' WART-HOG. 223 



this subject towards the really two-fold type in 

 the construction and the diversity in growth of 

 the back teeth of the Wart Hog. We find, 

 namely, the three anterior back teeth shaped and 

 nourished in quite the same manner as all other 

 teeth provided with enamel bodies and real roots. 

 We farther must suppose a decay and dying 

 away of the nourishing organ (bulbus) of these 

 anterior back teeth, whenever they have obtained 

 their full growth, (whether these animals expe- 

 rience a change of teeth we cannot say, as none of 

 the animals in our possession would justify us 

 in asserting such a change,) and thus they are 

 deprived of nourishment, which circumstance we 

 would state as the cause why the alveolae are then 

 filling with a bony substance, and loosen, and 

 finally push out the tooth they contained; which 

 tooth, in old age, is diminished to less than half 

 its size, in consequence of the drain sustained by 

 its solid organ of nourishment. The three 

 anterior back teeth are thus, by the nature of their 

 construction and functions, as much subject to 

 decay and falling out as the teeth of all other 

 animals advanced in age. It is altogether different 

 with respect to the fourth, the largest and hindmost 

 of the back teeth. The latter is, as Fred. Cuvier 

 observed, a compound tooth,* (dent composee,) and 



* S. des Dents des Mammiferes, Disc, praelim. p. xlvi. 



