Vol. VII No. 18 



November 4, 1917 



JOUKNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 N. Ernest Dorset Adolph Knopf A. S. Hitchcock 



BUREAU OF STANDARDS GEOLOGICAL SURVEY BUREAU OF PLANT INDUSTRY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST, AND SEPTEMBER, WHEN MONTHLY 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE of publication 



WILLIAMS it. WILKINS COMPANY 

 BALTIMORE, MD. 



Entered as second-class matter July 14. 1911, at the post office at Baltimore, Maryland, under the Act of 



July 16, 1894 



