PT. lY. 



PKUNING AND THINNING. 



193 



fork is inferior to that of the two leaders, or that stems 

 in general, which are the receptacles of the aggregate 

 descending sap of the branches, are inferior in qnahty 

 to the branches. 



As an example of what may by accident happen to 

 multiply leaders in the growth of forest-trees, I will 

 instance what does happen, and what must happen, 

 every year in the growth of the Paulonia. As in this 

 climate it never ripens the wood of the current year to 

 the end where the single leading bud is, the next year's 

 shoot begins from two opposite side-buds ; so that 

 every single shoot must the next year be continued by 

 a double shoot, unless this is remedied by pruning, 

 that is, by cutting each shoot back to a vigorous bud, 

 and pinching off its opposite rival 



Let us suppose the worst possible case against 

 pruning. Suppose that, in consequence of neglect, it 

 is necessary to take a large limb off at the centre of an 

 otherwise branchless stem ; that this makes so bad a flaw 

 that the tree, when felled, must be cut and nsed in two 

 lengths. Still, as long as it stands, as the root is 

 uninjured and undiminished, the same supply of sap will 

 be furnished. That sap will be elaborated in the head 

 by the new growth which it will impart to it, and the 

 girthing of the upper length of the stem will be 

 increased by all the growth which would have been 

 laid on the side-branch, while the increase in girthing 

 of the lower length of the stem will not be diminished. 



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