MYOLOGY 73 



the gluteus medius. Origin from the deeper dorsal fascia 

 extends from about the last lumbar to the third sacral 

 vertebrae. This part of the muscle is very thin, and some 

 of its deeper fibers are only with difficulty separable from 

 the gluteus medius, which lies deep to most of the gluteus 

 maximus. It passes just caudad of the head of the femur 

 and is inserted for a distance of some 7 mm. upon the 

 caudo-lateral border of the great trochanter and the 

 lateral ridge adjoining. 



In Neotoma and Teonoma the insertional portion is 

 slightly broader. 



The gluteus maximus is served by the inferior gluteal 

 nerve. 



M. gluteus medius (figs. 6, 32) has origin from the 

 superior gluteal fossa of the ilium, particularly the cranial 

 border, and from the dorsal fascia. Insertion is onto the 

 proximo-medial part of the great trochanter. 



M. gluteus minimus (figs. 6, 16, 32) is a rather com- 

 plicated muscle, being partly bipennated and lying chiefly 

 deep to the gluteus medius, its lateral edge only being 

 visible before transecting the latter. Origin is from the 

 lateral ridge of the ilium and its inferior gluteal fossa 

 caudad, with origin of its ventral portion also from an 

 aponeurotic sheet arising from the inferior border of the 

 ilium. Insertion is by tendon fibers onto the great tro- 

 chanter of the femur. 



Innervation of the glutei medius and minimus is by the 

 superior gluteal nerve. 



3. Obturator group 



The muscles of this group, numbering six, consist of 



Mm. gemellus superior gemellus inferior 



pyriformis quadratus femoris 



obturator internus obturator externus 



