MAMMALIA. 671 



rior portion. Moreover, the posterior part of the tooth is consi- 

 derably wider than the anterior ; so that, as the succeeding tooth 

 advances from behind, there is always sufficient room to receive 

 it ; and in this way, by the time that the first tooth is quite 

 destroyed and falls out, a new one from behind has already taken 

 its office. There is, therefore, no absorption of the roots of these 

 teeth, but they are ground down from the crown to the stump. 



The new tooth that thus advances from behind is always of 

 larger dimensions than that to which it succeeds ; because the 

 animal itself has grown in the interval, and the jaws have become 

 proportionally developed. 



The Elephant in this way may have a succession of seven or 

 eight teeth on each side in both jaws, or from twenty-eight to 

 thirty-two in all ; and nevertheless, seeing that the anterior ones 

 successively fall out, there are never more than two visible at once 

 above the gums on each side, or eight in all : generally, indeed, 

 there is only one visible at a time. Every successive tooth is 

 composed of more laminae than that which immediately preceded 

 it, and a longer time is required to perfect its growth. 



Nearly the same account of this process was found in the 

 Manuscripts of John Hunter,* who lucidly accounts for such an 

 aberration from the ordinary course of proceeding. " These crea- 

 tures," says that distinguished observer of Nature, " do not shed 

 their teeth as other animals do that have more than one ; for those 

 that have more than one tooth can afford to be for some time 

 without some of their teeth : therefore the young tooth comes up 

 in many nearly in the same place with its predecessor, and some 

 exactly underneath ; so that the shedding tooth falls sometimes 

 before the succeeding tooth can supply its uses. But this would 

 not have answered in the Elephant ; for if the succeeding tooth had 

 formed in the same situation with respect to the first, the animal 

 would have been for some time entirely deprived of a tooth on 

 one side, or, at least, if it had one on the same side in the oppo- 

 site jaw, that one could have been of no use ; and if this process 

 took place in both sides of the same jaw, and in either jaw, the 

 animal would have been entirely deprived of any use of the two 

 remaining." 



(749.) The teeth" of Mammalia being thus adapted to so many 

 various offices, and serving under different circumstances to hold, 



* Descriptive and Illustrated Catalogue of the Physiol. Series of Comp. Anat. in the 

 Mus. Roy. Coll. Surg. Lond. Part i. p. 100. 



