AS APPLICABLE IN PRACTICAL FORESTRY. 205 



changes from a cone to a cylinder. The cause of the latter 

 change is in the increase of woody deposit near to the live 

 branches, and decrease of it when the branches have withered 

 and fallen off. During this stage of growth, on dissecting a tree, 

 it is found that the zones of wood near the vital branches are 

 much thicker than at a distance from them, and the further 

 distant the thinner they are. Every possible effort should be 

 made in the thinning of plantations to preserve the proper 

 quantity of live branches upon each individual tree, for if once 

 the vitality is destroyed the best future skill will be defective 

 in restoring it. Another reason for early thinning is in order 

 not at any time to check the growth of the trees, for it must 

 always be borne in mind that the immediate effect of thinning 

 is to check the growth of the standing trees, and this is done 

 in at least two different ways. 



It is very consoling to be told that if thinning is done gently, 

 no evils will result from it. The most gentle mode of thinning 

 that can be practised is to cut down one tree that stands too 

 close to another. If many such trees are cut, the thinning may 

 be termed severe ; and if only a few are cut, it may be termed 

 gentle. With words and terms, however, we may do as w^e 

 please, but with the effects produced upon the standing tree, by 

 removing one that stood close by it, and for whose sake it was 

 cut down, we have some inquiries to make. When two trees 

 have grown up side by side, for many, or it may be only a few 

 years, they have formed such an aftiuity for each other that 

 separation becomes a painful ordeal, so far as trees can be 

 supposed to sympathise with, or feel, which for my part I do 

 not believe in to the same extent as some do. Whether trees 

 are affected through feelings or not is of little importance, 

 since it is certain they are influenced in two other ways at 

 least — namely, mechanically and chemically. That thinning 

 injuriously affects trees both ways there is little or no doubt ; 

 and we shall first see how they are injured mechanically. When 

 two trees grow near each other the branches on the confronting 

 sides are less developed than on the opposite sides, and the 

 roots underneath are developed in a corresponding manner ; and 

 if one of the trees is removed by thinning, the whole of the 

 weak side of the remaining tree is exposed suddenly, and the 

 wind acting upon it strains the tender weak roots to such an 

 extent as often to uproot the tree altogether. But apart from 

 actually uprooting and blowing over the tree, the roots are 

 strained and fractured so severely that they lose their vitality. 

 Any injury inflicted upon resinous trees, whether upon branch, 

 stem, or root, is succeeded by an accumulation of rosin, and 

 this, when it occurs to the roots, is fatal to them, as it obstructs 

 the sap vessels and stops the circulation. 



