FINAL SELECTION 



is to say the amount of nitrogeneous matter— in 

 the kernels of a given variety of corn. 



The specimen with which the experiment 

 started showed on analysis 10.92 per cent, of 

 protein. Selection was made, among the ears of 

 corn grown from this seed, of the individual 

 specimens having the highest protein content on 

 one hand, and those having the lowest protein 

 content on the other. 



By continuing this double selection for ten 

 generations, two races of corn were developed, 

 one of which produced seed having an average 

 protein content of 14.26 per cent., while the other, 

 grown in the same field, showed a decrease to 

 8.64 per cent. 



This experiment illustrates the possibility of 

 selecting out and fixing new races varying widely 

 as to a single important quality of grain among 

 the descendants of a parent plant of relatively 

 fixed strain. In point of fact no plant is so fixed 

 that its individual members do not show variation ; 

 none so fixed that it does not supply material with 

 which the experimenter may work in producing 

 new varieties. 



Another illustration of the same thing was 

 given by an allied series of experiments at the 

 Illinois Station at which selection was made with 

 reference to the height of the ear on the corn 



[293] 



