CARBON DIOXIDE EXCHANGE DX'RING THE SHORT INDUCTION PERIOD 1353 



longer the dark period (it varied between 5 seconds and 6 minutes), the 

 slower were the inhibition waves. After 3 or 6 minutes of darkness, a "pre- 

 liminary" wave appeared at about 1/2 minutes (fig. 33.13G). After a very 



CO2 

 content 



a : Adaptation/ine of Chlore/la in air witt) 3%C02 

 D ', M )• 3 leaf „ ,, ,, ,f 







1 



2 3 4 5 6 7 



Time in minutes 



Fig. 33.13H. CO2 induftion curve of Chlordla compared to that of a dahlia leaf; both 

 in air + 3% CO2; diaferometer record (after van der Veen 1950). 



CO2 



Chlorella in air -f 3% CO2 

 Temp. 15 °C 



800IUX 



—^4000 lux 



20000 lux 



Time 



Fig. 33.131. CO2 burst in Chlorella at different light intensi- 

 ties; diaferometer record (after van der Veen 1950). 



short dark period (5 or 15 seconds), photosynthesis was found to begin at 

 a higher than the stationary rate; lowering the temperature had an effect 

 similar to that of prolonging the dark interval. 



