1010 



THE LIGHT FACTOR. I. INTENSITY 



CHAP. 28 



Figure 28.22B shows the same three curves, replotted to represent yield 

 per single cell. The densest suspension now shows the lowest yield. 

 However, all three curves appear to approach (as expected) the same limit- 

 ing yield at high light intensity; thus, except for the sigmoid shape, they 



1100 



1000 



900 



800 



:e 700 



o 600 

 o 



u. 500 



cone 3 

 cone I 

 cone '/3 



cone 1 control, run 

 together with cone 3 



cone I control, run 

 together with cone '/3 



< 



a. 



3 



400 



300 



200 



INCIDENT INTENSITY, erq/cm sec. 



Fig. 28.22. Effect of cell concentration on light curves of photosj-athesis (Katz, 



Wassink and Dorrestein 1942). 



are of the type 3 in figure 28.20. (The latter refers to P/P"''-^; but, since 

 pmax. jg proportional to the number of cells, P/P"^^^- must be proportional 

 to the yield per cell.) Figure 28.22C, finally, shows the yields per cell as 

 function of average intensity of illumination throughout the vessel (in A 

 and B, the abscissae were the incident light intensities, as measured at the 



