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THE AMERICAN NATURALIST [Vol. LI 



periments of 1915. Only a part of the kinds of Prunus just 

 mentioned were thoroughly tested out and these only are included 

 in tabulated results. 



It will be noted that Tables II and III represent two varieties 

 of Prunus domestica. Not all varieties, however, are equally 

 resistant, but, in general, members of this group are much more 



