GENERAL PRINCIPLES OF BREEDING. 25 



regions of Northern Asia, retains the hue distinctive of 

 his family, but with a continually deepening shade as he 

 approaches to the inter-tropical countries. The native of 

 China, of a dull yellow tint at Pekin, is at Canton nearly as 

 dark as a Lascar The American Indian retains his dis- 

 tinctive copper hue amid the snows of Labrador, but on the 

 shores of the Caribbean Sea becomes nearly as black as an 

 African. 



Temperature likewise affects the size and form of the 

 body. The members of the Caucasian group towards the 

 Arctic Circle are of far inferior bulk of body to the natives 

 of temperate countries. The Central Asiatics, in elevated 

 plains, are sturdy and short, the result of an expansion of 

 the chest; the Hindoos are of slender form and low physical 

 powers, so that they have almost always yielded to the supe- 

 rior force of the northern nations from the first invasion of 

 the Macedonians to the ultimate establishment of European 

 power in the Peninsula. The Negro, on the other hand, in the 

 hottest and most pestilential regions of the habitable earth, 

 where the Caucasian either perishes or becomes as slender 

 as a stripling, is of a strength and stature which would be 

 deemed great in any class of men affording a strong pre- 

 sumption in favor of the opinion of the distinctness of his 

 race and its special adaptation to the region in which it has 

 been placed. 



In quadrupeds the effects of temperature are everywhere 

 observable in the covering provided for their bodies, whether 

 wool or hair, and which in the same species is always more 

 abundant in the colder than in the warmer countries. In all 

 quadrupeds there is a growth of down or wool underneath 

 the hair, and more or less mixed with it. In warm countries 

 this wool is little if at all developed; but in the colder it fre- 

 quently becomes the principal covering of the skin, forming 

 along with the hair a thick fur. In the warmest regions the 

 domestic sheep produces scarcely any wool; in temperate 

 countries he has a fleece properly so called, and in the cold- 

 est of all his wool is mixed with long hair which covers it 

 externally. The wool, an imperfect conductor of heat, pre- 

 serves the natural temperature of the body, and thus pro- 



