122 
ANATOMY OF THE HORSE. 
t 
ileum, above and rather in front of the acetabulum: inferiorly 
and posteriorly, to the supero-anterior part of the patella. 
Relations. —Its upper part lies between the iliacus and tensor 
vaginae. The body of the muscle is bounded laterally by the 
two vasti; posteriorly, by the femoral bone ; and anteriorly, by the 
faschia lata. It has also relations to the anterior crural nerve, 
and the femoral bloodvessels. 
Structure. —The superior attachment consists of a broad, flat, 
bifurcated tendon. The chief bulk is fleshv. The antero-infe- 
%j 
rior and lateral parts are covered by aponeurosis, which ends in 
a thick flattened tendon running to the patella. 
Action .—Similar to that of the vasti and crureus, 
• ** - . . 's/ i t _ ■ , » 
TRI-FEMORO-ROTULEUS. 
The three following muscles may either be considered under 
this name, as forming altogether a triceps muscle, or they may 
be viewed as three distinct muscles. The French anatomists 
prefer the former plan ; but our English schools, the latter; and 
in accordance with these schools, I shall here consider them 
separately. 
* 
vastus externus.— ( Outer Head of the Tri-femoro-rotuleus .) 
Situation. —Antero-external side of the haunch. 
Form. —Semi-oval: internal side, flattened ; external, convex; 
thickest in the middle. 
Attachment. —Superiorly' and anteriorly, to the root of the tro¬ 
chanter major, to the trochanter minor externus, and to the whole 
outward surface of the body of the femoral bone. Inferiorly and 
posteriorly, to the supero-external part of the patella. 
Relations. —On the inner side, with the preceding' muscle ; on 
the outer side, with the tensor vaginse and faschia lata; poste¬ 
riorly, with the femoral bone and biceps femoris. 
Structure. —Superior attachment, tendinous and fleshy: the 
other parts are fleshy, with the exception of a thin aponeurosis 
spread over its postero-external side. 
vastus internus .—(Internal Head of the Tri-femoro-rotuleus.) 
Situation. —Antero-internal part of the haunch. 
Form .— Semi ovoid : thicker in substance than the last muscle. 
Attachment. —Superiorly and anteriorly, to the neck of the 
femoral bone, to the root of the trochanter minor internus, and 
to the entire inner part of the body of the bone. Inferiorly and 
posteriorly, to the supero-internal part of the patella. 
Relations. —On one side with the rectus; on the other with 
