70 FOSSIL MAMMALIA. 



the swine and the hippopotamus, for the structure is similar. 

 It must have fed on tender vegetables, roots, and aquatic plants, 

 and could not have been carnivorous. 



The difference in the teeth of the mastodon consist, chiefly, 

 in the number of points, and the relation of length to breadth. 



There are three sorts : one almost square, with three pairs of 

 points ; another rectangular, with four pair ; a third, longer, 

 somewhat contracted behind, with five pair, and an unequal 

 heel. The first is the most worn, the last, on the contrary, very 

 little so. This points out the order of their growth and posi- 

 tion. The disposition of the cheek-teeth in the adult is thus, 

 I, two with six points, and two with eight points above ; two 

 with six points, and two with ten points below. 



Beside these eight molars in the adult, we find in the young 

 subject, that others preceded them, which fell successively. 

 The succession of growth took place, as in the elephant, from 

 front to rear. When the hinder molar began to pierce the 

 gum, the front one was ready to fall. 



The effective number of cheek-teeth which could act toge- 

 ther, was eight in the young subject, four in the old. This 

 shows that the mastodon could not have been of the enormous 

 size that Buffon and others imagined, who were led to this 

 conclusion by the error of believing the cheek-teeth equal in 

 number to our own. 



These teeth vary in magnitude, and are found in different 

 stages of detrition. But to pursue all their variations would 

 be inconsistent with our plan, and we must, therefore, refer 

 the reader for minuter information to the great work of the 

 Baron. 



On examining the lower jaw, we find that, like the elephant 

 and the morse, the mastodon had no incisors or canines below ; 

 that the lower jaw terminated in front in a hollowed point of a 

 sort of canal, and that the posterior angle, though obtuse, was 

 yet strongly defined, and not circularly rounded, as in this 

 elephant. The condyle differs little from that of the elephant, 



