Carbon Assimilation. 
135 
Fig. 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 illumination 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. 
To be continued. 
