Vol. VII No. 7 



April 4, 1917 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 N. Ebnest Dobsey Adolph Knopf A. S. Hitchcock 



BUREAU OF 8TANDABDS GEOLOGICAL 8UKVHT BUBEAUOF PLANT INDUSTRY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST, AND SEPTEMBER, WHEN MONTHLY 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



WILLIAMS & WILKINI3 COMPANY 



BALTIMORE, MD. 



Entered as Beoond-clas/matter July 14, 1911, at the poet office at Baltimore, Maryland, under the Act at 



July 16, 1894 



