CHAPTER XL 



LEAVES, AND LEAF DISEASES. 



If the leaves are stripped from a timber-tree early 

 in the summer, or during their young conditions in the 

 spring, the layer of wood produced in the current 

 year — and probably even that formed next year — will 

 be poor and thin. This is simply a fact of observa- 

 tion, and does not depend on what agent deprives 

 the tree of its leaves. Those oaks which suffered so 

 greatly from the ravages of certain tiny caterpillars 

 during the summer of 1887— many of them having 

 all their leaves eaten away before July— will have 

 recorded the disaster by a thin annual ring of wood : 

 It is true the more vigorous trees produced (at the 

 expense of what stores of food materials remained 

 over) a second crop of leaves in August, and so no 

 doubt the zone of wood will prove to be a thin 

 double one, but it was at the expense of the next 

 year's buds. 



