METHOD OF THINNINGS. 29 



is to mitigate the action of cover, and to allow heat 

 and rain to reach the ground in sufficient quantity. 

 This length of bole is so important that it is fre- 

 quently sufficient in itself to ensure the sowing of the 

 ground. It is the aspect presented by old high 

 forest that has grown up in close leaf-canopy. It 

 is on this account quite lawful to increase the length 

 of bole artificially by pruning even living branches, 

 whenever the operation is performed on thick 

 foliaged trees or on oaks which are to fall, at the 

 latest, in the final cutting. There is yet another case 

 in which it is essential to increase the height of cover 

 artificially, viz., when the leaf-canopy is formed by 

 a small number of trees which are thickly clothed 

 with branches from their very base. Under such 

 trees no seedlings spring up ; but once cut away the 

 lower branches, and in the next year of seedfall 

 numbers of young plants put in an appearance and 

 thrive. 



Besides selecting reserves with a lofty bole and 

 artificially raising the cover by pruning, the soil must 

 at the same time be carefully cleared of all brush- 

 wood and small shrubs with which it may happen to 

 be overgrown. This precaution is of the utmost 

 necessity, both to prevent the seed rotting in the 

 winter, and also to ensure at the right moment the 

 necessary amount of heat for its germination. The 

 very existence indeed of the young plants also 

 requires it ; for they would rapidly disappear with 

 such low cover just over their heads. 



SECOND AEY CUTTING. As soon as the young 

 plants have reachel a certain age and the crop of 



