DISTRIBUTION OF ORGANISMS. 205 



plants of kinds appropriate to temperate and arctic regions. 

 Even the neighbourhood of a salt marsh, however remotely 

 placed amongst grounds of a different kind, exhibits plants 

 appropriate to such a soil. 



Fewer distinct zoological regions are enumerated, but 

 perhaps only in consequence of imperfect observation. Here, 

 however, the evidences against communication of organisms 

 from one region to another are even more decided. If, how- 

 ever, it were surmised that the organisms of isolated regions 

 had been communicated from other countries, and merely 

 modified in their new abodes, the disproof of the conjec- 

 ture would be more positive with regard to the zoology of 

 the question than the botany. For, while it might appear 

 possible that seeds had been floated even five hundred miles 

 to a new soil like that of the Isle de Bourbon, how can we 

 account, by such a supposition, for the existence there of bats, 

 reptiles, and other animals, the progenitors of which could 

 never have swam so far for the sake of a change of residence ? 

 This island, be it remarked, is of volcanic origin, and known 

 to have become dry land at a comparatively recent period. 



The two great continents of the earth are the first zoolo- 

 gical divisions of its surface. The animals as well as plants 

 of the old and new world are specifically different, with very 

 few exceptions; that is, they are different in the degree 

 which naturalists agree to consider as sufficient to establish 

 distinct species. But even North and South America pre- 

 sent different animals. We also find that the animals in the 

 north and south of Asia are different, and that most of the 

 African species are distinct from those of Asia. 



The differences are in some instances so great as to be held 

 by naturalists as generic. Beyond this point, however, there 

 are parities or indentities. We see, for instance, in all these 

 various regions, feline animals, ruminants, pachyderms, 

 rodents, etc. Thus, for the lion and tiger of Asia, we have a 

 different lion and the panther in Africa, the jaguar in South 

 America, and the puma ranging from Brazil to Canada. 

 Instead of the elk of Northern Europe and the argali of 

 Siberia, we have, in North America, the moose deer and 



