48 



FAUNA ANTIQUA SIVALENSIS. 



creasing in size during the rest of the elephant's life. He 

 has described the variations in size, form, and direction which 

 the tusks present in the different sexes and castes of the 

 Indian species, the general character of which castes he has 

 accurately recorded; but the most valuable part of his 

 observations is comprised in what relates to the molar teeth. 

 He showed that they are reproduced several times during 

 life, and that the number of plates entering into the compo- 

 sition of each molar goes on increasing as the teeth are 

 successively renewed. This succession he has carefully traced 

 up to the fourth grinder : the first cuts the gum eight or ten 

 days after birth, is well out at six weeks, and is composed of 

 four plates ; the second is completely in use at two years, 

 and consists of eight or nine plates ; the thu-d serves the 

 period between the second and sixth year, and has twelve or 

 thirteen plates ; the fourth is in use between the sixth and 

 tenth year, and consists, according to Corse, of about fifteen 

 plates. Puzzled, probably by the irregularity in the nuinber 

 of plates, and the size of the rest of the molars in different 

 individuals, this faithful observer stops short at the point 

 where his observations ceased to be conclusive, and does not 

 attempt to define the number of plates in those which follow 

 after the fourth. He states, generally, that the plates go on 

 increasing successively up to the ' seventh or eighth set,' 

 when each grinder consists of twenty-two or twenty-three 

 plates, being the greatest number which he had observed.' 

 These observations were of especial vakie in furnishing a 

 standard of comparison for the teeth of the fossil species ; 

 and by establishing the existence of milk incisors, they proved 

 that part at least of the dental system of the elephant agreed 

 with that of the ordinary Pachydermata. But Corse was at 

 fault in the conjecture that eight molar teeth are successively 

 developed in an antero-posterior series in this animal; for if 

 this were the case, the elephant would form an exception to 

 a general law in the Pachydermata and allied orders, among 

 which the normal number of milk molars does not exceed 

 four, that of the true molars being invariably tlu-ee. 



Notwithstanding this objection. Corse's numerical state- 

 ment was adopted by Cuvier and by all other authors prior to 

 1844, when it was, for the first time, challenged by M. de 

 Blainville in the part of his ' Osteographie ' devoted to the 

 elephants. Bronn,^ in his ' Lethsea,' gives eight molars on 

 each side of both jaws to the genus Elephas ; and Dr. Grant,^ 

 in his memoir upon the Proboscidea, puts forward different 



' Corse, loc. cit. p. 224. 

 - Bronn, Letliaea Geognostica, 1838, 

 p. 1240. 



' Grant, Geolog. Proceedings, 1842, 

 vol. iii. p. 771. 



