220 
PRUNING AND THINNING. 
[Part IV. 
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 reme¬ 
died 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 ne¬ 
glect, 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 used 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 ela¬ 
borated 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. 
In such extreme cases, or when large branches 
