98 
Research Bulletin No. 2 
plants were ripe soon after the latest F 2 's were in blossom. The 
period of ripening extended between seven and eight weeks, or 
94 to 146 days from planting. 
As grown in Massachusetts in 1911, Tom Thumb pop (1126) 
had an average blossoming date (staminate flowers) of about 
64 days from planting, or practically the same as in Nebraska 
the year before. Missouri dent (1129, 1130, 1148), on the other 
hand, was about fifteen days later than the previous year, its 
average flowering date having been about 105 days from plant- 
ing. The comparatively cool weather of midsummer and later 
was doubtless responsible for the delay in case of Missouri dent, 
while the heat of early summer — unprecedented in Massachu- 
setts — brought Tom Thumb pop into flower as early as in Ne- 
braska the year before. No T\ plants were grown in 1911. The 
two F 2 families (1127, 1128). tho containing fewer individuals 
than the F, family of 1910, nevertheless showed a somewhat 
greater range of variation. It is possible that the same condi 
tions which made Missouri dent later than in 1910 and forced 
Tom Thumb pop into flower as early as in 1910 tended to ex- 
tend the F 2 range considerably. Notwithstanding this, the latest 
F 2 plants were in flower when the earliest Missouri dent plants 
began blossoming. 
The F 3 progenies, all grown in 1911, were of course subject to 
the same climatic influence as the parents and F 2 . Apparently, 
however, no F 3 family responded to this influence quite as Mis- 
souri dent did. The parents of some F 3 families were among the 
latest tho not the very latest F 2 plants, as indicated in Table 39. 
(The blossoming time of the parent of each F 3 family is shown 
in the table by black-faced type in the corresponding F 3 class.) 
It was expected that some of the F 3 lots would, therefore, be 
almost if not quite as late as Missouri dent. None of them, how- 
ever, had an average blossoming date later than 87.5 days from 
planting, while the average date of flowering of the earliest 
Missouri dent family was nearly 13 days later. It is probable 
that some of the plants chosen from among the later F 2 's of 
1910 were plus variates of only medium late types, — for their 
F 3 progenies, notwithstanding the cooler weather of the late 
summer of 1911, were considerably earlier than they were in 
1910. This was particularly noticeable in case of families 1140. 
1142, 1145, and 1146. The'parent of family 1145, for instance, 
blossomed about 88 days after planting, while not a single plant 
of 1145 was quite so late as that, and the average date of flower- 
ing for the family was only a little over 73 days. Families 1149 
and 1131 and the latters duplicate 1147, on the other hand, were 
from F 2 plants that blossomed in 1910 about 85 days after 
planting, and their average date of blossoming in 1911 was al- 
most the same. 86 days from planting. 
