FARM ANIMALS. 401 



surrounding our large cities. The vast popula- 

 tion creates a demand for milk. The high 

 price of land prohibits the owning of large 

 tracts by individuals, and the dairy business is 

 capable of enormous profit per acre. Hence 

 we see to-day the districts within reach of our 

 cities attentive to that branch of agriculture. 

 To make the dairy business profitable, high- 

 class dairy-cattle are necessary. 



The draft-horse in the Northern United States 

 is the result of a demand for animals to do 

 heavy work in the timber, on the streets of the 

 cities, and in the large fields. The heavy soil 

 and bad roads in Virginia and Kentucky brought 

 about the development of the American saddle- 

 horse. Many other instances of similar char- 

 acter might be cited. 



But without proper care all these improved 

 classes of animals tend to revert to their natural 

 conditions, under which they can protect and re- 

 produce themselves with the greatest certainty. 

 It is this retrogression that man guards against 

 by selection, care and management of his live 

 stock. 



VIII. Relation of Form and Function. 



It has been observed that animals possessing 

 great efficiency in some one direction have cer- 

 tain characteristics in common. This is true 

 whether they have been developed independ- 

 ently or in close touch with each other. As 



