THE

ARTISTIC ANATOMY
OP

THE HORSE.
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in 2016

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t

I
 THE

ARTISTIC ANATOMY
OP

THE HORSE.
BY

B. WATEEHOUSE HAWKINS, F.L.S. F.G.S.

AUTHOK OP

“ POPULAE COMPAEATITB AKATOMY,” “ ELEMENTS OP POEM,”

“ COMPAEATIYE VIEW OP THE HUMAN AND ANIMAL PEAME,” AND
EE8TOEEE OF THE EXTEBNAL POEMS OP THE EXTINCT ANIMALS AT
THE CEYSTAL PALACE PAEK, SYDENHAM.

LONDON:
WINSOR AND NEWTON, 38, RATHBONE PLACE,
iaanufacturing artiala’ Colourmcn, anti Oratoing
JPapcr Stationna, fig agpointmtnl,
lo ?Jtt fHajtatg, anti to m.ja.HJ. ilje ^prince ot OTalea.

1865.
 LIST OF PLATES.

PL.\TE.

1. Muscles of the Horse .... PAGE.

frontispiece

2. Skeletons of Horse and Man 12

3. Do {comparative view) 20
4. Bones of the Head and Neck 26
6. Muscles of the Head and Neck. .... 31
6. Front view of Horse (muscles). .... 41
7. Bones and Muscles of the Fore Logs. ... 46
Bones of the Knee
8.

9.

10.
Bones of the Foot. .......
(ccurpus)

...
Front limb of Horse and arm of Man.
49
64
57
11. Bones of the Hock {tarsus). 64
12. Hind limb of Horse and leg of Man. ... 67
13. Muscles of the Hind Quarters. .... 70
14. Back view of Horse {muscles) 73
 THE

ARTISTIC ANATOMY
OF

THE HORSE.

Befoeb proceeeding to the Anatomy of the Horse, it

may be desirable to glance at some of the varieties of

form which have been represented in the works of the

earlier masters, either of painting or sculpture ;
and to

observe how far they may be of value for imitation by

the art-student of the present day. Such varieties are

not very numerous, and those most frequently introduced

present distinctions often peculiar to the times in which
they were painted.
The external characteristics of the horse are stronglv
marked, and, as will be shown hereafter, are, to a
large extent, due to the proportions and prominence of
particular parts of the bony frame or skeleton.
Constant, however, as are these general characters, the
figure of the horse is as varied as the purposes for which
man employs him, and to which in obedience to the
demands of fashion, and the requirements of industiy or
8 THE ARTISTIC ANATOMT

spoi-t, a careful attention to scientific breeding has been

able to adapt Although such variations in external
it.

form are particularly marked at the present day, when

the horse is so universally employed, and when, as a
rule, each description of work is performed, by an animal
having qualities especially adapted for it, such was not
the case in earlier times. Horses were then chiefly re-
quired for warlike purposes, and there was little need of
any great diversity in their form or character.
In early historic times the horse was rarely, if ever,
used for agricultural purposes. Oxen were then, as in
many countries, they are now, the only animals employed
for draught in the laborious operations of husbandry.
In the East and in the warmer parts of Europe, the
horse was generally of a lighter and smaller type than
those in the West and North. It was wed-fitted by its

activity for the purposes of light draught and was in

coustaut use in the chariot —speed and good action being
among the most essential qualities of the horses thus
employed.
We find examples of them in the Nineveh Sculptures,
which give such evidently faithful representations of
the light and graceful horses then in use, that we need
only copy them with care to ensure entire accuracy.
The Greeks have also left us complete fac-similes of the

horses of their time. The sculptures known as the

“ Elgin Marbles” in the British Museum are perfect

studies from nature, and from these the art-student or

amateur, after he has acquired a thorough knowledge of
 OF THE HOESE. 9

the sheleton, may obtain all that can be learned of the

general side view of the horse.
If we turn now to the works of the great masters of
the sixteenth and seventeenth centuries we find a par-

ticular type of horse generally represented. This is

what, not very long ago, artists delighted in calling the

“ historical” horse —a large-boned, heavy animal in ap-
pearance, intermediate between a dray-horse and a
carriage-horse, such as we see in the pictures of Velas-
quez, Eubens, Vandyke, Wouvermans and others. These
were the horses of the period — the great Flemish and the
Norman horses, whose bone and substance were essential
to the fashion of the times which required them as
i chargers to cai'ry into battle a weight of armour, accoutre-
ments, and weapons of the heaviest description, or its

^ mimic-field, the tournament, to move with slow and

i
stately pace under the massive trappings of their knightly
•
riders. The horse in the well-known equestrian statue
i of Charles I. at Charing Cross is deservedly regarded as
; . an excellent representation of the once famous breed of
r
"
Flemish horses, now, however, replaced by others more

[
suited to the requirements of modern warfare.
The light dragoon with his small active horse must,
however, be considered as quite a recent feature in what
, arenow commonly spoken of as battle pieces. The typical
Norman horse may still be seen on the Continent, in the
few places where that almost extinct conveyance, the
^

[ diligencedrags on a lingering existence and the great

;

Flemish horse with his high bones, massive muscles and

10 THE AETISTIC ANATOMY

flowing mane still liolds his place in his native country.

But it must not be forgotten that these animals so com-
monly represented in the old paintings belonged to a
national type, which, in course of time, and in accordance
with the prevailing fashion, gradually extended into other
lands. It became the model in various schools of art
because it was the particular breed in general use, and
was familiar to the people in such scenes as painters
loved to represent. It need hardly be mentioned, how-
ever, that this historical horse can rarely have a place in
the works of modern artists, particularly those of the
English school. Fresh breeds have been introduced,
and English types now furnish the student or amateur
with abundant models of the forms best suited to the
varied subjects of his pencil.
For a due comprehension of the shape and action of
the horse it is essential that the art-student should
possess a thorough acquaintance with the arrangement
and position of the bones, and their relation to one an-
other. The osseous framework or skeleton must there-
fore be attentively studied as the only foundation upon
which can be based any hope of power to represent the
horse, either by drawing, painting, or modelling. The
importance of this first step cannot be too strongly in-
sisted upon, for without a knowledge of the bones, the
precise situation of the muscles cannot be determined,
or their action on their limbs properly understood.

Having mastered the details of the skeleton, the muscles

will then demand attention: and when once a
general
PLATK II,
 OP THE HOESE. 13

! knowledge of them has been acquired, the eye accus-

I tomed to habits of accurate observation will readily
) discern in the living horse, the true appearance of those

I
parts of the muscular system which are most prominently
! brought into view, and on whose alteration of form,
when called into action, the minute but important
t ohanges of outline in the various parts of the animal
principally depend.

PLATE n.

THE SKELETON OF THE HOESE.

1. Cranium. See Plate IV.

2. Cervical vertebrae. See Plate IV.
3. Dorsal vertebrae.
4. Lumbar vertebrae.
5. Sacral vertebrae.
6. Caudal vertebr®.
7. Ribs.
8. Sternum.
9. Scapula. See Plate X.
10. Front limbs. See Plate VII.
11. Pelvis. See Plate XII.
12. Hind limbs.

THE SKELETON.

The series of bones comprised in the skeleton may be

14 THE AETISTIC ANATOMY

conveniently divided into two groups, the first compjre-

hending the head, neck and backbone with the ribs,
sternum and haunch bones in other words, — the
vertebral column and aU those bones which are in
immediate connection with it, together constituting
the frame-work of the trunk, the second group com-
prising the bones of the limbs or legs, divided into a
double series of somewhat complicated articulations or
joints, necessary for the safety of the animal under the
manifold shocks and strains to which its varied and often
violent action continually exposes it.

In Plate II. is given a view of the entire skeleton of

the horse, showing the various bones in their natural
position and relation to one another. The head may,
for descriptive purposes, be divided into —
two parts the
skull and the face ;
each having its own particular bones,
whose relative size varies in some slight degree in the
different breeds, and considerably affects the intelligent
expression more or less to be observed in the face of
every horse. These bones will be more particularly de-
scribed in the chapter on the bones of the head and neck.
The bones composing the vertebral column are divided
into five groups.
The cervical vertebrae (PI. HE, 2. PI. IV, fig. 2), or those
of the neck, extending from the head to the ribs, are
seven in number in the horse, as in all other mammalia.
Eighteen are given to the back, and are called dorsal
(PI. II, 3) ;
these are the only ones bearing the ribs.
The third group contains six vertebrae, the lumbar (PI. II,
 :

OF THE HORSE. 15

4) or those of the loins, situated

between those bearing the
,

ribs, and the haunch bones. It should be borne in mind,

however, that the number of ribs is sometimes found to

exceed that stated above ;
nineteen, and, occasionally,

twenty ribs are found in the horse ;

but in such cases
there no actual increase in the number of bones in
is

the vertebral column. The dorsal and lumbar vertebrae

together are always twenty-four, so that if one or two
ribs above the normal number are present, thereby in-
creasing the contents of the dorsal series, the lumbar
vertebrae are proportionately reduced. The fourth (PI. II,

5) , the sacral, includes five bones which are anchylosed

or united together into one mass, and, thus joined act
as a kind of wedge or keystone to the arch formed by
the approximation, at this point, of the haunch bones.
Great strength and solidity are required here, as the
united bones of the haunch, or pelvic arch, as they are
calledby anatomists, are the great pivots on which
the hinder limbs turn, and by which they are enabled
to throw forward the whole weight of the animal. The
remaining vertebrse are those of the caudal (PI. II, Q),
usually fifteen they are, however, exceedingly subject to
;

variations to the extent of two or three above or below

the number above mentioned.
To recapitulate, the normal contents of each series Of
vertebrse will stand thus

Cervical, 7 ;
Dorsal, 18 ;
Lumbar, 6 ;
Sacral, 5 ;
Cau-
dal, 16 ;
total, 61.

The form of these bones varies considerably in the

 ;;

16 THE AETISTIC ANATOMY

diflferent parts of the vertebral column. It will be unneces-

sary, however, to describe them very minutely, as, except
in the case of those of the back, their shape does not
conspicuously affect that of the animah The most pro-
minent feature in each dorsal vertebra is the strong
spinous process or projection on its upper surface. These
processes are largely developed on the anterior portion
of the dorsal series, and produce the elevation or pro-
minence above the shoulder, commonly called the withers.

They are of considerable importance to all long-necked

quadrupeds, from their affording a large surface for the
attachment of the great ligament which supports the
head and neck. All together they form the ridge of the
back. On each side of the dorsal vertebrae transverse
processes are situated, and
articulating with the ribs ;

other smaller oblique projections serving to unite and

fit one vertebra to that adjoining. The spinal column
has considerable flexibility, as well as very great strength
these essential qualities being due to pads of cartilage
interposed between the several bones, and firmly

united to them. Besides these there are ligaments nm-

ning along the broad under surface of the vertebrae
others again between the transverse processes, and
similar strengthening ties uniting the upright pro-
jections or spinous processes, the whole mass for-

ming a marvel of strength, lightness and flexibility.

The ribs (PI. II, 7), eighteen in number, are jointed to

the transverse processes of the vertebrae, and curve with
some variations in their outline and direction, down
 OF THE HOESE. 17

towards the stermim or breast-bone, to which the first

seven or eight of them called the true ribs, the number

sometimes varying, are attached by their extremities, which
to provide the elasticity necessary for the expansion of
the chest, are composed of cartilage. The remaining ribs

are termed /aZse ribs, as they have no individual connec-

tion with the breast-bone ;
they are, however, united
together by cartilages, each on its own side, and this car-
tilaginous union ultimately terminates in the sternum ;

so that the whole of the ribs are enabled to expand or

act in uniformity. The sternum (PI. II, 8), in the young
horse consists of six bones, which become united into a
single piece in the full-grown animal. The front of this
bone is convex and sharply keeled, its upper extremity
projecting so as to be easily observed in the living horse.
This is known as the “ point of the breast,” and its place
will be easily ascertained when it is remembered that the
lowest part of the collar just covers it.

The haunch or pelvis (PI. II, II. PI. XII, 6), is in

reality made up of six bones —three on each side, the
whole firmly united into one. Of these the ilium is the
most important, and is strongly secured to the sacral
vertebrae, which we have already noticed as forming the
keystone of the pelvic arch. Lateral prolongations of the
Uium produce the prominences so conspicuous just above,
and in front of the hind quarters in every horse. The
ischium or hip-bone is a backward continuation of the
ilium, and bears a considerable tuberosity which projects
on each side a little below the tail. The pubis, apparently
18 THE AETISTIC ANATOMY

a single bone, is connected with

those already men-
tioned, and forms an inverted arch with them below
PL XII, d.

The bones of the limbs next claim our attention.

The natural attitude of the horse being that of a
quadruped supported on the extremities of its four limbs,

and with its body in a horizontal position, there is

a greater apparent difference between its skeleton and

that of man than really exists, as will be evident after
a very slight examination and comparison of the two
series of bones composing them.
In PI. m. we have given a comparative view of the
two skeletons in as nearly as possible the same attitude.
It willbe observed that besides the greater length of
jaws and neck in the horse, (although the number and
arrangement of the bones in these parts are the same
in both skeletons) the principal differences consist in
the form of the extremities and the uses to which they
are applied. Man rests on the entire length of the foot,

and his hands and fingers are constructed for grasping.

The horse, on the contrary, is supported on the extreme
points of its toes and fingers, reduced on each limb to
a single digit, and protected by the nail becoming modi-
fied into a hoof. The long-established phraseology of
horsemen, brought into use by the necessity for distin-
guishing the different parts of fore-legs and hind-legs,
and the strange confusion resulting from the introduction
of new names, and the misapplication of old ones, render a
due comprehension of the nature and relation of these
PLATE III.
 or THE HORSE.

limbs almost impossible to those who have given no

attention to the skeleton of the horse.
Many of the bones in each skeleton are known by the
same names, but some parts of the limbs in the horse
have been strangely miscalled. We have thought it desir-

able, therefore, to give in parallel columns, the names of

those bones and joints which, although exactly corres-
ponding in man and the horse, are spoken of under differ-
two skeletons,
ent titles in the ordinary description of the

i
Our references to the various woodcuts will show the
> true relation and correspondence of the several bones,
*

but as we shall have to speak specially of the horse,

it will perhaps be desirable to employ the terms generally
'
used in com action with that animal.

NAMES COMMONLY APPLIED TO CORRESPONDING BONES

IN MAN AND THE HORSE.

Front Limbs.
Man. Horse.
Arm (humerus) Lower bone of shoulder.
Fore-arm Arm.
Wrist (carpus) Knee.
Hand (metacarpus) Leg, cannon and splints.
Knuckles Fetlock.
Finger Pastern and foot.

Hind Limbs.
Thigh (femur) Upper bone of thigh.
Knee Stifle joint.

c
22 THE AETISTIC ANATOMY

Man. Horse.
Leg Thigh.
Ancle (ta/rsus) Hock.
Heel Point of Hock.
Foot (metatarsus) Leg.
Ball of Foot Fetlock.
Toe Pastern and foot.

The fore-leg or front limb is united to the body of the

horse by means of the shoulder which is here said to be

composed of two bones, both covered in and hidden by

numerous over-lying muscles. The upper bone or
shoulder blade has the usual flattened and long triangu-
lar shape, and is strengthened by a ridge or crest dividing
it longitudinally into two somewhat unequal portions.
The shoulder-blade or scapula rests on the ribs, the short
side or base of the triangle being placed just below the
withers, and its point directed downwards and forwards,
nearly on a level with the top of the breast bone. The
shoulder-blade has no osseous connection or articulation
with the body of the horse, but is united to it solely by
muscles, which wiU be spoken of more in detail in our
chapter on the shoulder. The clavicles or collar bones,
so well known in man and a few quadrupeds, do not exist
in the horse. The lower bone of the shoulder, as it is
commonly called, corresponds to the humerus or upper
bone of the human arm. It is a short, thick and some-
what twisted bone articulating by a rounded head with
the glenoid or cup-shaped cavity at the point of the
shoulder-blade. Its lower extremity, which is directed
 OF THE HOESE. 23

bactwards, terminates in two condyles, receiving be-

tween them the head of the principal upper bone of the
leg. This portion of the fore-leg, commonly called the
arm {fore-arm, human,) is composed of two bones, a
long one in front termed the radius which extends to
the knee, and a short one behind called the ulna. The
latter bone has a long projection above and behind the
upper joint, and forms the point of the elbow to which
some powerful muscles are attached for extending the
arm. It rapidly diminishes in size towards its lower
extremity, and terminates in a point before it reaches
the knee. In old horses these two bones of the arm be-
come firmly united into one.
The knee is a complicated joint uniting the arm to
the shank or leg, and
composed of six small bones
is

interposed between the upper and lower portions of the

fore-leg. We shall have occasion to describe the struc-
ture of this important joint at greater length in a subse-
quent chapter. Below the knee are the metacarpal
bones or those of the leg. They are three in number,
the cannon, and two splint bones behind. They repre-
sent the bones of the human hand, those between the
wrist and the The remaining bones of the fore-
fingers.
leg are the upper and lower pasterns, and the coffin bone
surrounded by the hoof or nail, together forming a single
stout finger —
the only one developed.
In the hind-leg we find a very similar arrange-
ment of the bones. We have already spoken of the
pelvic arch, made up of the several bones of the haunch.

c 2
24 THE ARTISTIC ANATOMY

At a point on the outer surface of the pelvis, and at the

junction of the three component bones on each side, a
deep cup-shaped cavity called the acetahulvm is formed

to receive the round head of the true thigh bone or

femwr (PI. XII. e). Great strain is thrown on this joint,
it is bony
therefore well protected by the cup or acetabulum,
to whose centre the head of the femur is further secured
by an exceedingly strong ligament. The femur or true
thigh bone is so much concealed by the large muscles of
the hind quarters that its true relations, or even its
existence may not be recognized in the living horse.
This circumstance has led to the confusion of names
into which horsemen have fallen when speaking of the
different parts of the hind leg.

The lower extremity of the femur is united to the

bones of the true leg (tibia) by the “ stifle joint,” which
also includes the ^patella or knee cap (PI. XII. /.), this
joint corresponding to the knee in human anatomy.
The bones of the leg (‘ thigh,’ of horsemen) are the Ubia

and fibula (PI. XII. g. h.) articulating below with the

numerous small bones of the ancle. The “ hock” (PI.
XII. i.) is formed by a number of small bones, one of
them having an elongated lever-like form with its free
extremity directed upwards. This is the os colds or
bone of the heel. Into this bone the tendons of several
powerful muscles are inserted, and a great deal of the
springing power of the horse, as well as in other jumping
animals, is due to the position and action of this part of
the hinder limb.
PLATE IT
 OF THE HORSE. 27

The remaining bones of the hind leg agree generally

with those of the corresponding portions of the anterior
limb.

PLATE IV.
Figs. 1 & 2.

BONES OF THE HEAD AND NECK.

a. Frontal.
b. Parietal.
c. Occipital.
d. Temporal.
e. Malar.
/. Lacrymal.
g. Nasal.
h. Superior maxillary.
i. Pre-maxillary.
k. Inferior maxillaries or lower jaw.
l. Orbit.
1. Atlas. \

2. Dentata.
]
3. Third.
I
4. Fourth. > Cervical vertebrae.
5. Fifth. I

6. Sixth.
I
7. Seventh. /

The bones of the head may be divided into two groups,

those of the cranium and of the face. The cranial bones
include all those which cover or enclose the brain. Thev
•r

are for the most part arranged in pairs, one on each side
 28 THE ARTISTIC ANATOMY

of tlie mesial line of the skull, hut may conveniently he

spoken of as single hones.
The frontal, or hone of the forehead (a) forms the
hi'oad flat surface between the eyes, and extends •with

a narrowing outline towards the top of the head. The j

frontal occupies the widest part of the head. Considerahle

difference in the width of this hone may he noticed in
various horses, and it will generally he found that the
broad and ample forehead is a mark of high breeding
and superior intelligence in the animal, as is often suffi-
ciently indicated by the expression of the face. The
parietal (6) extends backward from the frontal to the
poll. It has a ridge or crest of great strength and
hardness along the upper surface, from which the hone
slopes down like a roof on each side, covering the brain,

which it is mainly concerned in protecting.

Immediately behind the parietal, and covering the
entire back of the head, is the occipital (c), a hone whose

position exposes it to greater strain than any of the other I

component parts of the skull are liable. The occipital |

has to support the whole weight of the head, which is i

articulated by two rounded protuberances or condyles at |i

the base of this bone to the atlas or first vertebra of the w

neck. On the outer sides of the occipital, and beyond
the condyles, are two styliform processes or pointed pro- »
jections for the attachment of some of the muscles of the M:
neck which assist in supporting the head. |
,

The temporal bone (d) unites above with the parietal, and
behind with the occipital. It contains the internal parts jfrj
 OF THE HORSE. 29

of the ear, and has a depression or hollow beneath for

the articulation of the lower jaw. Anteriorly, this bone
joins the extremity of frontal, and continuing forward
unites with the malar or cheek-bone (e), making up the
xygomatic arch, and forming the greatest part of the
orbit, which is completed by the lacrymal (f), a small
facial bone at the inner corner of the eye. Immediately
before the frontal is the nasal bone (jf), one of the prin-
cipal bones of the face, and covering the delicate mem-
brane of the nose. The superior maxillary (h), is a
large bone occupying the side of the face. It carries all

the molar teeth or grinders and the tusk of the upper

jaw. The nippers or incisor teeth are inserted in the
pre-maxUlary (i), which uniting with the two bones last

mentioned completes the frame- work of the nose. The lower

jaw consists of two bones only, the inferior maxillaries (Jc).

These are rounded at the hinder extremity of the jaw

and terminate in two processes directed upwards.
The terminal projection or condyloid process articulates,
with the temporal bone at the base of the zygomatic arch,
and forms the hinge on which the whole lower jaw moves.
The second process, termed the coronoid, passes under the
arch,and receives the lower end of the large temporal muscle
which arises from the parietal bone, and is principally
concerned in moving the jaw in the act of mastica-
tion. There are also two small bones, in the lower
part of the cranium, under the parietal, the sphe-
noid, and ethmoid; they serve to connect the princi-
pal bones of the skull, but as they are not visible
30 THE ARTISTIC ANATOMY

externally, ttey do not need description for artistic

purposes. The bones of the neck, as we have already
mentioned, are seven in number. The atlas, which
articulates with the skull, is a ring-shaped bone with
broad lateral projections, but without any other promi-
nent characters. It has great freedom of motion on the
second bone, or dentata, and on the peculiar articulation
of these two vertebrae the power of turning the head
mainly depends. The remaining five bones of the neck
closely resemble one another; they have various small
processes for the insertion of muscles and ligaments, and
their form will be sufficiently understood by an examina-
tion of Plate rV.

PLATE V.

Figs. 1 & 2.

MUSCLES OF THE HEAD AND NECK.

Head.
a. Masseter.
h. Temporalis.
c. Orbicularis.
d. Levator.
e. Orbicularis oris.

f.
Dilator naris lateralis.
g. Zygomaticus.
h. Nasalis labii superioris.
i. Depressor labii iiiferioris.
PLATE V
 OF THE HOESE. 33

Neck.

j. Complexus major,
k. Splenius.
l. Levator anguli scapuloe.

m. Hyoideus.
n. Sterno-maxillaris.
0. Levator humeri or deltoides.

The muscles of the head are not very numerous, and

those requiring the most attention will he found in the
immediate neighboui’hood of the mouth and nostrils.
The largest superficial muscle is the masseter, (PI. V,
fig. 1, 2 a). This forms the cheek of the horse, and
extends along a ridge by the side of the head, below the
eye, to the rounded posterior angle of the lower jaw
which has a roughened surface for more secure at-
its

tachment. Its action is to close the mouth. The temporal

muscle (b) also assists in this office. It arises from the
medial ridge of the parietal bone, clothing its roof-like

walls, and is inserted within the zygomatic arch to the

coronoid process of the lower jaw-bone. The dimpling
which may be observed, during mastication, above the
eye of the horse is produced by the action of this muscle
in alternately raising and depressing the under jaw.
The orbicularis (c) is a circular muscle surrounding the
eye and closing the eyelids. Above the eye,and directed
inwards and upwards is a small levator muscle (d) which
passes over the orbicularis and raises the upper eyelid.
34 THE ARTISTIC ANATOMY

The muscles of the ear are not very conspicuous.

Three of them may he shortly noticed. The first pro-
ceeding from the base of the ear extends a short distance
forward and turns it in that direction the second, be- ;

hind the ear, directs it inward and backward, and

the third descends as a narrow strip at the back of the
cheek to incline the ear outward.
The frontal and nasal bones have no prominently
perceptible muscular covering ;
the difference in the shape
of these parts in various horses being entirely due to the
variation in the relative size and proportion of the par-
ticular bones.
Of the muscles of the lips and nose we may first_ men-
tion the orbicularis (e), one of the most important of them.
It entirely surrounds the mouth, and by its action the
lips are pushed out or closed. This muscle is brought
into play whenever the lips are required to seize or hold
anything between them. The dilator naris lateralis (f) is

a pyramidal muscle covering the whole exterior of

the nostril and having its origin close to the anterior
point of the masseter. It is the great side dilator
of the nostril, and also raises the upper lip. The zygo-
maticus (g) draws back the corner of the mouth
whence it may be traced upward, outside the mas-
seter to its origin on the zygomatic arch. The
buccinator, a muscle on the inside of the mouth and
cheek, and consequently scarcely visible externally, has
the same office as the preceding.
The nasalis labii superioris (li) extends from a depres-
 —

OB’ THE HOKSE. 35

sion in front of the eye towards the angle of the month,

a short distance above which it divides into two parts,

the side dilator of the nostril (/) passing between them.

One of these portions is continued straight to the
corner of the mouth which it raises ;
the other part ex-
pands under the side dilator, and assists it in the office

of dilating the nostril. It also helps to lift the upper

lip.

The under lip is drawn back by the depressor labii

inferior is (i), a narrow muscle which is inserted into the

lip below the angle of the mouth, and passing along the
side of the jaw, disappears under the masseter.
Independently of the muscles for supporting the head
and neck there is a very beautifal and simple arrangement
by which those parts are kept in an easy and natural
position when the horse is at rest. This consists of a
very strong and elastic ligament called the ligamentum
nuchce. It takes its origin from the back of the occipital
bone to which it is attached immediately below the
crest. At first it is in the form of a stout round cord.
It passes over the atlas, or first joint of the neck, to
allow full freedom of motion to the head, and is strongly
adherent to the dentata, on which the principal strain
from the weight of the head is thrown ;
it then proceeds
backward to its termination on the elevated spinous pro-
cesses of the first dorsal vertebrae. The withers as these
elevated parts are called have thus an important office

that of supporting the weight of the entire head and neck

when in their ordinary position. But provision must
36 THE AETISTTC ANATOMY

also bemade for lowering and raising the head, and for
these purposes there are special muscles. The first to
be noticed is the comjolexus major (Fig. 1. j). It arises
from the transverse processes of the four or five first
dorsal vertebrae, and also from the five lower bones of the
neck the fibres from these two points uniting to form
;

one large muscle which diminishing in size in the direc-

tion of the head terminates in a tendon inserted into the
occipital bone. This muscle makes up the principal por-
tion of the lower part of the neck. Immediately above
this is the splenius (Jc) specially employed in raising the
head. It arises from the entire length of the ligamentum
nuchce and is directly inserted into all the bones of the
neck, except thefirst, with which, however, and the
temporal bone of the head, it has a separate and less
distinct connection. To the form and development of
the splenius, the beauty of the neck of the horse is main-
ly due. It is here the greatest thickness is found ;
and
from being sometimes overloaded with cellular substam^e
or fat, an appearance of clumsiness may be produced.
The thick crest and massive neck of the entire horse are
to a large extent due to the abundant development of
this muscle; and the student or amateur will do well
to acquire a thorough knowledge of its form, which, in
every condition and breed of the horse so largely con-
tributes to give a character to the neck.
Behind the splenius, and extending along the superior
margin of the neck is the levator anguli scajnike (Z). It

is inserted into the back of the head, and attached to the

 OF THE HOESE. 37

first four bones of the neck as well as to the great liga-

ment, then descends to the shoulder where it is not
visible externally. It has a reciprocal action on the
neck and shoulder according to whichever is the fixed
point at the time.
Of the muscles in front of the neck we may first direct

attention to the hyoideus (Plate V, fig. 2, m). Its upper

extremity is always conspicuous immediately below the
head at its junction with the neck. It is attached to

the hyoid bone of the tongue, which it retracts, and

descends along the front of the neck to the shoulder,
but is covered in the greatest part of its length by other
muscles, and is only visible for a short distance below the
head. Outside this muscle, and partly covering it, is

the atemo maxillaris (Plate V. n), the principal de-

pressor of the head. It arises from the upper end of the
sternum or point of the breast, covers the lower front of
the neck, then proceeding upwards by the side of the
hyoideus, is insei’ted by a flat tendon into the posterior
angle of the lower jaw. It is not a very large muscle,
for, when those supporting the head and neck are re-
laxed, but little force is required to pull the head down.
Beyond the sterno-maxillaris, and extending from the
back of the head and upper part of the neck, along the
front of the shoulder, to the top of the fore-leg, is the
levatorhumeri or deltoides (Plate V. o'), a long and very
important muscle, having, in fact, a double function to
perform. When the head is kept up by its own proper
muscles, it becomes a fixed point from which the levator
38 THE ARTISTIC ANATOMY

humeri is enabled to raise tbe shoulder. This is pro-

bably its principal office. Its action, however, can also
be reversed, and with the shoulder for a fixed point, the
head can be depressed, a small slip of -the muscle being
carried forward to the point of the sternum to pull the
head in that direction.
Note. — It must be borne in mind that, with very few
exceptions, the muscles are all arranged in pairs, some-
times though rarely in contact, and that in speaking of
them in the singular number, unless otherwise stated, we
are referring to their position and function on each side
of the animal.

BONES AND MUSCLES OF THE SHOULDER.

The shoulder blade or scapula (Plate II, 9, Plate X.

fig. 1, a) consists of a single bone, and connects the
fore-leg with the trunk, corresponding in its relation to
that of the haunch bone to the hind-leg. There is, how-
ever, this important difference between them, the haunch
bones are anchylosed or united to the sacral portion of
the back-bone in order to provide a firm point from
which those powerful levers, the hind-legs can act ;
the
shoulder, on the contrary, has to receive a violent shock
from the weight of all the front part of the animal sud-
denly falling on the fore-legs. The shoulder has there-
fore only a muscular attachment to the trunk and by ;

this arrangement no jar is received by the spme, and any

 OF THE HORSE. 39

injury to the important viscera of the chest is rendered

unlikely.

The shoulder-blade is of a long triangular form, with

itsapex directed downwards, nearly on a level with the
point of the breast, and its somewhat rounded base
resting on the ribs immediately below the withers. It

is divided externally into two portions by a ridge or

crest running nearly the length of the blade, and a little

on one side of its mesial line. This ridge of bone gives

additional firmness to the shoulder-blade, and affords a
surface for the attachment of some very important mus-
cles. At the lower extremity of the shoulder-blade is a
cup-shaped hollow, called the glenoid cavity, with which
the rounded head of the bone (humerus) of the shoulder
articulates. Above on the anterior edge of
this joint,

the scapula, is the acromion process, to which in man and

some few quadrupeds the clavicle or collar bone is united.
This bone, however, is not found in the horse, or in other
animals which have but little power of lateral motion in
the front limbs.
Following the custom of horsemen, and adopting their
nomenclature for the bones of the horse, we shall next
speak of the “ lower bone of the shoulder” the humerus
(Plate II, 10, Plate X, fig. 1, t), in every respect corres-
ponding with that part of the human arm which extends
from the shoulder to the elbow, but which, in the
horse, is so hidden by the muscles as not to be externally
visible as a distinct bone of the front limb. The lower
bone of the shoulder is short and strong ;
it articulates
 40 THE AETISTIC ANATOMY

by a rounded head with the glenoid cavity of the Bcajmla,

and has considerable freedom of motion. Its direction is
backwards, and at almost a right angle with the shoulder-
blade. It has several large protuberances at the upper
end of the bone, and to which are attached the principal
muscles for moving it. The lower extremity terminates
in two condyles or heads between which the superior end
of the arm-bone is received.

PLATE VI.

MUSCLES OF THE SHOULDEE AND BACK.

X. Trapezius.
a. Pectoralia minor.
h. Antea spinatus.
c. Postea spinatus.
d. Teres minor.
e. Anconseus longus.
/. Anconseus externus.
g. Serratus major.
*. Latissimus dorsi.
f-m. Pectoralis major. See Plate XIV.

Of the muscles of the shoulder we may first notice the

trapezius (Plates I, VI, XIV). It rises from the ligament
of the neck and the principal bones of the withers, and
terminates in a pointed shape on a prominent part of
the ridge of the shoulder-blade. Its office is to raise and
support the shoulder, assisting the serratus major (Plates
 *'
7t

PLATE VI.
I
OF THE HOBSE. 43

t
'

YXj a very important muscle, but hardly visible

gr),

; externally, as it is principally situated between the

shoulder-blade and the ribs of the horse, forming the
main connection between them.
[
The antea spinatus (Plates I, VI, XIV, h), taking its

'
name from its situation, occupies the outer surface of

the scapula on the front side of the spine or ridge of

[

f
that bone. It proceeds to the lower bone of the shoulder,
and, dividing into two parts, is inserted into the two
[

t prominences in front of it, extending the bone forwards.

The postea spinatus (Plates I, VI, XIV, c) is situated on
the other side of the spine of the shoulder-blade, and is
I
inserted into the upper and outer head of the bone,
drawing it outward and raising it. Behind the postea
a small muscle called the minor, (Plates
'

< spinatus is teres

I, VI, XrV, d), or little pectoral ;

it draws the shoulder for-

ward towards the breast. The pectoralis major (Plate

I
V XIV, p.m.) is conspicuous inside the arm at its junction

\ with the body. It is an important muscle, and pulls the

whole fore-leg inwards, keeping it on a line with the body,
and ensuring an even and regular action of the limb.
On the outside of the shoulder, and readily seen in the
living horse when in motion, are two muscles, which,
arising from the lower bone of the shoulder, are inserted
^
into the point of the elbow. They are called the anconceus
. longus (Plates I, VI, XIV, e), and the anconceus externus
(Plates I, VI, XIV, /). Their office is to straighten and
extend the arm, in other words, to bring the front limb
into a perpendicular position, and as nearly as possible
D
 —

44 THE ARTISTIC ANATOMY

in a line witli the humerus, or, as lYe have called it, the
“ lower hone of the shoulder.” The muscles which bend
thearm upwards are not visible externally, but are al-

most entirely covered by those of the shoulder.

The muscles of the back do not require any lengthened
notice. The latissimua dorsi (Plates I, VI, XIV) is the
most important ;
it covers the whole back, extending from
the shoulder to the haunch, and is strongly attached to
the processes of the vertebrse, and the ribs. This mus-
cle is the principal one employed in raising the fore or
hind quarters in the act of rearing or kicking. That
part of it which comes nearest to the surface is generally
covered by an ordinary saddle, but no portion of this
muscle is at any time very distinctly visible.

PLATE Vn.

BONES ANn MUSCLES OE THE PKONT LIMBS.

EiG. 1. Bones.

A. Eadius.
B. Ulna, point of.

c. Klnee (ca/rpus).

D. Cannon or Shank.
E. Splints.
E. Sesamoids (behind Fetlock).
G. Upper and Lower Pasterns.
H. Cofiin Bone.
I. Navicular.
 —

OF THE HORSE. 47

FIG. 2. Mtiscles.

h. Extensor carpi radialis.

i. Extensor digitorum longior.

j. Extensor digitorum brevior.

k. Abductor polUcis longus.

ef. External Flexor.

mf. Middle Flexor.

if. Internal Flexor.

The upper portion of the fore-leg, or, as it is commonly

called in the horse, the arm, (fore-arm, human) extending
from the elbow to the knee (carpus), consists of two
bones, the radius and the ulna. The radius (Fig. 1. a)
is the more important of the two, and in the young horse
is the great support of the leg. It is the long front
bone, is nearly straight, and receives into depressions
on its upper end the two heads of the inferior extremity
of the lower bone of the shoulder. The other end of the
:
-radius fits on to the upper layer of the bones of the knee
(carpus). The ulna (fig. 1. b.) is situated behind, and
to some extent above, the radius, there being a consider-
able projection of the former received between the heads
of the lower bone of the shoulder, and called the elbow.
This forms a powerful lever into which are inserted thf
muscles for extending the arm as already noticed in our
account of the muscles of the shoulder. The ulna is
continued downwards, gradually diminishes in size, and

1 terminates in a point behind the middle of the radius.

These two bones of the arm are at first distinct and
D 2
48 THE AETISTIC ANATOMY

separate, but before many years have past the carti-

laginous and ligamentous connection between them
becomes ossified, and the two bones are firmly united
into one.
The knee, (Fig. 1, c) corresponding to the human wrist
{carpus), is a part of the fore-leg to which the attention
of the artist should be particularly directed, as its form
is always a characteristic and prominent feature in the
outline of the horse, and one to which, like the hand in
the drawing of the human figure, severe scrutiny is

likely to be applied. The knee is a complicated joint,

.

that is, it is composed of numerous small bones inter-

posed between the lower end of the radius and the upper
extremity of the shank or cannon bone.
The position and action of this joint render it pecu-
liarly liable to external injury and violent jars or strains ;

it is therefore so made up that any shock it may receive

will be distributed over a number of distinct bones, each
protected by a covering of cartilage, and resting on a
kind of semi-fiuid cushion, the whole being strongly
miited together by ligaments.

PLATE VTII.

BONES OF THE KNEE (carpUS)

FIG. 1. Left leg, outer side. fig. 2. Front view.

a. Kadius.
h. Pisiforme.
 PLATE VIII.

FIG. 1 . FIG. 2 .
 OT* THE HOESE, 61
n
>

c. Cunieforme.
d. Lunare.
,
'•
e. Scaphoides.
/. Trapezoides.
-
g. Magnum.
h. Unciforme.

^
The true carpal bones are seven in number, six of
^ them being being placed in two rows, each containing
three bones, in front of the joint, and the seventh, the
pisiforme (Plate VIII, figs. 1-2, h), by some persons
called the trapezium, being situated behind them, forming
the point of insertion for some of the muscles of the arm,
and otherwise aiding in the protection of the tendons
^
g running down behind the leg. By reference to Plate
VIII, the shape and arrangement of the bones of the
knee will be readily understood. Besides the advantage
of distributing a shock over several distinct parts, there
is another object to be gained by the interposition of
^
I
these small bones. The bending of the leg at this point
can be carried so far that a very wide opening between
•
the bones of the arm and the shank would necessarily
'
be the result, and this would take place at a part ex-
tremely liable to external injury. By the presence and
arrangement of the interposed carpal bones, however,
this wide opening is replaced by three narrow ones,

which are well protected from all ordinary dangers by

being covered with a capsular ligament, Extending from
52 THK ARTISTIC ANATOMT

the radius above, to the shank bone below them, A large

flatknee has always been considered a valuable point in
a horse, and from what we have shown of the action of
this joint, the advantages of its possessing a considerable
extent of surface will be sufficiently evident.
Between the knee and the fetlock are three bones, the
cannon or slianTc, and two splint bones, the whole making
up what is called the leg (metacarpus, human). The
cannon or shanJc bone (Plate VII, fig. 1, d), articulates
at its upper extremity with the lower row of the bones
of the knee, and at the other end with the upper pastern
at the fetlock joint. It is the principal bone of this
portion of the leg, and is aluiost entirely devoid of any
muscular covering, those iiarts of it which are not hidden
by tendons being only protected by the skin. This bone
is nearly straight, rounded in front,and flattened or
slightly concave behind. The sjMnt bones (Fig. 1, e) are
situated behind the cannon and a little on each side of
it. They also articulate with the lower bones of the
knee, and throughout their length are united by carti-
lage and ligaments to the cannon bone. The name
given to these bones well describes their character, they
are “ splints” — slender pieces attached to the cannon to
strengthen it, and diminishing to a point before they
reach the fetlock joint (Plate IX, c). Behind this

joint are two small supplementary bones termed

sesamoids (Plate IX, h ; Plate Vil, fig. 1, f.) ;
they serve
to protect the back of the joint and some important
ligaments passing over it.
 OP THE HOESE. 55

PLATE IX.

Figs. 1 — 4.

Bones of Foot.

a. Cannon or Shank.
b. Sesamoids.
c. Fetlock joint.
d. Upper pastern.
e. Lower pastern.
f. Coffin bone.
g. Navicular bone.

The two next bones in descending to the foot are the

upper and lower pasterns (Plate IX, d, e, Plate VII,
fig 1, g) ;
these have considerable motion one on the other
to allow the foot to be bent back. The toe is formed by
the coffin bone, (Plate IX, /, Plate VII, fig. I, h) which
is surrounded and covered in by the horny hoof, so that
its form is never visible externally. For all artistic
purposes, the shape of the hoof need only be considered.
Another small bone called the navicular (Plate IX, g,
Plate Vn, fig. I, I.) is and partly
found behind,
within, the junction of the coffin and lower pastern, and
like the former bone is enclosed by the hoof.
56 THE ARTISTIC ANATOMY

PLATE X.

COMPARATIVE VIEW OP THE BONES IN THE FRONT LIMBS OF

MAN AND THE HORSE.

a. Scapula. .

5. Humerus.
c. Olecranon or elbow.
d. Radius.
e. Ulna.
/. Carpus.
g. Metacarpus.
h. Digit.

1. Phalanx.
2. Do.
3. .
Do.

In order to render more intelligible the relation of the

several bones of the fore-leg in the horse to those of the
human arm and hand, there is given in Plate X, a com-
parative view of those parts of the two skeletons, by
which it will be seen that any differences existing between
them are due to alterations in the shape or proportions,
or in some cases, to the suppression or undevelopmeut of
particular bones, but not to any departure from the
general plan on which both skeletons are constructed.
.

A general agreement in form, although not in propor-

tions, will be noticed in the shoulder blades (a) and the
humeri (h) or first bones of the actual limbs ;
the same
PLATE X.
 OF THE HORSE. 59

may be observed in the next bones of tbe series, but with

a slight modification. The radius (d) is the same as in
both skeletons, but the human ulna (e) is completely
developed, and terminates at the wrist (carpus') which
gains additional power of motion by its articulation with
this second bone. There is also a general correspondence
in the carpal bones (/). In the metacarpals, (g), how-
ever, we find an important distinction. The five bones
bearing this name in the human hand are reduced to
three in the front limb of the horse, where they are con-
siderably increased in relative size, and are known as
the cannon and splint bones. Only one of the fingers is

developed in the horse, the middle digit, corresponding

to the middle finger (Ji) of the human hand, and tlie •

three bones composing it are in the horse known as the

two pasterns (1-2), and the coffin bone (3). The hoof, as
we have before mentioned, is only a modified form of
nail. In the accompanying woodcut those bones of the
human hand which have their homologues in the horse
will be found strongly indicated.
The muscles of the fore-leg may be divided into two
groups, those in front, and on the outer side of the limb ;

and those which may be seen from behind, and on the

inside.

The fleshy portions of aU these muscles ai»e placed

above the knee (carpus), and only their tendinous pro-
longations are continued to the several bones of the
^
lower part of the leg and foot.
The principal muscle in front of the so-called “ arm”
60 THE ARTISTIC ANATOMY

of the horse is the extensor carpi radialis, (Plates I, VI,

Vn, XTV, 70.

from the lower part of the lower bone of the

It arises
shoulder, and descends in front of the arm to the knee
where it becomes entirely tendinous. It then passes
over the knee, under a band of ligament which crosses
that joint, and is finally inserted in front of the cannon
bone. The action of this muscle is to strengthen the
lower part of the leg. Next to this muscle are those
whose office it is to extend the foot, the extensor digi-
torum longior and extensor digitorum trevior, Plates I,
VT, VII, i. j.) Their origin is much the same as that of
the extensor of the leg, but the tendons pass by the side
of the knee, under the capsular ligament of that joint,
down and of the fetlock joint to be
in front of the leg
inserted into the pasterns and coffin bone. The first of
these muscles is conspicuous on the outside of the arm,
but the second is in a great measure hidden by its com-
panion.
A small oblique muscle the abductor pollicis longus

(Plates I, VII, Tc), appears from under those last men-

tioned, and obliquely crosses the knee; it assists the

others in extending the leg.

On the outsideand rather behind the arm is the
of,

most external of the muscles which bend the leg, the

flexor carpi ulnaris, or external flexor (Plates I, VT, VII,
XTV, ef). It arises from the outer head of the lower
bone of the shoulder, and descends towards the knee,
the tendon dividing into two parts, one of them being
 OF THE HOESE. 61

inserted into tlie pisiforme (Plate Vli, fig. 1)>

seventh bone of the knee, and conspicuous behind

that

joint,the other going to the outer splint bone. On the

inside of the leg, and behind it is the middle flexor
(Plates VII, XIV, mf) springing from the inner hand
of the lower bone of the shoulder and terminating, like
the outer flexor, at the pisiforme. These two muscles
are the principal flexors of the leg, and are assisted in

their office by the internal flexor (Plates I, VII, XIV,

if) which having much the same origin as the others,

is inserted into the inner splint bone. The muscles
which bend back the foot are deeply seated, and covered
by those we have just described. The tendons in which
they terminate will be seen in the several figures in

Plates I, VI, VII, XIV.

BONES OP THE HIND LIMB.

It will be unnecessary to give any detailed account

of the bones of the haunch, as they have been suffi-

ciently described in our general sketch of the skeleton.

We shall therefore now proceed to point out the charac-
ters of the bones of which the hind leg is composed.
Beginning at the upper extremity of the liijib, the
first bone to be noticed, is the femur or true thigh
(PI. XII. e) ;
and here we must direct the student’s atten-
tion to the list of the names applied to corresponding
bones in the skeletons of man and horse, (see page 13)
62 THE AUTISTIC ANATOMY

that he may become familiar with the true relation of

the several parts of the hind leg, so commonly misnamed
when speaking of the horse. We shall, as before,
use the forms most familiar to the equestrian, ex-
plaining them as may appear desirable for the due
comprehension of the subject. This bone (femur) is so
entirely hidden by various muscles of the haunch as
to be unrecognised and unnamed by those persons who
are not acquainted with anatomy. We shall speak of
it as the “ upper bone of the thigh,” a term that may
be easily remembered by those who apply the name of
“ thigh” to the next lower bone of the series.

The “ upper bone of the thigh” (femur) is exceedingly

strong and stout. It is short for its bulk, which is
further augmented by several large projections or troch-
anters placed longitudinally for the attachment of some
important muscles. The upper extremity of the femur

has a distinct rounded head on the inner side, fitting

into and articulating with the acetahulum or bony cup

formed at the junction of the three pelvic bones. The
lower end of the bone bears two prominences which fit
into corresponding depressions in the next bone, and
in front of which is placed the patella or knee-cap (PI.
XU. making up the “
stifle joint” of horse-
f) together
actual “ knee” of ana-
men, or, more strictly speaking, the
tomists. The “ thigh” (leg, human) consists of two
bones, the tibia (PI. XII. g) and the fihila (PI. XU. h).

helps
The tibia extends from the stifle joint, which it

to form, to the “ hock” (ancle, human). The fibula is

 PLATE XT,

FIG. 1 . FIG 2 .
 —

OF THE HOESE. 65

placed behind on the outer side of it, extending from

its upper extremity to about one third of its length.

It is attached to the larger bone by cartilage, and

agrees in general character with the small bone or ulna

in the fore-leg. ,

PLATE XI.

BOXES OP THE HOCK, {taVSUs).

FIG. 1. Bach view, i/imer side, fig. 2. Front view, outer side.

a. Tibia.

h. Os calcis.

c. Astragalus.
d. Cuboides.
e. Naviculare.
/. Outer cunieforme.
g. Middle cunieforme.
h. Splint.
i. Cannon or Shank.

Note. As the great toe is unrepresented in the horse, the

inner cunieforme is not developed.

The hocTc (PI. XI) is an important and somewhat com-

plicated joint. It corresponds to the ancle and heel in
man, although, in the horse, it is at some distance from
the ground. Like the knee of the horse (carpus) the
hock (tarsus) consists of several small bones interposed
between the long ones of the lower part of the limb.
66 THE ARTISTIC ANATOMY

They are six in number, and of various shapes, for a

knowledge of which we must refer the student to Plate
XI. which gives a front and inner side view of the joint
with the several bones in their natural position. We
may, however, djrect attention to the projecting bone
at the back of the joint. This bone, the o» colds or heel
bone forms what is called the “ point 'of the hock.” It
acts as a lever to straighten the leg, and is moved by
the tendo Achilles and other tendons arising from the
muscles which spring from the upper part of the limb.
It is considerably developed in all fast moving animals,
an increase in the length of the lever adding considerably
to the force of the spring.

PLATE Xn.

COMPARATIVE VIEW OP THE BONES OP THE PELVIS AND HIND

LIMBS OP MAN AND THE HORSE.

e. Femur.
/. Patella.

g. Tibia.
li. Fibula.
i. Tarsus.
j. Metatarsus.
 PLATE XII,

t:
 PLATE XIIT,

IV I 221
.!
;
OF THE HOESE. 71

h. Digit.

1. Phalanx.
2. Do.
\
3. Do.
\
\

‘
The remaining bones of the hind-leg do not require any
j
lengthened description, as they agree generally with
those in the lower part of the fore-leg. The “ leg”
\

(metatarsus, XII. f) is composed of the shank and

PI.

I two splint bones, the former uniting at the fetlock joint

'
with the upper pastern, which is followed by the other
bones of the toe, as in the front limb.
In Plate XII. we have given a comparative view of the
;
hind limbs of man and the horse, by which the true
nature and relations of the several bones may be readily
understood, and to which our observations on a similar
comparison of the front limbs are generally applicable.

PLATES Xni AND XTV.

MUSCLES OP THE HIND QUAETEKS.

1. Glutasus extemus.

m. Glutaeus medius.
n. Triceps femoris.
0 . Biceps.
p. Semi-membranosus, Plate XIV.
q. Musculus fasciae latae.
r. Eectus.
8. Vastus extemus.
72 TIIE AETI8TIC ANATOMY

u. Gracilis.
V. Extensor pedis.
w. Peronceus.
X. Plexor pedis.
y. Gastrocnemi.
2. Plexor metatarsi.

Under this heading we shall include all the muscles

which are concerned in, and connected with, the motion
of the hind limhs.
The muscles of the hind quarters are for the most
part strongly marked, and the situation of the principal
ones easily recognized.
Prominent on the front and outer part of the haunch
is the glutceiis mediiis (Pis. I, XIII, XIV, ,m). It arises
from the processes of several of the vertehrse of the loins,
and from the prominent parts of the ilium, terminating
at its insertion in the great trochanter or projection on
the upper bone of the thigh (femur). It is a very im-
portant muscle, and acts with considerable power in
raising and bringing forward the femur. It has been
called the “ kicking muscle.’'’
The glutceus externus, (Pis. I, XUI, XTV, Z) is a slender
muscle attached to the glutceus medius, having a generally
similar origin and function.
Among the most conspicuous muscles of the hind
quarter, especially when the horse is in motion is the
triceps femoris XTTT, XIV, ti), or three-headed
(Pis. I,

muscle of the thigh (femur). Strictly speaking it is

made up of three muscles, but as they are united
PLATE XIV.
 OF THE HOESE. 75

and have a common action, it will be convenient

to speak of them as one. It takes its origin from
several of the bones of the spine, including some
•
at the root of the tail, and from various parts of the
haunch bones ;
it then curves downwards and forwards,
dividing into three heads which are inserted broadly into
the upper part of the lower bone of the thigh, behind
the “ stifle joint,” or true knee. Its action is evidently

to draw back the stifle joint, in other words, to straighten

the leg. It has therefore enormous power in impelling
the animal forward. The glutcei muscles bend the leg
preparatory to taking the spring, and the triceps acts in
opposition, forcing the leg straight, and consequently
lifting the body forwards. The posterior margin of this
muscle may be more or less distinctly observed, parallel
to the outline of the bullock, in all kinds of horses, but is
particularly evident in hunters and racers, where high
condition has resulted from the proper exercise of these
powerful springs of motion. Parallel with, and immediately
behind the triceps is the hiceps (Pis. I, XIII, XIV, o).

It springs from the sacrum and the first bones of the

tail, and descending to the inner side of the lower bone
of the thigh (tibia) forms the outer posterior border of
the haunch, and assists in straightening the leg. The
semi-mevibranosus (Pis. I, XIV, p), is also one of the
flexors of the leg ;
it forms the inner posterior border of
the haunch, and unites on the mesial line, under the
tail, with its fellow muscle of the other quarter.
On the outer front part of the haunch is the musculus
E
 76 THE AETISTIC ANATOMY

fascuB lake (Pis. I, XIII, j). It arises from the anterior

portion of the crest of the ilium and is enclosed be-
tween two layers of tendinous substance which disap-
pears below the stifle. This peculiar muscle binds
down and secures the other muscles in front of the
haunch. The rectus (PI. XIII, r) proceeds from the
ilium in front of the hip joint, and is inserted into
the patella or knee-cap. It forms the front edge of
the thigh. Behind the
rectus, and also inserted into
the patella, a large muscle called the vastus exter-
is

nus, (PI. XIII, s) of which a part only can be seen

externally. These muscles are powerful extensors of the
thigh.
Descending inside the thigh is a narrow strip of
muscle terminating just below the stifle joint. This is
the sartorius or “ tailor’s muscles it bends the leg (tibia)

and turns it inwards. It can hardly be seen. By the

side of this muscle, and to the rear of it, occupying the
principal surface of the inside of the thigh (femur), we
find the gracilis (Pis. I, XIII, u) inserted, like the sar-
torius, into the upper part of the lower bone of the
thigh (tibia). Of the muscles which move the lower
portion of the leg and the foot, the extensor pedis (Pis. I,

Xin, v) is the most important. It arises behind the

stifle, from the extremities of the two bones of the
thigh (femur et tibia) and descending to the hock, where
its tendon passes under a sheath confining it to its place
in front of that joint, continues its course to the foot,
and is inserted by a wide expansion into the front of the
 OF THE HOESE.

coffin The 'peronceus (Pis. I, XIII, w) follows

bone.
much the same course as the last muscle, but takes a
more lateral direction. It arises from the fibula, and
the tendon passes on the outside of the hock, after which
it descends to the foot with the tendon of the extensor
pedis. These muscles lift the foot forwards. Between
these muscles there is a small narrow one having the
same function as the others, and whose tendon is visible

just above the hock. The flexor pedis (Pis. I, XIII,

XIV, a:) is one of the principal muscles for bending the
foot. It arises from the upper part of the tibia, and
becoming tendinous before it reaches the hock, passes as
a large round cord through a groove at the back of that
joint then descends behind the shank bone to be inser-
;
it

ted into the two pasterns. At the back of the “ thigh”

(tibia) the extremities of the gastrocnemii may be seen
(Pis. I, Xni, XIV,
y) with united tendons (tendo achilles)
passing to the “ point of the hock” (os calcis), where
they are strongly inserted. There is some little difference
between the development of the muscles whose tendons
lead' to the heel in man and the horse. In man, the artist

will remember the soleus as forming the principal element

in the great tendon of the heel. The gastrocnemii also
contribute towards it. In the horse, however, these
latter muscles take a more important share, and are
aided by t\iQ plantaris which, in man, is extremely small.
The soleus, on the other hand, is as little developed in
the horse.
We may notice one muscle on the inside of the
E 2
78 THE ARTISTIC ANATOMY OP THE HOESE.

“tliigli” {tibia). In Pis. I, Xm, XIV, z, is the

fiexor metatarsi or bender of the “leg.” It originates
above the “ on the upper bone of the thigh (Jemvrr),
stifle,”

and is inserted into the shank and inner splint-bone. It

lies just within the anterior margin of this “thigh”
{tibia), and acts with considerable
power in bending the
hock, thereby raising the metatarsal bones. The metatar-
sus (PI. XII, j) is entirely without muscular covering,
its shape being solely due to the form of its component
bones, and the position of the tendons and ligaments which
pass over it in their descent to the pastern and foot.

THE END.

XOKDON :

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