i k 1 



Fig. 9. Action of Different Light Rays 



ON COLEUS AND ON LeTTUCE. 



u. Full radiation, h. red rays, c. green rays, 

 d. blue rays, e. open air, f. subdued li^ht, g. 

 diffused light, h. very dim light, i. blue light, /. 

 green li^ht, k. red light, /. white light (0-/ after 

 Flammarion) . 



