KVOLUTiON BY Cftlurella: 



H' 



the fact that the magnitude of the burst both with and without CO2 

 Hmitation increases with recovery from dark conditioning, thus 

 parallehng the disappearance of induction. 



In order to see the time coiu'se of this transient disclosed at low 

 CO2, Fig. 6 has been plotted on an expanded time scale. The rise to 

 maximum occurs in 6 to 9 seconds and the decay in 20 to 30 seconds. 



6 12 18 



TIME IN SECONDS 



54 



Fig. 6. Plot of initial O2 burst at low CO2 on expanded time scale from original 

 recordings at maximum gain. Upper curve, after 3-minute dark period; lower 

 curve, after extended dark period. 



In the dark, an opposite burst of oxygen uptake is found. This was 

 just barely observable in our former recordings, being shown only by 

 the first one or two points. With better time resolution these are 

 boldly defined. The slower fluctuations emphasized in our earlier 

 papers (3,4) are confirmed with the background "noise" reduced to a 

 relatively small fraction. 



In a following paper w^e will discuss other factors influencing the 

 initial transients and the relationship of our observations to those of 

 others. 



