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U.S. NATIONAl, MUSEUM BULLETIN 2 73 



semitendinous. The saphenous nerve and artery pass between the 

 distal part of these two muscles and the sartorius. 



Sirena (1871) remarks that the origin is not from an anterosuperior 

 iliac spine, but lower down on the anterior border of the coxal bone 

 above what he calls the anteroinferior iliac spine. I have observed a 

 well-defined though small eminence at this point. In other respects 

 the muscle is said (Sirena, 1871) to be like that of man. 



Figure 39. — Lateral view of the knee (1, m. rectus femoris; 2, m. vastus lateralis; 3, m. 

 biceps femoris, caput longum; 4, m. biceps femoris, caput breve; 5, trigonum 

 subtendinosum. 



Nerve supply: Two branches of the femoral nerve reach the 

 undersurface of the sartorius proximally. The saphenous nerve pro- 

 vides an additional branch to the deep aspect of its distal third. 



Function : Flexes the femur on the hip bone. Also flexes the knee, 

 and in this position it rotates the hind limb laterally, bringing it in 

 abduction. This last effect is important in the quadrupedal arboreal 

 movements of the animal when he carries these extremities partially 

 flexed and abducted. 



