PT. IV. 



PRUNING AND THINNING. 



191 



light, we not only encourage the heads to grow upward, 

 but prevent the overgrowth of side-boughs. All side- 

 boughs which are to be taken away, should be gradually 

 sawed off before they die and while they are small, 

 since the new annual growth over a wound is curved 

 till it is wholly healed. 



All branches, thouo;h they may be said to rob that Priming 



^ ^ ^ ^ does not m- 



part of the stem which is above them, feed that part ^g^n-eoSe 



which is below them with their descending sap. The wood^made^ 



growth of branches which are gradually taken off from but', by im- 

 proving its 



the side of a tree is transferred to its head, and the de- location, 



increases 



scending sap from this additional new growth of the ^ahiJiiSoQv. 

 head increases the bulk in girthing of the whole long 

 stem, instead of being wasted on the increase of side- 

 branches. If, indeed, too many side-branches are 

 taken off at once, so that the diminished head cannot 

 by extra growth elaborate the whole sap sent up by the 

 root, the whole tree receives a check, not only in the 

 increase of bulk in girthing, but in the growth of the 

 root, on account of the diminished supply of elaborated 

 descending sap. Thus bad pruning may diminish the 

 quantity of timber grown ; but I can by no means 

 concur in Loudon's idea that ])Yim\ng^hj increasing the 

 quantity of thnber, deteriorates its quality. No prun- 

 ing increases the quantity of wood made by a tree, but 

 only alters the location of it ; but the actual bulk of all 

 the side-branches which are gradually taken off, or 

 rather the bulk to which all those branches collectively 

 would have attained, may be considered as laid on to 



