24 CLASS MAMMALIA. 



as yet, been observed only in South America, New Holland, 

 and some islands of the Indian Archipelago. The Didelphes, 

 properly so called, or the Sarigues, and the Chironectes, 

 are proper to the first of these countries. All the others, 

 except the Phalangers, with naked and scaly tails, are 

 peculiar to the second; and those last mentioned Phalangers, 

 and a species of the Kanguroo, are alone to be met with 

 in the Indian Archipelago. It is remarkable that all the 

 Mammalia known in New Holland, to the present day, 

 with the exception of the Dog, and the Hydromys 

 with white belly and that with yellow, belong to the Mar- 

 supiata. 



To this continent also belong the Ornithorhynci and 

 Echidnae, which have also the marsupial bones in both 

 sexes, but whose organs of generation are peculiarly con- 

 formed, and in which no mammae have yet been observed. 

 These animals have so great an analogy with the Marsu- 

 piata, that M. De Blainville puts them in the same sub- 

 class. But M. Geoffroy has separated them from the 

 other Mammalia, to form an order which he calls Mono- 



TREMES. 



The first of the marsupiata, on which we shall hazard a 

 few particular observations, is the Didelphis Virginiana, 

 or Virginian Opossum. 



When in the study of animals, we consider nothing but 

 their organic structure, we often fail to ascertain a suffici- 

 ent cause for their peculiar modes of action, or for the 

 part assigned them to perform in the admirable economy of 

 nature. The organization of the Wolf is the same with 

 that of the Dog : the Marten and the Weasel are not to be 

 distinguished from each other without difficulty ; yet their 

 destination is far from similar. The lot of one species is 

 cast in the midst of the thickest and the wildest forests, 

 while the wants and instincts of the other are essentially 

 connected with the habitations of men. 



