Vol. III. . No. 11, 



June 4, 1913. 



JOUENAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS . 



Frederick Leslie Ransome Carl S. Scopield Fred. Eugene Wright 



GBOLOaiCAli 8URVHY BUREAU OF PLANT INDUSTRY GBOPaTSIOAL LABORATORY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST AND SEPTEMBER, WHEN MONTHLY, 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



/ 



OFFICE OF PUBLICATION 



THE WAVERLY PRESS 



BALTIMORE, MD. 



