56 



REMARKS ON THE DENTAL SYSTEM OF THE MASTODON. 



of new species except when the most positive evidences of difference in the 

 texture and number of the teeth existed. In regard to the latter, it may be 

 very safely asserted, that it is yet doubtful what was the entire amount of teeth 

 protruded in the Mastodon, from the beginning to the end of its dentition; 

 what were the teeth which were cotemporaneous, the periods of life of their 

 existence, the peculiarities of sex, and, lastly, the irregularities of dentition in 

 individuals. 



The teeth of the Mastodon are all formed upon one type of configuration, 

 the number of denticules excepted; they, therefore, like those of the elephant, 

 do not admit of the division into incisors, cuspidate, and molars, as in some 

 other animals. The teeth are, in fact, all molars. The lower jaw itself re- 

 sembles somewhat a human lower jaw, cut off in front of the molar teeth, and 

 there joined in the two posterior segments. These teeth invariably succeed 

 each other from behind, as stated; the hindmost ones as they emerge, pushing 

 the others forward, and out of their places, until the latter all drop out, and a 

 large, solitary tooth is finally left on each side of each jaw. 



The progress of dentition in the elephant is said to be as follows: the first 

 teeth protrude at eight or ten days after birth, and are fully out at three months. 

 "The second are completely protruded in two years from birth, and fall out 

 at six years. The third teeth appear at two years, and the fourth at nine years. 

 The entire succession brings forward eight teeth on each side of each jaw, or 

 thirty-two in the whole set. The periods at which the fifth, sixth, seventh, and 

 eighth teeth protrude, are not so well known; it is ascertained, however, that 

 the intervals of succession go on increasing. Such may have been the case 

 exactly with the Mastodon. 



The early ideas of naturalists on the teeth of the Mastodon were very ex- 

 travagant. Buffon, for example, supposed, from their rectangular form, that 

 they were very numerous; and having only insulated specimens of large teeth 

 to form a judgment on, he concluded that we might infer how enormous 

 would be the size of a head which had twenty-four or even sixteen teeth, each 

 of which weighed ten or eleven pounds, (Epoques de la Nature. Note Justif 9.) 

 He made the double mistake of supposing that all the teeth were of the same 

 magnitude, and that the entire set w^as co-existent in the animal. We now 

 know, with some degree of certainty, that the earliest teeth of this animal were 

 not more than an inch and a half square, and that the three immediately sue- 



