49 



obtained from self-pollination was even more pronounced in 

 apples than in pears. The crosses correspond to the better 

 specimens in the tree while the self-fertilized fruits corre- 

 spond to the undersized, poorly colored specimens. Prof. 

 Lewis goes a step further and gives actual figures obtained 

 from comparison of a large number of specimens. The 

 following table shows the effect of cross-pollination of the 

 Yellow Newtown a self -fertile variety, and Esopus a partialy 

 self-fertile variety. 



EFFECTS OF CROSS-POLLINATION 

 Ore. Exp. Sta. 1908. 



No comment on the above is necessary as the figure.? 

 speak plainly enough. 



AGENTS OF CROSS-POLLINATION 

 While working on the problems of self -fertility of the 

 various orchard fruits some of the investigators also made a 

 definite study of the means used in bringing about cross- 

 pollination. 



It has been mentioned that Mr. Waite used a coarse 

 mosquito netting for covering pear blossoms ; such a covering 

 would not materially interfere with cross-pollination if the 

 wind disturbed the pollen, but would, if properly adjusted, 

 exclude insect visitors. His results show no variation from 

 those in which the clusters were enclosed in paper bags. 

 Fletcher used this same covering for large trees and while 

 a few more fruits were set than on trees covered with sheet- 

 ing he attributed it to the fact that where blossoms were 

 closely pressed against the netting insects were able to cross- 

 pollinate them. 



