260 



EXISTING INDIAN ELEPHANT. 



Professor Schlegel's later communication, the statement is 

 modified as follows : — 



' The lamina) of the teeth afford another distinction which 

 however is less apparent to the eye than that taken from the 

 number of vertebra. These laminae, or bands, in E. Sunia- 

 tranus, are wider (or if one may so say, broader in the direc- 

 tion of the long axis of the teeth) than in E. Indians. In 

 mating the comparison, one may remark that the distinction 

 is less evident in younger individuals, and that there are met 

 with, in all species of Elephants within certain definite 

 limits, remarkable individual differences in respect of the 

 width of these laminae.' (Nat. Hist. Rev. ii. p. 75.) 



Here, it will be observed, the distinction is propounded 

 subject to so many qualifications, as to render it elusive for 

 any practical use. I have ascertained, after the examination 

 of a very large quantity of materials in India and Europe, 

 that the ridge-formula in the Indian Elephant runs 

 thus : — 



Milk molars. 



True molars. 



4, 8, 12 12, 16, 20-24. 



4, 8, 12 " 12, 16, 20-24. 



The increase in the number of the ridges of the successive 

 teeth takes place as in E. primigenius, by increments of 4, 

 repeated in two series, the first of which terminates with the 

 last milk molar. The second series commences with the 

 antepenultimate or first true molar, which constantly repeats 

 the number presented by the last milk molar, i.e. 12 ; the 

 penultimate (m. 2) shows an increment of 4, the number of 

 its ridges being normally 16. The last true molar never 

 shows less than 20, commonly about 22, but sometimes, in 

 the lower jaw, attaining as many as 27 ridges. This liability 

 to variation in the last true molar is well known, and runs 

 more or less through all the species of Elephant and Mas- 

 todon. 1 But the ciphers, shown above, are very constant, 

 in the three intermediate molars {i.e. the milk molar 

 and the antepenultimate and penultimate true molars), 

 namely, 12 : 12, 16. I do not mean to affirm that they are 

 absolute and invariable ; but that the above formula is a fair 

 exponent of the results yielded by a great majority of in- 

 stances, on the comparison of a very large quantity of ma- 

 terials. For example, the penultimate milk molar (m.m. 3) 

 occasionally presents only 7 ridges ; while the antepenul- 

 timate true molar of the lower jaw, in some cases, exhibits 



1 For illustrations of the fact in 

 Mastodon Ohioticus, vide Warren, Op. 

 cit. p. 79; and for its general occurrence 



in the family, vide Lartet, Bullet. Geul. 

 Soc. de France, 2e serie, torn, xvi., note, 

 p. 498. 



