430 ON THE FOSSIL BONES OP PACHYDERMATOUS QUADRUPEDS. 



scribed; that consequently the one-horned of Java, and that of India, 

 could hardly be considered as belonging to the same species. 



I should not have insisted on the detrition of the incisors of the 

 latter, which is accidental, nor on the posterior angle of the lower 

 jaw, which is less obtuse : it is the effect of the development of 

 the seventh molar tooth, and consequently produced by age. 



Neither should I have dwelt on the very great rugosities of the bones 

 of the nose, and of the zygomatic arch, which may also arise from 

 age. 



But we could not so easily account for the disproportionate elevation 

 of the cranium, and of the occipital ridge. The entire height of the 

 head placed on its lower jaw is, in the Indian adult, to the same dimen- 

 sion in the young one of Java, as four to three, while their lengths are 

 equal. In particular, it could not be conceived how the process ob- 

 served at the lower edge of the nostril could be entirely wanting in the 

 young skull of Java. 



There was observed again in the animal which I had before me, a 

 difference which struck me very much, but which I afterwards ascer- 

 tained to be merely the result of accident. 



We have seen, from Vicq-d'Azyr, that the one-horned rhinoceros of 

 India, an adult, had on one side a stump of external incisors outside 

 the great one above. We also saw, from Camper, Mem. de Petersb. 

 for 1777, plate 2, p. 211, that a very young head of a one-homed rhi- 

 noceros, exhibited in the incisive bone, on either side, two well-marked 

 alveoli ; and, in order to shew the matter clearly, we had copied, 

 plate 42, fig, 4, the figure given by Camper of this incisive bone, and 

 fig. 5, that of the extremity of the lower jaw corresponding to it. We 

 even give anew those parts, which we had caused to be designed from 

 nature, at Franeker, plate 43, figs. 2 and 3. 



Now this one-homed rhinoceros of Java, of intermediate age, (plate 

 42, fig. 2, and plate 43, fig. 1), has no external incisors, and presents 

 no trace of alveoli which could contain them. 



How, said I to myself, could that be, if the skull was of the same 

 species, as this very young and this very old one, each of which exhi- 

 bited traces of this tooth ? 



Peter Camper appears to have already recognized this difference be- 

 tween the rhinoceroses of Asia : " I had an opportunity (says he in a letter 

 to Pallas, inserted in the Neue nordische Beyt?-cege, vii, 249), to distin- 

 guish two"species of Asiatic rhinoceroses, which have each four large in- 

 cisors. I shall send, on this subject, toi the Academy of Petersburg, 

 the continuation of my memoir on these animals. The death of this 

 great man, which happened a little after, prevented him from executing 

 his design : but as it is one of the heads in his cabinet, which has served 

 as the base of my preceding observations, it is probable that his had 

 the same source, and led him to the same result. 



The conjectures which these characters caused me to form, on the 

 existence, at Java, of a second species of one-horned rhinoceros, have 

 been fully confirmed by the observations of two of my pupils, MM. 

 Diard and Duvaucel, contained in a memoir which they presented to 

 the Society of Sciences at Batavia, and by an adult skeleton and a 

 skin of this species which they sent to us. 



