104 ANALOGOUS TYPES. 



animals resemble ours so closely that the Eng- 

 lish settlers have called many of them by the 

 same names, there are no genuine Wolves, Foxes, 

 Sloths, Bears, Weasels, Martens, Squirrels, or 

 Rats in Australia. The Australian Mammalia 

 are peculiar to the region where they are found, 

 and are all linked together by two remarkable 

 structural features which distinguish them from 

 all other Mammalia and unite them under one 

 head as the so-called Marsupials. They bring 

 forth their young in an imperfect condition, and 

 transfer them to a pouch, where they remain 

 attached to the teats of the mother till their 

 development is as far advanced as that of other 

 Mammalia at the time of their birth ; and they 

 are further characterized by an absence of that 

 combination of transverse fibres forming the large 

 bridge which unites the two hemispheres of the 

 brain in all the other members of their class. 

 Here, then, is a series of animals parallel with 

 ours, separated from them by anatomical fea- 

 tures, but so united- with them by form and ex- 

 ternal features that many among them have been 

 at first associated together. 



Cuvier has already alluded to this, when he 

 speaks of subordination of characters, distinguish- 

 ing between those controlling the whole organ- 

 ization and those that play only a secondary 

 part in it. The skill of the naturalist consists 



