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i VOLUME 2 MAY, 1916 NUMBER 5 | 
PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
EDITORIAL BOARD 
Arthur A. No yes, Chairman Edwin B. Wilson, Managing Editor 
Arthur L. Day, Home Secretary George E. Hale, Foreign Secretary 
J. J. Abel J. M. Coulter W. H. Holmes 
W. B. Cannon C. B. Davenport J. P. Iddings 
J. McK. Cattell Simon Flexner R. A. Millikan 
J. M. Clarke E. B. Frost E. H. Moore 
E. G. Conklin R. G. Harrison Alexander Smith 
Publication Office: Williams & Wilkins Company, Baltimore 
Editorial Office: Massachusetts Institute of Technology, Boston 
Home Office of the Academy: Washington, D. C. 
Entered as second-class matter at the Post Office at Baltimore, Md., under the Act of August 24, 1912 
