THE VASCULAR SYSTEM. 151 



ulnar artery in the cat is so small that it is frequently 

 not filled by the starch injection, but in man it is larger 

 than the radial. 



THE ARTERIES OF THE HIND-LIMB. 



As in the forelimb, the branching of the arteries in the 

 hind-limb varies considerably in different specimens. 

 The main artery of the leg lies on the ventral or mesal 

 aspect of the femur, passing obliquely to the caudal side 

 of the knee-joint, where it divides into two branches (Fig. 

 73), one extending along the cephalic, the other along 

 the caudal aspect of the crus. The cat, or at least the 

 caudal half of a cat, should be fastened to the dissecting 

 tray on its back, the abdominal wall removed, and the 

 viscera pushed laterad to demonstrate the origin of the 

 artery of this limb. As in the forelimb, the main artery 

 in different portions of the leg takes the name of the 

 corresponding region. 



The external iliac is the largest artery arising from the 

 aorta in the lumbar region. It gives off but one im- 

 portant branch, the profunda, which, extending caudad, 

 soon gives off a large epigastric artery to the abdominal 

 wall, then smaller branches to the external genital 

 organs, and numerous branches to the muscles on the 

 caudal aspect of the femur. 



The femoral artery, which is a continuation of the 

 external iliac, extends along the mesal aspect of the 

 femur. In the proximal half of its course it is quite 

 superficial, but the distal portion is covered by the 

 gracilis, sartorius, and semimembranosus muscles. It 

 furnishes four important branches: the anterior femoral, 

 supplying mainly the quadriceps extensor muscle; the 

 superior posterior femoral, supplying the adductor and 



