FLUORESCENCE INDUCTION PHENOMENA 



1379 



figure 33.23 (where it is marked Z>i). Kautsky suggested that this de- 

 pression becomes the main feature of the induction curves under anaerobic 

 conditions, or in the presence of certain poisons (cf. figs. 33.33A and 33.39). 



(A) 



[Fluorescence 



C02 Consumption 



COj Consumption 



Fig. 33.21. Induction phenomena in wheat (after McAlister and Myers 1940). (A) 

 Normal air (0.03% CO2), strong Ught (5 X 10^ erg/cm.2 sec.) after 40 min. light and 12 

 min. dark, 24° C. (B) High CO2 (0.36%) in air, strong light after 10 min. light and 10 

 min. dark, 24° C. Broken lines indicate approximate correction for time lag of gas 

 exchange curve; time marks 1 min. apart. 



I 



(A) 



(B) 



(C) 



Fluorescence 



.J I i__L. 



COz Consumption 



Fluorescence 

 __ L i__L_. 



COz Consumption 



Fig. 33.22. Induction phenoma in Chlorella (after McAlister and Myers 1940). (A) 

 Grown in 4% CO2, studied in 0.24% CO2; 6 min. light, 10 min. dark. (B) Grown in 

 air, studied in 0.33% CO2; 2 min. dark. (C) Grown and studied in normal air (0.03% 

 CO2); 3 min. light, 40 min. dark. Broken curve indicates approximate correction for 

 time lag of gas exchange curve; time marks 1 min. apart. 



A second, equally persistent feature is a "bulge" on the declining slope of 

 the first peak (cf. lower fig. 33. 19b) . (Kautsky assumed the existence of two 



