122 Selection Does Not Lead to Origin of Species. 



forth. Many races are no good except in small districts, 

 and sometimes even on single farms. Each race has its 

 own taste in the matter of soil and manure, and we can 

 only count on the expected harvest when this taste is 

 satisfied. They behave in just the same way as the local 

 races of our wild flowers. 



9. Natural Selection in the Field. Much too little 

 attention is usually paid by the biologist to this phenom- 

 enon although it is of such tremendous practical im- 

 portance. Cold, frost, moisture, crowding together and 

 late ripening select as effectively in the field as the most 

 vigilant husbandman. Sometimes they cooperate with 

 him but generally they are opposed to him. In the case 

 of acclimatization they are usually on the same side in- 

 asmuch as the new climate only spares those individuals 

 which can stand it. And the same is true of the effort 

 to keep up old-established races of any particular country. 

 In the cultivation of the better sorts and in empirical 

 selection the work of the breeder might well be said to 

 consist simply in suspending the action of natural selec- 

 tion. If nature and art have equal weight in the balance 

 the value of the race does not change. In methodical 

 selection of improved races nature almost always works 

 against the breeder by favoring the stronger and coarser 

 individuals. The breeder's task is therefore first to main- 

 tain his race and then to improve it. 



§ 14. THE BEHAVIOR OF IMPROVED RACES AFTER THE 



CESSATION OF SELECTION. 



As soon as selection ceases the qualities of an im- 

 proved race disappear. That which has been attained 

 by the work of many years may disappear in a few gen- 

 erations. The most experienced breeders express the 



