FINAL SELECTION 67 



more than 23.92 per cent, nearly one-fourth 

 sugar, as against the 15 per cent of its ancestral 

 type, will be recalled. In a similar way the sugar 

 beet has by mere selection been developed until 

 the races now cultivated contain several times 

 the proportion of sugar of the ancestral beets 

 even of twenty years ago. 



An interesting experiment in causing the 

 progeny of a certain plant to vary in opposite 

 directions through selection, has been made at 

 the Illinois Agricultural Station. Here the 

 quality under consideration was the protein 

 content- that is to say the amount of nitrog- 

 enous 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 

 the 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. 



