3G8 



J. A. BASSHAM AND K. SHIBATA 



synthetic rate be saturated with respect to Hght intensity under the 

 conditions used. The saturation was tested with the longest dark 

 periods (one-hole disc) for two light periods, Vseo second and '/^s 

 second. One of the results, where te = Vseo second and ta = "/sio 

 second, is shown in Fig. 1, where relative photosynthetic rate per 

 flash (Pf) is plotted against the relative light intensity (I red- The 

 arrow in the figure indicates the light intensity at which all other 

 experiments reported here were carried out. With, this light intensity, 

 the yield is well saturated even with the one-hole disc. The concen- 

 tration of the suspension of Scenedesmus was 0.2% in packed cell 

 volume units. 



RESULTS 



The results are shown in Fig. 2, where the relative photosynthetic 

 rate per flash {Pf) is plotted against the dark period {ta). Each curve 



Fig. 2. Change of oxygen generation per flash with changing dark periods. 



represents the change of photosynthetic rate for a particular light 

 period (4) as a function of the dark period. The points for zero dark 

 period were calculated from the continuous light rate. The relative 

 unit of Pf was chosen so as to make Pf equal to unity for 1^ = Vseo 

 second and /<< = second ; hence the values for the intercepts for the 

 curves at U = Vseo, Viso, '/so, and ^'45 second are 1, 2, 4, and 8, re- 



