Vol. III. ' No. 15. 



September 19, 1913. 



JOUENAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDi'rORS 

 Frederick Leslie Ransome Carl S. Scofibld Fred. Eugene Wright 



OBOLOaiCAL SURVEY BUREAU OP PLANT INDUSTRY GBOPHTSICAL LABORATORY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST AND SEPTEMBER, WHEN MONTHLY, 



WASHINGTON ACADEMY OF SCIENCES 



/ 



OFFICE OF PUBLICATION 



THE WAVERLY PRESS 



BALTIMORE, MD. 



