BEES AND FRUIT-GROWING 



cently orchards of 10 to 100 acres have been planted consisting 

 of one or more of the standard varieties. 



In order to determine the cause and remedy these failures 



Fig. 117. Apple-Blossom. Pyrus malus 



Gardner investigated the poUination of the sweet cherries. 

 Thousands of flowers were pollinated with their own pollen, 

 and insects excluded by bagging. All of the 16 varieties tested 

 proved to be self-sterile. Ninety per cent of the commercial 

 plantings consisted of the Lambert, Napoleon, and Bing, which 

 were not only self-sterile but intersterile, i. e., each was sterile 



269 



