190 THE MUSCLES. 



Origin from the ventral half of the ilium, from near its 

 cranial end to a point midway between the posterior iliac spine 

 and the spine of the ischium. The muscle ends in a strong 

 flat tendon. 



Insertion into an oval facet at the base of the dorsal surface 

 of the great trochanter on its lateral side. 



Relations. — Outer surface with the gluteus medius (Fig. 

 90, b) and at the caudal border with the gemellus superior 

 (Fig. 163, c). Inner surface with the capsularis and rectus 

 femoris (Fig. 92, b'). 



Action. — Rotates the femur so as to carry the foot out. 



M. capsularis (gluteus quartus, or epimeralis). — The cap- 

 sularis is a small flat bundle of muscle-fibres which lies obliquely 

 beneath the gluteus minimus (Fig. 163, 5) and gemellus superior 

 (c) on the lateral or outer surface of the ilium. 



Origin by fleshy fibres from the surface of the ilium over a 

 triangular area between the origin of the rectus femoris (Fig. 

 92, U) ventrad, the gemellus superior (Fig. 163, 6) dorsad, and 

 of the gluteus minimus (Fig. 163, 5) craniad and the aceta- 

 bulum caudad. The muscle passes over the smooth surface of 

 the ilium and the pubis ventrad of the acetabulum and then 

 over the capsule of the joint. 



Insertion by fleshy fibres for about one centimeter in the 

 middle line on the dorsal surface of the femur distad of the 

 great trochanter. 



Relations. — Outer surface with the gluteus minimus (Fig. 

 163, 5), the gemellus superior (e), and the vastus lateralis (Fig. 

 90, d^. Inner surface with the ilium, the rectus femoris (Fig. 

 92, b), the capsule of the joint, and the vastus medialis (Fig. 

 92, c). 



Adtion. — Rotates the thigh so as to carry the foot inward, 

 hence antagonizes the iliopsoas. 



M. gemellus inferior. — The gemellus inferior is a flat tri- 

 angular muscle situated just caudad of the gemellus superior 

 and beneath the obturator internus (Fig. 90, e), so that it is 

 seen on reflecting the latter 



Origin from the dorsal one-half of the whole lateral surface 

 of the ischium between the ischial spine and the ischial tuber- 



