16 FARM ANIMALS 
was stronger than himself. The longer his snout, the better he 
could dig for roots; and worms were good to his palate, and whole- 
some medicine. If his hide was tough and thick, he could better 
withstand the cold, the thorns, or the enemy’s tooth; and the 
stronger his tusk the better able he was to win the fight. 
7. Artificial selection——Either purposely or tncon- 
sciously man weeds out the unfitted and reserves for 
breeding purposes the strong, hardy, vigorous that best 
perform their work. He chooses the “best milkers,” and 
in time establishes a line or strain that produces a large 
quantity of milk. His horses are heavier or swifter than 
their wild antecedents, because he selected them for work 
or speed. His hogs are finer in fiber, reach maturity 
Four LEADING BREEDS OF Docs 
Showing how artificial selection has brought about extreme types in form and use. 
more quickly and possess more flesh than their relatives 
of the woods, because by man’s selection the more desir- 
able qualities were sought and when obtained were pre- 
served by means of breeding only animals having such 
characteristics, This artificial selection has become a 
most valuable aid in fitting every class of domestic ani- 
mal life for the highest and best service. 
8. Heredity.—-‘“If the parentage is chosen to a definite 
end, the process of heredity will develop the form de- 
sired by a force as unchanging as that by which a stream 
turns a mill.” This is the keynote in breeding and im- 
