VOLUME 5 JANUARY, 1919 NUMBER 1 
PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
I 
I 
EDITORIAL BOARD 
Raymond Pearl, Chairman Edwin B. Wilson, Managing Editor 
C. G. Abbot f Acting Home Secretary George E. Hale, Foreign Secretary 
J. M. Clarke 
H. H. Donaldson 
E. B. Frost 
R. A. Harper 
LuDviG Hektoen 
H. S. Jennings 
Jacques Loeb 
Graham Lusk 
A. G. Mayor 
R. A. Millikan 
E. H. ? rooRE 
A, A. No YES 
W. A. NuYES 
E. L. Thorndike 
W. M. Wheeler 
Publication Office: Williams & Wilkins Company, Baltimore 
Editorial Office: Massachusetts Institute of Technology, Cambridge 
Home Office of the Academy: Washington, D. C. 
Entered as second-class matter at the postoffice at Baltimore, Maryland, under the act of August, 24, 1912. Acceptance {or maUinc at special 
rate of postage provided for in Section 1103, Act of October 3, 1917. Authorized on July 3, 1918. 
Price per annum, $5.00 
