﻿VOLUME LXI 



THE 



Botanical Gazette 



JANUARY 1 916 



THE ACTION OF SCHUMANN RAYS ON LIVING 

 ORGANISMS 



(with four figures) 

 The effect of light upon organisms is a subject of steadily growing 

 interest and importance. The work of recent years indicates that 

 we may hope to discover the fundamental principles involved in the 

 action of light on protoplasm more readily by turning attention to 

 the shorter light waves than by continuing to investigate the action 

 of the longer waves which occur in sunlight. The chief reason for 

 this is that light of shorter wave lengths acts more rapidly and pro- 

 duces chemical and structural changes in such a way that its action 

 can be much more readily followed. While these changes may 

 not be identical with those produced by light of longer wave 

 lengths, it may be taken for granted that the knowledge gained 

 by studying the effects of the shorter light waves will prove to be 

 of the greatest assistance in explaining the action of the longer 

 waves. 



The present paper is a report of some observations by the writer 

 on the effects upon protoplasm of light in the Schumann region of 

 the spectrum, the region containing wave lengths between 2000 and 

 1250 Angstrom units. This region of the spectrum is of particular 

 interest because the light which it contains has a much more 

 injurious action upon protoplasm than has the light of longer wave 



