166 FOURTH REPORT 1834. 



also read by Geoffrey to the Academy of Sciences at Paris, both 

 during the last and the present year, connected with this question. 

 Nothing, however, has as yet been brought forward serving to 

 prove the incorrectness of Mr. Owen's views, whicli certainly 

 on the whole appear far more probable than those of Geoffroy. 

 We may add in conclusion, that Mr. Owen has recentlj^ dissected 

 a young Ornithorhynchus, the stomach of which was found filled 

 with coagulated milk*, which milk examined under a high mag- 

 nifying power, and compared ivith that of the cow, was found 

 strictly analogous to this last in respect to its ultimate globules. 

 Tiiis seems uhnost decisive of the matter. At the same time 

 the mode of generation in these animals, whether oviparous, or 

 ovoviviparous as appears more likely, remains yet to be ascer- 

 tained. 



No one has paid so much attention to those organs in the 

 3Iummalia employed by zoologists in characterizing genera and 

 species as M. Fred. Cuvicr. The teeth have been particularly 

 studied by him with reference to this point. His memoirs on 

 this subject in the Aiui. and Mtin. du Mus.f formed the basis 

 of a complete work|, published in 1825, in which he has given 

 an accurate description of the dental system in each of the prin- 

 cipal genera thi-oughout the Mainmalia, illustrated by figures. 

 He has observed a remarkable uniformity of character in the 

 molares, in all those genera which are manifestly natural, and 

 generally admitted to be such by naturalists §. With reference 

 also to their zoological characters, he has more recently made a 

 study of the various productions of the cuticle. As yet he has 

 only treated of the structure of the spines of the Porcupine ||, 

 which he selected in the first instance as most readily examined, 

 and likely to throw much light on the structure and development 

 of hair in general. His researches, as far as they have been 

 hitherto conducted, lead him to regard the hair as furnishing 

 the zoologist with characters of more importance than has been 

 usually supposed. He proposes, however, to follow up this sub- 

 ject on another occasion. In a memoir published in the same 

 volume with the one just alluded to, F. Cuvier has pointed out 



* Proceed. &c. 1834, p. 43. 



\ toms. X. xii. and xix. of the former, and torn. ix. of the latter. 



X Dents des Mammiferes considerees comme Caracteres Zoologiques. 8vo, Par. 

 1825. 



§ On the subject of the teeth of the Mammalia, their structure and zoological 

 characters, see a memoir recently published by Geoffroy. {Mem. de I'lnslUiit, 

 torn. xii. p. 181.) His chief object is to prove that the long anterior tcc'th of 

 the Rodentia, usually considered as incisors, strictly represent the canine teeth. 



II Nouv. Ann. du Mus.., torn. i. p. 409. 



