CHARACTERISTIC EFFECT OF THE DIFFERENT RAYS I93 



The curves given (fig. 51) show the distribution of 

 energy and of photosynthetic activity. The absorption- 



lon % 



eg 

 h2^ 



eao ess 



390 



'itt 



I 



3 



Fig. 51. Curves showing Distribution of Energy in the Spectrum 

 (thin line) and corresponding Photosynthesis (thick line) 



Absorption-bands of chlorophyll of the leaf are shown below : 

 phototropic responses indicated above, effective rays being 

 the infra-red to the left of A, and the rays between F and G. 



bands of the visible spectrum are indicated below ; the 

 phototropic responses in the infra-red and the blue-violet 

 are given as up-curves above. 



Characteristic Effect of Different Rays on 

 Photosynthesis 



There is a considerable difficulty in discovering the relation 

 between either the intensity or the wave-length of radiation 

 and the resulting photosynthesis. It has been thought 



o 



