ALGAE BY ULTRAVIOLET MEIER 



13 



£XPOSU*£ -MtHUTfS 



eXPOSVRE -SECOMQS 



EXPOSURE - SECONDS 



Fig. 2. — Stimulative action on cell multiplication of the alga Stichococcus 

 bacillaris Naegeli resulting from exposures to ultraviolet rays. Dark line, 

 smooth curve ; light line, actual values. The figures indicate the number of 

 observations. 



