XCI 
LEAVES ARE TREE ASH CANS 
I SN’T IT ODD that the trees use the leaves they dis¬ 
card in the autumn as ash cans into which to dump 
their waste! 
The whole process of shredding its leaves is to the tree 
what fall house-cleaning is to us. 
The broad-leafed trees have found from experience that 
they must get rid of their leaves in winter, or the snow 
will break down their branches. They have learned how 
to form two rows of cork-like cells across the stems of their 
leaves that will break at just the right time and release 
them. 
Weeks in the autumn are taken up in getting ready 
for this parting. If the leaf it to be thrown away, the 
tree first takes everything of value out of it. The green 
of the leaf, for example, is a very important substance. 
It is the green that breaks up the sun’s rays and uses the 
power that it gets from them in taking carbon out of the 
air. The wood of the tree is made from this carbon. 
The tree wants to save this green. It changes it into a 
liquid that it may draw back into the tree and be stored 
up. That liquid is yellow. It has much to do with the 
leaves turning yellow in the autumn. 
There is a great deal of other material in the leaf that 
the tree may want to use in the spring. This is drawn 
out and stored. If you examine a leaf that has fallen 
naturally in the autumn you will find it to be little more 
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