z 

 o 



u 



tu 



o 



Eugleno - colorless strain 



'mf^jj^ 



1 -i- -k 



',10 -gaussf--^^ 



^ ^ \ \ \ \ \ \ \ \ \ \ \ \ \ V\ 



MAGNETIC FIELD 



Fig. 4. Upper curves: ESR signals in the dark and in the light of a normal green 

 strain of Euirletm gracilis var. bncillaris and of a colorless heterotrophic nuitant 

 derived from the former (from Indiana University culture collection). Modida- 

 tion amplitude: '] gauss. Lower curves: K.SR signals from RhodosfnriUum rubrum 

 m the light and the dark. The scale of the dark signal is 5 times greater than 

 that of the light signal. Modulation amplitude: 3 gauss. 



368 



