Vol. VIII No. 8 



April 19, 1918 



JOUENAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 Adolph Knopf A. S. Hitchcock J. Franklin Meter 



GEOLOGICAL SURVET BUBEAU OP PLANT INDUSTRY BUBEA0 OP STANDARDS 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST. AND SEPTEMBER, WHEN MONTHLY 



BT THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 

 WILLIAMS & WILKINS COMPANY 

 BALTIMORE, MD. 



Entered as second-class matter July U, 1911, at the post ofiee at Baltimore, Maryland, under the Act of 



July 16, 1894 



