NO. 3 



RESPONSE OF ALGAE TO ULTRAVIOLET MEIER 



2800 



Fig. I. — Radiotoxic spectral sensitivity of Chlorclla vulgaris to ultraviolet rays. 

 The abscissae are wave lengths in angstroms. The ordinates are relative lethal 

 effectiveness in arbitrary units. Black line, smooth curve ; dash line, actual 

 values; dot line, curve obtained by Meier (1932). 



0.5 



2500 



2600 



2700 



2800 



2900 



3000 



3IOO 



Fig. 2. — Radiotoxic virulence determined from Chlorclla vulgaris. The ab- 

 scissae are wave lengths in angstroms. The ordinates are radiotoxic virulence in 

 arbitrary units. 



