706 



Walter F. Bertsch, J. B. Davidson, and J. R. Azzi 



+ HYDROXYLAMINE 



+MONURON 

 TIME AFTER LIGHT FLASH (n:isec) 



Figure 4. Effect of hydroxylamine and monuron on delayed-llghl- 

 emission from 0.6 to 4 msec . The emission as presented on the 

 oscilloscope screen was photographed for unpoisoned Chlorella 

 cells, cells poisoned with hydroxylamine sulfate (10"3 M), and 

 cells poisoned with monuron (10"4 M). Vertical grid indicates 

 time aftermiddleof exciting flash in 0.5 msec per unit, horizontal 

 grid indicates Intensity of delayed light emission in arbitrary units 

 (5 millivolts per unit on top and middle photographs, 2millivolts 

 per unit on bottom photograph). Center of exciting flash is in- 

 dicated by the small pip in the zero line on either side of the 

 decay curve. The decay from unpoisoned cells fits neither mono- 

 molecular nor bimolecular kinetics. Poisoning with hydroxylamine 

 resulted in a nearly exponential decay. Poisoning with monuron 

 resulted in a flat decay without fast components. 



