THE HORSE AND ITS VARIETIES. 



603 



The horse (Equus caballus Linn.) is the most useful of all 

 domestic animals, and next to ships a prime means of the 

 diffusion of civilization. By artificial selection a great num- 



ber of varieties, races, and strains have been produced, 

 adapted for the performance of different kinds of work. The 

 horse only exists in a domesticated state. Sanson states that 



