ABSORPTION SPiiCTKUM CiL\NGES 



93 



several seconds of illumination and a short period in the dark follow- 

 ing the illumination in order to appear. 



7. In order to determine whether the 520-m/x and 648-m)Li changes 



100 200 300 



Light Intensity (Foot Candles) 



Fig. 4. Light saturation curves for 525 m^, 648 m/i, and luminescence using a flow 

 system and illuminating the algae for about 0.1 second prior to measurement. 



30 



90 



60 

 Time (seconds) 



Fig. 5. Time course of luminescence, 525-mM, and 648-mM absorption in a flow 



system. 



are due to the same compound, we have measured the dependence of 

 the two processes on illuminating intensity. The intensity dependence 

 appears to be different for these two wavx'lengths. These results and 

 the time course of the luminescence compared to the absorption spec- 

 trum changes are illustrated in Figs. 4 and 5. The luminescence paral- 



