1907.] PLANT BREEDING — PRINCIPLES AND RESULTS. 12/ 



From the crop of 1896, two bushels, containing one hundred 

 and sixty-three ears, were selected from a crib of white com, 

 each ear was analyzed and a great variation was shown be- 

 tween individual ears. 



Selections were then commenced in two directions, for in- 

 crease of protein, and for decrease of protein. A few of the 

 best ears for each purpose were selected and each lot was 

 planted by the ear-to-row method in a separate and isolated 

 plot in order to prevent mixing with other kinds. From the 

 crop of each of these plots another selection of seed for the 

 following season was made by analyzing a large number of 

 ears. This process has been repeated year after year with 

 results as shown in the tables following: 



Table Xo. I. 

 BREEDING FOR INCREASE AND DECREASE OF PROTEIN. 



This table shows the average percentage of protein each 

 year in the seed planted and in the crop harvested in each of 

 the breeding plots. We can in this way compare the results 

 of the different seasons. 



The last column shows practically a continuously in- 

 creasing separation between the high-protein and the low- 

 protein strains. It shows that there have been developed ^wo 

 strains of corn one of which is now one and one-half times as 

 rich in protein as the other. The importance of this can be 

 better understood perhaps by considering that the average 

 protein content of wheat is 13.3 per cent., and the average 

 protein content of oats is 13.2 per cent. 



