187 



A skull of the Capybara, Hydrochcerus Capybara, Erxl., was exhi- 

 bited, and Mr. Owen read some Notes thereon. After adverting in 

 terms of high eulogium to the genius of Cuvier, as shown by his de- 

 tection of concealed affinities among the animal kingdom, he observed 

 that " perhaps the most extraordinary instance of the enlarged views 

 which result from unwearied observation of the internal structure of 

 animals is afforded by Cuvier's bold enunciation of the affinity of the 

 Elephant to that order of the Mammalia which contains the most 

 minute forms of the class." Mr. Owen dwelt in succession on each 

 of the evidences adduced in the ■ Ossemens Fossiles' in support of 

 this affinity, and then proceeded as follows : 



" The truth of these observations was very strongly impressed on 

 my mind when examining the cranium of a huge Rodent, which Mr. 

 De la Fons obligingly left with me for the purposes of comparison, and 

 for the exhibition of which this evening the Committee is indebted 

 to that gentleman. The person from whom he procured it assured 

 him that it was from Africa; but this is only another of the numerous 

 instances of the little confidence to be placed in the assertions of 

 ignorant salesmen, since the specimen presents all the characters of 

 a genus exclusively South American, viz., the Capybara, Hydrocharus, 

 Erxl. It has every appearance of having belonged to an old animal, 

 and is much larger than a cranium in the museum of the Royal Col- 

 lege of Surgeons, which, from its dentition, I had always regarded 

 as having appertained to an adult specimen. Nevertheless, although 

 the cranium belonging to Mr. De la Fons is wholly deficient of the 

 teeth, as well as wanting the lower jaw, I have no doubt, from the 

 perfect accordance between the two specimens in the forms and con- 

 nexions of the several bones, that they are identical as to species. 



" There is, however, a difference exhibited in the alveola? of the 

 last molar tooth in Mr. De la Fons's specimen, which, although by 

 no means sufficient for the founding of a specific difference, is impor- 

 tant, as evidencing an additional analogy between the molars of the 

 Rodent and those of the Elephant j viz., that the number of trans- 

 verse lamina increases as the jaw enlarges with age, the whole num- 

 ber not coming into use at once. 



" In the Capybara, the posterior grinders, like those of the Elephant, 

 present a greater number of component lamina? than the anterior 

 ones which are of earlier formation. Those of the upper jaw, accord- 

 ing to the figure and description in the ' Ossemens Fossiles' (v. pi. 1 . 

 p. 24.) are composed of eleven lamina, of which all but the first 

 (which is notched externally) are simple. In the figure too, it is 

 worthy of observation that the last or eleventh lamina is imperfect, 

 and exhibits a construction analogous to the imperfectly- formed 

 lamina or denticles in the Elephant's grinder, viz., a division into 

 component columns. In the work of M. Fred. Cuvier ' Sur les Dents 

 des Mammiferes,* the number of lamince in the last grinder of the upper 

 jaw of the Capybara is stated as "onze ou douze ;" but eleven only are 

 exhibited in the figure, and we may suppose therefore the doubt as 

 to the precise number to be founde4 on uncertainty as to the pro- 



