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I VOLUME 8 DECEMBER, 1922 NUMBER 12 I 
PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
/4 
EXECUTIVE COMMITTEE 
Edwin Bidweli. Wilson, Managing Editor 
Raymond Pearl Vernon KelI/Ogg 
1 PUBLISHED MONTHLY 1 
1 Publication Office: Eschenbach Printing Company, Eastoii, Pa. | 
1 Editorial Office: Harvard School of Public Health, Boston 17 1 
g Home Office of the Academy: Washington, D. C. 1 
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Entered as second-class matter June 21, 1920, at the postoflSce at Raston, Pennsylvania, under the ac< oi August 24, 1912- 
Acceptance for mailing at special rate of postage provided lor in section 1103. Act o\ October 3, 1917 Anthorized June 18, 1920- 
Price pyiinnum, ^5.00 
