The Inheritance of Quantitative Characters in Maize 69 
none such was to have been expected, since none of them came 
from the smallest F 2 plants. One of the F 3 families, 1149, from 
the tallest F 2 plant of the previous year, however, exceeded the 
Missouri dent parent stock in height. This fact is probably not 
to be ascribed to any new combination of height factors not 
found in the tall parent variety but rather to the fact that the 
vigor of the Missouri dent families grown in 1911 had been re- 
duced by previous selfing. Xos. 1129, 1130, and 1148, the latter 
two duplicates, were from selfed ears of No. 353, which was 
grown from a selfed ear of No. 146. 
C^.aST 23? iff f7S- /SS /3$~ //J- <T& 
Ac-, x jr /o zz /r ? 3 2. 
Fig. 15. Height of plants of the F, generation of Tom Thumb pop X 
Missouri dent, as grown in 1911. 
The variation in height within any lot of the parent varieties 
and within the ¥ t generation would necessarily be influenced by 
heterozygosity in the size factors of the parent stocks, the varia- 
tion increasing with an increasing number of heterozygous size 
genes. The same condition might also result in noticeable dif- 
ferences between F. 2 families grown from different F x ears as 
well as between different selfed strains of the parent varieties. 
Nothing of the sort, however, can explain the great variation 
within any one F 2 progeny, nor the pronounced differences be- 
tween the several F z fraternities arising from a single F 2 family. 
