Influence of Selection 211 



tion. The fact that so many of the domesticated races breed true 

 furnishes the strongest evidence in favor of the view that they 

 have originated as sports and not as the result of the selection of 

 fluctuating individuals. In fact, as has been said, it appears 

 that a race produced by selection of fluctuations can only be 

 kept up by a rigorous process of selection, as shown in the cases 

 of some cultivated grains, flowers, and beets. Most domesti- 

 cated races, however, differ from these in one all-important re- 

 spect. They do not need a process of selection to maintain 

 them after they have appeared, and, as I have said, this is very 

 strong, indirect evidence in favor of the view that they have 

 arisen by the selection of sports or discontinuous varieties, whose 

 chief peculiarity is that they transmit from their inception the 

 new characters to their offspring. 



LITERATURE, CHAPTER XIII 



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