophagus, 
to let it fall gently and gradually ; by that 
means it will pass over the pillars of the 
cesopiiagean canal, and on to the third 
stomach ; otherwise it would fall into the 
rumen, and defeat the object in view. 

CAiiPHon. — A narcotic vegetable concre- 
tion. This medicine, says Dr. White, " is 
employed both internally and externally. It 
is given inwardly as an anti-spasmodic, as 
in lockjaw, when it is commonly joined with 
opium ; and as a febrifuge, or fever medi- 
cine, joined with nitre and antimonial 
powder." Mr. Morton writes : Camphor 
has been occasionally given in tympanitis, 
and it has been supposed to act by rousing 
the vital energies. In a state of fine powder 
it is sometimes sprinkled over a linseed- 
mcal poultice, when it has been found to 
allay irritation ; although, as a sedative, thus 
applied, it is not equal to the extract of the 
deadly nightshade. 

On account of its sedative influence, it 
may be advantageously combined with 



A DICTIONARY. 



231 



opium or digitalis for chronic coughs. 
Given for any length of time, it pervades 
the system, and is excreted by the lungs and 
kidneys. 

Cantharides. — Spanish Fly* — Several 
preparations of cantharides are now in use 
for example, 

Viner/ar of Cantharides. 
Take of Catharides in powder, . 1 part, 
" Diluted acetic acid, . . 8 parts. 
Macerate for fourteen days, and filter. 

Oil of Cantharides. 
Cantharides in powder, . . 1 part. 

Olive oil, . . . . .8 parts. 
Digest in a water bath for two hom-s, and filter for use. 

Ointment of Cantharides. 
Take Cantharides in powder, . 1 part. 

" " Hogs lard, . . 6 parts. 

Digest in a water bath and filter thi'ough paper. 

Capped Hock. — A swelling on the point 
of the hock, generally occasioned by blows ; 
they seldom cause lameness ; but, as they 
are a considerable blemish, an attempt 
should be made to reduce them by counter- 
irritants ; friction is also useful. 

Capsicum. — In its pure state it contains 
tonic and stimulant properties. It increases 
the physiological or healthy action of the 
system. 

Capsular Ligament. — The ligament by 
which two bones are joined together. It 
forms a complete sac round them, and serves 
to confine the synovia, or joint oil. 

Caraway Seeds. — These are cordial 
and carminative. The dose is from one to 
two ounces. 

Carbon. — Pure charcoal, unmixed with 
any foreign body. It is antiseptic and 
absorbent ; useful as a poultice for putrid 
sores. 

Carditis. — Inflammation of the heart. 

Caries. — Ulceration or rottenness of a 
bone. 

Carminatives. — Medicines that connect 
flatulency, or expel wind ; the principal of 
these are the caraway and fennel seeds. 

Carotid Artery. — A large artery, that 
runs on each side of the neck, near the 
windpipe. The jugular vein runs immedi- 

* Morton's M.inual. 



ately over the artery. Yet at the upper p^'.rt 
of the neck they are at such a distance that 
there is no danger of wounding the latter in 
bleeding. 

Cartilage. — Gristle. A smooth, clastic 
substance attached to bones. Cartilages 
are situated in parts where elasticity is 
required ; they render the parts connected 
with them capable of slight changes of form, 
and instant recovery, to accommodate them- 
selves to accidents and circumstances, with- 
out serious injury to themselves. There are 
also inter-articular cartilages ; that is, flat, 
smootly cartilages, between the ends of two 
bones. These, being covered with synovia, 
or joint oU, serve to facilitate the motion of 
the joint. 

Castor. — A peculiar matter found in 
sacs, near the rectum of the beaver. It is 
used as an anti-spasmodic, in doses of two 
drachms (for a horse), mixed In thin gruel. 

Castration. — An operation often per- 
formed on horses, and other domestic ani- 
mals. The best method of performing it is 
by means of the clams, and ligature. 

Cataplasm, or Poultice. — This appli- 
cation, when designed to promote suppura- 
tion, or formation of matter, is best made 
by mixing together equal pcfrts of slippery 
elm and flax-seed, pouring a sufficient 
quantity of boiling water on the mixtiure, to 
make it of the consistence of mush, and 
binding it on the part ; the bandage should 
not be so tight as to interfere with the 
return of blood by the veins. A poultice 
should always be renewed every twelve 
hours. 

Cataract. — A disease of the horse's 
eye. A cataract may be partial or total. 
The partial cataract is known by s]iccks in 
the pupil, which interrupt vision in propor- 
tion to their size, and according to their 
situation. In the total or complete cata- 
ract, the whole of the pupil becomes of a 
white or pearl color. A horse's sight is least 
injured by partial cataract, when the speck 
is most remote from the centre of the pupil, 
and near to the upper margin. "When a 
complete cataract takes place in one eye, 
the streiiffTh of the other becomes estab- 



2?, -2 



A DICTIONARY. 



lished, so that the horse soon accommo- 
dates himself to the loss. 

Catarrh, or Cold. — This is, perhaps, a 
disorder more common in horses than any 
ot her. The author attributes some colds (in 
this cify) to the bountiful use of Cochituate 
water. When the liorse has just arrived 
from a journey, or is in a state of perspira- 
tion, Ihc showering process, so much in 
fashion just now, is decidedly injm-ious. If 
the legs of the animal are sluiced with water, 
and he is afterwards suffered to stand where 
a current of air blows on liira, he is likely to 
take cold. Horses accustomed ta warm 
clothing and warm stables are, of course, 
most liable to cold. The symptoms arc 
cough, dulness, want of appetite, discharge 
from the nostrils, frequently accompanied 
by sore throat and difficulty of swallowing. 

Catarrh, Epidemic. — The epidemic ca- 
tarrh is so named from its spreading over a 
country as a general disorder, often for a 
considerable time. When the disease is so 
prevalent, it is supposed to depend on a cer- 
tain state of the atmosphere. 

Catheter. — A gum elastic tube, for tlie 
purpose of di'awing off the urine. The one 
used for the horse is about four feet in 
length. 

Caustics. — Preparations that destroy 
the part to which they are applied. 

Cellular Membrane. — The substance 
by which various parts of the body are 
united to each other. The cells of which 
this structure is composed communicate 
with each other; which is proved by mak- 
ing a small opening in the skin of an ani- 
mal, introducing a blow-pipe,, and blowing 
through it, by which the adjacent skin will 
puff up ; if sufficient power were employed, 
the air may be thus forced all over the body. 

Cerebellum. — The small brain. It is 
situated immediately behind the cerebrum, 
or large brain, and upon the origin of the 
spinal marrow. 

Chest Founder. — (See Founder.) 

Chronic. — A term used to denote a dis- 
ease of long standing, unaccompanied by 
fever or inflammation. 

Chyle. — A milky fluid, formed by the 



action of the gastric, pancreatic, and bilious . 
fluids. Chyle is absorbed and carried by 
the lacteals to the thoracic duct; but, pre- 
vious to its arrival there, it passes through 
the mesenteric glands, where, probably, it 
undergoes some change. 

Cicatrix. — The mark that remains after 
a sore, wound, or ulcer has been healed. 

Circulation of the Blood. — (See 
Heart.) 

Clipping. — Cutting the long, rough hair 
of a horse. It is chiefly done to improve 
the appearance of the horse. The author 
doubts its utility. (See article Hair, part 
first.) 

Clothing. — A pernicious custom is 
often adopted of keeping horses clothed in 
the stable ; maldng no difl'erence in the 
warmth of the clothes, whatever the season 
of the year or the state of the weather may 
be. (This custom is not so prevalent here 
as in England.) In a good stable, it is 
probable that even in vrinter it miglit be dis- 
pensed witli ; and a horse will then be much 
less liable to take cold, when he happens to 
stand in a cold wind or rain. When a horse 
is moulting, or shedding his coat, light cloth- 
ing might be useful ; and, at such periods, 
showering, or standing out in the rain, 
would be very injurious. In summer, the 
horse should have a net thrown over him to 
protect him from the flies. 

Clysters, or Glysters. — A liquid 
preparation, forced into the rectum by means 
of a syringe. 

Coffin Bone, or Os Pedis. — The bono 
which is inclosed by the hoof 

Coffin Joint. — (Sec Hoof.) 

Colic — A very common disease in 
horses. It begins with an appearance of 
uneasiness; he paws his litter; sometimes 
makes ineffectual attempts to stale ; stamps 
with his feet; gathers up his legs, and lies 
down heavily ; groans, and looks round to 
his flank ; lies down heavily again, as before, 
and rolls on his back. The body sometimes 
swells. If relief is not promptly afforded, 
all the above symptoms gradually increase; 
the pulse becomes quick, the breathing dis- 
turbed, and the pain is so great that a vio- 



A DICTIOXARY. 



233 



lent perspiration breaks out, and the liorse 
becomes almost delirious, throwing himself 
about the stall, so that it is dangerous to 
come near him. 

Condition. — This term is used to imply 
a horse being in perfect health. 

Conjunctiva. — The external coat or 
membrane of the eye. (See Eye, part first.) 

Consumption. — In consumption there is 
a gradual loss of flesh and strength, while 
the appetite is seldom impaired in the early 
stages. It is sometimes accompanied by a 
discharge from one or both nostrils, and a 
swelling of the glands under the jaw ; such 
cases are often mistaken for glanders. Con- 
sumption does not often take place sud- 
denly, but is very insidious in its attack ; 
and it often happens, that the complaint is 
not much noticed till tubercles are formed 
in the lungs, and the mesenteric glands are 
diseased. When a horse is observed to lose 
flesh, his coat staring, his skin feeling as if 
fast to the ribs, he should be warmly 
clothed, and fed on scalded shorts, oats, and 
boiled carrots ; by proper attention to stable 
management, he may gain flesh and strength, 
his coat will become smoother, and his skin 
looser. Should it now be the season of the 
year when good grass can be procured, this 
will perfect the recovery. The best medi- 
cines are cod liver oil and phosphate of lime. 

Contagion. — The mode in which a dis- 
ease is communicated from one animal to 
another. It is derived from the word contact, 
or touch, and is used in conti-adistinction 
to infection, which implies the commu- 
nication of disease by unwholesome mias- 
mata, sometimes spreading to a very con- 
siderable distance. 

Convalescence. — A state of recovery 
from illness, or an approach to a state of 
health. 

Convulsions.- — Under this name, Gib- 
son has classed lockjaw and staggers. 
Modern writers treat of these diseases under 
their respective heads. Calves are subject 
to convulsive diseases, from indigestion, and 
the consequent formation of acid in the 
stomach. It is often occasioned by some 

30 



bad quality in the millc they drinlc, when 
fed by hand. Taking too much milk will 
often bring on the disorder. Carminatives 
and tonics generally alTord relief; after 
which, it is necessary to be more attentive 
to the futm'e mode of feeding, giving a little 
gruel occasionally. 

Cordials. — Medicines are thus termed 
that possess warm and stimulating proper- 
ties, such as ginger, caraway seeds, anise 
seeds, etc. 

Cornea. — The outer transparent part of 
the eye. 

Corner Teeth. — The outermost of the 
front teeth are thus named. 

Corns. — Corns generally appear at the in- 
ner angles of the fore feet, from injuries, etc. 

Coronet Bone. — Os corona. The sec- 
ond of the consolidated phalanges of the 
horse's foot. 

Coronet. — The u]iper part of the hoof, 
where the horn terminates. 

Corrosive Sublimate. — Among the 
poisons that are given, with a view of 
curing disease, corrosive sublimate seems to 
stand foremost in the destruction of vitality, 
and the production of incm-able diseases. 
Dr. White remarks : " It is necessary to 
observe carefully its effects ; for, whenever 
it takes off the appetite, or causes uneasi- 
ness of the stomach or bowels, it should be 
immediately discontinued. A solution of 
corrosive sublimate in water has been em- 
ployed as a lotion in mange, but is gener- 
ally considered dangerous ; a fatal disorder 
of the bowels having in several instances 
followed its use. Five cows, that were 
bathed with a solution of corrosive subli- 
mate in tobacco water, died soon after. 

Cough. — A cough is sometimes the first 
symptom of a cold, or catarrh ; but there 
is another kind of cough, which accompa- 
nies indigestion. Horses that eat too much 
hay, and drink a large quantity of water, 
often have chronic cough. This can be 
removed by proper attention to feeding. 

Cows, Disease of. — The disorders of 
cows are not so numerous as those of the 
horse ; they are often brought on by feeding 



234 



A DICTIOXAnY. 



on improper food, or by being kept on low, 
marshy grounds. Cattle that are brought 
from a warm to a colder climate, and such 
as are naturally of weak constitution, are 
most liable to disease. 

Cramp. — A spasmodic affection of the 
muscles, either of a particular part, or of the 
whole body. In lockjaw, for example, the 
muscles of the jaw are at first chiefly affect- 
ed ; but, gradually, unless relief is afforded, 
the spasm, or cramp, generally extends to 
the neck, limbs, and at length to all parts 
of the body. 

Crassamentum. — Red globules, or color- 
ing matter, of the blood, mixed with coagu- 
lable lymph. 

Cremaster. — A muscle which surrounds 
the spermatic cord, as it passes out of the 
belly into the scrotum. Its use is to sus- 
pend and draw up the testicle. 

Crib Biting. — A disagreeable and in- 
jurious habit, which some horses acquire ; 
it consists of laying hold of the manger 
with their teeth. It generally proceeds from 
indigestion. 

Cropping the Ears. — The ear may be 
inclosed between the two parts of a car- 
penter's rule, which can be adjusted and 
held so as to give the ear any shape that 
may be required. All that part outside the 
rule is then cut off" with one stroke of a 
sharp knife, and then bathed with tincture 
of myn-h. 

Crupper. — A strap affixed to the saddle, 
with a loop at the end, for the purpose of 
admitting the horse's tail. 

Cud. — The food contained in the first 
stomach, or rumen, of a ruminating animal, 
which is rettuned to the mouth to be chewed 
at the animal's leisure. 

Cumin Seeds. — A carminative, or cordial. 

Curb. — A swelling of the horse's hock, 
generally caused by blows or strain. 

Cutaneous Diseases. — Diseases whose 
seat is in the sldn, as the mange, for ex- 
ample. They are generally dependent on 
a vitiated state of the secretions, and a dis- 
ordered state of the bowels. 

Cuticle, or Scarf Skin. — A thin, in- 
sensible membrane, which covers and de- 



fends the true skin. It is this which forms 
the bladder raised by blistering. 

Cutis. — The skin, or hide, which lies 
under the cuticle. Besides the cuticle and 
skin, horses and other large animals have a 
muscular expansion, which lies immediately 
under the latter, called the fleshy pannicle, 
by which the skin is moved, so as to shake 
off" dust or flies, or anything that hangs 
loose upon the hair. 

Cutting. — A horse is said to cut, when 
he sti'ikes the inner and lower part of the 
fetlock joint, in travelling. The usual mode 
of correcting this, is to make the outer side 
of the shoe higher than the inside. 

Debility. — Debility may be permanent 
or temporary. In the first, the constitution 
is naturally weak, or has been rendered so 
by improper treatment, or sickness ; the 
second generally arises from over-exertion, 
and, if the exciting cause be frequently re- 
peated, terminates very commonly in a total 
decay of the constitution. Rest and kind 
treatment are the best cure for weakness in- 
duced by fatigue. The greatest attention 
should be paid to the degree of work that 
a horse is capable of enduring, as what 
may be salutary for him at one period may 
greatly exceed his strength at another; and 
this generally depends on the mode of sta- 
ble management. The common practice 
of working horses too early frequently 
results in debility. 

Decoction. — The process of extracting 
the virtues of a substance by boiling it in 
water. The liquid so prepared is termed 
decoction. Almost all the medicinal prop- 
erties of plants may be extracted by pour- 
ing boiling water over them. In boiling 
they lose their volatile properties. 

Deglutition. — The act of swallowing. 
The power of swallowing is often impeded 
in the horse by sore throat, distemper, etc. 
This impediment is only of a temporary 
nature ; but there is another, which is of a 
more serious kind, and interferes with mas- 
tication as well as with swallowing. The 
gi-inding teeth of horses often wear down 
in such a manner, that the outside edge of 
the upper grinders irritates or wounds the 



A DICTIONARY. 



235 



cheek, and the inside of the lower grinders 
acts siiniliiriy upon the tongue, or the skin 
connected with it. Whenever a horse is 
observed to void unbroken oats with his 
dung, the teeth and cliceks shoukl be ex- 
amhied. It will often be found necessary 
to rasp the outside edges of the upper 
grinders, and sometimes the inner edges of 
the lower ones. 

Dejiulcf.nts. — Medicines of a mucila- 
ginous kind, which sheath the mucous 
membranes when they are tender and irri- 
table, and defend them from the action of 
what would otherwise injure them. Of 
this kind are marsh mallows, linseed tea, 
solution of gum arable. 

Dextitiox. — The act of changing the 
teeth, wliich is going on from the second to 
the fifth year. During this period, the horse's 
mouth is apt to become tender, which ren- 
ders it necessary to keep him for a short 
time on scalded shorts, or boiled carrots. 

Diabetes. — An excessive discharge of 
urine, accompanied by thirst and debility. 
There are three outlets for the fluids of the 
body, — the surface, the lungs, and the 
urinary passage. When either is deficient 
in action, one or both of the others must 
make up that deficiency ; so, excess in one 
produces deficiency in the others ; hence, in 
diabetes we often find a dry sldn and stare- 
ing coat; and in excessive perspiration, the 
urine is scanty, whatever be the organs 
all'ected or whether the one or the other be 
excessive or diminished. The indications 
are, to equalize the action of these opposing 
or sympathizing surfaces, by restoring the 
diminished secretions, and cleansing and 
toning the organ whose action is excessive. 
All direct efforts to produce specihc effects, 
without regard to a balance of action 
through tiie whole animal, do more harm 
than good. 

Diaphoretics. — Medicines that promote 
insensible perspiration, or excite moderate 
sweating. Of this class are lobelia and 
emetics, given in infusion. 

Diaphragm, Midriff, or Skirt. — A mus- 
cular and tendinous expansion, which divides 



the cavity of the chest from the abdomen, 
or belly. 

Diarrhcea, or Purging. — In Professor 
Percivall's lectures on diarrhcea, he states 
that, " for the majority of cases brought to 
us, we are indebted to the gi-oom, the far- 
rier, and stable-keeper, who used to kill 
many horses by literally purghig them to 
death. Thirty years ago, an ounce and a 
half or two ounces of aloes, occasionally 
combined with one or two drachms of 
calomel, composed the common purge ; and 
even now, among these people, nine, ten, 
and eleven drachms are by no means un- 
usual doses. Young horses, on their first 
arrival in the metropolis, are all physicked ; 
they have given to them, indiscriminately, 
doses of aloes, every one of which would 
be sufficient to purge two of them ; the re- 
sult is, that the light-carcassed, irritable 
subject is carried off at once by superpurga- 
tion, while another, or two, may linger in 
misery and pain from a dysentery that will 
end in gangrene and death, or be rendered 
more speedily fatal by the doses of opium, 
or some other powerful astringent, which 
are so perniciously resorted to on these 
occasions. There is another not uncommon 
cause of this disease, and that is, continuous 
and excessive exertion. After having been 
ridden for many hours, a horse will often 
express irritation in the bowels, by fre- 
quently voiding his excrement, which will 
be found to be enveloped in a slimy or 
mucous matter, that is called by some 
molten grease." 

Dilutents. — Those substances that in- 
crease the fluidity of the animal economy. 
Water may be justly considered as the only 
dilutent. 

Director. — A grooved instrument, made 
for the purpose of conducting the knife in 
opeuiug sinuses and in several other opera- 
tions of surgery. 

Dislocation. — A displacement of a 
bone from its socket. A dislocation of the 
fetlock joint may be replaced, and kept in 
its position by bandages ; the horse should 
not take any exercise until it is completely 



£36 



A DICTIONARY. 



healed. A dislocation of the stiBc, or 
patella, must be reduced by bringing the 
horse's leg under the belly, and then depress- 
ing the outer angle of the patella, or stifie 
bone, with the hand, which gives the 
muscles the power to draw the bone into its 
place. Generally speaking, dislocations are 
rare. 

Distemper. — This name is applied to 
diseases that prevail at particular periods, 
and spread to a considerable distance. 
(See Epidemic.) 

Docking. — Cutting ofF part of the tail. 
If this is ever necessary (and the author 
doubts it), then the operation should be 
performed before the animal is two years 
old. 

Drastic. — A term applied to purgatives 
that operate powerfully. 

Drenches, or Drinks. — When it is 
necessary that any medicine should operate 
speedily, this is the best form in which it 
can be given. A bottle with a short neck is 
the best drenching instrument. In giving a 
drench, the tongue should be at liberty, the 
head moderately elevated ; the ckench is 
then poured down moderately. The head 
is to be kept in an elevated position until 
the drench is swallowed. If the animal 
happens to cough while the drench is in his 
throat, the head should be immediately let 
down. 

Dressing. — A term employed to desig- 
nate medical applications to a wound, or 
ulcer, and the operation of cleaning a horse. 

Dropsy. — This disease consists in a col- 
lection of serous or watery fluid, either in 
cavities, as the chest, belly, or ventricles of 
the brain, or in the cellular membrane under 
the skin. Dropsy is more a symptom of 
disease than a disease itself; but some- 
times, on account of the violence and danger 
of the symptom, it is often treated as a 
disease. The proximate cause is a check to 
perspiration ; the remote cause is bleeding, 
or any thing that can debilitate the general 
system. 

DnopsY OF the Chest. — This is some- 
times a consequence of disease of the lungs ; 
and, when it happens, those important 



organs generally are so far disorganized, or 
injured, that there is very little chance of the 
animal's recovery. 

Dropsy of the Belly, or Ascites. — - 
The causes are the same as above ; the only 
difference is, that, from circumstances pre- 
disposing, the fluid is determined on the 
peritoneum (see Peritoneum) instead of 
the pleura. 

Duct. — A membranous tube, or canal, 
through which certain fluids are conveyed. 
Thus the lachrymal duct conveys tears friim 
the eyes to the nose. 

Dung. — By examining a horse's dung, 
we are enabled to judge of the state of his 
health. When the dung is hard, and in 
small knobs, and covered with slime, laxa- 
tive medicines are beneficial ; and when it 
is passed in too great (luantities, it com- 
monly arises from too liberal allowance of 
food. If oats are voided whole, it will 
generally be found to be caused cither 
by a defect of the teeth, or by a too 
voracious appetite, occasioning the food 
to be swallowed without mastication ; in 
Vvdiich case the animal should be fed on 
shorts, or scalded food. 

Duodenum. — The first intestine that 
comes from the stomach. (See Intes- 
tines.) 

Dura Mater. — A strong membrane that 
invests the brain and divides it into two 
lobes. It likewise separates the large brain 
(cerebrum) from the small, or cerebellum. 

Ear. — The horse's ear is merely an organ 
for collecting sound; consequently he has 
complete power over the muscles attached 
to them, and can turn them in dilTcrent 
directions. 

Effluvia. — Invisible vapors that arise 
from bodies. 

Effusion. — The oozing out of serum, or 
coagulahic lymph, from the blood-vessels. 

Embrocation. — A liquid preparation for 
rubbing upon the skin, and generally used 
for strains, bruises, and enlarged glands. 

Embryotomy.* — "When, from weakness, 
a very narrow pelvic opening on the fore part 
of the mother, or monstrosity on the part of 
* Blaine. 



A DICTIONARY. 



the foal, no efforts can bring the foetal mass 
away entire, it must be dismembered. A 
Icnife made for the pm-pose, having the blade 
concealed, with the haft lying within the 
hollow of the hand, is to be taken up into 
the vagina. We are told that, occasion- 
ally, hydrocephalus in the colt prevents 
the head from passing. Such a case 
will detect itself by the volume that will 
be felt on examination, and which will 
be easily lessened by plunging the point of 
the knife in the forehead, and evacuating the 
contents by pressing the skull in ; when, 
laying hold of the muzzle, the head may be 
brought through the pelvic opening. But it 
is usually the natural size of the head which 
forms the obstruction; in which case the 
head itself must be removed. When the 
head has been dissected oil' and brought 
av\"ay, it will be necessary probably to con- 
tract the volume of the chest; which will 
not be difficult, by cutting the cartilaginous 
portions of the ribs, detaching the thoracic 
viscera, and then crushing, or rather mould- 
ing, the empty thorax together ; after which 
the rest of the body will offer little obstruc- 
tion. When the head cannot be got at, the 
limbs must, one by one, be detached : after 
which the body, and at last the head, may 
be drawn out either entire, or lessened con- 
siderably. 
' Emetic, Tartar. — Tartarized antimony. | 
A corrosive metalhc poison. Dr. White 
relates: " From examining the stomachs of 
horses that have taken this mineral, I am 
satisfied that irreparable mischief may be 
done with it, and certain it is that a vast 
deal of unnecessary pain has been thus 
inflicted."' 

Emphysejia. — Swellings which contain 
air. Such swellings are known by a kind of 
crackUng noise, or sensation, when they are 
pressed with the finger. 

Emulgext Arteries. — The arteries 
which convey blood to the kidneys. 

Encaxtiiis. — A disease of the inner 
corner of the eye. 

Encysted. — A term applied to tumors 
which consist of a solid or liquid substance, 
contained in a sac, or cyst. 



Enteritis. — Inflammation of the bowels. 
This is a very serious form of disease, and is 
the result of plethora, or the sudden applica- 
tion of cold to the surface. It is sometimes 
owing to an overloaded state of the stom- 
ach and bowels. Obstinate spasm will also 
produce it. 

Epidemic. — Diseases which spread over a 
whole country, at certain seasons, are thus 
named. If many suffer in the same manner, 
it is called epizootic. There are very few 
diseases which assume, in its latter or earlier 
stages, such a variety of forms ; perhaps 
depending on the location, and the pecuhar 
state of the constitution. Youatt v.'rites : 
" In 1711, an epidemic commenced, which, 
although it sometimes suspended its ravages, 
would visit new districts ; it also appeared 
in a certain distiict, and confined itself to 
that location. In 1747, it appeared, and 
would seem as if there was a strange caprice 
about it. It would select its victims, the 
best of the herd, around a certain district, 
and confine itself to that location for a short 
time ; then disappear for several months, 
return, and pounce itpon this privileged spot. 
In some districts, it would attack the mouth 
and throat ; commencing with a loss of 
appetite and difficult respiration, terminat- 
ing with a discharge of blood from the 
anus. Sometimes the animals will cat and 
work until they suddenly expire ; others will 
linger in dreadful agony." It appears that 
this malady is not infectious ; for the same 
author ^\Tites: " Cattle were in the same 
barn as those infected ; they ate of the same 
fodder that the distempered beasts had 
slavered upon, di-ank after them, and con- 
stantly received their breath and odor, 
without being the least affected. In 1756, 
it assumed a different form ; some cattle 
were taken all at once with violent trem- 
bling of every limb, and blood ran from the 
nose, and bloody slime from the mouth, and 
the animals died in a few hours." 

Epiglottis.- — The cartilage which covers 
the larynx, or top of the v.'indpipe, at the 
time food or water is passing into the gullet. 

Epilepsy. — The falling sickness; fits. 
Horses, cats, and dogs are subject to fits, 



236 



A DICTIONARY. 



which often depend upon an accumulation 
of water in the ventricles of the brain, or 
upon the irritation of worms in the stomach 
or bowels. During the present year, the 
author's attention was called to a horse, 
(the property of Mr. Downs, of this city ;) 
the horse was lying down, and at times 
appeared insensible ; convulsive struggling 
would take place occasionally. The mus- 
cles of the eye were afl'ected by spasm, and 
distorted ; the duration of the fit varied. 
As the disease progressed, the hind extremi- 
ties were paralyzed, and the horse would 
struggle violently at intervals of fifteen 
minutes. On an examination, after death, 
nearly a peck-measure-full of the long round 
worm was found in the small intestines. 
The author examined the brain of a horse 
that was said to die in a fit, and found about 
five ounces of water in the ventricles of the 
brain. These fits in horses do not exactly 
resemble those occurring in man. 

Epistaxis. — Bleeding at the nose. This 
sometimes occurs in glanders, and denotes 
a considerable ulceration within the nostrils. 
When it happens to a horse in health, it 
shows an unequal circulation of the blood. 

Epsom Salts. — Sulphate of magnesia. 
A neutral salt, often employed as an aperi- 
ent for cattle ; but it is very uncertain in 
horses, and is apt to gripe them. 

Eschar. — A slough formed by the appli- 
cation of caustic. 

Excrescence. — Any preternatural for- 
mation on any part of the body, as warts, 
wens, etc. 

Exostosis. — An osseous tumor originat- 
ing from a bone ; such as splent, spavin, 
ringbone, etc. Perhaps no animal is more 
subject to this disease than the horse ; and 
in no department of the veterinary science 
is there a greater need of reform than in the 
treatment of the disease now under con- 
sideration. Almost every man who knows 
anything about a horse can detect a 
spavin, etc. ; but not one in a hundred can 
tell anything about the true nature of the 
malady, or the indications to be fulfilled in 
the treatment ; and in consequence of a lack 
of knowledge on this subject many a poor 



animal has suffered immensely, who, if he 
was not deprived of the power of speech, 
would make the ears of his oppressors tingle 
with a tale of man's barbarity and inconsis- 
tency. 

The bony structure, being composed of 
vital solids, although studded with crystal- 
lizations of saline carbonates and phos- 
phates, is liable, like other parts of the struc- 
ture, to take on preternatural or morbid 
action, and may result from or accompany 
constitutional idiosyncrasies, resulting from 
hereditary taints on the side of the dam or 
stallion. The most frequent causes of 
splent, spavin, etc., are undue acts of exer- 
tion on hard pavements, and the imposition 
of weight disproportioned to the strength of 
the animal: young horses are particularly 
liable to exostosis when severely worked or 
over-burdened. Any sudden or extraordi- 
nary efforts in backing or suddenly pulling 
up at full speed, racing before the horse shall 
have arrived at maturity, while the joints 
are yet in a state of imperfection, very fre- 
quently lay the foundation of exostosis. 
The parts being sprained and taxed beyond 
endurance, disease is excited in the liga- 
mentous substance, and extendsitself to the 
periosteum and bones ; the ligaments often 
become ossified, and are rendered fixtures ; 
the periosteum, being raised by bony ac- 
cumulations, presents itself in the situation 
of splents, spavin, or ringbone. 

Sir A. Cooper divides exostosis, in refer- 
ence to its seat, into two kinds, periosteal 
and medullary ; and again, as to its nature, 
into cartilaginous and fungous. " But," 
says Mr. Percivall, " it is to that kind only 
which is situated between the shell of the 
bone and the periosteum covering it, tliat 
we have to attend in veterinary practice. 
On dissection we find the periosteum thicker 
than usual, with cartilage beneath it, and 
ossific matter within the cartilage, extend- 
ing from the shell of the bone nearly to the 
internal surface of the periosteum, still 
leaving on the surface of the swelling a thin 
portion of cartilage unossified." 

When the accretion of these sweUings 
ceases, and the disease has been of long 



A DICTIONARY. 



239 



standing, ihey are found to consist on theiv 
exterior sm-face, of a hell of osseous matter 
similar to that of the original bone ; conse- 
quently, when an exostosis has been formed 
in the manner here described, the shell of 
the original bone becomes absorbed, and 
cancelii are desposited in its place. 

" In the mean time, the outer surface of 
the exostosis acquires a shell resembling 
that of the bone itself. When the exostosis 
has been steeped in an acid, and by this 
means deprived of its phosphate of lime, 
the cartilaginous structure remains of the 
same form and magnitude as the diseased 
deposits ; and, as far as I have been able to 
discover, it is effused precisely in the same 
manner as healthy bone. 

" An exostosis, abstractedly considered, 
does not appear to occasion much incon- 
venience to the animal, except in the early 
stages. A ringbone, confined to the pastern 
bones, is of little consideration ; but, should 
it show itself at or near the joint, it seldom 
fails to produce lameness, which is often of 
a permanent nature. Lameness, therefore, 
is not an invariable symptom of exostosis ; 
for most splents, and many ringbones, and 
even spavins, exist without lameness. 
"When this disease invades ligamentous 
structure, however, lameness generally ac- 
companies it, — an effect we would refer to 
the excessive tenderness of the part. Should 
the tumor interfere, either from its bulli or 
situation, with the motions of joints, mus- 
cles, or tendons, lameness is a concomitant, 
and often irremediable, symptom." 

It appears that various constitutional and 
local remedies have been tried for the pre- 
vention and dispersion of exostosis, viz., 
" the acttial cautery, ammonia, cantharides, 
caustic, and setons." The constitutional 
remedies are of the same destmctivc nature, 
and have but too often aggravated that 
which they were intended to relieve : we do 
not believe that any specific ti'eatment has 
ever had the honor of cming these forms of 
disease ; that course of treatment we have 
ever found the most satisfactory that is cal- 
culated to promote the general health by 
sanative means; we cleanse the system, 



equalize the circulation, and excite healthy 
action to the parts by stimulants and coun- 
ter-irritation (if the parts are inactive) ; 
poultices, fomentations, etc., if there is pain, 
or increased action. If this is done early, 
exostosis is easily arrested, unless an hered- 
itary taint is manifest. 

The removal of exostosis by an operation, 
we are told, has been performed with suc- 
cess, and no doubt there are cases in which 
it may safely be performed ; yet it cannot 
be successful on spavined horses, the nat- 
ural termination of spavin being anchylosis 
of the bones of the hock and inter-articular 
cartilage. A knowledge of this fact has led 
men to suppose that Nature has turned a 
summerset ; and they endeavor to set her 
right with the firing iron and the imple- 
ments of death ; whereas, if her intentions 
were aided, the result would prove more 
satisfactory. 

Extravasation. — The escape of blood 
or other fluids from their proper vessels. 

Eve. — (See part first.) 

Falling of the Yard or Penis. — This 
disease sometimes happens to horses and 
bulls, in consequence of swellmg, excres- 
cence, and ulceration of the ' parts, some- 
times of an obstinate or malignant nature. 
It may also be occasioned by too frequent 
sexual intercourse. It may also depend on 
weakness of the part ; and, when this is the 
case, there is no ulceration nor excrescence 
about it. If it depend on debUity, then 
tone up the whole animal, and wash the 
parts, first with castile soap, then with cold 
water. K it result from ulceration, wash 
with weak vinegar and water, afterwards 
with a mixture of powdered charcoal and 
water. The latter may be thrown up the 
sheath with a common syringe or injection 
pipe. AVhen the ulcers show a disposition 
to heal, a little powdered bayberry bark 
will generally complete the cure. When 
excrescences form on the sheath or inside 
of it, they should be taken off by applying 
a ligature tight around their base. 

False Quarter. — This can hardly be 
considered as a distinct complaint, but, 
more properly, as a consequence resulting 



240 



A DICTIOyART. 



from some one of the former diseases ; in 
which, from, the injury done to the coronary 
vascular ligament, it can never afterwards 
secrete horn ; but the break or interruption, 
produced by the interposition of a portion 
of non-secreting substance, causes a part of 
the outer crust of the wall to be absent. 
Such a blemish is called z. false quarter; 
and it is evident that it must greatly tend 
to weaken the hoof. It likewise sometimes 
produces the same unpleasant effects as a 
sand-crack, by the separation of the under 
layer of the wall admitting the vascular 
laminffi between the opening. The treat- 
ment can be only palliative. Keep the neigh- 
boring horn always thin : use a bar shoe, 
and " lay off" (as a smith calls it) the de- 
ficient quarter. This may be done either 
by paring the crust, or by an indentation in 
the shoe ; the choice of which is left to the 
prudence of the operator, with this excep- 
tion, that, in a weak^thin foot, the alteration 
should always be made in the shoe, and in 
a strong one, in the crust. 

Farcy. — A disease of the lymphatics or 
absorbent vessels. Its most usual form is 
that of small tumors, or huds^ as they arc 
termed, which make their appearance in 
different parts of the surface, gradually be- 
come soft, or suppvuratc, and burst, and be- 
come a foul ulcer. Its cause may be found 
in anything that will derange the general 
system, or produce debility ; its proximate 
cause is immoderate work, inattention to 
diet, hot unhealthy stables, sudden changes 
of temperature, standing on filthy litter, etc. 
• Fauces. — That part of the throat which 
lies behind the tongue. 

Femoral Artery. — The principal ar- 
tery of the thigh. 

Femur, or Os Femoris. — The thigh bone. 

Fetlock. — A lock of hair at the lower 
part of the fore and hind legs. 

I'^EVER is a powerful effort of the vital 
principle to remove all obsti-uctions to or- 
dinary and proper action. The reason why 
veterinary practitioners have not ascertained 
this fact heretofore, is, because they have 
been guided by the false principle that/ei>er 
15 disease. Let them but receive the truth 



of the definition we have given, then the 
light will begin to shine, and medical dark- 
ner<s will be rendered more visible. 

Fever, as we have said, is an effort of the 
vital power to regain its equilibrium of 
action through the system, and should never 
be subdued by the use of agents that de- 
prive the organs of the power to produce it. 
Fever will be generally manifested in one 
or more of that combination of signs com- 
monly given as a description of fever, viz : 
increased velocity of the pulse, heat, red- 
ness, pain and swelling, thirst, obstructed 
sm'face, etc., some of which will be present, 
local or general, in greater or less degree, in 
all forms of disease. In what is called 
acute attacks these signs are very manifest : 
in chronic cases, they are often faint ; but 
still they exist. When an animal has taken 
cold, and there is power enough in the sys- 
tem to keep up a continual warfare against 
obstructions, the disturbance of vital action 
being unbroken, the fever is called pure, or 
unbroken. The powers of the system may 
become exhausted by efforts at relief, and 
the fever will be periodically reduced : this 
form of fever is called remittent. It would 
be as absurd to expect that the most accu- 
rate definition of fever would correspond, in 
all its details, with another case, as to ex- 
pect all animals to be alike. 

There are many agents that obstruct 
vital action, and many an organ to be 
obstructed, which some have classed as dis- 
tinct fevers ; for example, milk fever, puer- 
peral fever, symptomatic, typhus, inflamma- 
tory, etc. Our system teaches us that there 
is but one cause of fever, viz., the natural 
motive power of the system, and but one 
fever itself, viz., accumulated vital action ; 
hence the treatment must be physiological. 

Veterinary Surgeon Percivall,in an article 
on fever, says : " We have no more reason, 
nor not near so much, to give fever a habita- 
tion in the abdomen, as we have to enthrone 
it in the head ; but it would appear, from 
the full range of observation, that no part 
of the body can be said to be insusceptible 
of inflammation [local fever] in hmnan 
fever, though, at the same time, no organ is 



A DICXIOKAKV. 



241 



invariably or exclusively affected. All I 
wish to contend for is, that both idiopathic 
and svniptomatic fevers exhibit the same 
form, character, and species, and the same 
general means of cure ; and that, were it 
not for the local affection, it would be 
difficult or impossible to distinguish them. 
When we come to examine the accounts 
of different authors on fever, and compare 
them one with another, we can hardly re- 
frain from coming to the conclusion that 
their descriptions were originally derived 
from human medicine, and have been but 
variously modified to suit the prevailing 
doctrines of the day; they have gone through 
a system of imaginary fevers, and regularly 
transferred the observations and language 
of ancient authors upon diseases of the 
human species to the constitution of quad- 
rupeds." 

In the treatment of disease, and when 
fever is present, manifested by a determina- 
tion of blood to the head, the object is to 
invite the blood downward and outward; 
or, in other words, equalize the circulation 
by warmth and moisture externally, as in 
lockjaw. 

In neat cattle, should fever be present, 
the eyes appear dull and watery, the muzzle 
dry, and rumination has ceased; then the 
blood, for want of room in the nutritive tis- 
sues, is forced upon the lungs, liver, spleen, 
brain, or other glandular tissues, and men 
have named the disease congestive fever. 
The author advises the reader not to feel 
alarmed about the fever, but set to worU 
and relieve the congestion. Disease of the 
bowels, garget of the teats and udder, will 
requhre fomentation and stimulants to the 
parts. 

FiLLV. — A name given to a marc until 
she is two or three years old. 

Film. — Opacity of the cornea. 

Filtration. — Straining liquids through 
unsized paper ; also through sand or porous 
stone. 

Firing. — A severe operation, often per- 
formed on horses, for spavins, cu^bs, ring- 
bones, etc. Such barbarity should never be 
practised : it is a disgrace to this age of im- 

31 



provemcnt. When discoveries are leaping 
on discoveries, and medical reform has ger- 
minated, shall we not |)ermit tiie poor dumb 
brute to share the benefits of our investiga- 
tion ? Every man who loves a horse, or 
wishes well to the cause of horse-manity,v>ill 
say that a more safe and effectual system of 
veteruiary practice is necessary to rescue 
from the torture of the firing iron one of the 
noblest and most valuable quadrupeds in 
the world. 

" The rage of firing is very genen.lly, and 
much too frequently, adopted, and no doubt 
upon most occasions, humed on by the 
pecuniary propensity and dictation of the 
interested operator, anxious to display his 
dexterity, or, as Scrub says, 'his newest 
ffourish ' in the operation ; and when per- 
formed, and the horse is turned out to grass, 
if taken up sound, I shall ever attribute 
much more of the cure to that grand speci- 
fic, rest, than to the effects of his fire." 
(See Taplin's Farriery, p. S3.) Hence the 
firing iron, like all other destructive agents, 
excites the system to rally her powers and 
resist the encroachments of disease ; yet the 
process is like taking a citadel by storm ; 
the breaches that are made by the weapons 
of warfare (such as the firing iron, scalpel, 
lancet, and poison) can be traced, and leave 
unmistakable evidences of their encroach- 
ments. Instead of provoking the vital 
powers to action by such destructive en- 
ginery, we should afford Natiire all the aid 
we can, but never interfere with her opera- 
tions. 

FisTui-A OF THE Withers. — "An ob- 
stinate disease of the horse's withers, or 
points of the shoulder, commonly produced 
by a bruise of the saddle." No wonder 
Dr. White calls it "obstinate," when the 
following treatment is recommended by 
hhn: "The scalding mixture — it consists 
of any fixed oil (as lamp or train oil), spirit 
of turpentine, verdigris, and corrosive sub- 
limate. These are |)ut into an iron ladle, 
and made nearly boifing hot ; and in this 
state the mixture is to be applied to the 
diseased parts, by means of a little tow 
fastened to the end of a .stick I It is ncces- 



242 



A PICTIOXARY. 



sary to prevent the raLxture from flowing 
over the sound parts, as it would not only 
take off the hau-, but cause ulceration of the 
skin." If this mixture will produce diseased 
action in the sound parts, we need not ask 
what will be tlic result when applied to 
parts already diseased. The author has 
cured many cases of fistula, by treating 
them aa common abscesses, with the appli- 
cation of stimulating antiseptic and tonic 
poultices (see Poultices), and by a puri- 
fying course of treatment, with proper 
attention to diet, etc. 

Fleam. — An instrument with which 
horses and cattle are bled. 

Flesh. — A common name for tlie mus- 
cles of the body. 

Flexor. — The flexors are those that 
bend one bone upon another. The tendons 
that serve to bend the log, for example, are 
named flexors. 

FoALixc. — The bringing forth young in 
mares is not so often attended with difTiculty 
as in cows, and they have seldom occasion 
for assistance. They should be placed in a 
situation where they may have shelter, and 
where they are free from danger. 

Fomentations. — Fomentations are gen- 
erally made by pouring boiling water on 
camomiles, burdock, poplar bark, etc. For 
an emollient fomentation, ground slippery 
elm is preferred. In inflammation of the 
bowels, for example, the parts may be 
fomented w"ith flannels wrung out in a thin 
mixture of slippery elm. 

Foot. — (See part first.) 

Foot Rot. — This name is applied to a 
disease in the feet of sheep. This disease 
often happens to such as are fed in low 
meadows, or where the grass holds the frost 
or cold dews for a considerable time. Prob- 
ably a foul habit of body may be a predis- 
jjosing cause. In the treatment of foot rot, 
we should endeavor to find out the cause, 
or causes, of the disorder, and change the 
food or location of the sheep. If the disease 
has spread under the horny covering, aU the 
superfluous horn should be carefully pared 
away, so that the dressing may be applied 
to the whole of the atl'ected parts. The 



dressing is composed of powdered lobelia, 
formed to the consistence of paste, with 
honey. 

Foul Feedehs. — Horses are so named 
that have depraved or vitiated appetites, 
eating foul litter and earth from the ground. 

Founder. — A term expressive of the dif- 
ferent forms of rheumatism and ruin in the 
horse. • Veterinary writers describe three dif- 
ferent forms of this diseas-c, viz., founder of 
the body, chest, and feet. This is one andthc 
same disease, only located in different parts, 
and may arise from the same general causes; 
which consist in chilling the animal when 
exhausted, by which means the persphation 
is obstructed, by much fatigue, and by vio- 
lent and long-continued exertion : exposing 
the animal to cold wind or rain, or washing 
his legs and thighs, and sometimes his body, 
is often the cause of founder. Dr. White 
calls " founder, a term expressive of the 
ruined state of the horse." And well he 
might call it "rained." Hov»^ many thou- 
sand animals have been ruined, not by the 
disease, but by the treatment 1 Here is a 
specimen of it. Dr. White says : " The 
horse ^vas bled before I saw him : five quarts 
of blood were taken off. I desired he might 
be bled again, when half a pailful more was 
abstracted. In less than an houu" I saw him 
again, and, finding that he was not relieved, 
took another half-pailful, amounting in all 
to four gallons ! The horse was sent home, 
and seemed to be doing well in a straw yard, 
though very weak and thin. [ No wonder, 
after such a loss sustained by the vital 
powers. ] At the end of three or four months 
he began to lose his fore hoofs, and, after de- 
clining some time longer, he died" — a 
victim to science. It is evident, from expe- 
rience and facts, that the above treatment 
renders the disease incurable, and is the true 
cause of death ; therefore, not suitable to 
the true ends to be accomplished. Whav. 
then, are the true ends to be accomplished'.' 
To relax muscular structure, determine 
action to the surface, impi„- . e the secretions, 
and remove obstruct ;ns which disturb or 
repel vital action. Ti 's wil' --qualize the 
civ'Milatior> of the blocd, xvhen it iri/l he 



A DICTIONARY. 



243 



found tlinl there icill he no necessiti/ for 
dimini.'i/iiii^- ils (juanfiti/. The inilaiuma- 
tion, as it is termed, is always sufficiently 
controlled when the circulation of the blood 
is free and universal. Therefore, instead of 
■vithdrawing vital action, promote its equal 
.lud universal difiusion. 

Frog. — The posterior part of the horse's 
foot. 

Galbaxum. — A gum resin, sometimes 
employed as an expectorant and anti-spas- 
modic ; the dose, three or four drachms. It 
is used, also, in the composition of \varra 
adhesive ]ilasters, such as gum and diachy- 
lon plaster. 

Gai.i.. — A common name for bile. 

Gai.i,. — A sore produced by pressure, or 
chafing, of the saddle or harness. 

Gall Bladdcr. — The horse has no gall 
bladder, or reservoir for bile. A consider- 
able quantity of bile, however, is formed by 
tlie horse's liver, and is conveyed by the 
hepatic duct into the first intestine, or duo- 
denum. In the cow and sheep, the gall 
bladder is of considerable size. 

Ga.xglio.v. — This term is applied to a 
natural enlargement, or knot, in the course 
of some of the nerves. 

(taxgrene. — An incipiejit moiiiiication. 
In this stage of the disease, there is gener- 
ally absence of pain; the part is deprived 
of vital force, by causes inducing a loss of 
tone. 

Garlic. — It operates upon the horse as 
a diffusible stimulant and expectorant ; 
possessing, also, diuretic properties. The 
author considers garlic a valuable remedial 
agent in the treatment of any disease where 
the constitution has suffered through hard 
work, or ill usage. It is a general custom, 
on the eastern coast of China, to allow cattle 
to eat as much as they choose. They are 
never known to suffer any inconvenience 
from it ; on the contrary, they appear to 
thrive, and are scarcely if ever sick. The 
only objection to its long-continued use in 
cattle is, that it imparts an unpleasant flavor 
to tlie meat It is considered by Gibson to 
be a valuable remedy in coughs. He advises 
two OS three of the cloves or kernels, cut 



small, to be given in each leod, and observes 
that, by continuing this practice, with riglit 
and well-timed exercise and careful feedino', 
he has known many horses to recover, even 
when there has been a suspicion of their 
wind. 

Gastric Juice. — A juice formed in the 
stomach for the purpose of digestion. 

Gastritis. — Inflammation of the stom- 
ach. 

Gau.nt-Bellied. — A term applied to a 
horse when he is drawn up in the flank. 

Gelatine. — A component part of ani- 
mal matter. 

Gelding. — A castrated horse. Such 
horses are not so vigorous as stallions ; the 
latter are freer from disease than geldings, 
and will do more work, and keep a better 
appearance, as to coat and flesh, upon the 
same quantity of food. 

Gentian Root. — A good tonic for a 
horse : the dose is two or three drachms. 

Gestation. — Being with young. The 
time of gestation in the mare is eleven 
months; in the cow, nine months. 

Ginger. — An aromatic root, possessing 
stimulant and carminative properties. 

Glanders. — A contagious disease pecu- 
liar to the horse, the ass, and the mule. 
Many persons suppose that glanders and 
farcy are the effect of a specific poison in 
the blood ; but tliis theory is exploded. 
The following will throw some light on the 
subject, for which we are indebted to R. 
Vines, V. S. : " All the symptoms of disease 
which constitute glanders and farcy invari- 
ably depend on the unhealthy state of the 
system into which it is reduced or brought, 
and not, as is supposed, from a specific 
poison contained in the blood; and these 
symptoms of disease are found to depend 
on, and arise from, a variety of causes; 
whether they occur at the latter states or 
stages of common inflammatory diseases, 
such as strangles, common cold, distemper, 
disease of the lungs, dropsy, etc., or whether 
they arise independently of such causes ; 
for, when the system is brought into an un- 
healthy state, and is more or less debilitatet^ 
from neglect, or by the impropei 'i-.i 



214 



A DICTIONARY. 



of any of these diseases, [many of them are 
improperly treated], farcy, or glanders, is 
the result. The disease of every animal 
will, therefore, assume a character accord- 
ing to the state of the system." Mr. Perci- 
vall, V. S., says : " The state of the body, or 
constitution, will always have considerable 
inliuence on the character and tendency of 
disease. In horses whose bodies are, and 
have long been, in an unthriving and un- 
healthy condition, a common swollen leg 
will occasionally run into farcy ; and a com- 
mon cold or strangles, or an attack of influ- 
enza, be followed by glanders. In other 
cases, such unfortunate sequels will super- 
vene without any ostensible or discoverable 
cause." The great fault of those who have 
employed their talents in the investigation 
of the subject (glanders) is, that they take 
hold of the wrong end of it : they are 
engaged in attempting to discover the 
" specific poison," where none exists, when 
their time would be more profitably engaged 
in studying the principles of a system of 
medication that would rid the system of 
these early exciting causes, viz., common 
colds, etc., and thus prevent this great bug- 
bear, glanders. The author can at any 
time, within a period of a few months, and 
without the assistance of " specific poison," 
manufacture a case of genuine glanders out 
of the following materials : A horsewould 
be selected — and many such could be found 
in the city of Boston — whose general health 
shall be impaired ; let the surface be ob- 
structed by standing in a shower of rain, 
v>-ithout anything to protect the animal 
from the pelting storm ; then put him into 
a stall n«ar the door, where a cuiTont of 
cold air will pass the hind extremities : he 
remains in this situation during the night. 
On the following morning, the animal ap- 
pears dull, and is off his feed. It is soon 
ascertained that he has taken cold ; now 
treat him according to the kill-or-cure prac- 
tice : " If there is difficulty of breathing, and 
the throat is sore, — or, in other words, the 
usual symptoms, — the first thing to be 
done is, to ble<'d largely, until the horse 
faints. He sliould then be put into a cool 



place. It is often necessary to rejieat the 
bleeding two or three times. If the throat is 
very sore, blister the part." (See CantiiaU- 
iDES.) The secretions now become im- 
paired, there is loss of appetite, the coat 
stares ; there is a dull, sleepy appearance 
about the animal ; the discharge from the 
nostrils now assumes an acrimonious and 
putrid character, which, acting chemically 
on the membrane of the nose, constitutes 
ulceration : the latter corrode the cartilage 
and bones, and glanders is the result. Now 
we will view it in another form. The ani- 
mal has taken cold (see Catarrh) ; the 
lungs — from previous disease, and the sub- 
sequent inhalation of impure air in a hot 
and crowded stable — are incapacitated, 
and their power to purify and vitalize the 
blood is destroyed; hence we have deposits 
of morbific matter on the mucous mem- 
brane, which corrode, ulcerate, and finally 
attack the substance of the lungs, and 
tubercle is the result, which may terminate 
in glanders. The expectoration, or passage 
of acrimoniovis humors tlirough the nostril 
of the horse fi'om the lungs, does, in its pas- 
sage, irritate the schnciderian membrane at 
a point where it is in immediate contact 
with ossific or cartilaginous structure, and 
sufficiently accounts for the ulcers found in 
the nostrils in the above case. We do not 
hesilate to saij that glanders can be pro- 
(liircd wilhoni infection, or contagion, and 
that a common cold or catarrh, neglected or 
improperly treated, loill often terminate in 
glanders. Mr. Vines, V. S., states "that 
the practice of p,hysicing horses, and expos- 
ing them to vfet and cold, v.hen they have 
common catarrh, will produce confirmed 
glanders." 

According to the testimony of Mr. G. 
Fenwick, V. S., of London, " Glanders is 
a symptom of tubercles in the lungs in nine 
times out of ten;" hence, when a horse 
has taken cold, and the surface is obstructed, 
the prudent owner will endeavor to force a 
crisis ; that is, to open the pores of the skin, 
and promote perspiration. This can be 
done by the use of warmth and moistmc 
externally, and the administration of^varm, 



A DICTIOXARY. 



245 



anti-spasmo.lic drinks. Tliu will relieve 
the stricture of tlic surfnce, nnd permit the 
egress of morbific matter, wiiich would 
otherwise Ije thrown on tin- lungs, or kid- 
neys. If there is not sufficient power in 
the system to determine action to the sur- 
face, then administer diffusible stimulants. 
i\Ir. Youatt remarks : " Improper stable 
management is a more frequent cause of 
glanders tlian contagion. The air which is 
necessary to respiration is changed and cm- 
poisoned in its passage through the lungs; 
and a fresh supply is necessary for the sup- 
port of life. That supply maybe suthcient 
barely to support life, but not to prevent 
tlie vitiated air from again and again pass- 
ing to Die lungs, and producing irritation 
and disease. The membrane of the nose, 
possessed of extreme sensibility, is easily 
irritated by this poison. Professor Cole- 
man relates a case which proves to demon- 
stration the rapid and fatal agency of tliis 
cause. ' In the expedition to Quiberon, the 
horses had not been long on board the 
transports, before it became necessary to 
shut down the hatchways : the consequence 
of this was, that some of them were suffo- 
cated, and that all the rest were disem- 
barked eitlier glandered or farcied. In a 
close stable, the air is not only vitiated by 
breathing, but there are other and more 
powerful sources of mischief. The dung 
and the urine are suffered to remain, fer- 
menting and giving out injurious gases.'" 

Glands. — Soft, spongy substances in 
various parts of the body, which serve to 
secrete particular humors from the blood. 
They are vulgarly called kernels. 

Gleet. — A discharge of a mucous fluid 
from the urethra, vagina, or nostrils. 

Glottis. — The upper part of the larynx, 
or top of the windpipe. The sensibility of 
ihis part is so great, that, if any substance 
hajjpen to fall into the larynx, the most 
j)ainful and distressing symptoms are pro- 
duced ; and, unless the extraneous matter be 
expelled by coughing, or removed by an 
operation (bronchotomy), a fatal termina- 
tion will b'j the consequence. 

(iorfhi:D. — A term applied lo cattle with 



an overloaded stomach. When they are in 
this state, they are said to be blasted, blown, 
or hoven ; probably from the quaniity of 
carbonic acid gas that is generated, and by 
which the stomach is so distended that cat- 
tle often die in consequence of it. When 
cattle are put into a pasture, which abounds 
in imtritious food, to which they have been 
unaccustomed, or have an improper quan- 
tity given them, they frequenily fill the 
paunch to sucii an extent Ihat they are in- 
capable of ruminating: hence, the food re- 
maining in a warm situation, the combined 
action of heat and moisture generates the gas. 

Granulations. — A term applied to the 
little, red, grain-like, fleshy bodies, which 
arise on the surface of ulcers and suppm-at- 
ing sores. Their use is to fill up cavities, 
and approximate the sides. 

Grease. — A swelling of the horse's 
heels, and discharge of stinking matter. 

Gripes.* — (See Colic.) 

Gristle. — A name commonly given to 
cartilage. (See Cartilage.) 

Grogginess. — A horse is said to be 
groggy, when he has a tenderness, or stifl- 
ness, about the feet, which causes him to 
go in an uneasy, hobbling manner. 



♦Scientific Treatment of Colic, or Gru'Es. — 
" 0;i tlic ritl) Sept., 1824, a voiiiij; bay marc was ailmittcd 
into the iiilirmary, with symj^toms of colic, for which slio 
lost oiglit [lonnds of Ijlooil before she cnme in. Tlio fol- 
luwi!ig drench was prescriljeil to be given iinmctliatcly : 
laudanum and oil of turpentine, of each, tlu'co ounces, 
with the .addition of six ounces of decoction of aloes. In 
the course of half an hour tliis was repeated ! But, shortly 
after, she vomited the greater part by the moutli and nos- 
trils. No relief having been oljtaincd, twelve pounds of 
lilood were taken from her, and the same drink was given. 
In another hour this drench was repeated ; and lor the 
fourtli lime, during the succeeding hour; bjfli of which, 
before death, she rejected, as she had done the second 
drink. Notwithstanding these active measures were 
promptly taken, she died about three liours after her ad- 
mission." (Sec Clarke's Essay on Gri])es.) It appears 
that tlie doctors made siiort work of it. Twelve oftnces 
of laudiinum, and tlie same of turpentine, in three hours!' 
But tliis is sccumlum artem. Tliis is called skilful treat- 
ment, and justitiabic in every case where the symptoms arc 
urgent. 

Had the relaxing and stimulating plan, practised Ijv ns, 
been resorted to, and in a proper time and mansicr, it 
would probably liave saved the poor brute. We lia\e at- 
tended a large nuujber of the same sort of cases, and ha\e 
not vet lost the first. 



24G 



A DICTIOXAHY. 



Gullet, ok ffi^oniAGUs. — A muscular 
and membranous tube, by which the food, 
etc., is conveyed from the mouth to the 
stomach. The upper part, or funnel-like 
cavity, is named pharynx. The gullet 
passes down the neck behind the windpipe, 
along tlie nt'ck, through the diaphragm, and 
terminating in the stomach. 

Gums. — The fleshy parts of the sockets 
of the teeth. 

Habit. — By tliis term is meant the dis- 
position, or temperament, of tlie body or 
constitution, whether natural or acquired. 
The term habit is also applied to any vice, 
as starting, kicking, rearing, etc. Ail bad 
habits, whether of the body, constitution, 
temper, or disposition of animals, may be 
in some measure corrected, if not entirely 
put a stop to, by proper attention to break- 
ing, breeding, and stable management. 

Haltkr Cast. — Owing to tlie improper 
length of the lialter, the horse is apt to get 
his fore leg across it, falls down, and some- 
times injures himself considerably. 

Ham. — This is the name given to the 
muscular part of the hind leg, terminating 
in the great tendo Achillis, or hamstring. 

Hand. — The division in the standard for 
measuring horses is thus named. A hand 
is four inches. 

Haw. — (See Eye, part first.) 

Heart. — (See part first.) 

Heel. — A term applied to the back part 
of the termination of the hoof. 

Hemlock. — A narcotic vegetable poison, 
deriving its deleterious properties from an 
alkaline principle, called conia. It has been 
known to kill many horses who have par- 
taken of ft. 

Hemorrhage. — A flow of blood from 
any part of the body, in consequence of 
the rupture of an artery or vein. Hemor- 
rhage, from external injury, is most readily 
stopped by taking up the bleeding vessel, 
and tying it witli saddler's silk; but, when 
this cannot be done, the bleeding may gen- 
erally be sto])ped by pressure, or styi)tics. 

Hepatitis. — Intlamination of the liver. 

Hide-Bound. — When horses are out of 
condition, and have harsh dry coats, the 



sliin will be contracted, and found tiglit 
about the ribs. It is a symptom of disease, 
and shows tliat the general health is im- 
paired. 

Hii'-SHOT. — This is known ! one of tlie 
hip bones being lower than '(her. It 

generally depends on a fracii.i. cif the os 
innominatum, or part of the peh i.^ ; the part 
having formed an irregular icind of union, 
so that the bone on that side is shorter tlian 
the other. 

HocK. — The horse's hock is composed 
of six bones. These bones are all con- 
nected together by very strong ligaments, 
which prevent dislocation, but allow a 
slight degree of motion among them. The 
surfaces that are opposed to each other 
are tliickly covered by elastic cartilage, and 
by a membrane secreting the synovia, or 
oily fluid, which guards against friction. 
These bones are so strongly bound together 
as almost to defy dislocation. 

HooF-BOUND. — A dry, brittle, and mor- 
bid state of the foot. A want of vital 
action, occasioned, says Dr. White, "by in- 
flammation," which he calls disease. Now 
it is evident that no vital action, as that of 
fever and inflammation, can be properly 
termed disease. The only action tliat can 
be properly termed disease, is the chemical 
action manifested in suppuration and gan- 
grene. This is the great popular error that 
we are laboring to overcome. It is that of 
attributing disease and death to the action 
of the powers of life. When a part has be- 
come diseased, especially the foot (for from 
it tiic blood has a kind of up-hill work to 
perform, in returning to the lieart by th3 
veins), there is a low state of vitality ; very 
little can be ;■ ;eomplished by the vital pow- 
ers, amounting only to a Iovn' form of in- 
flammation. And, of course, the chemical 
power of decomposition, always present 
and never tired, gets the advantage and 
decomposes tlie part ; we then have thrush, 
wliicli, if im])roperly treated, the hoof falls 
oil' by the process of decomposition, or, in 
other words, mortification. It becomes sep- 
arated from the living parts, for want of 
inflammalion, or vital supremacy,' over 



A DICTIONARY. 



247 



chemical agLnicy ; and then the loss of the 
hoof iri strangely attributed to inflamma- 
tion, or the vital power, wliicli did all it 
could to prevent such a termination. 

IIoof-Casting. — A partial or complete 
separation of the horse's hoof from the sen- 
sitive foot. 

HoosE. — A term used by cow doctors. 
It signifies a cough, either clironic or acute, 
with whieli cattle are affected, from expos- 
ure to cold winds or rain. 

HoREnoiNo. — A bitter vegetable, used 
in horse practice as a tonic and expectorant. 

HovEN. — (See Blasted.) 
Tydatid. — A thin bladder, containing a 
fluid resembling water, and nearly trans- 
parent. It is found in different animals. 
In sheep, it occasions a disease named gid, 
or giddiness ; the hydatid being found in 
one of the ventricles of tlie brain, or in its 
convolutions. On account of the pressure 
it malvcs on tlie brain, it disturbs the func- 
tions of that important organ, especially 
Avhen the slieep are hurried or driven. 

Hydrocele. — Dropsy of the testicle and 
its appendages. 

Hydrophobia. — Canine madness. 

Hydrotuorax, or Dropsy of the Chest. 
— Mr. Percivail informs us, " that the ob- 
jects to be pm'sued in the treatment of 
hydrothorax are twofold : first, we are to 
diminish any excess of action that may 
show itself in the sanguineous system,* and 

* In i)Uiin Enfclisli, alistract Ijlood. Tliis not only di- 
minislies the sanjjnineous system, but every other funrtion 
or system. The regulars have tried blood-letting to their 
hearts' content; their patients have been rowelled, blis- 
tered, calomclized, turpentinized, and hellebored, yet they 
have never been able to preserve lite, "exeejit tivo solitary 
cases in Mr. Sewcll's practice; " for Mr. Percival tells us, 
in his lectures, that " ho never saw a case terminate favor- 
ably." Is not this a proof that our brethren are on the 
Tvrong track 1 AVe arc told that the proximate causes 
of ilropsy are "debility and an obstructed perspiration ; " 
and that it may result from " lo.ss of blood, diarrhoea, dia- 
betes, and other circumstances that rapidly exhaust the 
system." Hence the processes of cure are just the means 
calculated to produce the disease. The true indications 
in the treatment are, to warm and rcl.ax the siirfai-c, and 
promote i)crs]iiration ; for whatever ehecUs it stops the 
egress of morbilic matter from the system, and, ofeonr.se, 
determines It upon the internal surfaces. DiiVn :able stim- 
ulants r.-.uy be given, to keep up the action on the suii'ace. 
The gciieral hcilth must b(f improved. 



thereby lessen the eOusion of fluid into the 
chest ; and secondly, by increasing the ac- 
tion of the absorbent system, effect the 
removal of what is already accumulated."* 
Most surgeons reconunend early tapping in 
drop.sy. The operation may be perforrned 
with tlie common trocar and canula. The 
best place for the introduction of the instru- 
ment is the space between the eighth and 
ninth ribs, close to their cartilages; not be- 
tween the latter, lest the pericardium be 
punctured. Here, making the skin tense 
with the fingers of the left hand, the instru- 
ment, with its point dkected upwards and 
inwards, may, with a little rotary move- 
ment, gradually be thrust in, until the re- 
sistance to its entry suddenly ceases ; when 
the trocar should be withdrawn, and the 
canula at the same time pushed onwards, 
lest it slip out. If the flow of water sud- 
denly ceases, a small whalebone probe 
should be introduced througii the pipe. 

Ichor. — A thin, acrimonious discharge 
from ulcers, or diseased parts. 

Icterus. — Jaundice, or yellows. 

Idiosyncrasy. — A peculiar constitution, 
or temperament. 

Ileum. — The last portion of the small 
intestine. It terminates in the large intes- 
tine, or blind gut, named csecum. 

Lmposthu.me. — A collection of matter, or 
pus, in any part. 

I.xcoNTiNENCE OF Urin'e. — A coutinual 
dripping of the urine from a horse's sheath. 

I.NFLA.MMATioN. — Inflammation and fever 
are one and the same tiling. When fever 
is confined to a small part, it is called in- 
flammation. (See 1nflam:matio.\, part 
first.) Dr. White, altliough an advocate of 
the popular error, viz., blood-letting, makes 
some very sensible remarks on tlie subject. 
If men generaUy would carry oitt these 

'-■ The action of the absorbent system never was, nor 
never can be, excited when the lancet is cooperative. Ab- 
sorption is a physiological result, and cannot be excited by 
agents that act pathologically. The balance between ex- 
halation and absorption is lost, in consequence of ^vhich, 
more fluid is ])onred out than is taken uj) : hence, if we 
excite the exhalcnts to throw off the morbid fluids from 
the surface, there will be less for the absorbents to take up, 
and the chances of success will I)C greater. 



248 



A DICTIONARY. 



principles, they would prevent a great loss 
of property. " It must be obvious, that 
when an animal is laboring under general 
inflammation, or fever, in consequence of 
a suppression of the natural discharges, 
whether it be perspiration, urine, or dung, he 
cannot be cured merely by the abstraction 
of blood; for, however large the quantity 
abstracted, that which remains will be im- 
pure, or acrimonious, and unfit for carrying 
on a healthy action. It is absolutely neces- 
sary to restore the natural discharges by 
means of suitable medicines, unless that be 
effected by an effort of natm-e, which is not 
an uncommon occurrence, especially when 
the animal is supplied with some bland 
fluid, such as bran water, or thin bran 
mashes. The morbid matter sometimes 
runs oflf by the nostrils, sometimes bj' the 
kidneys or bowels, and sometimes by a gen- 
eral relaxation of the skin, and the body is 
thus restored to health." From the above 
we are led to the conclusion that, after all, 
Nature is the most elTicient doctor, and that 
man should be her servant, to procure what 
she wants, merely to be used in her own 
way. 

Influenza. — Epidemic catarrh. Ca- 
tarrhs, or violent colds, attended with sore 
throat, and a thin, watery discharge from 
the eyes and nose. It appears to be infec- 
tious, seldom making its appearance with- 
out attacking several horses in the same 
stable. The horse should subsist on warm 
gruel, and have a blanket thrown over him, 
and a drink of hyssop tea. As soon as the 
surface of the body is relaxed, and becomes 
moist, the catarrh will disappear. 

Injection. — A term sometimes applied 
to clysters. 

Inosculation. — The running of arteries 
and veins into one another, or the inter- 
union of the extremities of arteries and 
veins. 

Inspiration. — The act of drawing air 
into the lungs. 

Integument. — Any common covering of 
the body : it generally includes skin, nuiscle, 
and membrane. 

Intercostal. — A term given to parts 



situated between the ribs : thus, we have 
intercostal muscles, etc. 

Intermittent. — A name given to dis- 
orders that appear to go oft' at certain peri- 
ods, and return after some interval. 

Intestines. — The horse's intestines are 
about ninety feet in length. 

Intls-susception. — This is occasioned 
by one portion of the bowels being drawn 
within the other. 

Iris. — That part of the eye by which 
the light admitted to the retina is regu- 
lated. 

Irritability. — All muscular parts pos- 
sess the property of contracting, or shrink- 
ing, when irritated, and are therefore en- 
dowed with irritability. 

Issues. — (See Rowels.) 

Itching. — Itching in horses is generally 
a consequence of foul feeding, and may be 
occasioned by mange. 

Jaundice. — In jaundice, the natural 
course of the bile is perverted, and re-ab- 
sorbed into the circulation. 

Jaw-Locked.— (See Lockjaw.) 

Jejunum. — Part of the small intestine is 
thus named, from its being generally found 
empty. 

Joints. — A joint is formed, generally 
speaking, by the heads of two or more 
bones. These ends are covered by a layer 
of cartilage or gristle, which is of a yielding 
nature. There is formed within the joint a 
slippery fluid, called synovia, or joint oil. 
The ends of the bones, thus covered with a 
smooth, yielding surface, so slippery that 
they move freely on each other without suf- 
fering from friction, are then firmly tied to- 
gether by a strong substance, named liga- 
ment, which completely smTOunds the head 
of the bones : this is termed capsular liga- 
ment. In some joints we find an additional 
ligament within the capsular ligament, or 
cavity : thus, in the hip joint, a strong lig- 
ament connects the head of the thigh bone 
with the socket that receives it. 

Joints arc subject to disease, either from 
external injury, or from long-continued ex- 
ertion of them. In (he former, the capsular 
ligament is penetrated, and a discharge of 



A DICTIONARY. 



249 



synovia ensues. Mr. Percival remarks 
"Uiat, in many cases of open joint (com- 
monly caUed so), there is no division nor 
injury wliatever of tlie capsular ligament; 
but merely the exposure of some bursa mu- 
cosa placed between the joint and the ex- 
lernal wound: the discharge is of the same 
kind as in the former case, and we can only 
determine which it is by carefully probing 
the wound. Most of all, we are likely to 
make this mistake in the shoulder joint and 
hock, when heat and swelling are present. 
From the acute sensibility of ligamentous 
parts when inflamed, the system quickly, 
and almost invariably, sympathizes ; so that, 
in all severe cases of this nature, symptom- 
atic fever supervenes, the pulse becomes 
accelerated, the horse heaves at the flanks, 
refuses his food, and shov>"s symptoms of 
(he most affecting suffi?ring. It must be 
borne in mind that, although a joint be not 
open in the first instance, subsequent slough- 
ing may expo.se its cavity. Now, the ordi- 
nary effects of disease in the synovial 
membrane are, first, a preternatural secre- 
tion of synovia, — hence the profuse dis- 
charge observed in these cases ; second, an 
effusion of adhesive matter into the cavitv 
of the joint; third, a thickening of the 
synovial membrane, a conversion of it into 
a substance resembling gristle, and an efi"u- 
sion of adhesive matter, and probably 
serum, into the cellular substance around, 
by which the external parts and those of 
the joints are finnly cemented together. 
In the latter stage the disease commonly 
extends itself to the cartilaginous surfaces ; 
they exfoliate, leaving the extremities of the 
bones denuded, to grate on each other as 
often as the joint is moved. The bonco, in 
their turn, throw out deposits from their 
ends around the joint, — a process that ulti- 
mately ensues, and anchylosis is the result." 
The indication to be fulfilled is to pro- 
mote adhesion by bringing the edges to- 
gether and confining them in contact, cither 
by taking a few stitches, or shaving the hair 
ofl' around the parts and applying strips of 
adhesive plaster. The parts may have a 
pledget of lint bound on, moistened with 

32 



healing balsam ; and, if the limb will admit 
of it, a splint may be bound to the back part 
of it, so as to prevent all possibility of ilex- 
ion. If union cannot be produced by this 
means, llic parts may be poulticed with 
astringent.-. The object is to close the 
joint, and promote granulation. If the 
parts are inactive, sprinkle the surface of 
the poultice with charcoal and capsicum. 
In a case that came under the author's 
care in this city, and one in which there 
was no hope of its healing by the first in- 
tention, the tincture of caj^sicum was daily 
injected : this, together with tonic, stimulat- 
ing, astringent poultices and fomentations, 
completed the cure. In cases where the ex- 
ternal wound is large, and there is much 
heat, pain, and loss of motion, poultices of 
a relaxing and lubricating natm-e should be 
used ; such are lobelia and slippery elm. A 
severe injury of this kind may be converted 
into a simple wound by the combined influ- 
ence of these remedies. The horse should 
be kept at rest, on a light diet of scalded food, 
and an occasional dose of alterative medi- 
cine. 

When lameness is manifest wdthout heat 
or swelling, and there is reason to suppose 
that the animal has been ovenvorked, rest 
and proper attention to diet will be all that 
is necessary. When the case is one of long 
standing, a run at grass may effect a cure, 
unless there is reason to suppose that the 
articulatory surfaces of the bones are dis- 
eased; w^e are not supposed to do more 
for these subjects than alleviate their suf- 
ferings, or, what amounts to the same thing, 
diminish their lameness, 

JcGui.AR Veins. — The large veins of the 
neck, where a horse is bled. 

Kernels. — A common name for glands : 
thus, the parotid glands, situated beneath 
the car, are termed the kernels under the 
ear. 

Kino. — An astringent gum resin. 

Lacteals. — Absorbent vessels, which 
convey the chyle from the bowels into the 
tiioracic duct. 

Lameness. — The cause of lameness in 
horses is often very obscure, and can only 



250 



A r)ICTIO:."AKY. 



be discovered by a patient and careful ex- 
aminaticn. A slisrht doGfrce of lameness 
of I en passes unnoticed ; or, if it be observed, 
Ihe owner too often persuades liimself that 
it will pass off. It is al\va3's the most pru- 
dent plan to lay up a horse the moment he 
is observed to be lame, and submit to the 
inconvenience of doing without his services 
until he is cured. When lameness is caused 
by v."ounds or bruises, the injured part is 
generally discovered v/ithout difticulty, 
though pricking, in shoeing, is not always 
so easily seen. All lameness from injuries 
within the hoof is often detected with diffi- 
culty. Slight lameness is most readily seen 
by making the horse trot gently, without 
giving any support to the head by the bridle 
or halter, and without m-ging him with the 
whip : the lameness is then seen by his 
dropping harder and dvvelling longer on the 
sound leg than on the lame one, in order to 
favor the latter ; and this, when the lame- 
ness is at all considerable, is attended v.'ith 
a corresponding motion of the head, v.diich 
drops a little whenever he steps on the sound 
limb. An experienced observer can at any 
time distinguish lameness merely by seeing 
a horse walk out of the stable. It often hap- 
pens, in very severe lameness of one or both 
fore feet, that the horse, when led out, will 
appear to be lame in tlie hind feet also : this 
is occasioned by the animal endeavoring to 
f ivor the fore foot or feet by throwing the 
balk of his weight on the hind legs. In all 
cases of lameness, unless the cause is so evi- 
dent as to render it unnecessary, it is proper 
to examine the foot carefully in the first 
place ; and it should never be forgotten that 
swelling, heat, and tenderness of the fetlock 
joint, or even the leg, may arise from an in- 
jury to the foot. In lameness of the foot, 
the affected foot v.'iil be warmer than the 
other. Considerable relief rnay almost 
always be afforded in foot lameness by keep- 
ing the feet moist, or pasturing the animal 
in soft meadov/ land, or by stopping the 
bottoms of the feet with a wet sponge, by 
paring tlic-.n when necessary. We some- 
times Had, on examining a lame foot, that 
there is an enlargement immediately above 



the coronet, at the heels and quarters, and that 
tills enlargement feels hard and bony. This 
is termed ossification of the lateral carti- 
lages ; it is more distinctly seen by compar- 
ing it with a sound foot. In lameness of 
the foot, there is sometimes a crack in the 
horn towards the heels, extending from the 
coronet a little way down the hoof: thia 
happens sometimes after a horse has been 
travelling. This is named a sand-crack. 
When th.e seat of lameness is in the fetlock 
joint, some degree of heat or swelling v.nll 
be perceived. As the horse stands, he will 
be observed to favor the joint. Lamenesj 
of the back, sinews, or flexor tendons of the 
leg, is easily perceived by the heat and ten- 
derness of the part. 

Lampas. — A swelling and sometim.es ten- 
derness of the roof of the mouth, adjoining 
the front teeth. When the part is tender, 
and prevents the horse from feeding, ho 
should be fed on scalded shorts for a few 
days ; during that time, the mouth may be 
washed twice a day with an infusion of 
powdered bayberry bark. Two ounces of 
bark may be infused in one quart of boiling 
water: after macerating for one hour, it v/ill 
be fit for use. 

Larynx. — The upper part of the trachea 
or windpipe. 

Lax. — (See Scouri.^g.) 

Laxativi^,. — Medicines that purge gen- 
tly ; the most simple and safe is aloes. 

Ligaments are strong, elastic membranes, 
connecting the exti'emities of the movable 
bones. 

Licatuke. — Twine, thread, or silk, 
waxed, for the purpose of tying arteries, 
veins, or other parts. 

Lights. — A common name for lungs. 

Lily. — The root of the white lily is fre- 
quently iised for poulticing. 

Linseed, or Flaxseed. — An excellent 
emollient drink is made by ponring two 
quarts of boiling water on four ounces of 
linseed, and su^ffering it to stand in a warm 
place for a short time. It is useful in cold, 
catarrh, and in diseases of the kidneys or 
bladder. 

LiQuoiucE. — The root, di'ied and pow- 



A DICTIONARY. 



251 



tiered, is used for the same purpose as llie 
last arlic.le. 

LoDi:. — A portion of tlic lungs and liver 
is thus named. 

Lockjaw. — Tliis disease is too well 
Known to require a particular description. 
It is evidently a disease of the s])inal sys- 
tem,— other parts becoming sympatlicti- 
cally ail'ected, — and often arises from a 
vround of a tendon, or nerve : it occasion- 
ally follows nicking, or docking. I\Ir. You- 
att tells us, " This is one of the most fatal 
di.seases to which the horse is subject." 
Fin the information of our readers, we will 
detail the treatment reconiiuended by the 
above author. Wc presume that every man 
of common sense xAli come to the conclu- 
sion that the disease could not be otherwise 
than fatal under such unwarrantable bar- 
barity. We have no personal disrespect for 
iMr. Youatt. It is the system of treatment 
recommended by him that wc war against ; 
a cystcm that has killed more than it ever 
cured. Mr. Youatt observes : " The rational 
method of ciire would seem to be, first to 
remove the local cause ; but this vrill seldom 
avail much. The irritation has become 
general, and the spasmodic action constitu- 
tional. Tlie habit is formed and will con- 
tinue. It will, however, be prudent to en- 
deavor to discover tlie local cause. If it be 
a wound in the foot, let it be touched v.'ith 
the hot iron, or caustic, and kept open v%-ith 
digestive ointment. If it follows nicking, 
let the incision be made deeper, and stimu- 
lated by digestive ointment ; and, if it arise 
from docking, let the operation be repeated 
higher.-' In treating the couiiitutional 

* " Fii-st, to remove l!ic loeal oausc ; but iliis -n-iil sel- 
dom avail mm!i." Then why torture the poor brute' 
Wc need not trouble ourselves about tlie particular nerve 
afleeted to cnal]le us to relievo a sympatlietic disease, 
when wo have a medieine — lobelia and milkweed, orlndian 
hemp — lli.it wi!l relax every nerve in llie ani:nal. " If it 
lie a wound In the foot, let it be touched with tlw hot iron." 
This is a moans bettor calculated to injure t!;an relievo. 
Wo should apply, at once, the mean;; that are knov.-n to 
art on tlio whole nervous structure. " If it follows nick- 
in;,', let the incUion be made deeper ; and if it arise from 
do-kin.^', lot tlie operation bo repcatod higher." What 
beauillal pliilosophy this ii! — make one disease to cure 
ajiothcr. L it ctrango that " this is one of the most fatal 



disease, efforts must be made to tranquillize 
the system ; and the most powerful agent is 
bleeding. [Yes, most powerful to kill.] 
Twenty pounds of blood may be taken away 
with manifest advantage. There is not a 
more powerful means of allaying general 
irritation ; the next thing is to resort to phy- 
sic. Here again that physic is best which 
is speediest in its operation ; the Croton nut 
has no rival in this respect; the first dose 
should be lialf a drachm, and the medicine 
re])oatcd every six hours, in doses of ten 
grains, until it operates.* The bowels, in 
all these nervous aflections, are very torpid.' 

" Then, as it is a di-seased action of the 
nerves, proceeding from the spinal marrow, 
the whole of the spine should be blistered 
three or four inches wide. (See Ca.vtuar- 
iDES.) Having bled largely, and physiccd, 
and blistered, we seel! for other means to 
lull the irritation ; and wc have one at hand, 
small in bulk and j^otent in energy, — 
opium ! f Give at once a quarter of an 
ounce, and an additional clrachm every six 
hours."' 

The best method we know of, in the 
treatment of lockjaw, is, first, to apply a 
poultice to the foot (if it has been wounded), 
consisting of about six ounces of lobelia, 
four ounces of slijipery elm, two ounces 

disc.iFcs?" Is it not a wonder that .iny live ? Must not 
thoh- escape bo .attributed to the conservative power of the 
system, in spite of the violence done ? When Jlr. Youatt 
recommends cutting the tail a little higher, to cure a dis- 
ease lh.1t was produced by the same operation, — vii., 
docking, — he puts the author in mind of the n:an wIm 
filed tlie edge of his razor to sharpen it. 

* In the first part of this paragraph, Mr. Youatt ob- 
scn-cs, "the most powerful agent to tranquillize the sys- 
tem is bleeding." Go say tlio butchers when they bleed 
the ox, and conduct the process till no blood remains. 

f This is a narcotic, vegetable poison, and, although large 
f|uantities have been occasionally given to the l-.orsc with- 
out apparent injun-, experience teaches us that ]>oisons 
in general — notwithstanding the various modes of their 
action, and the dificrcnco in their .symptoms — all agree in 
the abstraction of vitality fix)m the system. Dr. Kberlo 
says, " Opiates never fail to ojicrate pcmiciou.-Iy on the 
whole organisation." Dr. Gallup says: "The ])racticcof 
using oiiiatcs to mitigate pain is greatly to bo deprecated. 
It is probable that ojiiuni and its )>rcparations have done 
seven times the injury that they have rendered benefit oa 
the great scale of the civilized world. Opium is the most 
destructive of all naxcotics." • 



9«;9 



A DICTIOXARY. 



of capsicum, powdered ; mix them with a 
suitable quantity of moal sufficient for two 
poultices, which should be renewed every 
twelve hours. After the second application 
examine the foot, and, if sujipuration has 
taken place, and the luatter can be felt, or 
seen, a small puncture may be made, taking 
care not to let the instrument penetrate 
beyond the bony part of the hoof. Next 
stimulate the sm-face to action, by warmth 
and moisture, as follows : take about two 
quarts of vinegar, into Vviiich stir a handful 
of lobelia; have a hot brick ready {the 
animal having- a larg-e cloth, or blanket, 
thrown around him), pour the mixture gradu- 
ally on the brick, which is held over a 
bucket to prevent waste ; the steam arising 
will relax the surface. After repeating the 
operation, apply the following mixture 
around the jaws, back, and extremities : 
chloroform, and olive oil, equal parts ; rub 
the mixture well in with a coarse sponge ; 
this will relax the jaws a trifle, so that the 
animal can manage to suck up thin gruel, 
which may be given v.'arm, in any quantity. 
This process must be persevered in ; al- 
though it may not succeed in every case, 
yet it will be more satisfactory than the 
blood-letting and poisoning system. No 
medicine is necessary; the gruel will soften 
the fffices sufficiently; if the* rectum is 
loaded with fasces, give injections of an in- 
fusion of lobelia. 

Lumbar Muscles. — Muscles of the loins 
within the body, and in the region of the 
kidneys. These muscles are sometimes in- 
jured by violent exertions, and the kidneys 
often ]nirticipate in the injury. 

LuxGs, or L:g!ITS. — The organ of res- 
piration. (See RnspiRATroN, part first.) 

LuxATiox. — A partial displacement of 
the bones forming a joint. 

Ly.mpii. — (See Bi-ood.) 

LvMrnATics. — (Sec part first.) 

Macrkatiox implies soaking or steeping 
any substance in water, or other fluids, so 
as to soften, dissolve, or separate it from 
some other parts with which it is combined. 

Mallexders. — A scurvy kind of eruption 
ou the bad; part or bend of the knee joint. 



Mange. — A disease v/hich manifests it- 
self in the skin, and causes a horse to be 
joerpetually rubbing himself. Cattle, sheep, 
and dogs are also subject to mange. It is 
a well known fact, that horses are very apt 
to become mangy, if kept long in the stable 
without grooming ; yet the disease may 
arise from causes independent of a neg- 
lected skin, though it seldom attacks a well- 
cleansed animal. Mr. PefciVall observes : 
'' It seems that mange may be generated 
either from immediate excitement to the 
skin itself, or through the medium of that 
sympathetic influence winch is known to 
exist between the skin and tiic organs of 
digestion. Yv'c have, it appears to me, an 
excellent illustration of this in the case of 
mange supervening upon poverty, — a fact 
too notorious to be disputed, though there 
may be diflerent ways of theorizing upon 
it." 

Mr. Blaine says, " Mange has three 
origins — filth, debility, and contagion." 

Owners of horses must bear in mind, Ihat 
mange can be communicated by the brush 
or comb itsed about a mangy subject; the 
pustules on the sm-face contain acari or 
nites. The author has . been very success- 
ful in the treatment of this disease, by the 
daily iisc of sulpb.ur and soda. 

Marasmus.— A decay or wasting of the 
whole body. 

Marsu Mallows. — A plant used for 
making emollient drinks and fomentations. 

Mash. — A mash is made by pouring 
boiling Vv'ater on bran, or shorts, then cov- 
ering the bucket until sufficiently cool for 
use. Mashes are excellent for sick and 
convalescent horses, and such as have not 
sufficient exercise to keep them in health. 

Masseter. — The name of a muscle of 
the cheek, by which mastication is per- 
formed. 

Mastication". — (Sec part first.) 

Materia Medica. — A catalogue and 
description of the various articles used in 
medicine. 

Maxilla.— The jav.'. 



?Jaxillarv. — Belonging to the ja'.v 



the maxillarv 



arteries and glands. 



The 



A DICTIOXARY. 



253 



glands niider the jaw are named sub-max- 
illary glands. 

iMivDiA.sTiNL'M. — A du])llcatiire of the 
monibraiio, named pleura, by which the 
cavity of the chest is divided into two 
parts. 

Mi;dicin'e. — I\Ir. Clark, veterinary sur- 
geon of Edinburgh, says : " Medicine is often 
given to the i>oor brutes unnecessarily, and, 
of course, mischievously. If a man, or 
horse, be in a state of health, what more is 
required, or how can they be rendered bet- 
ter ? Health is the more proper state of 
the animal body, and it is not in the power 
of medicine to make it better, or to preserve 
it in 1,'ic same stale." 

Dr. White says : " The custom of giving 
medicines too frequently, is a bad one ; the 
constitution adapts itself to it, which cir- 
cumstance renders medicine incflicacious 
when necessary, or, at least, it greatly re- 
duces the oflects." 

If a horse is in health, the proper way to 
promote it is to proportion the food to the 
labor. 

Dr. White continues : " Medicines are 
given to the horse under the title of alter- 
atives. These alteratives are composed of 
antimony, viercury, su/p/uir, nitre, aloes, 
sa/ls" [<re lie rally altering bad for ivorse). 

Ml-. Clark says, " That sulphur not only 
opens the body, but the skin also, and there- 
fore should be used with caution, as horses 
are very apt to catch cold on too liberal a 
use of it." 

Salts bring on gi-eat sickness, and some- 
times violent purging, and, instead of pro- 
moting the secretions, occasion great dryness 
of the skin. 

"Aloes given in small quantities, by way 
of alteratives, and too frequently repeated, 
weaken the stomach, so as to bring on a 
lax, or what is called a washy, habit of 
body. 

" Antimony should always be rejected, if 
coarse and black, lilic gunpowder." (See 
White's Farriery, p. 559.) 

The above author says : " It is amazing 
what different kinds of trash arc forced down 



horses' throats. The following is a striking 
instance: A gentleman, in London, was 
greatly prejudiced in favor of vinegar, as a 
cure in many diseases. His favorite horse 
was taken ill in very warm weather, and, 
as lie thought vinegar was a cooling ariicle, 
he ordered a pint to be given to his horse at 
once. It was no sooner given, than the 
horse lay down, stretched himself out, and 
died." 

IVIedllla Oblo.ngata. — The commence- 
ment of the spinal marrow, within the cra- 
nium. 

Membrane, Mucous. — This membrane 
is folded into all the oriiices of the anim.al, 
as the mouth, eyes, nose, cars, lungs, intes- 
tines, bladder, etc. ; in fact, into every cavity 
that has a direct communication with tlie 
external surface. Its structure of arterial 
capillaries, venous radicles, nervous projec- 
tions, etc., is similar to the skin, and is 
considered a duplicate of the external sur- 
face. Its most extensive surfaces are those 
of the lungs and intestines. This mem- 
brane furnishes from the blood a fluid called 
mucus, to lubricate its own surface, and 
protect it from the action of materials taken 
into the system. The skin and mucous 
membrane are a counterpart of each other. 
If the action of the skin is suppressed, the 
mucous membrane performs a part of its 
office ; thus, a cold, which closes the ])orcs 
of the skin, stops' perspiration, vrhich is now 
forced througii the membrane, ))roducing 
discharges at the nose, eyes, etc. 

SEnoi-s MEMBRANE.-Of this kind are. 
the pleura and jjeritoncnm : they are dis- 
tributed in all parts of the system, lining 
muscles, tendons, and tendinous sheaths, 
the ends of movable bones, etc. ; in short, 
wiierevcr there is need of the protection of 
parts against friction. They secrete from 
the blood a fluid called scrum, for the pur- 
pose of affording this protection. The, 
excessive discharge of fluids into cavities 
lined by serous membrane, constitutes the 
dificrcnt forms of dropsy. There are other 
membranes, viz., adipose, which secrete the 
fat of the body; synovial, which secrete 



254 



A DICTIOXAR/. 



synovia, or joint oil ; and cellular mem- 
branp, or tissue, is the common connecting 
substance of most parts of the body. 

Mesexteryj — A thin membrane by 
which the bowels are held together, and 
over which the lacteals, or chyle vessels, 
pass. Besides the chyle vessels, there are 
considerable veins and arteries passing over 
the mesentery. The arteries are distributed 
to the bowels, and the veins terminate in 
the vena porta, or groat vein of the liver. 

Metacarpus. — The metacarpus of the 
horse consists of one great bone, commonly 
named the canon, shank bone, or fore leg, 
and two small bones, or splent bones, at- 
taclied by ligaments to the back part of the 
canon bone, rather towards the sides. The 
suspensory ligament passes down on the 
back part oi the canon bone, and between 
the two splents. The llexor tendons, or back 
sinews, pass down over the suspensory lig- 
ament. When the bones only of the fore 
leg are spoken of, they are termed meta- 
carpus. They begin at the knee, and end 
at the fetlock joint. 

Metatarsus. — The hind leg, between 
the hock and fetlock joints. 

Metatarsal Boxes. — The hind canon, 
or shank bone, with the two small splent 
bones attached to it. The large blood- 
vessels and nerves, in this situation, arc also 
named metatarsal. 

Miasmata. — Poisonous effluvia. 

MmniFF. — (See Diaphragm.) 

MoLAPvES. — The name of the grinding 
teeth. 

Molten Grease. — A name which I\L-. 
Blaine has given to dysentery. 

Morbid Displacements of the Intes- 
tines, etc — Rupture, or Iiilesliiial Hernia.'^' 
Hernia, in its strict sense, is a protrusion of 
any viscus out of its natural cavity ; hence 
we have hernia of the brain, of the lungs, 
and of the various viscera of the abdomi- 
nal regions. Hernia, as w-e propose to 
consider it, is a displacement of the intes- 
tines from the abdominal cavity, either 
through some of the natm-al openings, or 

• " Blaioo'a Outlines," by MaUow. 



through artificial ones, the ciTects of acci- 
dent. When such protrusion takes place 
through a moderate opening, and the por- 
tion of gut can be readily returned, it is 
called a reducible hernia; but when it oc- 
curs through a small opening, and Ihc in- 
testine cannot be replaced, it is termed an 
irreducible hernia. If the mouth of llic 
opening, round the intestine, constringc, 
and prevent the return of the bowel, it then 
forms a strangulated hernia, and usually 
|)roves fatal, unless relief be promptly ob- 
tained. 

The hernia, by far the most common in 
the horse, is the inguinal, of vrhich the 
scrotal, or when the bowel descends into 
the scrotum, is most frequently observed in 
the stallion. Bubonocele, cr that of the 
groin, is a very rare form of disease, but it 
is occasionally witnessed in geldings. In 
the former, the intestine accompanies the 
spermatic cord by the inguinal canal 
through the abdominal rings into the scro- 
tum : in the latter, the bowel alone lodges 
in the groin. The ruptures we have named 
may be considered as the only ones com- 
mon to the horse. Some of them are very 
rarely seen : hernia is more frequently on 
the right than on the left side ; and scarcely 
ever appears in mares. However, ventral 
hernia, or rupture of the muscles of the 
abdominal sides, and |)rotrusion beneath 
the skin of a portion of intestine, is some- 
times beheld in either sex, and perhaps, of 
the two, is more frequently witnessed in 
the female. 

The causes which produce hernia are 
various, but all arise from violence of exer- 
tion, or the effects consequent upon external 
injuries. With us the efibrts used in racing, 
and the leaps taken in hunting, are causes, 
as we may readily suppose ; when we con- 
sider that the dilatation of the abdomen, 
restrained as it is by weight and tight girth- 
ings, must press backwards the intestinal 
mass. Rearing and kicking also, and being 
cast for operations, particularly the rising 
up after castration, have all brought it on, 
Blows with a thick stick, or from the horn 
of a cow, may likewise induce it. 



A DICTIONARY. 



255 



The arjip.pfoms of sfranfrulatcd hernia are 
very similar lo tho.-?c of acute enicriti.s: 
thcve id llic same uneasiness, shifting of 
position, getting up and lying down again. 
The horse rolls in the same manner, and in 
turning on his l)ack sometimes seems to 
get a momentary respite from pain ; yet it 
is but momentary, for the suffering is not 
one of remission ; it is constant ; this will 
serve as one distinguishing mark between 
it and spasmodic colic, with which it has 
been confounded. In stallions, a pathog- 
nomonic symptom is, that the testicle on 
the hernial side is di'awn up to the abdo- 
men, and is retained there, with only mo- 
mentary fits of relaxation; toward the last, 
the pulse is quick and wiry ; the horse 
paws, looks at his flanks, but seldom kicks 
at his belly. We assure ourselves of her- 
nia by an oblong tumor in the groin, of 
larger or smaller bulk ; hard or soft, as it 
may contain cither faeces or gas, in which 
latter case it will also be clastic. "When 
the tumor i.s raised by the hand, or pressed, 
a gurgling sound is emitted ; or, if the horse 
be coughed, it will be sensibly increased in 
dimensions. 

Tlie treatment of strangulated hernia. — 
The horse suflering under the afTection we 
will suppose to be a stallion, and then de- 
scribe the various manipulations for his 
relief: firstly, the examination into the state 
of the hernia ; secondly, the application of 
means preparatory to the application of 
pressure ; thirdly, the application of pres- 
sure itself; also, the operation of removing 
the stricture; and, likewise, the application 
of the various processes to hernia in the 
horse. 

The treatment of hernia in a stallion. — 
First, tlie examination of the hernial sac. 
In this manipulation both hands are em- 
ployed ; one is inti-oduced into the rectum, 
the other into the sheath. The one within 
the rectum must seek the internal ring; 
while the other, pursuing the course of the 
cord on the side affected, is to be pushed up 
to the external ring; and thus, in the nat- 
ural state, the opposed fingers may be made 
nearly to meet, and so estimate the size of 



the opening. However small the protruded 
portion of gut, the praclitioner will be able 
to detect, and even to reduce it. Tins ex- 
ploration may be made in the standing pos- 
ture ; but it tvill be conducted ivith more 
facility and certainty if the animal be cast, 
ivhich is the preferable mode of proceeding. 

Secondly, the application of means pre- 
paratory to the taxis : these are said to be 
bleeding, and partially paralyzing the parts 
by administration of chloroform ; or lessen- 
ing the volume of distention by dashing 
the part with cold water ; or, if the horse 
be already cast, by spreading ice over the 
belly. 

Thirdly, tlte manual efforts to return the 
displaced gut. To fulfil this indication, we 
arc, with the same hope, at once to proceed 
thus; The horse is to be thrown upon the 
opposite side to that disordered ; and, after 
one hind leg has been drawn and fixed for- 
ward, as for castration, he is to be turned 
upon his back, and in that position main- 
tained by trusses of straw, while other 
trusses are placed under him to raise the 
croup. With both arms well oiled, or cov- 
ered with some mucilaginous decoction, 
the operator will now commence his explo- 
ration, taking the precaution of emptying 
the rectum as he proceeds. As soon as he 
shall have ascertained that it is a case of 
hernia, — have assured himself the gut pro- 
truded through the ring is undergoing 
neither stricture nor strangulation, — he may 
endeavor to disengage the hernial part, by 
sofily drawing it inward within the cavity, 
at the same time pushing it in the like 
direction with the hand within the sheath. 
Should he experience much difficulty in 
these attempts, he is to desist; violence 
being too often the forerunner of strangu- 
lation and gangi'ene. He must bear in 
mind, also, that, although the reduction is 
effected, unless it be followed by immediate 
castration, it does not always prove to be a 
cure : the protrusion recurs after a time, 
and occasionally even the moment the ani- 
mal has risen. If the taxis should be fortu- 
nate enough to reduce the hernia, and it be 
not intended to castrate the horse, apply a 



256 



A DICTIONARY. 



well-wadded pledget, or folded cloth, to the 
part ; this may be retained with a bandage 
crossed between the legs from side to side, 
and fastened by one part under the belly to 
a girth ; and also passing between the legs, 
it may be again made fast to the back por- 
tion of the same girth ; the intention of 
this is, to prevent the protrusion of the 
gut by the exertion of rising, and conse- 
cjuenlly it should be removed as soon as 
that danger is over. If a radical cure were 
attempted, of course the clams would su- 
persede this, either in the stallion or gelding. 

And concerning the treatment of strangu- 
lated hernia in geldings. Inguinal- hernia, 
talcing the same course, is susceptible of 
the same terminations, and requii-es the 
same treatment as in staOions. The taxis 
is to be employed, and will be used with 
most effect, the operator (the horse lying 
upon his back) extending the hernial sheath 
v\'ith one hand, while he manipulates with 
the other ; or, should this fail, by instructing 
his assistant to hold up the hernial mass 
from the belly, so as to take its pressure off 
tlie ring, and thus give him an opportunity 
to renew his efforts with more effect. In 
some cases, the introduction of one hand 
into the rectum becomes necessary. The 
reduction of the hernia should be followed 
up immediately by the application of the 
clams, if we unite with the reduction an 
attempt at permanent cure of the hernia ; 
taking care, at the time, to draw out the 
part of tiie scrotum to which the vaginal 
sheath is adherent, and to push up the 
clams as close as possible to the belly ; they 
are tiien to be closed, as for castration. 

Of congenital hernia, our limits allow of 
little more than the mention ; nor need 
more be detailed, as its consequences are 
seldom injurious. It appears that inguinal 
hernia commonly exists in the fcrtus in 
utero. M. Lincguard, V . S., of Normandy, 
where breeding is very extensively pursued, 
has ascertained that enterocele is invariably 
present at birth ; even in abortions, and in 
subjects still-born. The congenital enter- 
ocele is an attendant on birth, increasing up 
to the third or sixth month, but afterwards 



diminishing, and ultimately vanisliing. 
Should it continue beyond a year or cieht- 
een months, it is to be regarded as a chronic 
or permanent hernia. Chronic or perma- 
nent hernia, it may be remarked, our obser- 
vations being so much limited to geldings, 
we see little of. Castration, however, with 
the armed clams, is the evident cure. 

Sirangidation of the Intestines, or Morbid 
Displacement of the Intestines. The intes- 
tines, in consequence of their peristaltic 
motion, become sometimes entangled to- 
gether, and a fatal strangulation takes place; 
this happens, occasionally, from some of 
the mesenteric folds entwining them ; some- 
times by their rupturing the mesentery, and 
becoming strangulated by passing through 
the opening they have made : but it is much 
oftener the consequence of spasmodic ac- 
tion, and during colic these inversions, invo- 
lutions, invaginations, and inlrosusceptions 
occur. "When thus affected, it is not un- 
usual for the ileum to become reversed in 
its usual course ; in which case, a portion, 
then contracted by spasm, becomes forced 
into a part less constringed, and an impen- 
etrable obstruction thence is formed. We 
may draw a practical inference from these 
cases, — that in spasm we should attempt 
an early relief; and likewise that we should 
endeavor, in all cases of failure in bowel 
affections, invariably to make ^post-mortem 
examination: and this we may do on the 
ground that repeated cases may enable us 
accurately to interpret symptoms ; then, al- 
though we cannot relieve, we may offer 
such an opinion as will convince our em- 
ployers it is not our ignorance of the signs, 
but our circumscribed means, which is the 
cause of our inability to afford assistance.* 

Mortification. — A part deprived of 
vital force, by causes inducing a loss of tone. 

Moulting.— Casting the coat. In spring 
the old coat is shed, or thrown off, and the 
horse gradually improves in spirit and in 
appearance ; but, during the change, he is 
more liable to take cold. In the latter part 
of the year, the coat becomes longer and 

*Blaincs' "Outlines." 



A DICTIONARY. 



257 



coarser, and loses its healthy gloss ; at the 
same time, the horse often becomes weak, 
sweats readily upon moderate exercise, and 
is often incapable of performing his usual 
labor. This is more especially the case 
with horses that have been hard worked 
and badly fed. At both these periods it is 
necessary to take particular care of horses, 
and work them moderately. A horse, when 
moulting, .should not be exposed in the 
stable to a current of air, but kept in a ven- 
tilated stable. Warm clothing is improper. 

Mucilage. — A solution of gum, or any- 
thing that partakes of the natm-e of gum. 
Gummy or mucilaginous drinks are useful 
in internal disease ; the cheapest is an in- 
fusion of linseed or marsh-mallows ; but the 
best, perhaps, is a solution of gum arable. 

Mucous Membranes. — (See Membrane.) 

Mucous. — Many of the secretions of the 
body are of a mucous nature. 

Mucus. — A fluid secreted by raucous 
surfaces. 

Muscle. — The parts that are usually in- 
cluded under this name consist of distinct 
portions of flesh, susceptible of contraction 
and relaxation. 

Musk. — A powerful odorous substance, 
whose medical virtues are chiefly anti-spas- 
modic. 

Myrrh. — A gum resin of a fragrant 
smell and bitter taste. It is given internaUy, 
as a tonic, in doses of one or two drachms. 
Tincture of myrrh is sometimes applied to 
wounds, ulcers, and sinuses. 

Nag. — A name sometimes applied to 
road horses, and such as have been docked, 
in contradistinction to those that have long 
tails, or are used in harness. 

Narcotics. — Medicines which stupefy, 
relieve pain, and promote sleep. There 
are, however, two difl'erent ways to efleet 
these objects, and, of course, two diflerent 
characters of remedies to be used for the 
purpose. The popular method is to ad- 
minister opium, whose natural tendency is 
to depress the vital powers, and deprive 
them of sensibility. AH mixtures, in any 
form, that contain opium, though soothing 
for the present, are ultimately and suurely 

33 



pernicious. The true plan is to give anti- 
spasmodics. (See Anti-spasmodics.) 

Nares. — The nostrils. 

Necrosis. — The mortification and sepa- 
ration of a portion of dead bone from the 
other parts of the bone. 

Nepiiritics. — Medicines that act dn the 
kidneys. 

Nerving, Nekve Operation. — It con- 
sists of cutting out a portion of the nerve 
which supplies the foot, either just above 
the fetlock joint, which is named the high 
operation, or in the pastern, which is called 
the low operation. In the former the sen- 
sibility of the foot is supposed to be entirely 
destroyed, and in the latter only partly so. 
Dr. White observes, serious mischief, such 
as the loss of the hoof, has sometimes fol- 
lowed the higher nerve operation. 

" After the division of a ner\'e, the ex- 
tremities of the divided portion retract, 
become enlarged and more vascular; but 
especially the upper portion ; and coagu- 
lable lymph is efl'used, which soon becomes 
vascular. In a few days the coagulable 
lymph from each portion becomes united, 
and anastomosis forms- between the blood- 
vessels; the lymph gradually assumes a 
firmer texture, and the number of the blood- 
vessels diminishes, and the newly-formed 
substance appears to contract, like all other 
cicatrices, so as to bring the exti-emities of 
the divided portions nearer and nearer to 
each other. It is difficult to determine, 
from an experiment on the limb of an 
animal, the exact time at which the nerve 
again performs its functions after being 
divided. In eight weeks after the division 
of the sciatic nerve, I have observed a rab- 
bit to be in some degree improved in the 
use of its leg; but at the end of eighteen 
weeks it was not perfect. When the nerves 
of the leg of a horse are divided just above 
the foot, they are sufficiently restored to 
perform their functions, in some degi-ee, in 
six or eight weeks ; but it must be observed 
that these nerves are only formed for sensa- 
tion, and it is very diflerent with the nerves 
of nutrition, voluntary motion, etc.; the re- 
union is sometimes accomplished by gran- 



258 



A DICTIONARY. 



ulations. Secondly, I would observe, that 
punctures and partial divisions of nerves 
heal in the same way as wiicn there has 
been a total division; and that, even on 
the first infliction of the wounds, the func- 
tion of the nerves is very little impaired."' 
(See Swan's work on morbid local affec- 
tions.) 

Mr. Sewell finds " that, in cases of entire 
section of a nerve, sensation returns in 
about two months ; but in others, in which 
a portion of nerve has been exercised, that 
the period of restoring feeling can by no 
means be foretold : in one of his own 
horses, he ascertained that there was no 
sensibility in the foot, even at the expiration 
of three years ; and in some others, after a 
longer interval, the organ appeared to be 
wholly destitute of feeling." 

Nicking. — An operation often performed 
on horses, to raise the tail, and make them 
carry it more gracefully, or rather to suit 
the taste of man. 

Nippers. — The front teeth, above and 
below, have been thus named. 

Nitre. — Mr. Morton writes : " Nitre 
given internally is a febrifuge and diuretic. 
The dose is from two to four drachms. In 
order to obtain its full etlect as a febrifuge, 
it should be exhibited in the form of ball, so 
that it may undergo solution in the stom- 
ach ; but as a diuretic, it is best given in 
solution. It passes to the kidneys un- 
changed, and its presence may be readily 
detected in the urine by means of bibulous 
paper immersed in it, which, on being 
dried, deflagrates ; or, if the quantity given 
be great, it may be procured in crystals 
from the urine. Very large doses of this 
salt act as an irritating poison. Two 
pounds being given in six pints of water to 
a horse, apparently in health, within lialf an 
hour irritation of tlie mucous lining of the 
alimentary canal began, evidenced by the 
ftpces being voided frequently and in small 
tpiantities. The kidneys were soon after 
excited into increased action, the urine being 
forcibly expelled, and the act acconi])anied 
with uneasiness. In about four hours after, 
the pulse had risen to nearly double the 



number of beats, and the visible mucous 
membranes were highly injected. Blood 
being withdrawn from the jugular vein, it 
presented all the appearances of arterial 
blood. In the serum the existence of the 
salt could be detected, but it wa.s obtained 
in abundance from the urine. From this 
period the symptoms became less in-gent, 
and the pulse gradually regained its healthy 
standard ; but the dung and mine continued 
to be passed more frequently than natural 
throughout the day. 

Externally a|)plied, nitrate of potassa is a 
valuable stimulant to wounds, and it may 
be employed with much benefit when gan- 
grene has taken place. For this purpose, 
a saturated solution is ordered to be kept in 
the pharmacy. 

Oats. — According to Sir H. Davy's 
analysis, oats contain 742 parts of nutritive 
matter out of 1000, which is composed of 
641 mucilage, or starch, 15 saccharine 
matter, and 87 gluten, or albumen. New 
oats are difficult of digestion. 

Oblique Muscles. — The muscles of 
the abdomen, or belly, are thus named. 
There are four of them ; two external and 
two internal. Some of the muscles of the 
eye are also named oblique muscles. 

Occiput. — The back part of the head. 

CEdejia. — A watery or dropsical swell- 
ing. 

(Esophagus, or Esophagus. — The tube 
passing from the mouth to the stomach. 

Ointments. — Unctuous substances of 
the consistence of butter ; when made con- 
siderably thinner by the addition of oil, 
they are termed liniments ; but when their 
solidity is increased by wax, rosin, etc., 
they are termed plasters. 

Olecranon. — The head of the bone 
named ulnar (see cut), in the horse ; it 
aflbrds a powerful lever for the triceps ex- 
tensor cubiti muscle to act upon, in straight- 
ening the fore arm upon the humerus. 
(See Skeleton.) 

Olfactory Nerves are spread over all 
the interior of the nostril, and constitute 
the sense of smell. 

Omentum. — The omentum, or caul, is a 



A DICTIONARY. 



259 



double membrane, containing within its 
folds a considerable quantity of fat, in the 
human body and many animals. But in 
the horse this is never seen ; nor does the 
omentum contain much fat ; what there is 
lies in the region of the stomach. 

Opacity. — A want of transparency in 
those parts of the eye named pupil, or 
cornea. 

OPERATIONS. 

Of surgical operations,* and the vari- 
ous RESTRAINTS IT IS SOMETIMES NECESSARY 
TO PLACE THE HORSE UNDER FOR THEIR PER- 
FORMANCE. — " When it is necessary to per- 
form any painful operation on so powerful 
an animal as the horse, it is of consequence 
to subject him to a restraint equal to the 
occasion. Horses are very dissimilar in their 
tempers, and bear pain very differently ; but 
it is always prudent to prepare for the worst, 
and few important operations should be at- 
tempted without casting. Humanity should 
be the fundamental principle of every pro- 
ceeding, and we ought always to subject 
this noble animal to pain with reluctance ; 
but when circumstances absolutely call for 
it, we should joyfully close our hearts to all 
necessary suffering. The resistance of the 
horse is terrible, and it is but common pru- 
dence to guard against the effects of it. The 
lesser restraints are various : among them 
may be first noticed the twitch. The twitch 
is a very necessary instrument in a stable, 
though, when frequently and officiously 
used, it may have the ill effect of rendering 
some horses violent to resist its application. 
In many instances blindfolding will do more 
than the twitch ; and some horses may be 
quieted, when the pain is not excessive, by 
holding the ear in one hand, and rubbing 
the point of the nose with the other. A 
soothing manner will often engage the atten- 
tion and prevent violence ; but it is seldom 
that either threats or punishment render an 
unruly horse more calm. Inexperienced 
persons guard themselves only against the 
hind legs; but they should be aware that 
gome horses strike terribly with their fore 

* Blaincs' " Outlines." 



feet: it is prudent, therefore, in all opera- 
tions, t'l blindfold the animal, as by this he 
becomes particularly intimidated, and if he 
strikes he cannot aim. When one of the 
fore extremities requires a very minute ex- 
amination, it is prudent to have the oppo- 
site leg held up ; it may, in some cases, be 
tied : and when one of the hinder feet is the 
object of attention, the fore one of the same 
side should be held up, as by this means the 
animal is commonly prevented from strLlc- 
ing. K this precaution be not taken, still 
observe to keep one hand on the hock, while 
the other is employed in Avhat is necessary ; 
by which means, if the foot become elevated 
to lack, sufficient warning is given, and the 
very action of the horse tlirows the operator 
away from the stroke. Without the use of 
these art^the practitioner will expose him- 
self to much risk. * The trcvis is the very 
utmost limit of restraint, and is seldom used 
save by smiths, to shoe very violent and 
powerful horses : whenever recovirse is had 
to it, the greatest caution is necessary fo 
bed and bolster all the parts that are likely 
to come in contact with the body. On the 
Continent we have seen horses shod in this 
machine, and apparently put into it from no 
necessity greater than to prevent the clothes 
of the smith from being dirtied. Horses 
have been destroyed by the trevis, as well 
as by casting ; or their aversion to the re- 
straint has been such, they have died from 
the consequences of their own resistance. 
The stdc-line is now very generally used, not 
only in minor operations, but also in those 
more important. Many veterinarians do not 
use any other restraint than this, in which 
they consider there is safety both to the 
horse and to the operator. It is applicable 
to sucfi horses as are disposed to strike be- 
hind; and consists in placing a hobble strap 
around the pastern of one hind leg, and then 
carrying from a web collar passed over the 
head the end of a rope through the D of the 
hobble, and back again under the webbing 
round the neck. A man is then set to pull 
at the free end of the rope, by which the 
hinder leg is drawn forward without elevat- 
ing it from the ground. By this displace- 



2G0 



A DICTIONARY. 



merit of one leg the horse is effectually 
secured from kicking with either. Occasion- 
ally it is thus applied : hobbles are put 
on both hind legs, and the rope is passed 
through each of the rings. According to 
this last method, the horse is actually cast, 
as he must fall when the ropes are pulled. 
Take a long rope, and tie a loop in the mid- 
dle, which is to be of such a size as it may 
serve for a collar ; pass the loop over the 
head, letting tlie knot rest upon the withers ; 
then take the free ends, pass them through 
the hobbles, and bring it iinder the loop. 
Let two men pull at the ropes, and the hind 
legs will be drawn forward. 

" Casting: — The objections to this prac- 
tice arise from the dangers incurred by forc- 
ing the horse to the ground. Mr. Bracy 
Clark simplified casting, by iuvenftng some 
patent hobbles, having tf running chain in- 
stead of rope, and which, by a shifting D, 
made the loosening of all the hobbles, for 
the purpose of getting at a particular leg, 
unnecessary. These were still further im- 
proved by Mr. Budd, so as to render a 
release from all the hobbles at once practi- 
cable. Hobble leathers and ropes should be 
kept supple and pliant with oil, and ought 
to be always examined previous to using ; 
nor should the I) or ring of the strap be of 
any other metal than iron. Brass, however 
thick, is brittle, and not to be depended on. 
To the D or ring of one pastern hobble, a 
chain of about four feet long is attached; to 
this a strong royic is well fastened, antl, ac- 
cording to the way the horse is to be thrown, 
this hobble is to be fixed on the fore foot of 
the contrary side : the rope is then passed 
from the hobble on the fore foot to the D of 
tiie hind foot of that side, then to the other 
hind foot, and, lastly, through the D of the 
other fore foot. After this, much of the ease 
and safety of the throw depend on bringing 
the legs as near togetlier as possible. This 
should be done by gradually moving them 
nearer to each other, without alarming the 
horse; which will very much faciUtate the 
business, and is really of more moment than 
is generally imagined. A space sufficiently 
large should be chosen for the purpose of 



casting, as some horses struggle much, and 
throw themselves with great violence a con- 
siderable way to one side or the other ; and 
they are able to do this if the feet have not 
been brought near together previous to at' 
tempting the cast. The place should be also 
very well littered down. The legs having 
been brought together, the assistants must 
act in concert; one particularly should be 
at the head, which must be carefully held 
throughoiit by means of a strong snaffle 
bridle ; another should be at the hind part 
to direct the fall, and to force the body of 
the horse to the side which is requisite. 
Pursuing these instructions, the animal may 
be at once rather let down than thrown, by 
a dexterous and quick drawing of the rope ; 
the whole assistants acting in concert. The 
moment the horse is down, the person at the 
head must throw himself upon that mem- 
ber, and keep it secure ; for all the efforts of 
the animal to disengage himself are begun 
by elevating the head and fore parts. The 
rope is tightened. The chain is fixed by 
inserting a hook through one of the links, 
of sufficient size not to pass the hobbles. 
When the operation is over, the screw which 
fastens the chain to the hobble, first put upon 
one fore leg, is withdrawn. The chain then 
flies through the D's of the otJier hobbles, 
and all Ihe logs are free, save the fore leg 
first alluded to ; the strap of this has to be 
afterwards unbuckled. There are also other 
apparatus used in casting, as a strong 
leathern case to pass over the head, serving 
as a blind when the animal is being thrown ; 
and as a protection against his rubbing the 
skin off his eyes when down. Then a sur- 
cingle is also used. This is fastened round 
the horse's Jjody, and from the back hangs a 
broad strap and a rope : the strap is fastened 
to the fore leg of that side which it is de- 
sired should be uppermost; the line is given 
to a man who stands on the opposite side 
to the generahty of tlie pullers. On the 
signal being given, the men havyig hold of 
the hobble rope pull the legs one way, while 
he who has hold of the rope attached to the 
surcingle pulls the back in a contrary direc- 
tion, and the horse is immediately cast 



A DICTIONAUY. 



261 



" Sling-ing' is a restraint which horses 
submit to with great impatience, and not 
without much inconvenience, from the vio- 
lent excoriations occasioned by the friction 
and pressure of the bandaging around liis 
body. Graver evils are also brought about 
by the abdominal pressure : some horses 
stale and dung with difTiculty when sus- 
pended; and inflammation of the bowels 
has not unfreqtiently come on during sling- 
ing. The slings are, however, forced on us 
in some cases, as in fractured bones, the 
treatment of open joints, and some other 
wounds where motion would be most un- 
favorable to the ciuative treatment. Sus- 
pension may be partial or complete. Sus- 
pension of any kind will require the appli- 
cation of pulleys and ropes affixed to the 
beams, that the whole body of the horse 
may be supported. A sling may be formed 
of a piece of strong sacking, which is to pass 
under the beUy, the two ends being fastened 
firmly to pieces of wood ; each of about 
three feet long, and which are to reach a 
little higher than the horse's back : to the 
pieces of wood, cords and pulleys are to be 
firmly attached, by which means the sacking 
can be lowered or raised at pleasure. To the 
sacking, also, are to be sewn strong straps, 
both before and behind, to prevent the horse 
sliding in either direction, without carrying 
the sacking with him. Upon this so-formed 
cradle he is to recline. If horses when they 
are fresh should be placed in this machine, 
most of them would either injiu:e themselves, 
or break through all restraint. However, by 
tying up their heads for three or four nights, 
their spirit is destroyed. The slings may 
then be applied without the fear of resist- 
ance : it is tiie best method not to pull the 
canvas firm up, but to leave about an inch 
between the horse's belly and the cloth, so 
that the animal may stand free, or throw his 
weight into the slings when he pleases. In 
this fashion a horse may remain for months 
in the slings, and at the end of the time dis- 
play none of the wear and tear so feelingly 
described by old authors. 

" Castration. — This practice is of very 
ancient origin ; and is as extensive as ancient, i 



It is founded on the superior placidity of 
temper it gives. The castrated horse no 
longer evinces the superiorities of his mas- 
culine character, but approaches the softer 
form and, milder character of the mare. 
Losing his ungovernable desires, he submits 
to discipline and confinement without resist- 
ance ; and, if he be less worthy of the paint- 
er's delineation and the poet's song, he is 
valuable to his possessor in a tenfold degree. 
In England, where length in the arms and 
of the v.'ide spread angles of the limbs is ab- 
solutely necessary in the horse to accomplish 
the rapid travelling so much in vogue among 
us, the exchange of the lofty carriage and 
high action of the stallion is absolutely 
necessary ; and, when we have added the 
lessened tendency of the gelding to some 
diseases, as hernia, founder, cutaneous 
affections, etc., we may be content to leave 
the sexual type with the racer for his breed ; 
also with the drayhorse for his weight, and 
the fancy of his owner. Supposing it, 
therefore, eligible to castrate our horses, 
what is the proper age for the operation ? 
What are the relative advantages and dis- 
advantages of the different methods of per- 
forming it ? The proper age to castrate 
the young horse must depend on circum- 
stances ; as on his present appearance, his 
growth, and the future purposes we intend 
him for ; observing, generally, that the more 
early it is done, the safer is the operation : 
for, until these organs begin to secrete, they 
are purely structural parts, and as such are 
not so intimately connected with the sym- 
pathies of the constitution. Some breeders 
of horses castrate at twelve months ; others 
object to this period, because they think the 
animal has not sufficiently recovered the 
check experienced from weaning, before this 
new shock to the system occurs. In the more 
common sort of horses used for agricultural 
purposes, it is probably indifferent at what 
time the operation is performed; this con- 
sideration behig kept in view, that the 
earlier it is done the lighter will tlie horse 
be in his fore-hand; and the longer it is 
protracted the heavier will be his crest, and 
the greater his weight before, which in 



262 



A DICTIONARY. 



heavy draught work is desirable. For car- 
riage horses it would be less so, and the 
period of two years is not a bad one for 
their castration. The better sort of saddle- 
horses should be well examined every three 
or four months ; particularly at the ages of 
twelve, eighteen, and twenty-four months ; 
at either of which times, according to cir- 
cumstances or to fancy, provided the fore- 
hand be sufficiently developed, it may be 
proceeded with. Waiting longer may 
make the horse heavy ; but, if his neck ap- 
pear too long and thin, and his shoulders 
spare, he will assuredly be improved by be- 
ing allowed to remain entire for six or eight 
months later. Many of the Yorkshire 
breeders never cut till two years, and think 
their horses stronger and handsomer for it : 
some wait even longer, but the fear in this 
case is, that the staUion form will be too 
predominant, and a heavy crest and weighty 
fore-hand be the consequence ; perhaps also 
the temper may suffer. Young colts require 
little preparation, provided they are healthy 
and not too full from high living ; if so, 
they must be kept somewhat short for a few 
days ; and in all, the choice of a mild season 
and moderate temperature is proper. When 
a full grown horse is operated on, some fur- 
ther preparation is necessary. He should 
not be in a state of debility, and certainly 
not in one of plethora : in the latter case, 
lower his diet, and it would be prudent to 
give him a purgative. It is also advisable 
that it be done v>hen no influenza or stran- 
gles rage, as we have found the ellects of 
castration render a horse very obnoxious to 
any prevalent disease. The advanced spring 
season, previous however (o tlie flies becom- 
ing troublesome, is the proper time for the 
performance of the operation upon all valu- 
able horses ; and be careful that it be not 
done until after the winter coat has been 
shed, which will have a favorable effect on 
the future coating of the horse, independent 
of the circumstance, that at a period of 
change the constitution is not favorable to 
any unusual excitement. 

" Castration is performed in various ways, 
but in all it expresses the removal of the 



testicles; there are methods of rendering 
the animal impotent without the actual de- 
struction of these organs ; for if by any 
other method the secretion of the spermatic 
glands is prevented, our end is answered. 

" Castration by cauterization is the method 
which has been principally practised among 
us. But this by no means proves it the best; 
on the contrary, many of our most expert 
veterinarians do not castrate by this method. 
Air. Goodwin, and many other practitioners 
of eminence, never castrate by cautery. 

" A preliminary observation should be 
made previously to casting, to see that the 
horse is not suffering from a rupture : such 
cases have happened ; and as in our method 
we open a direct communication with the 
abdomen, when the horse rises it is not im- 
probable that his bowels protrude until they 
trail on the ground. Hernia as a conse- 
quence of castration may easily occur by 
the uncovered operation ; for, as already 
observed, it makes the scrotal sac and ab- 
dominal cavity one continuous opening. 
It is not to be wondered at, therefore, if the 
violent struggles of the animal should force 
a quantity of intestine through the rings 
into the scrotal bag. Should we be called 
on to operate on a horse which already had 
hernia, it is evident we ought not to proceed 
with it, unless the owner be appriied of the 
risk, and willing to abide by it. In such 
case we would recommend that the method 
of Girard be practised, /. e. to inclose the 
tunica vaginalis within the clams (suffi- 
ciently tight to retain them, but not to pro- 
duce death in the part) pushed high up 
against the abdominal ring, and then to re- 
move the testicle, being very careful to 
avoid injuring any portion of intestine in 
the operation. When a discovery is made 
of the existence of hernia after an opening 
has been already made for the common pur- 
pose of castration, should the operator con- 
tinue his process, and castrate ? We should 
say, by no means ; but, on the contrary, we 
would greatly prefer the method recom- 
mended by Mr. Pcrvicall, — firmly to unite 
the lips of the external wound by suture, 
allowins; the testicle itself to as.sist in block- 



A DlCTIO>;AnY. 



263 



ing up the passage ; with a hope also that 
ihe iiiflammation caused by the e^ccision 
might altogether stop up the scrotal com- 
munication with the abdomen. But, in the 
appalling case of immense jKotrusion of 
intestine, what is to be done ? Mr. Cole- 
man, in such a case, proposes to make an 
opening near the umbilicus, large enough 
to introduce the hand, and thus draw in the 
bowels. Mr. Percivall would prefer dilating 
the external ring : but the testicle must be 
very firmly, retained, and even permanently 
fixed against the dilated ring, or the bowels 
would again descend. The intestines 
probably would become inflated in any 
such case. 

" As unbroken young horses are the most 
usual subjects of this operation, and as such 
often have not yet been bridled, if a colt 
cannot be enticed with oats, etc., he must 
be driven into a corner between two steady 
horses ; where, if a halter cannot be put on, 
at least a running hempen noose can be got 
round his neck ; but, which ever is used, it 
should be flat, or the struggles, which are 
often long and violent, may bruise the neck, 
and produce abscess or injury. When his 
exertions have tired him, he may be then 
led to the operating spot ; here his attention 
should be engaged while the hobbles are 
put on, if possible ; if not, a long and strong 
cart-rope, having its middle portion formed 
into a noose sufficiently large to take in the 
head and neck, is to be slipped on, with the 
knotted part applied to the counter or breast; 
the long pendant ends are passed back- 
ward between the fore legs, then carried 
round the hind fetlocks ; brought forward 
again on the outside, run under the collar- 
rope ; a second time carried backward on 
the outer side of all, and extended to the 
full length in a direct line behind the animal. 
Thus fettered, Mr. Percivall says his hind 
feet may be drawn under him toward the 
elbows ; it has been, however, often found 
that, at the moment the rope touches the 
legs, the colt cither kicks and displaces the 
rope, or altogether displaces himself; but 
his attention can generally be engaged by 
one fore leg being held up, or by having his 



ear or muzzle rubbed, or even by the twitch ; 
if not, the rope may be carried actually 
round each fetlock, which then acts like a 
hobble ; and this rope may be gradually 
tightened: this last, however, is a very ques- 
tionable method, and the others therefore 
ought to be long tried before it is resorted 
to ; in this way people have succeeded with 
very refractory colts ; but it requires very 
able assistants, and, if possible, the man 
who has been used to the individual colt 
should be present. In either way, as soon 
as the rope is fixed, with a man to each end 
of it behind the colt, let them, by a sudden 
and forcible effort in concert, approximate 
his hind legs to his fore, and thus throw 
him. Before the colt is cast, however, it 
should be endeavored to ascertain that he 
is free from strangles and hernia. 

" Being satisfied that no hernia exists on 
either side, proceed to cast the colt, tiirning 
him, not directly on the left side, but prin- 
cipally inclining that way ; and, if possible, 
let the croup be very slightly elevated ; it is 
usual to place him directly flat on the left 
side, but the above is more convenient. 
Next secure the near hind leg with a piece 
of hempen tackle, having a running noose ; 
or, in default of this not being at hand, 
make use of the flat part of a hempen hal- 
ter, which should for safety be put on be- 
fore the hobble of that leg is removed ; as 
may be readily done, if the hobbles having 
shifting or screw D's, as described in cast- 
ing, are made use of. Every requisite being 
at hand, the operator, having his scalpel 
ready, should place himself behind the 
horse, as the most convenient way to per- 
form his manipulations ; and, firmly grasp- 
ing the left testicle with his left hand, and 
drawing it out so as to render the scrotum 
tense, he should make an incision length- 
ways, from the anterior to the posterior 
part of the bag. The resistance of the 
cremaster muscle has to be overcome be- 
fore the testicle can be forced to the bottom 
of the scrotum ; and this is the more readily 
accomplished if the annimal's attention be 
engaged. The incision may be carried at 
once tlu-ough the integuments, the thin dar- 



26-t 



A DICTIONARY. 



tos expansion, and the vaginal coat of the 
testicles, with a sweep of the scalpel : but 
with one less dexterous at the operation, it 
will be more prudent to make the fu-st in- 
cision through the scrotum and dartus only, 
to the required extent ; and then to do the 
same by the vaginal coat, thus avoiding to 
wound the testicle, which would produce 
violent resistance, and give unnecessary 
pain. We, however, take this opportunity 
of noting, that cases have occiu-red, when 
the tunica vaginalis was divided, no testicle 
followed ; firm adhesions between this tunic 
and the tunica albuginea having retained it 
fast. In such cases the scalpel must be 
employed to free the testicle, by dissecting 
it away from the vaginal sac. When no 
such obstruction occurs, the testicle, if the 
opening be sufficiently large, will slip out ; 
but the operator must be prepared at the 
moment of so doing to expect some violent 
struggles, more particularly if he attempt 
to restrain the contractions of the cremas- 
ter, and by main force to draw out the tes- 
ticle. Preparatory to this, therefore, the 
twitch should be tightened ; the attendants, 
especially the man at the head, must be on 
the alert ; and the testicle itself, at the time 
of this violent retraction of the cremaster, 
should be merely held, but not dragged in 
opposition to the contraction. If the clams 
have been put on over the whole, according 
to Mr. Percivall's method, they will assist 
in retaining the retracting parts ; but they 
must not be used with too much pressure. 
The resistance having subsided, the clams 
must now be removed ; or, if they have 
not been previously in use, they must now 
be taken in hand, and, having been prepared 
by some tow being wound round them, 
should be placed easily on the cord, while 
time is found to free from the gi'ip of the 
pincers the vas deferens, or spermatic tube, 
which is seen continued from the epididy- 
mis. The Russians, Mr. Goodwin informs 
us, cut it through when they operate. Hu- 
manity is much concerned in its removal 
from pressure, because of the excess of 
pain felt when it is included. It is neces- 
sary, before the final fixing of the clams, to 



determine on the part where the division of 
the cord is to take place. To use Mr. Per- 
civall's words, ' If it be left too long, it is 
apt to hang out of the wound afterward, 
and retard the process of union;' on the 
other hand, if it be cut very short, and the 
arteries happen to bleed afresh after it has 
been released from the clams, the operator 
will find it no easy task to recover it. The 
natural length of the cord, which will mainly 
depend on the degree of the descent of the 
gland, will be our best guide in this partic- 
ular. The place of section determined on and 
marked, close the clams sufficiently tight to 
retain firm hold of the cord, and to effectu- 
ally stop the circulation within it. There 
are now two modes of making the division : 
the one is to sever it with a scalpel, and 
then to sufficiently sear the end of it as to 
prevent a flow of blood. The other, and 
in some respects the preferable method, is 
to employ a blunt-edged iron, which is to 
divide by little crucial sawings, so that, 
when the cord is separated, it shall not pre- 
sent a uniform surface, but ragged edges, 
which will perfectly close the mouths of the 
vessels. This done, loosen the clams suf- 
ficiently to observe whether there be any 
flow of blood ; gently wipe (he end of the 
cord also- with the finger, as sometimes an 
accidental small plug gets within the vessel; 
this had better be removed at the time. 
Retain a hold on the clams a few minutes 
longer ; and, while loosening them gradu- 
ally, observe to have an iron in readiness 
again to touch the end of the cord, if any 
blood makes its appearance. Satisfied on 
this point, sponge the parts with cold water ; 
no sort of external application is necessary, 
still less any resin seared on the end of the 
cord, which can only irritate, and wiU never 
adhere. On the after-treatment much dif- 
ference of opinion has existed, and even yet 
exists. The powerful evidence of accumu- 
lated facts has now convinced us of the 
necessity and propriety of some motion for 
the newly castrated horse, as a preventive 
of local congestion ; such practice is com- 
mon in most countries, and seems salutary 
in aU. Hm-trel d'Arboval, thus impressed, 



A DICTIONARY. 



265 



recommends the horse, immediately after 
the operation, to be led out to walk for an 
hour ; and it is a general plan in France to 
wailc such horses in hand an hour night and 
morning. JVIi'. Goodwin, in proof of its 
not being hurtful, informs us that whole 
studs of horses, brought to St. Petersburgh 
to be operated on, are immediately travelled 
back a certain portion of the distance, night 
and morning, until they arrive at home. 
We have, therefore, no hesitation in recom- 
mending a moderate degree of motion in 
preference to absolute rest. 

" The French method of castration is advo- 
cated by Mr. Goodwin ; and it is sufficient 
that it receives his recommendation to en- 
title it to attention ; it is rendered the more 
so, as he obser^'es on the method in general 
use among us, ' that the operation per- 
formed by the actual cautery always in- 
duces, more or less, symptoms that often 
become alarming; and that it cannot be 
performed on the adult without incurring 
more swelling and severer consequences 
than attend other methods of operation. If 
I ever use the actual cautery, it is for the 
sake of expedition, and then only on a 
yearling, or a two-year old ; but I am re- 
solved never to employ it again on an 
adult.' These observations, as emanating 
from such a source, must be deemed im- 
portant. Mr. Goodwin then offers the de- 
scription of the French method of operating, 
from Hurtrel d'Arboval. ' Castration, by 
means of the clams, is the method in gen- 
eral use, if not the only one now employed ; 
it is the most ancient, since it was recom- 
mended by Hieroclius among the Greeks. 
It is performed in two ways, the testicle 
being covered or vncovered. In the former, 
the exterior of the scrotum, formed by the 
skin and dartos muscle, is cut through, and 
the testicle is brought out by dissecting 
away the laminated tissue, the gland being 
covered by the tunica vaginalis ; the clam 
is then placed above the epididymis, oi'Iside 
the external peritoneal covering, of the cord. 
In the uncovered operation, the incision is 
made through the servus capsule of the tes- 
ticle ; the tunica vaginalis being divided, 
a 



the testicle presents itself, and the clam is 
placed well above the epididymis, on the 
cord. The operation, performed in either 
way, requires us to provide ourselves with a 
scalpel, a pair of clams, a pair of long pin- 
cers, made purposely to bring the ends of 
the clams together, and some waxed string. 
The clams may be formed of different kinds 
of wood ; but the elder is considered the 
best, and generally made use of» To make 
a clam, we procure a branch of old and dry 
elder, whose diameter should be about an 
inch, and whose length should be from five 
to six inches : of com'se, the dimensions 
must at all times be proportioned to the 
size of the cord we have to operate on. At 
the distance of half an inch from each end, 
a small niche, suthcicntly deep to hold the 
string, must be made, and then the wood 
should be sawed through the middle length- 
ways. Each divided surface should be 
planed, so as to facilitate the opening of 
the clams, either when about to place them 
on or take them off. The pith of the wood 
is then to be taken out, and the hollow 
should be filled with corrosive sublimate and 
flour, mixed with sufficient water to form it 
into a paste. Some persons are not in the 
habit of using any caustic whatever; then, 
of course, scooping out of the inside of the 
clam is not necessary : notwithstanding, the 
caustic, inasmuch as it produces a speedier 
dissolution of the parts, must be useful, and 
ought not to be neglected.' The addition 
of the caustic, however, Mr. Goodwin ob- 
jects to with gi-eat reason, remarking, that 
unless it be a very strong one, and therefore 
dangerous to employ, it cannot be of any 
use to parts compressed and deprived of 
circulation and life. He furtlier informs us 
that he has operated in six cases in succes- 
sion with the same effect, without any es- 
charotic matter whatever. An experimental 
case of Mr. Percivall's terminated fatally: 
by the use of caustic the cord was greatly 
inflamed, as high as the ring, and which 
unquestionably produced the unfortunate 
result. ' The covered operation,' continues 
Mr. Goodwin, ' is the one that I am about 
to advocate, and wliich difiers only inso- 



2G6 



A DICTIUNARY. 



much, that the scrotum and dartos muscle 
must be cautiously cut through, without 
dividing the tunica vaginalis. It was Mon- 
sieur Berger, who was accidentally at my 
house when I was about to castrate a horse, 
and who, on my saying that I should prob- 
ably do it with the cautery, expressed his 
surprise that I should perform the operation 
in any other way than on the plan generally 
approved of in France. Being a stranger 
to it, he kindly consented to preside at the 
operation, and, after seeing him perform on 
the near testicle, I did the same on the 
right, but, of course, not with the same fa- 
cility. After opening the scrotum, and 
dissecting tlirough the dartos, which is very 
readily done by passing the knife lightly 
over its fibres ; the testicle, and its covering, 
the tunica vaginalis, must be taken in the 
right hand, while the left should be em- 
ployed in pushing back the scrotum from 
its attachments ; and, having your assistant 
ready, as before, with the clam, it must be 
placed well above the epididymis, and great- 
er pressure is, of course, necessary, as the 
vaginal covering is included in the clam.' 

" Mr. Goodwin fm-ther observes, that in 
Russia he has seen hundreds of horses op- 
erated on, even after the human fashion, 
with safety ; and, he remarks, it certainly 
produces less pain, the animal loses less 
flesh and condition, and is sooner recovered 
than when operated on by the actual cautery. 

" Castration by ligature is a painful, bar- 
barous, and very dangerous practice : and 
consists in inclosing the testicles and scro- 
tum within ligatures, until mortification oc- 
curs, and they drop off". It is practised by 
some breeders on their young colts, but it 
is always hazardous, and disgracefully cruel. 
The substance of the testicle in some coun- 
tries is also broken down either by rubbing, 
or otherwise by pressure between two hard 
bodies : this is practised in Algiers, instead 
of excision, and tetanus is a frequent con- 
sequence of it. In Portugal they twist 
round the testicle, and thus stop the circu- 
lation of the gland. Division of the vas 
deferens has been performed, it is said, with 
success, on many animals ; and is proposed 



as a safe and less painful process than the 
emasculation of the horse. It consists in a 
longitudinal section tlirough the scrotum, 
dartos, and vaginal sheath, so as to expose 
the cord, from which the vas deferens is to 
be separated and severed from the artery and 
vein. There is a certain consent of parts, 
by which the sympathy of an organ remains 
after its functional offices are apparently 
destroyed. There can be little doubt but 
the nervous excitement would continue, the 
vein and artery remaining entire. There 
are certain nice conditions of the organ 
necessary for propagation ; thus, the horse 
who retains his testicles within his abdo- 
men, possesses all the roguish qualities of 
him with one perfectly evolved : he is lust- 
ful, and can cover, but is seldom fruitful. 
Of the morbid consequences of castration 
we have little to say : by early evacuations, 
green food, a loose box, a cool air, moderate 
clothing, but particularly by walking exer- 
cise, swellings of the parts may be prevent- 
ed : if not, bleed and foment ; shoiJd sup- 
puration follow, and sinuses form, treat as 
directed under those heads ; and if tetanic 
symptoms start up, refer to that article. 
There has been lately practised in India a 
novel mode of castration, which is said to be 
the invention of a Boer settled at the Cape 
of Good Hope. The cord is exposed in the 
usual manner ; from the cord the artery is 
singled out ; this vessel is scraped through 
with a coarse-edged blunt knife, when the 
other constitutents of the cord arc cut away, 
and the operation is finished. This method 
is much praised by those who have adopted 
it, and is said to be always attended with 
success. 

^'■Lithotomy. — Hurtrel d'Arboval's ac- 
count of the progress of lithotomy in veteri- 
nary practice commences in 1774. The 
second case was successfully operated on in 
1794 ; and at later periods other veterinary 
surgeons have also performed it. ' In mo- 
nodactyles there are two methods of oper- 
ating for the stone ; one through the rectum, 
the other tlirough the bladder. The first, 
which consists in lying open the bladder by 
a longtitudinal incision made through the 



A DICTIONARY. 



267 



parietes of the part of the rectum adherent 
to it, by means of a straiglit bistoury, is 
easily practised ; but in its consequences is 
dangerous in the extreme: in fact, it is an 
operation never to be adopted but in a case 
where the magnitude of the stone precludes 
its extraction through the neck of the blad- 
der. In all other cases, lithotomy by the 
urethra is to be ])ursued. For its perfor- 
mance, are required a straight probe-pointed 
bistoury, a whalebone fluted staff, and a 
pair of forceps curved at the extremities. 
The animal should, if practicable, be main- 
tained in the erect posture. The tail plaited 
and carried round on the right quarter, the 
operator feels for the end of the staff intro- 
duced up the urethra, and makes an incision 
directly upon it, from above downwards, an 
inch and a half or two inches in length. 
Next, he introduces the sound, and passes 
it onward into the bladder. Now, placing 
the back of the bistoury within the groove 
of the sound, by gliding the knife forwards, 
the pelvic portion of the urethra, and also 
the neck of the bladder, become slit open ; 
the latter in two places, in consequence of 
a second cut being made in withdrawing 
the bistoury. The opening made being 
considered of sufficient dimensions, the oper- 
ator introduces the forceps into the bladder, 
and seizes the calculus, one hand being up 
the rectum, to aid him in so doing. The 
forceps clasping the stone are now to be 
withdrawn, but with gentleness ; and with a 
vacillating sort of movement of the hand 
from side to side, in order more easily to 
surmount any difficulties in the passage, and 
the more effectuaUy to avoid contusion or 
laceration. M. Girard tells us, ' That the cut 
through the pelvic portion of the urethra 
ought always to be made obliquely to one 
side ; the operator should hold his bistoury 
in such a direction that its cutting edge be 
turned toward the angle of the thigh. By 
tills procedure we shall gain easier access to 
the bladder; and not only avoid wounding 
the rectum, but also the artery of Ihe bulb, 
as well as the bulb itself, and suspensory 
ligaments of the penis.' The parts cut 
through in the operation are, 1st, the fine 



thin skin of the perineum, smooth externally 
and marked with a ra]5he ; densely cellular 
internally : 2ndly, adhering to the tissue, 
the faschial covering; derived from the fas- 
chia superficialis abdominis, which has here 
become fibrous : it forms the common en- 
velope to the parts underneath, and is closely 
connected with the corpus musculosum ure- 
thra : 3rdly, the corpus miisculosiim nrethrce, 
that penniform band of fleshy fibres which 
springs by two branches from the ischiatic 
tuberosities embracing the sphincter ani, and 
concealing the arteries of the bulb ; whence 
they unite, and proceed to envelop the 
lu-ethra: 4thly, the corpus spongiosum ure- 
thrcB, the part immediately covered by the 
muscular envelope, and which here is bulb- 
ous. It is more particularly worthy our 
remark, from tAvo arteries penetrating the 
bulb, which come from v.nthout the pelvis, 
ascending obliquely outward to reach the 
part : 5thly, the suspensory ligaments of the 
penis, pursuing the course of, and adhering 
to, the tendinous union of the erectores. 
An attention to the relative position of these 
parts will demonstrate the advantages of 
the lateral oblique incision over one made 
directly along the raphe : by pursuing the 
latter, we necessarily cut through the sus- 
pensory ligaments and into the bulb, wound- 
ing thereby the arteries; whereas, by the 
former, all this danger is avoided, besides 
that it renders the operation more simple 
and facile. 

" Tracheotomy. — Cases occur when this 
operation is required ; as in sti'angles, when 
the tumors threaten suffocation, or when 
any substance has remained utiswallowed 
in the oesophagus, the pressure of which ob- 
structs respiration. In a distressing case of 
gunpowder bursting immediately under a 
horse's nose, the effects of which tumefied 
his mouth and nostrils, so as to prevent free 
inspiration, the animal mved his life en- 
tirely to our excising a portion from the 
tracheal rings, about ten inches below the 
angle of the tiiroat. The operation is a very 
simple one, and may consist either in a 
longtitudinal section made through two or 
three of the rings, or a portion, occupying 



2G8 



A DICTIONARY. 



about an inch round, may be excised from 
the anterior cartilaginous substance. The 
proper mode, when it can be done, however, 
is to malce a circular opening with a very 
narrow knife, removing a portion of two 
cartilages, or taking a semicircular piece from 
each ; and this last, although it is seldom 
performed, is by far the best method : the 
integuments should be first divided in the 
exact centre of the neck, three or four inches 
bdow the obstruction; then the skin and 
tissues should be sufHciently separated to 
allow a tube adapted to the size of the tra- 
chea to be introduced ; the tube having an 
acute turn and a rim, which must be fur- 
nished with holes for the adaptation of tapes 
to secure it around the neck. There are 
several instruments of this sort in use, of 
wliich that adopted by the French, or the 
one invented by Mr. CTOwing of Camden- 
Town, is to be preferred. The operation 
has lieen also performed in cases of roaring, 
under an idea of dividing the stricture which 
impeded respiration ; but, unless the exact 
situation of this were discovered, it would 
be but an experimental attempt. 

" CEsophag-oloDii/. — It was long thought 
that a wound in the oesophagus must be 
necessarily fatal, but we have now sufficient 
proofs to the contrary on record; so that 
v^-e are not deterred from cutting into the 
esophageal tube when it is necessary; but 
it is an operation requiring skill and anato- 
mical Icnowledge ; and its future results are 
sometimes very serious. The cases that 
call for esophagotomy are the lodgment of 
accidental substances within the tube. An 
apple once so lodged was removed by inci- 
sion by a veterinary surgeon at Windsor. 
CaiTots, parsneps, beets, etc., are liable to 
produce such obstruction when not sliced. 
Too large a medicinal mass also has lodged 
there ; and a voracious eater has, by at- 
tempting to swallow too large a quantity of 
not salivated bran or chaff, produced an ob- 
struction which pressed on the trachea and 
threatened suffocation. In all cases of ob- 
struction of ihis Icind we will suppose that a 
probang well oiled has been previously at- 
tempted to hu passed, and has completely 



failed. The probang for the horse, however, 
differs materially from that used for the cow. 
It is formed after the fashion of the one 
adopted by the human practitioner, consist- 
ing of a )Dliable piece of whalebone, having 
a sponge tied to one end. The operation 
being determined on may be practised stand- 
ing ; if the swelling be large, no fear need be 
entertained about cutting important organs, 
as the enlargement will push them on one 
side. Cut down, therefore, directly upon 
the centre of the impacted substance. If 
the horse be cast, which is quite unnecessary, 
have him of course thrown with his left side 
uppermost. It will also be necessary to 
command a good light. The part of the 
neck chosen for the opening must of course 
be governed by the obstructing mass. A 
section should be made through the integu- 
ments and cellular tissue beneath them, 
right into the oesophagus, if possible with 
one cut, and into the centre of the pipe. If 
this be not done at once, and it requires some 
dexterity so as to effect it, mind to make all 
future incisions in a line with the first open- 
ing ; as it is important that the cellular tis- 
sue should be little interfered with. The 
oesophagus, fairly cut into the impactment, 
should jump forth; should it not do so, do 
not manipulate, or attempt to force it out, 
but enlarge the opening, and the substance 
will come through when that is long enough ; 
but no fingering could compel its exit while 
the opening is too small. The end gained 
for which the incision was made in the 
CBSophagus, the wound may be then closed 
by the interrupted sutures, each holding a 
small piece of tow above the orifice, and 
having their ends hanging out of the exter- 
nal opening, which should also be brought 
together by sutures. The after-treatment 
should be, to interdict all dry food ; the ani- 
nial ought to subsist on very thick gruel for 
three, four, or five days. If the condition 
appears to suffer much, allow malt mashes, 
and when so doing watch the wound ; and 
if the matters taken in are seen to ooze out, 
wash them away frequently with warm 
water, to prevent lodgment, which might 
encourage sinuses to form ; and after each 



A DICTIONARY. 



269 



washing, syringe with some very mild stimu- 
lant, as a very weak solution of sulphate of 
zinc {white vitriol), etc. etc. 

" Neurotomy. — Division of the sentient 
nerves of the fool. — Neurotomy has now 
stood the test of very extensive application : 
our WTiters offer innumerable proofs of its 
restoring almost useless animals to a state 
of much utility. And, if there are chances 
that it may occasion such injury as to 
hasten the end of some horses, it is usually 
in such as the disease would have done the 
same for at no distant period. Having 
stated thus much in its favor, it must not 
be supposed that we recommend it as an 
unqualified benefit, even where it succeeds 
best. No neurotomized horse ever after 
goes with the same freedom, nor with equal 
safety, as he did before the operation was 
performed : indifference to the nature of the 
ground gone over, is said to have fractured 
legs ; it is quite common to batter the feet 
to pieces ; and, although horses have hunted 
afterwards, and hackneys have carried their 
riders long distances, yet it is more calcu- 
lated to prove beneficial to carrriage than 
to saddle horses. This we believe to be a 
just statement of its merits ; but there are 
benefits which it offers to the animal of a 
more extensive and constitutional kind. 
Those gained by the bodily system gener- 
ally have been in some cases very marked: 
thus, an aged and crippled stallion, from the 
irritation constantly kept up, became so 
emaciated as to be unable to fecundate ; 
but, being relieved from a constant state of 
suffering by neurotomy, improved in health 
and condition, and was again used to cover. 
It happened, also, that a mare similarly cir- 
cumstanced ceased to feel oestrum ; but 
after neurotomy it again returned, and she 
resumed her character of a brood mare. It 
appears to act with most certainty when a 
portion of the irritated nerve is excised. 
One case has actually occurred where the 
tetanus, occasioned by a wound in the 
foot, was arrested and removed by neuroto- 
my. It also promises much in the painful 
state of some cankers, where the irritation 
has rendered the application of dressings 



almost impossible : here, by depriving tlie 
foot of sensibility, we deprive the horse of 
that which is injurious to him: the sore it- 
self is often amended by it ; but in every 
instance the dressings can be effectively 
applied, and the healthy processes cannot 
be at all suspended. 

"With respect to whether the lower or 
upper incision ougiit to have the preference, 
the decision should be guided by the cir- 
cumstances, as regards the intensity and 
the seat of the disease. The operation 
commonly leaves, for a considerable time, 
some enlargement around the spot, the 
effects of the adhesive matter interposed 
between the severed portions of nerve ; and 
which can be remedied by no application 
of bandages. This bulging remains so 
long as life continues ; and, however cun- 
ningly the incision be concealed, this can 
be felt with ease, and tells the truth ever 
after the operation has been performed. 
Such a circumstance has, however, led 
some practitioners, when it has been wished 
to make the upper section, and yet to avoid 
the chance of detection, to operate on the 
metacarpal nerve on the outside, and on the 
pastern or plantar nerve on the inside. 

^•Modc of performing the operation. — The 
situation of the section through the skin 
being determined on, a guide to which may 
be gained from the perforatus tendon, and 
having firmly secured the leg to be first 
operated on, cut the hair from the part. 
This being done, and the exact course of 
the artery being ascertained by its pulsa- 
tion, make a section close to the edge of 
the flexor tendon. Let the cut be near, but 
rather behind, the artery, if below the fet- 
lock joint. The cellular substance being 
cleared away will bring the vessels into 
view, and the nerve will be readily dis- 
tinguished from them by its whiteness. 
Elevating it from the vessels, and its mem- 
branous attachments, by means of a crooked 
needle armed with thread, pass a bistoury 
under it, as near to the u)jper angle of the 
section as possible. The violent spasm the 
division of the nerve produces may be 
somewhat lessened by pressing the nerve 



270 



A DICTIONARY. 



between the finger and the thumb ; when 
an opportunity may be taken, either with 
the scalpel or scissors, of dividing it ; then, 
taking hold of the lowermost portion be- 
tween a pair of forceps, excise about three- 
fourths of an inch of its trunk. Having 
finished, if both feet are affected, proceed 
to operate upon the contrary side of the 
other leg ; after which turn the horse, and 
repeat the operations on the like parts of 
each leg as they come in succession. The 
integuments may be now drawn neatly 
together, and secured by a twisted suture, 
the whole being properly covered by a 
light compress. Tie up the head for a day 
or two, after which put on a cradle ; keep 
the horse very quiet and low ; give mashes 
to open the bowels ; but we should avoid 
physicking, from the fear that griping might 
occur, which would make him restless, or 
probably require exercise. 

" Periosteotomy. — This operation consists 
in having the horse thrown upon his side, 
and the leg to be operated upon released 
from the hobble, and extended upon a sack 
filled with refuse hay or straw : this is done 
by means of a piece of webbing passed 
yound the hoof, and the end given to a man 
to hold, who pulls rather violently at the 
member. The operator then kneels down 
and feels for the exostosis he intends to per- 
form periosteotomy upon. This may be a 
splint or a node, and commonly exists upon 
the metacarpal portion of the fore limb. 
The operator having found the excrescence, 
snips just below it with a pair of rowelling 
scissors. He then takes a blunt seton nee- 
dle and drives it through the cellular tissue, 
and immediately over the enlargement. 
Next, another slit in tlie skin, above the 
exostosis, is made with the rowelling scis- 
sors, and through this last opening the 
point of the seton needle is forced and then 
withdrawn. Into the free space thus made 
a curved knife is introduced: the point of 
this knife is blunt, and the blade curves up- 
ward, the cutting part being below. Some 
persons use a very diminutive blade, but the 
editor prefers a rather large instrument, as 
being more under the command of the hand. 



Having introduced this knife, he turns the 
cutting edge downward, and with it incises 
the enlargement, sending the blade right 
through the periosteum, and also through 
the substance of the exosto:?is, if it be not 
too solid for the knife to penetrate. This 
latter fact is only to be ascertained by ac- 
tual experience, and no opinion formed 
after an external examination can be of any 
value ; such being much more the guess of 
a pretender than the judgment of a surgeon. 
The age of the animal may be some guide, 
but even this it is better not to depend upon 
too entirely. It is true that young horses 
freely cast forth exostoses, which aged ani- 
mals mostly absorb ; but this rule, though 
very general, has exceptions, and by no 
means is to be absolutely depended upon. 

" The enlargement being cut through, next 
take a seton needle armed with a tape, and 
draw it through the channel already made : 
tie a knot at either end of the tape, large 
enough to prevent its being pulled through 
the opening at either end, and the business 
is over. The affair is very simple, and the 
horse may be at once let up. It is, how- 
ever, in some cases, and only in some, of so 
much benefit that the horse, being thrown 
' dead lame,' gets up and trots off quite 
sound. However, ere you adopt the opera- 
tion, apprise the owner of the risk incurred, 
and that it is by no means a certain cure. 
Leave the choice with him, but be sure and 
tell liini the openings made for the entrance 
and exit of the seton commonly leave a 
blemish behind them ; and where the seton 
travelled, often there remains a thickening, 
which it may require months to obliterate. 

" The after part of the treatment consists 
in merely having the seton daily moved to 
and fro : though some persons apply an 
active blister all over I lie parts immediately 
in the neighborhood of the seton ; under 
the idea that the vesicatory renders the 
operation of greater eflicacy, which how- 
ever is very questionable. When perioste- 
otomy acts at all, it mostly does so at once ; 
and when its benefits are not imme