216 



Plant- Breeding 



itself by buds. The element of chance, therefore, is one 

 hundred, or more, to one in crossing plants as compared 

 with crossing animals. Then, again, the plant-parents 

 may be modified profoundly by every environmental condi- 

 tion of soil and temperature and sunshine, or other ex- 

 ternal conditions, since they possess no bodily tempera- 



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N 



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FIG. 52. Crop averages in corn breeding for high and for low protein. 

 Results of twelve generations. (Illinois Experiment Station.) 



ture, no choice of conditions, and no volition to enable 

 them to overcome the circumstances in which they are 

 placed. Animals, on the contrary, have all these ele- 

 ments of personality, and the breeder is also "able to con- 

 trol the conditions of their lives to a nicety. In view of 

 all these facts, it is not strange that animals can be bred 

 by crossing with more confidence than can plants. But 

 there is another and even more important difference 



