VOLUME 2 JUNE, 1916 
i 
PROCEEDINGS 
OF THE 
NUMBER 6 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
i 
EDITORIAL BOARD 
Arthur A. Noyes, Chairman 
Arthur L. Day, Eome Secretary 
Edwin B. Wilson, Managing Editor 
George E. Hale, Foreign Secretary 
J. J. Abel 
W. B. Cannon 
J. McK. Cattell 
J. M. Clarke 
E. G. CONKLIN 
J. M. Coulter 
C. B. Davenport 
Simon Flexner 
E. B. Frost 
R. G. Harrison 
W. H. Holmes 
J. P. Iddings 
R. A. Millikan 
E. H. Moore 
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 
