POUCHED MAMMALS, OB MARSUPIALS. 185 



The only other Marsupials are the Opossums of 

 America, which are readily distinguished by the 

 absence of a pouch in which to carry the young. In 

 consequence of this, the young of some species are 

 carried upon the back of the female, with their tails 

 tightly twisted round the tail of their parent, which 

 is arched for this purpose over its back. All the 

 Opossums are of carnivorous habits, while the Crab- 

 eating Opossum is peculiar in being partly aquatic, 

 As we have already said, Opossums are most abundant 

 in South America, where the mammalian fauna is 

 mostly of a low grade of organisation ; and they make 

 their first appearance in the Eocene Tertiary of 

 Europe. 



Such, very briefly, is the history of the Marsupials 

 of the present day a history deeply interesting to 

 the zoologist as showing how, humanly speaking, a 

 type of animals, characteristic of an early part of the 

 earth's existence, has been preserved to us in one 

 remote region by the complete isolation of an island- 

 continent, and in another by the retiring habits of its 

 representatives and the absence of severe competition 

 in the struggle for existence. 



