$36 RELATION TO ENVIRONMENT. 



phyll bodies, other colors, which in some cases were masked by 

 the green, appear. In other cases decomposition products result 

 in the formation of other colors, as red, scarlet, yellow, brown, 

 purple, maroon, etc., in different species. These coloring sub- 



Fig. 497- 



Conifers overtopping broad-leaved, deciduous trees in the forest (New Hamp- 

 shire). A "mixed forest. 



stances to some extent are believed to protect the nitrogenous sub- 

 stances in the leaf from injury. The colors absorb the sun's rays, 

 which otherwise might destroy these nitrogenous substances before 

 they have passed back through the petiole of the leaf into the stem, 

 where they may be stored for food. The gorgeous display of color, 

 then, which the leaves of many trees and shrubs put on is one of 

 the many useful adaptations of the plants. 



