50 



FAUNA ANTIQUA SIVALENSIS. 



boyau cylindrique, qui se developpe d'arriere en avant dans le 

 canal dentaire, dont I'enorme diametre est en partie du a eette 

 particularite. C'est quelque cliose de semblable a ce qui 

 existe dans les elephants.' This statement is subsequently 

 modified in the portion of the work devoted to the elephants. 

 M. de Blainville there prefers a claim to having first indicated 

 the normal number, the mode of succession, and the true 

 signification of the molar teeth in this genus. ^ He admits, 

 on the evidence of Corse, milk and permanent incisors, but 

 sees no occasion to apply a similar division of ' milk ' and 

 ' permanent ' to the molar series. He follows their succession 

 from first to last, and vindicates the first part of his claim by 

 showing that in the existing species, and probably in the 

 mammoth, the number of developed gi-inders is neither more 

 nor less than six. But ui regard to their signification, viewed 

 as a series, we cannot, with every respect for this eminent 

 anatomist, admit that he has been equally successful. He 

 divides the six molars into three sets, each consisting of two 

 teeth. The first includes the two anterior molars, which are 

 characterized by being worn out in the part of the jaw where 

 they first protrude ; the second set is characterized by being 

 formed in the posterior part of the jaw, and at last pushed 

 out in front ; and the third set, formed behind like the two 

 preceding teeth, is characterized chiefly by serving the adult 

 stage of the animal's life, and by the greater space which the 

 teeth have to traverse in progressing forwards. This, how- 

 ever, is at best but an setal division, and cannot be received 

 as a philosophical interpretation of the theoretical significa- 

 tion of the molar series : for the second of these sets groups 

 together the last milk and the first permanent molar. Fur- 

 ther, M. de Blainville exj^resses, by a numerical formula,^ his 

 view of the dental system of the elephant, which, if inter- 

 preted according to the exposition of his peculiar method of 

 symbols, laid down in the first part of the ' Osteographie,' 

 would imply that the elei^hant has three premolars and three 

 back molars, the milk series being suppressed : whereas, in 

 the three species of which the dentition is known, it is in 

 reality the three milk molars that are invariably developed, 

 while the three premolars are constantly suppressed. 



' Loc. cit. p. 58. ' Aussi dans aucun 

 ouvrage le nombre normal, la mode de 

 succession des dents molaires de I'^le- 

 phant, et leur signification reelle, n'ont 

 pas ete determines, ce que nous croyons 

 pouvoir faire aujourd'hui d'une maniere 

 positive, en nous aidant, il est vrai, des 

 dents fossiles que possfedent nos collec- 

 tions en plus grand nombre peut-etre 

 que des dents r^centes.' 



IS 



^ Loc. cit. 



+ 77 + 



The formula given 



+ f . The sig- 



p. 75. 



1 , 0. , i , 

 .030+3+. 

 nification of these figures, indicated in 

 the opening memoir ' Siir les Mammi- 



fferes en general,' p. 34, is y in. + % 



can. + ■§- avant mol. + \ princip. + 



■3 arrifere mol. 



