THE MUSCLES OF THE LOWER EXTREMITY. 



167 



names of glutceus quartus and glutCBUs quintus, in the 

 Cassowary ; one of them is absent in most birds " (Anat. 

 of Verts., vol. ii. pp. 100-101). 



The two smaller gluteals pull the thigh-bone forwards 

 while at the same time they abduct it. 



The group of gluteal muscles are also powerfully de- 

 veloped in our Geococcyx calif or manus. In it " the 



FIG. 45. Anterior aspect of left femur of a Raven, designed to show the muscles 



that are attached to it. 

 FIG. 46. The same bone seen from behind ; a, femoral head of the flexor 



pcrforans digitorum profundus. 

 FIG. 47. The same bone viewed from its inner side. All life-size, by the author, 



from his own dissections. 



glutens primus (Fig. 62 bis} constitutes that great and 

 rather complex muscle which makes up the central fleshy 

 portion of the outer aspect of the thigh. It arises by a 

 strong fascia from the summit of the co -ossified neural 

 spines of the anterior sacral vertebrae, and by carneous 

 fibres from the outer rim and under surface of the 



