248 DIVERSIONS OF A NATURALIST 



development. Very probably the ape (the creature more 

 ape-like than man-like, of which more anon) from which 

 man took his direct descent had already developed a 

 plantigrade foot — that is a foot of which the sole is 

 placed on the ground for support, as it is in gibbons, 

 baboons, and bears, but not in most apes, nor in cats, 

 dogs, sheep, and horses ! And probably the hands of 

 that ancestral ape were already used more dexterously in 

 consequence, and the dog teeth were less needed either in 

 fighting or in breaking up food and so had become smaller. 



This reflection brings us to the differences between 

 the teeth of a man and those of apes. The face of 

 apes is drawn forward so as to approach in form the 

 " muzzle " of a dog. It is far less muzzle-like in the 

 more man-like apes than in the dog-faced baboons, and 

 in the least civilized living races of man is much less 

 prominent — what is called " prognathous " — than in the 

 highest existing apes. In civilized living races of man it 

 is markedly reduced, so that in the habitual carriage 

 of the head, with the eyes looking forward over a 

 horizontal plane at right angles to the vertical or up- 

 right body, the front border of the jaws, in which the 

 chisel-like incisor teeth are set, usually projects but very 

 little beyond the brow or forehead. In Greek sculpture 

 and other examples regarded by us as types of " beauty," 

 the jaws do not project at all. Such a face is called 

 " orthognathous." This modification of the shape of the 

 face is due to the progressive dwindling in the size of the 

 front part of the jaw and its teeth in the series dog, ape, less- 

 civilized man, highly-civilized man, and is accompanied by 

 an increase in the size of the front part of the brain. The 

 number of the teeth and their arrangement in groups are 

 identical in man and the apes. The most important differ- 

 ence is in the size of the front teeth,and especially in the size 



