68 
Research Bulletin No. 2 
genes. That the seeds of the original ear of Missouri dent had 
different size potentialities is indicated by the difference between 
the four fraternities, 353, 354, 357, and 358, which were grown 
from selfed seed of different individual plants of No. 146. 
In 1911 the parent stocks, two F 2 families, and several P 3 
lots were grown side by side. The F 2 's again showed greater 
variation than the parents as indicated both by the range of 
heights and by the coefficients of variation, tho no individuals 
CW-. fS- GS ZC5- *j& US' /& 
Jkc / /& X V fC /$- 3 SL 
Pig. 14. Height of plants in 1911— Tom Thumb pop at the left and Mis- 
souri dent at the right. 
were quite so small as those of the small parent and few so 
large as those of the large parent. None of the F 3 progenies 
exhibited the range of variation shown by the F 2 fraternities, 
tho as measured by the coefficient of variation some of them were 
practically as variable. Measured by the same standard, how- 
ever, some of them were even less variable than the parent 
stocks, but whether any of them were homozygous in all or 
most of their size factors can only be told by growing another 
generation. No family was so small as Tom Thumb pop and 
