Vol. II 



July 19, 1921 



No. 13 



JOURNAL 



OF THE 



WASHINGTON ACADEMY 

 OF SCIENCES 



Robert B. Sosman 



OBOPBVSICAL LABORATOKT 



BOARD OF EDITORS 

 S. F. Bl^KB 



BORBAD OP PLANT INDUSTRY 



SiDNBT PAIGB 



obolootcai. sdrvbv 



ASSOCIATE EDITORS 



H. V. Harlan 



botanical socibtv 



N. HOLLISTBR 



BIOLOGICAL SOCIETY 



S. A. ROHWBR 



ENTOMOLOGICAL SOCISTV 



F. B. SiLSBBB 



PHILOSOPHICAL SOCIBTV 



G. W. Stose 



OBOLOOICAL SOCIETY 



J. R. SWANTON 



ANTHROPOLOGICAL SOCIBTV 



PUBLISHED SEMI-MONTHLY 

 EXCEPT IN JULY, AUGUST, AND SEPTEMBBR, WHEN MONTHLY 



BY THE 



WASHINGTON ACADEMY OF SCIENCES 



OPFICB OP PUBLICATION 



211 CHURCH STREET 



E ASTON, 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 postaEe provided for 



in Section 1103, Act of October 3, 1917. Authoriied on July 3, 1918. 



