AUTUMNAL FOLIAGE 



L THE LIFE OF THE LEAF 



In order to understand the world-wide phe- 

 nomenon of autumnal foliage it is necessary 

 to think of each individual leaf as an active 

 working unit, living its life and doing its work, 

 apart from and independent of its thousands of 

 companions. In spring when the buds swell and 

 the awakened protoplasm begins to stream 

 through the new growth, each leaf's work be- 

 gins, and its work is a very definite task. This 

 task simply stated is to hold its protoplasm in 

 such relations to light, air, warmth, and moisture 

 that chlorophyll can be produced. When this 

 is done the leaf is green. The structure of the 

 leaf, its thin body, its broad flat surface fits it 

 to do this work. Through every leaf there runs 

 a woody network which divides and subdivides 

 throughout its structure, which supports its 

 softer tissues and gives the leaf its shape and 



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