46 



ANIMAL SKETCHES. 



CHAP. 



This folded structure is, however, not the only remark- 

 able thing about the grinding teeth of the elephant. 

 Instead of the milk teeth being succeeded vertically by 

 permanent teeth coming up from below, as is usual among 

 mammalian animals, the teeth succeed one another from 

 behind forwards. During the long life of the elephant, 

 which runs to a hundred years or more, six cheek-teeth in 

 each jaw and on each side are developed. Of these the 



(c) Cement. 



SECTION OF ELEPHANT'S TOOTH. 

 (d) Dentine. (e) Enamel. (6} Portion worn away. 



first three seem to answer to milk-teeth, while the last 

 three belong to the permanent series. The teeth are 

 successively larger and more complexly folded from the 

 first to the last ; and the whole series of teeth is gradually 

 pushed forward in the jaw, those in front being worn away 

 and their roots absorbed before the hinder ones come into 

 use. Thus there are never more than portions of two 

 teeth in each jaw and on either side in use at the same 

 time, and sometimes only one. If you will visit the saloon 



