Vol. III. No. 19 



November 19, 1913. 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 Frederick Leslie Ransomb Carl S. Scofibld Fred. Eugene Wright 



GBOLOaiCAL SUBTBT BURBAU OP PLANT INDUSTRT OEOPHTSICAL LABORATOBT 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST AND SEPTEMBER, WHEN MONTHLY, 



EY THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



THE WAVERLY PRESS 



BALTIMORE, MD. 



