CHAPTER, XV. 



THE NEARCTIC REGION. 



This region consists almost wholly of Tempemte North America 

 as defined by physical geographers. In area it is about equal 

 to the Neotropical region. It possesses a vast mountain range 

 traversing its entire length from north to south, comparable 

 with, and in fact a continuation of, the Andes, — and a smaller 

 range near the east coast, equally comparable with the mountains 

 of Brazil and Guiana. These mountains supply its great river- 

 system of the Mississippi, second only to that of the Amazon ; 

 and in its vast group of fresh-water lakes or inland seas, it 

 possesses a feature unmatched by any other region, except 

 perhaps by the Ethiopian. It possesses every variety of climate 

 between arctic and tropical ; extensive forests and vast prairies ; 

 a greatly varied surface and a rich and 1 leautiful flora. But these 

 great advantages are somewhat neutralized l)y other physical 

 features. It extends far towards the north, and there it reaches 

 its greatest width ; A\hile in its southern and warmest portion it 

 suddenly narrows. The northern mass of land causes its 

 isothermal lines to l)end southwards ; and its winter tempera- 

 ture especially, is far lower than at corresponding latitudes 

 in Europe. Tiiis diminishes the available area for supporting 

 animal life ; the amount and character of which must be, to a 

 great extent, determined by tlie nature of the least favourable 

 part of the year. Again, owing to the position of its mountain 

 rant.es and the direction of prevalent winds, a large extent of its 

 interior, east of the Eocky Mountains, is bare and arid, and often 

 almost desoi't ; Mhile the most favoured districts, — those east of 



