180 Proceedings of the Royal Physiced Society. 



lower fibres of origin of gluteus maximus. It was narrow 

 and fleshy at its origin. It gradually expanded as it pro- 

 ceeded down the thigh. It was inserted by fleshy fibres 

 partly into the middle third of the posterior surface of 

 the shaft of the femur, between the insertions of gluteus 

 maximus and adductor magnus, and to a much greater 

 extent into the inner lamina of the fascial sheath of the 

 gluteus maximus. 



It was supplied by the nerve to the hamstrings from the 

 great sciatic, i.e., ultimately from the 4th, 5th, and 6th 

 lumbar nerves, and by a branch from the great sciatic dis- 

 tributed to it and to the gemelli, i.e., ultimately from the 

 4th and 5th lumbar nerves. 



Caudo-femoralis receives various names — coccygeo-femor- 

 alis, agitator caudae (15), cruro-coccygien (16), and is 

 present in several mammals though not in all. Leche(l7) 

 states that the part of gluteus maximus named by Testut 

 the caudo-femoralis is not the homologue of the muscle so 

 named by him. 



The muscle does not appear to be distinct in lemurs. 

 In Windle's Hapale it was present, but differed slightly 

 in its origin from mine. It arose close by, not in conjunc- 

 tion with, the caudal head of semi-tendinosus. 



It exists in the Macacus, the Semnopithecus, and Cerco- 

 pithecus, and it probably exists occasionally in the Anthro- 

 poids as an anomaly (15). Hepburn regards the ischial 

 origin of the gluteus maximus in the Anthropoids as a 

 caudo-femoralis which has lost its original attachment. 



Semi-tendinosus arose by two heads, one in conjunction 

 with the caudo-femoralis from one of the upper caudal 

 vertebrae, the other in conjunction with the flexor cruris 

 lateralis (biceps). The coccygeal or caudal head crossed 

 superficially to the biceps, and joined the ischial head about 

 half an inch from its origin. Towards the lower end a tendon 

 was developed. The tendon crossed the semi-membranosus, 

 and was inserted mainly by becoming continuous with the 

 fascia over the inner and posterior surface of the leg, and 

 also by a small, round, tendinous slip attached to the upper 

 part of the inner surface of the shaft of the tibia under cover 



