126 BOARD OF AGRICULTURE. [Jan., 



we select seed and thus forcing a cross from the other rows 

 which bear tassels. 



In an experiment at the Illinois Agricultural Experiment 

 Station, the continuous selection of seed from rows which were 

 left tasseled and which became more or less inbred, reduced 

 the yield to fifteen per cent, less than that of continually 

 selected detasseled rows from the same plot. This effect ap- 

 peared as early as the second year's breeding and was cor- 

 roborated by the third year's work : and the discrepancy would 

 probably have been even greater, except that the pollen falling 

 on the detasseled rows came from rows more or less inbred. 



In our plan of breeding, the entire lot of corn planted in 

 the breeding plot comes from rows which have been detasseled 

 in every previous year of breeding, and thus we get absolutely 

 no effect of inbreeding. 



CONCRETE EXAMPLE OF RAPIDITY OF PROGRESS, 



I next wish to illustrate the rapidity of progress which may 

 be expected in breeding work by an example of work done by 

 the Illinois Experiment Station. 



In 1896 Hopkins showed that while the variation in 

 chemical composition of different ears of the same variety is 

 very great, the variation in composition of the kernels of each 

 single ear is very small. That is, the protein in individual 

 kernels of a single ear may vary as much as one-half of one 

 per cent, from the protein content of the whole ear, but in no 

 case did they exceed this amount. On the other hand, the 

 protein in different ears of the same variety grown in the same 

 field, may vary as much as six per cent, from each other. 



This uniformity of the individual ear makes it possible to 

 determine the composition of an ear of corn by the analysis 

 of a few kernels. The remainder of the kernels of the ear 

 may then be planted if desired. The wide variation in composi- 

 tion between different ears furnishes a starting point for the 

 selection of seed in any of the several different lines of desired 

 improvement. Thus by shelling off two rows of corn from the 

 ear as a sample to be analyzed, the composition of an ear is 

 found, leaving practically eighty per cent of the com of known 

 composition to be planted. It was in this manner that selection 

 for breeding to change the composition was started at the 

 Illinois Station. 



