MAN AND APE COMPARED 



7 



bone ; it is the thin, soft bone to which the ribs are 

 joined in the front of the body. In the young of 

 both man and ape it is a mere cartilage which slowly 

 ossifies from the top downward. The process 

 appears to begin at different centres, the largest 

 nucleus being at the top. There appear to be five 

 of these centres. The bone never becomes quite 

 hard in either man'^or ape, but always remains some- 

 what porous, and even in advanced age the outline 

 of the lower part is not defined by a smooth, sharp 

 line, but is irregular in contour and merges or blends 

 into the cartilages that hold the ribs in place. 



In man, this bone in maturity is usually found in 

 two segments, while in the ape it varies. In some 

 specimens it is the same as in man, while in others 

 it is found to be in four or five segments. But the 

 sternum in each is always regarded as one bone, and 

 is developed from one continuous cartilage. The 

 separate parts are never considered distinct bones. 

 The reason that it is found in separate sections in 

 the ape is doubtless due to the stooping habit of the 

 animal, by which the bone is constantly flexed and 

 alternately straightened. In man this bone varies 

 to a great extent. 



With these trifling exceptions in point of struc- 

 tures alone, the skeletons of man and ape may be 

 truly said to be exact counterparts of each other, 

 having the same number of bones, of the same 

 general type arranged in the same order and articu- 

 lated in the same manner. The corresponding bone 

 in each is the same in design and purpose. The 



