Vol. 9 , ]vhY 19, 1919 No. 13 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 

 OF SCIENCES 



BOARD OF EDITORS 



A. S. Hitchcock J. Franklin Meyer R. B. Sosman 



BDRSAU OP PLANT INDUSTRY BUREAU OP STANDARDS GEOPHYSICAL LABORATORY 



ASSOCIATE EDITORS 



H. V. HarIvAN Sidney Paige 



BOTANICAL SOCIETY GEOLOGICAL SOCIETY 



N. HOLUSTER S. A. ROHWES 



BIOLOGICAL SOCIETY ENTOMOLOGICAL SOCIETY 



E. C. McKelvy F. B. Silsbee . 



CnCMICAL SOCIETY PHILOSOPHICAL SOCIETY 



J. R. Swanton 



ANTHROPOLOGICAL SOCIETY 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST, AND SEPTEMBER, WHEN MONTHLY 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



OFFICE OP PUBLICATION 



211 CHtTRCH STREET 



EASTON, PA. 



Bntered aa Second Class Matter, January 25, 1919. at the post-ofTice 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 



