TDSKS AND MOLARS. 



tusks are restricted as a rule to the male, and are not, 

 indeed, invariably present in all individuals of that sex. 

 In the female Indian elephant the tusks are usually very 

 small, and soon shed. The primitive elephants, or masto- 

 dons, frequently, however, had tusks in both the upper 

 and lower jaws ; and since these did not generally attain 

 the huge dimensions which they reach iu many true 

 elephants, it is evident that in this respect the mastodons 

 departed less from the ordinary type of mammals, where 

 the front teeth are not greatly larger than the hinder ones, 

 and those of the upper and lower jaws correspond with 

 one another in size and number. Before leaving the 

 subject of tusks, it may be mentioned that the ivory of 

 which they are composed differs from the so-called ivory 

 of other teeth in a manner which renders it always easy 

 to determine whether a reputed ivory article is genuine. 

 This peculiarity consists in the circumstance that a trans- 

 verse section of a tusk exhibits a series of fine, decussating, 

 curved lines radiating from the centre to the circumference, 

 and forming curvilinear lozenges at their intersections. 

 This remarkable structure is in fact precisely similar to 

 the " engine-turning " on the back of a watch ; and in an 

 ivory knife-handle it should be distinctly visible at the 

 butt. 



We turn now to the grinding or molar teeth, which 

 jjresent far more remarkable jjeculiarities. So jjeculiar, 

 indeed, and unique are the structure and mode of suc- 

 cession of the molar teeth of elephants, that they are often 

 very im])erfectly understood, even by those who have spent 

 half their lives among these animals. For instance, we 

 find the late veteran elejjh ant-hunter, Sir S. Baker, in his 

 " Wild Beasts and their Ways," making a statement in 

 regard to elepihants that " both the Indian and the African 

 varieties have only four teeth," whereas, as a matter of 

 fact, every elepjhant has, in the course of its life, six 

 molars on each side of both the upper and lower jaws. 

 Instead, however, of all these teeth being in use at one 

 and the same time, as are those of a cow or a horse, in 

 existing elephants there are never more than portions of 

 two teeth in use at any one time, although, in the extinct 



