122 TREES IN NATURE, MYTH & ART 



sets up certain changes in the leaf." The 

 change of colour, from green to yellow or red, 

 is the most noticeable of these changes. The 

 change of colour in ripening apples, hips and 

 haws is due to a like cause. There are other 

 changes, which we cannot see, but which 

 /'include the passage back into the stem of 

 many important food substances, so that when 

 it is shed the leaf is partly emptied of its con- 

 tents ". Some of this material is used to form 

 what is called an absciss layer or layer of 

 separation, close to the cork layer mentioned 

 above ; and it is here that the final separation 

 of the leaf from the tree, by tearing wind or 

 disorganising frost, takes place. **Nor does 

 the fall of the leaf leave an open wound ; for 

 the above-mentioned cork layer is already 

 formed, and constitutes an impervious cover- 

 ing of the leaf scar." 



Clearly, if we are to grieve for anything, it 

 must be for the leaves, not for the tree. The 

 tree, all the time, is taking good care of itself. 

 It is dismissing its old servants, the leaves, 

 not only without a pension, but after taking 

 back food it has previously given them. It 

 pushes them out on to the doorstep — we may 



