68 



Carbon Assimilation. 





03 



r 



J 



■o<> 



Fio. 6. Inter-relation of environmental factors and assimilation in Elodea. 

 (After Blackman and Smith). 



The first curve shows the relation between assimilation and carbon 

 dioxide supply when this latter is the limiting factor ; the second 

 curve shows the amount of assimilation at different temperatures 

 when temperature is the limiting factor, and the third the relation 

 between assimilation and illuminatioil when the intensity of light 

 is limiting. From these three curves we can obtain the minimum of 

 carbon dioxide supply, temperature and light intensity which are 

 required for any quantity of assimilation. 



