The Inheritance of Quantitative Characters in Maize 101 
that should be noted. The strain of Tom Thumb pop employed 
in these tests was strongly protogynous as seen from Table 39, 
where the frequency distribution of days to first exposure of 
silks in case of protogynous families is shown in italics im 
mediately below the frequency distributions for days to first 
shedding of pollen for the same families. Of Tom Thumb pop 
(family 1126), the plants showed their silks from one to eight 
Fig. 21. Two F 3 families of Tom Thumb X Missouri dent as they ap- 
peared in the field July 26, 1911. Note difference in earliness. 
days earlier and on the average four days earlier than the first 
shedding of pollen. The Missouri dent used was evidently 
heterozygous for this condition, since one 1911 lot (family 1129) 
was protandrous turnout while the other lot (family 1130 and 
its duplicate 1148) was protogynous thruont, all but three 
plants of the latter having had their silks lirst exposed from 
one to six days and on the average just three days before any 
pollen was shed. Both of the P 2 families grown in 1911 (1127 
