CHROMATIC TRANSIENTS IN RED ALGAE 



445 



3 



MINUTES 



Fig. 1. Time course of oxygen evolution by Porphyra perforata, first in red light 

 (675 ni/i); then in green (560 xnju), of intensity adjusted to give the same steady- 

 state rates. Dark exposures (D) are shown before, between, and after the light 

 exposures. Dotted line indicates compensation point. Time in minutes. Some 

 records show no cusp in green light, but a more rapid rise to the final rate. (Tracing 

 of "Speedomax" recording from oxygen cathode circuit.) Note the somewhat en- 

 hanced respiration after green light. 



3 

 MINUTES 



Fig. 2. Time course of photosynthetic time course in P. perforata exposed to 

 alternating red light (R) and green light (G) of equal steady state effectiveness. 

 (R = 675 rufx; G = 540 m^.) Short oxygen "gushes" occTur at each exposure to 

 green light, followed by a depression and recovery; in red light the level at first 

 falls, then recovers. Dark periods (D) before and after the light sequence; com- 

 pensation point shown by the dotted line. 



