NATURAL HISTORY STUDIES 



gone before. Is it not true to say that the ebb-tide 

 gleams with the glare of burning wrecks ? 



Throughout the summer the leaf has lived an 

 intense life, far more intense than we are inclined to 

 give plants credit for, building up with the aid of 

 the sunlight no small quantity of sugar and more 

 complex carbon-compounds, which are laid up in 

 reserve in various parts of the plant. In autumn, 

 however, the vitality is checked ; the movements of 

 the sap become very slight ; and the leaves begin 

 to die. It is partly that they are in some measure 

 worn out by the summer's work, just as the bees 

 are ; it is partly that the outer world has changed. 

 It is well that they should die, lest they begin to 

 undo what they have so well done. 



But before they die they surrender to the plant 

 that bears them all the residue of their industry that 

 is worth having. There is a gentle current of sugar 

 and other valuable materials from the dying leaf 

 into the stem before the breath of approaching 

 winter. 



The leaf, useful in dying as well as in living, 

 becomes more and more empty of all but waste, and 

 as the retreat of valuable material into winter 

 quarters is being accomplished, there is also prepara- 

 tion for the actual fall. Across the base of the 

 leaf-stalk, in a region which is usually firm and 

 tough, there grows inward a partition of soft juicy 

 cells, actively multiplying and expanding into a 

 springy cushion, which either foists the leaf off, or 

 makes the attachment so delicate that a gust of 

 wind will soon snap the bridge binding the living 



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