AUTUMNAL FOLIAGE 



in the sunlight, and does Its bit for the tree and 

 the world. 



The working life of a leaf In our climate is 

 about four months, farther north it is shorter. 

 All this time the leaf laboratory is at work, re- 

 ceiving from the root a continuous stream of 

 water, absorbing from the air an unending sup- 

 ply of carbon, and by means of the sun's energy 

 transforming these into food. Midsummer 

 marks the height of Its activities. 



All summer long there has been this continu- 

 ous intake of water, laden more or less with 

 earthy or mineral substances; what has not 

 been used has been released as vapor, leaving 

 behind these earthy particles to clog the cells 

 and consequently to lessen the leaf's power to 

 work. In course of time more has been stored 

 than the leaf knows what to do with, and often 

 the accumulation appears as minute crystals in 

 the cells of both leaf and petiole. From this 

 point on the end Is Inevitable. 



All summer long the intake and the outgo of 

 the leaf laboratory have been fairly balanced 



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