Vol. II. No. 6. 



March 19, 1912; 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 George K. Burgess Frederick Leslie Ransome Carl S. Scofield 



BUREAU OF STANDARDS GEOLOGICAL SURVEY BUREAU Or PLANT INDU8TRY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST AND SEPTEMBER, WHEN MONTHLY, 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



THE WAVERLY PRESS 



BALTIMORE, MD. 



