4 APES AND MONKEYS 



four apes here alluded to and named in the order of their 

 physical resemblance to man are : the gorilla, the chimpan- 

 zee, the orang, and the gibbon ; but if placed in the order 

 of their mental and social characteristics they stand as fol- 

 lows : the chimpanzee, which is next to man, the gorilla, 

 the gibbon, and, last, the orang. It is possible, however, 

 that it may yet be found that the gibbon is intellectually 

 the highest of this group. 



As the skeleton is the framework of the physical 

 structure, it will serve for the basis upon which to build up 

 the comparisons ; and as, on the whole, the chimpanzee is 

 the nearest approach to man, we select and use him as the 

 standard of comparison. The skeleton of the chimpanzee 

 may be said to be an exact duplicate of that of man. The 

 assertion, however, should be qualified by a few facts of 

 minor importance ; but since they are facts, they should 

 not be ignored. The general plan, purpose, and structure 

 of the skeletons of man and chimpanzee are the same. 

 There is no part of the one which is not duplicated in the 

 other, and there is no function discharged by any part of 

 the one that is not discharged by a like part of the other. 

 The chief point in which they differ is in the structure of 

 one bone. To this we shall pay special attention. 



Near the base of the spinal column is a large compound 

 bone, known as the sacrum. It is a constituent part of 

 the column, but in its sino-ular form and structure it differs 

 slightly from the corresponding bone in man. The general 

 outline of this bone has the form of an isosceles triangle. 

 It fits in between the two large bones that spread out 

 towards the hips and articulate with the thigh bones. In 



