Vol. II. No. 15. 



September 19, 1912. 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 



OF SCIENCES 



BOARD OF EDITORS 

 George K. Burgess Frederick Leslie Ransome Carl S. Scofield 



BUREAU OP STANDARDS ■ GEOLOGICAL SURVEY BUREAU OF PLANT INDUSTRY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST AND SEPTEAIBER, WHEN MONTHLY, 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



THE WAVERLY PRESS 



BALTIMORE, MD. 



