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THE AMEHICAN NATURALIST [Vol. LI 



tlie determination of the relative resistance of the different spe- 

 cies of Prunus. Most of the different species and varieties were 

 budded or grafted on other stock, the scions or bud wood being 

 secured from several reliable sources, such as the Arnold Arbo- 

 retum, several of the larger nurseries. The methods used are 

 somewhat different from those usually employed in seeking for 

 disease resistance among plants. The plan was to artificially 

 inoculate with pure virulent laboratory cultures the different 

 kind of Prmius under experimentation. A number of suscep- 



