Vou III. No. 7. 



April 4, 1913. 



JOUENAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 Frederick Leslie Ransome Cahl S. ScoFiEtD Fred. Eugene Wright 



anOLOQICAL 8URVB1T BURBAD OF PLANT INDUSTBT QBOPHTSICAL LABORATORY 



PUBLISHED SEMI-MONTHLY 

 JEXCEPT IN JULY, AUGUST AND SEPTEMBER, WHEN MONTHLY, 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



/ 



office of PtJBLICATION 



THE WAVERLY PRESS 



BALTIMORE, JMD. 



