Vol. 9 



April 4, 19 19 



No. 7 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 

 OF SCIENCES 



A. S. Hitchcock 



BORBAU OF PLANT INDUSTRY 



BOARD OF EDITORS 

 J. Franklin Meyer 



BUREAU OF STANDARDS 



R. B. SOSMAN 

 GEOPHYSICAL LABORATORY 



ASSOCIATE EDITORS 



N. HOLLISTER 



BIOLOGICAL SOCIETY 



E. C. McKelvy 



CHEMICAL SOCIETY 



J. B. Norton 



BOTANICAL SOCIETY 



J. R. SWANTON 



Sidney Paige 



GEOLOGICAL SOCIETY 



S. A. Rohwer 



ENTOMOLOGICAL SOCIETY 



F. B. SitSBEE 



PHILOSOPHICAL SOCIETY 



ANTHROPOLOGICAL SOCIETY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, 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-office 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 



