104 JBotani? 



colored bracts. The beech-drojjs, or Indian-pipes, 

 are parasitic on roots, and become entirely waxen 

 white or pale yellow. The dodder changes its green 

 stem to red, and divests itself of leaves entirely. The 

 mistletoe keeps its green leaves because it is not en- 

 tirely parasitic, but continues to manufacture plant- 

 food for itself.^ 



Trees that shed their leaves in autumn are called 

 deciduous. Such trees, before losing their foliage, 

 are very gorgeous, the green of the leaves changing 

 to yellow, purple, scarlet, orange, bronze, brown. 

 This change is produced chiefly by the withdrawing 

 of green color, because the clogged cells are no longer 

 taking in carbon or discharging oxygen. The excess 

 of ox^^gren now changes the failing leaf-green itself to 

 some gay color, or aids other colors which have lain 

 hidden to gain strength and assert themselves, appear- 

 ing in glory in place of the vanished chlorophyl. 



Along with leaf -green in the plant other colors lie, 

 even in stems and leaves, ready to appear whenever 

 room is made for them by the departing green, and 

 strength is added to them by oxygen. In the vari- 

 colored foliage, for some reason peculiar to the par- 

 ticular plant, the chlorophyl politely admits a pro- 

 portion of other colors to share its reign. 



*This subject will be discussed in a future chapter. 



