100 ANATOMY OF VERTEBRATES. 



however, it is exclusively inserted into tlie leg, it is here described 

 with the other muscles moving that segment of the pelvic ex- 

 tremity. The removal of this muscle, of the sartorius, and the 

 hiceps cruris, is requisite to bring into view the true glutm. 



Gluteus externus^ is smaller than the middle glutmis, but is 

 relatively larger in the Apteryx than in birds of flight. Besides 

 its orio-in from the outside of the pelvis, it overlaps part of the 

 (jlutmis medius, and has its insertion into the femur at some 

 distance below the great trochanter, all of which are marked 

 characteristics of the glutcBus magnus. It takes its origin from 

 the superior margin of the os innominatum, extends along an inch 

 and a quarter of that margin, directly above the hip-joint, and is 

 chiefly attached by distinct short tendinous threads, which run 

 down upon the external surface of the muscle : it rises also by 

 carneous fibres from the external surface of the os innominatum 

 for three lines below the superior margin. The fibres converge 

 and pass into a tendinous sheet, beginning on the external surface 

 of the muscle half-way down its course, which ends in a broad, 

 flat, strong tendon, inserted into a rising on the outer side of the 

 femur nearly an inch below the great trochanter. It abducts and 

 raises the femur. 



The gluteus medius'^ is a large, triangular, strong and thick 

 muscle, which has an origin of three inches' extent from the 

 rounded anterior and superior margin of the ilium, and from the 

 contiguous outer surface of the bone for an extent varying from 

 an inch to eight lines. Its fibres converge to a strong, short, 

 broad and flat tendon, implanted in the external depression of the 

 oreat trochanter, having a bursa mucosa interposed between the 

 tendon and the bony elevation anterior to the depression. 



The glutcEus minimus^ rises below and internal to the preceding 

 muscle from the anterior and inferior extremity, and from one 

 inch and three-fourths of the inferior and outer margin of the 

 ilium, and contiguous external surface, as far as the origin of 

 the glutceus medius ; also by some fleshy fibres from the outside 

 of the last rib. These fibres slightly converge as they pass back- 

 ward to terminate in a broad flat tendon which bends over the 

 outer surface of the femur, to be inserted into the elevation ante- 

 rior to the attachment of the glutceus magnus. 



A muscle * which may be regarded either as a distinct accessory 

 to, or a strip of, the preceding one, arises immediately behind it 

 from half an inch of the outer and inferior part of the ilium ; its 



' xr. vol. iii. p. 290, pi. 32, a - lb. pi. 32, b. ^ j^ j,]. 32, c. '' lb. pi 32, d. 



