366 
THE HORSE.-NO. 7. 
The muscles are strong enough to dislocate and 
even fracture the hones, when acting in their proper 
direction ; they would be more powerful to do so, 
if acting out of their proper direction, and therefore 
require the support and confinement of this tendi¬ 
nous coat. When this coat is dissected off, another 
is found (which is represented at a, in the cut, and 
turned back) larger than the fascia, thicker, and 
more muscular. It proceeds from the haunch-bones 
to the stifle upon the fore and outer part of the 
haunch and thigh, and is intended to assist and 
strengthen the fascia. 
Muscles of the Inside of the Thigh.—Fig. 90. 
Under the part of this binding muscle, shown in 
the cut at a, lies the straight muscle, so called from 
its direct course. It is a large round one, proceed¬ 
ing from the ilium, not far from the socket, into 
which is inserted the upper bone of the thigh, and 
runs straight down that bone, and hence its name. 
This muscle is inserted into the bone of the stifle ; 
and it is so situated as to be enabled to exert its 
great power in the most advantageous way. It is 
a very prominent muscle, and possesses great 
strength. It unites with the tendons of the muscle 
seen at c and b in the cut, and with the tendons of 
those seen at g and i, in the cut, page 240, August 
No. After this union it terminatesffn a short and 
very strong tendon. ^ 
At c, is seen the vast muscle, so called from its 
great size and strength. This muscle is double, 
being on both the outside and inside of the thigh, 
and arises from the outer and inner surface of the 
bone of the thigh. It is inserted into the upper 
part of the bone of the stifle, and on both sides of 
it. This muscle acts at a mechanical disadvantage, 
as it forms a very slight angle (far from a right 
angle, which is the direction of greatest power) and 
of course must be very large to be efficient. It is 
accordingly a muscle of immense size, and occupies 
all the forepart of the thigh, from the stifle up¬ 
wards. It is inserted into the stifle-bone, which is 
connected by strong tendons with the bone of the 
leg. From position it is a powerful extending mus¬ 
cle of the thigh and whole leg. 
At d, is a long, narrow, prominent muscle, aris¬ 
ing partly from the bones of the back at the loin, 
and extending down the thigh. It assists to bind 
the leg; it turns it inward and gives it a rotary mo¬ 
tion ; it is besides of service in many of the motions 
of the hind-leg. 
At e, is a broad, thin muscle, occupying the 
greater portion of the surface of the inner part of 
the thigh and particularly the prominent part of it. 
It arises from the lower part of the haunch-bone ; 
it proceeds downward and unites with the muscle 
dj and when united, both are inserted into the 
inner and upper part of the lower bone of the thigh 
and continued over the stifle. Its power is very 
great, although it acts at a great mechanical disad¬ 
vantage. Its office is to bend and rotate or turn 
the leg inward. 
On the inside of the thigh at /and g, and forming 
the rear or hind edge of the thigh, lies another im¬ 
portant muscle; it is mostly on the inside of the 
thigh, and makes much of the bulk of the hind part 
of the thigh Its office is to bend the thigh up¬ 
ward and forward upon the bones of the haunch, 
and to lift and bend the leg. It is an extending mus¬ 
cle. As it has to raise and bend forward the whole 
limb it must be a very powerful muscle. It there¬ 
fore acts with very great mechanical advantage, 
viz. at a right angle, or nearly so; and is one of 
the most effectual of the extending muscles.' 
At A, is a muscle whose office is to lift and bend 
forward the foot. It is called the extending muscle 
of the foot. At w, it becomes a tendon. 
At f, is a muscle called the bender of the leg. 
Its office is to bend the hock and turn it somewhat 
inwards. It arises from the thigh-bone, and is in¬ 
serted by a tendon into the large and small bones of 
the hock. It is a muscle of considerable power, 
although disadvantageously situated, both as to its 
direction and its insertion into the bones of the hock, 
so near the joint of the hock. 
At Z, is another extending muscle. It is attached 
to the whole of the splent-bone of the lower thigh; 
it becomes a tendon, extends in the shape of a ten¬ 
don over the hock, to which it is attached, down¬ 
ward to the foot, into the coffin-bone of which it is 
inserted. Its office is to co-operate with the exten¬ 
sor of the foot in raising it from the ground, and 
bringing it forward under the body. It is the Same 
as the muscle at m in the cut page 240 Aug. N.o. ! 
At m, is seen a portion of a very powerful mus¬ 
cle, arising from the head of the upper bone of the 
thigh and ending in a flat tendon about midway 
down the lower bone of the thigh and continuing 
to the hock, into the point of which it is inserted. 
It extends the hock; it is most advantageously 
