H 



Vol. II. No. 20. 



December 4, 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 OP PLANT INDUSTRY 



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. 



