232 MYOLOGY. 



Gluteus externus. 

 Gluteus maxim us. 

 Gluteus internus. 

 Rectus parvus. 



Obturator externus. 

 Obturator internus. 

 Pyriformis. 

 Gemellus anticus. 

 Gemellus posticus. 



GLUTEUS EXTERNUS. 



{Ilio-trochanterius Medius.) 



(Pl. IL 56 ; Fig. 84. 6.) 



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

 croup, its fibres converging 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 

 fleshy 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 

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

 ment. 



lielation. — Externally with the gluteal fascia ; anteriorly with 

 the fascia lata ; posteriorly with the triceps abductor ; internally 

 with the maximus. 



Action. — It abducts the thigh. 



GLUTEUS MAXIMUS. 



{Ilio-trochanterius Magnus.) 



(PL. IIL 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- 



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