416 TRANSACTIONS OF ROYAL SCOTTISH Al;BORICULTURAL SOCIETY. 



retain their lower branches. This is uccoinpanieil by all the evils 

 which have already been indicated, and attention may be directed 

 to one other, which applies more to dicotyledonous trees than to 

 conifei's. 



When a wood is over-thinned large crowns develop on the 

 individual trees, and the increase of leaf-sui-face, combined with 

 the less restricted action of the wind, causes greater expiration of 

 water to take place than would occur weie the crowns smaller 

 and more sheltered. But if the soil be not of the best quality, it 

 by no means follows that, when the quantity of water raised from 

 the soil to the leaves increases, so does the quantity of inorganic 

 salts therein contained increase. What may, and in fact generally 

 does happen, is that the same amount of I'aw plant food is merely 

 contained in a lai'ger amount of water ; in other words, the solu- 

 tion becomes weaker. But, in order to pi'ovide a passage for the 

 extra water, the liquid-conducting channels in the wood must be 

 enlarged without a correspondingly increased formation of new 

 wood resulting. This, then, increases the porosity of the timber, 

 and consequently reduces its specific gravity and quality. The 

 truth of this has been frequently demonstrated. Trees have been 

 selected whose stems were clad with branches almost down to the 

 ground, and one-half to two-thirds of their branches have been 

 removed. In this state they have been allowed to grow for some 

 years, and have then been felled and examined, when it has been 

 found that the annual quantity of wood formed after pruning has 

 been as great as, or even greater than, it was before the operation 

 was conducted, while the specific gravity and the quality have 

 been greatly raised. This clearly shows that large and heavy 

 branches can often be advantageously dispensed with, for they 

 themselves consume all the nutritive materials which they pro- 

 duce ; so that, while adding nothing to the nourishment of the 

 cambium of the stem, they lower the specific gravity of the wood 

 there by keeping open an enlarged water-channel. 



Other hindrances to a properly conducted system of forestry 

 could be easily traced to the influence of game, but enough has 

 probably been said to show that the game question as affecting 

 sylviculture is a very pressing one. As is the case with most 

 other great questions, so with this, it is much easier to point 

 out the ditKculties than to suggest means by which they 

 can be overcome. Game in this country is not only a 

 luxury, but also a marketable commodity, and, as such, yields 



