354 



B. KOK 



eral instances a high initial rate of oxygen evoUition upon iHumina- 

 tion, which lasted a few seconds. Also a high initial uptake could be 

 found upon darkening. 



It appeared, however, that there was no correlation, between the 

 transitory reactions of O2 and CO2. Variations of 7 over a wide range 



20 40 60 80 100 



20 40 60 80 100 

 (icondt 



Fig. 1. Differentiation of a recording (reproduced in the inset) of transitory 

 volumeter changes. Chlorella suspended in acid medium 10% CO2 Vf/Vg = 0.77. 

 After Kok and Spruit (1 ). 



were observed. Without attempting to explain these complex phe- 

 nomena, we concluded that polarographic experiments yield no evi- 

 dence to support a one-quantum mechanism of the type proposed by 

 Burk and Warburg (2) . 



II. KINETICS OF PHOTOSYNTHESIS 



B. Kok and J. A. Businger 



Extensive flashing light experiments were made with improved tech- 

 niques of illumination and volumetry. 



Flash saturation could still be obtained with flashes shorter than 

 10-" second half-width, alternated with long dark periods. Above 

 this limit the flash time could be adjusted to any value; the dark 



