TOMATO 289 
the house is properly heated, the pollen grains will germi- 
nate, and each produce a slender, threadlike tube that 
will pass down through the style to an ovule, and each 
ovule thus fertilized will develop into a seed. 
If pollination does not occur, the flower withers and 
drops off. When only a few pollen grains germinate, the 
fruit is likely to be small, rough and lopsided. In other 
words, thorough pollination is essential to satisfactory 
crops. Numerous experiments and observations have 
been made to determine the effect of cross pollination 
and the influence of various degrees of pollination. 
Some of the most exhaustive studies were made by 
Fletcher and Gregg at the Michigan Experiment Station, 
who report as follows in Special Bulletin 39: 
SUMMARY OF EXPERIMENTS 
‘4. The six varieties under experiment were Ignotum, Stirling 
Castle, Earliana, Best-of-All, Lorillard and Frogmore. The blos- 
soms on four plants of each variety were self-pollinated, and the 
blossoms of eight plants of each variety were cross-pollinated with 
two other varieties. All set fruit equally well. The 265 fruits pro- 
duced from self-pollination on all six varieties had an average 
weight of 77.3 grams. The 534 fruits produced from cross-pollina- 
tion on all six varieties had an average weight of 79.1 grams. 
“2. Four plants of each variety were used in an experiment to 
determine the effect of using varying amounts of pollen. All the 
flowers on one plant of each variety were emasculated and pollinated 
on one side of the stigma only. These invariably produced lop- 
sided and small fruits. All the flowers of one plant of each variety 
were pollinated with from one to five pollen grains. These produced 
very small, solid fruits, with an average weight of but 34 grams and 
having no seeds, or but one or two. All of the flowers on one 
plant of each variety were pollinated with a large amount of pollen, 
spread all over the stigma. These produced fruits that were 
smoother and that averaged 12 grams heavier than fruits produced 
from flowers that had but a small amount of pollen applied all over 
the stigma. 
CONCLUSIONS 
‘4. The results of the investigation indicate that it is not of 
