32^ The y OH ma I of Forestry . 



The liquid i'uud of the lice being hirgely derived from the soil, all 

 iiiKlue cutting away of roots will considerably diminish the quantity 

 of ibliage in the following spring; and this again reacts upon the 

 tree in causing a great diminution of wood growth. 



The liquid food, or crude sap, enters the spongioles througli their 

 countless pores, passes along the roots, and ascends the sapwood of 

 the tree, passing through the branches to the leaves, where, by the 

 action of light and an admixture of carbonic acid, it is elaborated into 

 the true sap, a portion of the moisture being given off by evaporation. 

 This sap afterwards descends througli the inner bark, forming the 

 new layer of wood. That the wood is formed during the descent of 

 the sap will be apparent to all who observe the large lip or swelling 

 which forms en the upper port of the section of the severance, or the 

 enlargement of the sapling above the parts where it is embraced by 

 the v/oodbine. The new wood of the tree is laid on externally, and 

 the new bark internally. 



Some trees, such as the plane and birch, slied their bark annually. 

 The starcli wliicli is formed in the new sapwood is carried up by 

 the ascending sap of the following spring to develop the buds and 

 blossoms. 



Having made an intimate acquaintance with the laws which 

 govern vegetable life, the forester will exercise a wise discretion in 

 using his axe and pruning-knife, and study closely the requirements 

 of the trees under his care. 



For thinning trees no precise rules can be laid down. The guiding 

 principles should be to prevent all nurses overtopping or whipping 

 the standard trees, and ultimately to give every permanent tree suffi- 

 cient space to enable it to develop a well-proportioned and healthy 

 head, equal in length to one-half the height of the entire tree. Or, 

 where the production of lengthy and quick-growing poles is aimed at, 

 the preservation of a complete canopy of leaves overhead should be 

 secured, which will so distribute the sunshine that it shall fall upon 

 the ground riddled, and not in large patches. IMuch must depend 

 upon the climate and soil in fixing the proper distances apart at 

 which trees should stand. 



"Where they have been planted in rows the work of thinning and 

 clearing will be greatly facilitated, and regular intervals can be thus 

 assigned to the standards. 



Thinnings should always be lighter round the margins of planta' 

 tions, especially in the directions of prevailing winds. The direc- 

 tions irom which these winds come may easily be ascertained in any 

 district by noticing the position of uprooted trees. If such winds 

 come from the south and west, thinning should commence from the 

 north and east. The violence of the prevalent winds must be the 



