Self-sterility in Dewberries and Blackberries 
35 
flowers were lifted every day during tlie blooming season and the in¬ 
closed flowers crossed with pollen from other varieties until the last 
bloom was past the stage of receptivity. After this, these bags were 
also allowed to remain untouched until the inclosed fruits were ready 
for comparison. 
Results and Discussion .—Of the dewberries, all of the bags were re¬ 
covered. Both branches of each variety that was self-pollinated differed 
in no respect from similar branches that had been carefully crossed; 
nor did they differ from normal branches of fruit that were found in the 
open and had been left to insect pollination. The individual fruits 
were much alike in size, shape, color, and general condition. 
With the hybrid vines, Wilson and Cox, similar results were obtained. 
Fig. 9.—Lucretia dewberry (Rubus villosus). A good crop of dewberries produced by 
a self-fertile vine. 
No deleterious effect of selfing was noticed. In the case of the black¬ 
berries, Snyder behaved in similar manner. Early Harvest produced 
two branches of good fruits and two branches of poor fruits; but it so 
happened that the “selfed” lot, like the “crossed” lot, produced one good 
branch and also one poor one. In this instance the poor development of 
fruit cannot be attributed to self-fertilization, but must be ascribed to 
some other unknown agent that attacked the branches of both plants 
alike. 
It must be remembered, however, that in this experiment only known 
self-fertile varieties from each type were selected. Had we included 
partially self-sterile varieties or wholly self-sterile varieties, the results 
would have been most striking and to the contrary. 
