The G-litteal and Femoral MiL>^cles in a Marmoset. 177 



tuberosity and ramus of the ischium, under cover of the 

 adductors and hamstring muscles attached thereto, and 

 extending to the edge of the obturator foramen. 



It had a V-shaped insertion into the femur; one limb 

 of the V was the lower half of the posterior surface of 

 the great trochanter, and a small part of the shaft of 

 the femur below, behind the insertion of gluteus 

 maximus; the other limb was an oblique line leading 

 outwards and downwards from the small trochanter across 

 the posterior surface of the shaft of the femur to meet the 

 vertical limb. 



The nerve supply was derived from the 5th lumbar 

 nerve. 



In lemurs (2) quadratus is a " voluminous " muscle. Its 

 origin is from the ischial tuber deep to the hamstring origin. 

 Its insertion occupies the whole interspace between gluteus 

 maximus and adductor magnus. Its attachments are there- 

 fore very like those of the muscle in Hapale. 



In Cynocephalus anubis, and in the Anthropoid apes, ex- 

 cepting the gorilla, the insertion is similar in its disposition ; 

 a vertical insertion into the posterior surface of great tro- 

 chanter, a horizontal insertion into a line leading out from 

 the small trochanter. 



In the gorilla, only the vertical part is present. 



Obturator externus arose from the front of the pubis 

 adjoining the obturator foramen, from the pectineal surface 

 of the ascending ramus of the pubis in its inner half, ex- 

 tending up to the pectineal line, and from the outer surface 

 of the obturator membrane. It wound round the neck of the 

 femur, and its tendon was inserted into the digital fossa, 

 where it was hidden by, and closely adherent to the super- 

 jacent tendon of obturator internus. It was supplied by 

 both divisions of the obturator nerve. 



This muscle is very constant in its characters, and very 

 like the same muscle in man. The extent of origin is 

 greater in some cases, e.g., in Ha^pale, and in the lower 

 group, the Lemuroids, than in man. In the Anthropoids 

 it is as in man, except that the tendon is partly fused with 

 obturator internus, as in Ilajpale. 



