EVOLUTION AND VARIATION 67 



attained through favorable environment and the 

 permanent results of selection of the best indi- 

 viduals for continuing the race. 



What would be the result if all apple, plum, 

 corn, melon, or petunia seed was indiscriminately 

 planted? Soon worthless mongrels only, having 

 no character and no value for any purpose. 



Only by constant selection of the best can any 

 race ever be improved. No education, no en- 

 vironment of any nature can ever make any 

 appreciable progress, even though these same 

 favorable surroundings may produce through 

 ages a definite but infinitely slow increment, 

 which by constant repetition becomes slowly 

 available in heredity, but through many gener- 

 ations by no means fixed, so that reproduc- 

 tion true to the better type can be depended 

 upon. 



It is becoming increasingly necessary to im- 

 press the fact that there are two distinct lines in 

 the improvement of any race; one by favorable 

 environment which brings individuals up to their 

 best possibilities; the other ten thousand times 

 more important and effective — selection of the 

 best individuals through a series of generations. 

 By this means, and by crossing, can any race 

 of plants, animals, or man be permanently or 

 radically improved. 



