PaUKING FOB TIMBER. 



397 



useless parts, compelling a free to expend its force in the 

 production of what is valuable ; pruning is the abstraction of 

 useless parts upon forming which a tree has expended some 

 part of its power. Stopping is prevention ; pruning is cure — or 

 is intended to be. 



The respective ^ 



effects of , doing 

 nothing, stopping, 

 and pruning may 

 be illustrated by 

 diagrams. Let A 

 represent a young 

 tree disposed to be 

 bushy-headed, all 

 its branches being 

 equal. If nothing rig. lxxxiii. 



is done to such a plant, each branch will grow larger at an equal 

 rate, and produce a few laterals ; by the end of a second season 

 the tree will be somewhat larger, but in other respects much 

 what it was before, as is shown at B. 



But suppose that A, instead of having been D 



left untouched, had had three of its branches 

 stopped by breaking off their points, as is shown 

 at C. In such a case the current of sap being 

 arrested in the laterals, would flow strongly 

 into the leader, which 

 would lengthen rapidly, 

 while the laterals would 

 only produce some small 

 spray ; and the result, at 

 the end of a second year, 

 would be what is repre- 

 sented at D. In this 

 case the tree would have 

 been very little deprived 

 of its foliage, and yet 

 the production of a permanent leader would have been effected 

 as well as if the pruning-knife had been employed, or indeed 



Fig.'LXXXIV. 



