78 



Carbon Assimilation. 



while for the fourth hour it is given at 30'5"C. Thus the optimum 

 value obtained will depend upon the time that has elapsed between 

 the commencement of the experiment and the measurement of the 



5Z0 



o 





s IXO 



•I 80 



20 



Tempeuaturk. 



40X 



Fig. 11. Curves of assimilation and respiration of Helianthus and Cheri-y 

 Laurel at different temperatures. A, curve of initial assimilation maxima for 

 Helianthus ; B, the same for Cherry Laurel ; C, curve for assimilation of 

 Cherry Laurel two hours after the initial moment of heating to the particular 

 temperature ; D and E, temperature-respiration curves for Helianthus and 

 Cherry Laurel respectively. (After Blackman and Matthaei). 



