THE PHOTOSYNTHETIC CURVE 



115 



above the concentration of 12 mg. per 100 c.c, when the 

 curve exhibited a reversal. 



I give detailed results obtained with three different 

 specimens taken from the same pond during the winter 





S5 



o 



HO 



Oh 



y&OTtcetrfiia/urri/ of Go. 



Fig. 33. The Photosynthetic Curve under Variation of CCy 

 concentration in mg. per ioo c.c. 



months from Novembei to January. The plants were less 

 sensitive in winter than in spring, as will be seen from other 

 results which will be given presently. 



I compare my results (see Table XI Va, p. 116) with others 

 obtained by Pantanelli and by Blackman in their experi- 

 ments with Elodea. Pantanelli (1903) employed the method 

 of counting the bubbles from the cut end of the plant ; the 



