Vol,. 9 



March 19, 1919 



No. 6 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 

 OF SCIENCES 



A. S. Hitchcock 



BUREAU OF PLANT INDUSTRY 



BOARD OF EDITORS 



J. Franklin Meyer 



BUREAU OF STANDARDS 



R. B. SOSMAN 



GEOPHYSICAI, LABORATORY 



ASSOCIATE EDITORS 



N. HOLUSTER 



BIOLOGICAL SOCIETY 



E. C. McKeloy 



CHEMICAL SOCIETY 



J. B. Norton 



BOTANICAL SOCIETY 



J. R. SWANTON 



Sidney Paige 



GEOLOGICAL SOCIETY 



M 



S. A. ROHWER 



entomological society 



F. B. Silsbee 



philosophical society 



ANTHROPOLOGICAL SOCIETY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JITLY, AUGUST, AND SEPTEMBER, WHEN MONTHLY 

 ' BY THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OF PUBLICATION 



211 CHURCH STREET 



EASTON, PA. 



Entered as Second Class Matter, January 25, 1919, at the post-oflGce at Easton. Pa., under the 

 Act of August 24, 1912. Acceptance for mailing at special rate of postage provided for in 

 Section 1103, Act of October 3, 1917, Authorized on July 3, 1918 



