1 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME 95. NUMBER 20 



INACTIVATION OF PLANT GROWTH 

 SUBSTANCE BY LIGHT 



(With Two Plates) 



BY 



PAUL R. BURKHOEDER 



Department of Botany, Connecticut College 



AND 



EARL S. JOHNSTON 



Division of Radiation and Organisms, Smithsonian Institution 



^ FEB t> r,. 



(Publication 3403) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



FEBRUARY 5, 1937 



