UNITY OK PLURALITY OP SPECIES. 263 



three last true molars not only increase successively in the 

 number of their component ridges, but that the latter are 

 proportionally thicker in the older teeth, being an adaptation 

 of nature, to suit the long term of use which the last molars 

 have to serve. Here then are two consecutive molars of the 

 same skull, which, if detached and introduced into a museum 

 without a knowledge of their origin, might be cited — the 

 penultimate as a typical illustration of E. Sumatranus, and 

 the last of E. Indians. 



Nor is this width of the bands, in worn molars, confined to 

 the Southern Elephant. 1 have now before me two grinders, 

 picked up by Sir Proby Cautley, in the swamp of Azufghur, 

 a habitual resort of wild Elephants, in the Terai of the ' Sal 

 Forests,' at the foot of the Himalayahs north of Meerut, 

 which present the characters of the discs of wear attributed 

 to the Sumatran Elephant. There is, doubtless, a certain 

 amount of difference to be met with in the teeth of different 

 Elephants living in the same forests ; but it is common to the 

 Northern as well as to the Southern form, and as yet there 

 are no good grounds to believe that it ever attains the 

 importance of a specific distinction. The discs of wear in 

 the Ceylon and African Elephants never present a similitude, 

 except when the slightly abraded crown of the latter is con- 

 fronted with the worn out and torso crown of the former. 



The most important part- of Professor Schlegel's case re- 

 mains to be considered, namely, the number of the dorsal 

 vertebrae and ribs. Here, also, I find my observations at 

 issue with the conclusions of this distinguished zoologist. 

 He avers not merely that the number of the former differs in 

 the supposed three living species, namely, 21 in the African, 

 20 in the Sumatran, and 19 in the Indian, but thinks that he 

 has detected a curious inverse relation between these num- 

 bers and the thickness of the laminae of the molars ; where 

 the latter are most attenuated the number of dorsal vertebrae 

 is least. If the inference were well founded it would be of 

 high interest. I quote the passage containing it inextcnso: 

 ' If we take into consideration at once the size of the laminse 

 of the teeth, in the different species of Elephant, and the 

 number of the ribs and dorsal vertebrae, we obtain the 

 remarkable result, that as the latter numbers decrease the 

 laminae become narrower. In E. Africanus these laminae are 

 widest, and here we find the greatest number of dorsal ver- 

 tebrae and pairs of ribs : E. Sumatranus, in which the laminae 

 are narrower, has twenty dorsal vertebrae and pairs of ribs : 

 E. Indicus, in which they are still narrower, only nineteen. 

 In the Mammoth, E. primdgenius, where they are narrowest 

 of all, the number of dorsal vertebrae and ribs appears to be 



