232 MYOLOGY. 



Gluteus externus. Obturator externus. 



Gluteus maximus. Obturator internus. 



Gluteus internus. Pyriformis. 



Rectus parvus. Gemellus anticus. 



Gemellus posticus. 



GLUTEUS EXTERNUS. 



(Ilio-trochanterius J/ediics.) 



(Pl. U. 56; Fig. S4. b.) 



This is a V-shaped muscle situated on the external part of the 

 croup, its fibres coaverging downwards. It consists of a muscular 

 and an aponeurotic portion ; the former is double, the parts con- 

 verging and ending in a flat tendon ; the aponeurotic joins the 

 llesh}^ portion posteriorly, and is hidden under the triceps abduc- 

 tor femoris. 



Origin. — The anterior portion arises from the anterior spine 

 of the ilium, the posterior from the second and third sacral 

 spines ; also from the gluteal fascia. 



Insertion. — To the trochanter minor ; the aponeurotic portion 

 reaches the tuberosity of the ischium and the sacro-sciatic liga- 

 ment. 



Relation. — Externally with the gluteal fascia ; anteriorly with 

 the fascia lata ; posteriorly with the triceps abductor; internally 

 Avith the maximus. 



Action. — It abducts the thigh. 



GLUTEUS MAXIMUS. 



[Ilio-trochanterkis Magnus.) 



(Pl. in. 30; Fig. 84. c.) 



This is a very large muscle occupying the iliac dorsum, and 

 stretching forwards over the lumbar region ; it is fleshy and thick 

 in its centre, terminating in two tendons. 



Origin. — From the iliac shaft, crest, dorsum, and spines, 

 anterior and posterior, the side of the sacrum, the sacral and part 

 of the sacro-sciatic ligaments, and the tendinous envelope of the 

 longissimus dorsi as far forward as the last rib. 



Insertion. — By two tendons, one to the summit of the tro- 

 chanter major, the other anteriorly to the crest below the con- 



