Vol. VII No. 10 



May 19, 1917 



JOURNAL 



OP THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 



N. Ernest Dorset Adolph Knopf A. S. Hitchcock 



BUREAU Or STANDARDS GEOLOGICAL 6UBVET BUREAU OF PLANT LNDUBTBT 



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-claes matter July 14, 1911, at the post office at Baltimore, Maryland, under the Act of 



July 16, 1894 



