10 PACHYDERMATA. 



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 grinders is neither more nor less than 

 six. But in 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 charac- 

 terized 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, however, is at 

 best but an aetal division, and cannot be received as a philosophical 

 interpretation of the theoretical signification of the molar series : for 

 the second of these sets groups together the last milk and the first 

 permanent molar. Further, M. de Blainville expresses, by a 

 numerical formula, 1 his view of the dental system of the Elephant, 

 which, if interpreted according to the exposition of his peculiar 

 method of symbols, laid down in the first part of the Ost^ographie, 

 would imply that the Elephant 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 pre- 

 molars are constantly suppressed. 



Professor Owen, down to the close of 1844, appears to have 

 held with Cuvier the opinion that the developed molars in the 



mines, ce que nous croyons pouvoir faire aujourd'hui d'une maniere positive, en nous 



aidant, il est vrai, des dents fossiles que possedent nos collections en plus grand nombre 



peut-etre que des dents recentes." 



10 3 12 



1 Loc. cit. p. 75. The formula given iSy-f + 3 + j+^ The signification 



of these figures, indicated in the opening memoir " Sur les Mammiferes en general," 



o, . 1 • i ,3 , , 1 • • , 2 



p. 34, is j m. t q can. + g avant mol. + j princip. + ^ arnere mol. 



