Corn Investigations 
83 
upon kernel weight, a large number of ears should be used to 
overcome variation in the degree of reaction to cross-pollination 
by individual ears. The method of comparing pure and hybrid 
kernels in pairs has been found far superior at this Station 
(Table 31) to that of contrasting hybrid kernels with all the 
pure kernels grown on the same ear. 
In the case of two varieties: (1) When the hybrid kernels 
were largely localized on the tip third portion of the ear and 
all were compared as to average kernel weight with all the pure 
kernels on the ear, the average weight of hybrid kernels was 
26.58 per cent less than that of the pure kernels; whereas, when 
removed in pairs the hybrid kernels weighed only 0.27 per cent 
less than the pure. (2) When the hybrid kernels were largely 
localized on the butt third of the ear, their weight exceeded that 
of the pure kernels by 11.91 per cent when compared by the 
former method, and by only 1.90 per cent when taken in pairs. 
(3) When the hybrid kernels were largely localized on the mid- 
dle third of the ear, the hybrid kernels outweighed the pure by 
2.02 per cent when the former method was used and by only 0.19 
per cent when taken out in pairs. (4) When the hybrid kernels 
were quite generally distributed thru the ear, their average 
weight was 0.88 per cent less than that of the pure when com- 
pared by the former method and 1.14 per cent more when re- 
moved in pairs. When all the hybrid kernels were contrasted 
with all the pure kernels on each ear, the variation in weight, 
for all ears, of the hybrid kernels was from 26.58 per cent less 
to 11.91 per cent more than that of the pure; and when the 
kernels were removed from each ear in pairs, the extreme range 
of variation in weight of the hybrid kernels for the various ears 
used was from 0.27 per cent less to 1.90 per cent more than the 
pure. 
RESULTS WITH VARIETIES 
During five years (Table 32) a large number of ordi- 
nary Hogue’s Yellow Dent ears were selected which had been 
grown near a field of Nebraska White Prize corn and were 
therefore subject to partial cross-fertilization. The hybrid and 
pure kernels were removed in pairs only and the two groups 
compared for weight. The results for different years were slightly 
variable, ranging from 1.8 per cent increase for hybrid kernels 
in 1914 to 0.7 per cent reduction for hybrid kernels in 1917 and 
1920. As an average for the five years, the 38,017 hybrid ker- 
nels weighed 0.32 per cent heavier than the 38,017 pure kernels. 
