MUSCLES OF THE THIGH. 447 



ing the thigh inwards. From their common action and very 

 close connexion at their insertions, they are sometimes described 

 as one, under the name of Triceps Adductor, and with great 

 propriety. The pectineus muscle is also associated with them 

 so closely in its course and character, that, as Meckel has sug- 

 gested, it ought to be considered as a fourth head to the triceps. 



The Glutceus Magnus, 



Arises, fleshy, from the posterior third of the crista of the 

 ilium, from the side of the sacrum below it, from the side of the 

 os coccygis, and from the posterior surface of the large sacro- 

 sciatic ligament. The fibres of this muscle are collected into 

 large fasciculi, with deep interstices between them ; and the 

 lower edge of it is folded over the sciatic ligament. . 



Its fibres pass obliquely forwards and downwards, and ter- 

 minate in a thick, broad tendon, the upper part of which goes 

 on the outside of the trochanter major, and is very strongly 

 inserted into the fascia femoris; while the lower part is inserted 

 into the upper third of the linea aspera, going down as far as 

 the origin of the short head of the biceps flexor cruris. 



This muscle is placed immediately under the skin, the fasci- 

 culi being separated to some depth by processes from the fascia 

 femoris. It covers nearly all the other muscles on the back part 

 of the pelvis, laps over its inferior margin laterally, and conceals 

 the origins of the ham-string muscles. 



There is a very large bursa placed between the tendon of this 

 muscle and the external face of the trochanter major; another 

 of almost equal magnitude, between it, the superior extremity 

 of the vastus externus, and the inferior end of the tensor fasciae 

 femoris; and there are two smaller ones between the same ten- 

 don and the os femoris, which are placed lower and more pos- 

 teriorly. 



The glutaeus magnus draws the thigh backwards, and assists 

 in keeping the trunk erect. 



