THE LAWS OF PHOTOSYNTHESIS 



247 



The Law of Photosynthesis under Variation 

 of C0 2 -Concentration 



The photosynthetic curve for variation of C0 2 -concentra- 

 tion of the typical specimen I. (p. 116), is given in fig. 58. The 

 straight part of the curve cuts the abscissa at 1 • 2, which is 



Fig. 58. Photosynthetic Curve under Variation of 

 CCyConcentration 



Physiological zero at i • 2 mg. 



therefore the physiological zero for the specimen. The C0 2 - 

 concentration on the physiological scale will be represented 

 by C. Table XXXV. (p. 246) gives the detailed results for 

 the winter-specimens I. and II. previously referred to in 

 Table XIVa. 



The coefficients for different points in the median range 



