164 GEOGRAPHICAL DISTRIBUTION OF ANIMALS. 



the southern continent, along the shores of the Orinoco and 

 the Amazon, that our traveller will be forcibly struck with 

 the astonishing variety of the animals which people the 

 forests, the prairies, the rivers, and the sea-shores, most of 

 which he will also find to be different from those of the 

 northern continent. By this extraordinary richness of new 

 forms, he will become sensible that he is now in the domain 

 of the tropical fauna. 



418. Let him still travel on beyond the equator towards 

 the tropic of Capricorn, and he will again find the scene 

 change as he enters the regions where the sun casts his rays 

 more obliquely, and where the contrast of the seasons is 

 more marked. The vegetation will be less luxuriant ; the 

 palms will have disappeared to make place for other trees ; 

 the animals will be less varied, and the whole picture will 

 recall to him, in some measure, what he witnessed in the 

 United States. He will again find himself in the temperate 

 regions, and this he will trace on, till he arrives at the ex- 

 tremity of the continent, the fauna and the flora becoming 

 more and more impoverished as he approaches Cape Horn. 



419. Finally, we know that there is a continent around 

 the South Pole. Although we have as yet but very imper- 

 fect notions respecting the animals of this inhospitable 

 clime, still the few which have already been observed 

 there, all present a close analogy to those of the arctic re- 

 gion. It is another glacial fauna, namely, the antarctic. 

 Having thus sketched the general distribution of the fauna, 

 it remains to point out the principal features of each of 

 them. 



420. I. ARCTIC FAUNA. The predominant feature of 

 the Arctic Fauna is its uniformity. The species are few in 

 number ; but, on the other hand, the number of individuals 

 is immense. We need only refer to the clouds of birds 

 which hover upon the islands and shores of the North ; the 



