370 Contributions to the 



of these muscles. Man stands or walks erect with ease, 

 and his Gtutcei are very large ; the ape with dilTiculty ap- 

 proximates to the erect position, and it is doubtful if he is 

 at all able to stand on one log, whence it seems to be 

 inferred that his Glutcei must be very small and weak. 

 But suppose we had first studied their actions in the ape ; 

 having seen that by means of them he leaps well, and 

 knowing that man does not leap so well, the same reason- 

 ing would lead us to believe that the Glutcei of man can- 

 not be very large. The truth is, that these same muscles 

 perform two sets of movements in both man and the ape, 

 but in the former they are so disposed, in conformity to 

 the rest of his structure, as to be best adapted to assuming 

 and maintaining the erect position, while in the latter their 

 form and direction are so modified as to be more favorable 

 to leaping. Many of the lower animals, the Horse for in- 

 stance, have a very large Glutams mediiis. Yet they 

 never stand erect. It is the muscle with which they kick, 

 and kicking differs from leaping only in the position of 

 the fixed point of the action. I do not believe that the 

 size alone of the Glutcei in the ape has any influence upon 

 his natural attitude, but that if his body and legs were so 

 balanced as to enable him to assume the erect position at 

 all, the muscles as they are would have sufficient strength 

 to maintain it, though no doubt with less steadiness than 

 those of man. But the entire skeleton and many other 

 points in the muscular system show conclusively that they 

 never were designed to do any such thing; even with the 

 great bulk of our extensors we find it extremely tiresome 

 to stand or walk with the limbs and trunk semi-flexed, 

 and that is the natural attitude of the ape, who is then 

 principally supported by his long arms, the hands either 

 resting on the eartii or grasping some object. The pelvis 

 of man is short and broad, the iscliia being short and near 

 together, allowing the limbs to swing freely by them. 

 The Glutceiis mcucimvs lies about equally above and be- 



