20 
H. C. Agricultural Experiment Station 
small amount of pollen that is produced by some varieties account for 
the nonsetting of fruit? 
In Table TSTo. 6 is found the answer to this question. Pollen carefully 
gathered from the self-sterile varieties was actually applied by hand 
to the pistils of flowers of the same varieties, and no fruit was obtained. 
Therefore, the insufficiency of pollen production does not account for the 
absolute sterility of any variety of dewberries or of their hybrids. 
Fig. 6.—Flowers of Lucretia (dewberry), showing well developed stamens. 
However, in the growing of berry crops for commercial purposes we 
must bear in mind that the factor of pollen production is an important 
item. Insufficiency of pollen under these conditions may he the real 
cause of a crop failure, even although it will not account for the self¬ 
sterility of the variety. Because not enough of pollen is produced to 
satisfy the requirements of the pistils in all of the flowers of the whole 
field, the resultant crop is not only reduced in size, hut also in quality, 
for the individual berries have suffered because a certain percentage 
