106 ELEMENTS OF SYLVICULTURE. 



In the valley of the Adour, some forests of pure 

 oak are worked on the selection method. But these 

 are forests which are open to grazing throughout 

 their whole area from one year's end to another, and 

 in which therefore it would be useless to look for 

 self-sown seedlings. Hence after the old mature oaks 

 are felled, tall saplings as high as thirteen to twenty 

 feet are planted out in the gaps. By this method 

 they obtain trees with well-developed crowns and 

 tough-grained wood, but of no length of bole. 



GENERAL RULES. It is obviously very difficult 

 to lay down precise rules for working forests on the 

 selection method ; they depend entirely on local 

 conditions. Still some that will be found generally 

 applicable may be formulated. 



Selections are to be continued as heretofore, that is 

 to say they should extend every year over rather a 

 large area. Only to avoid returning too often to the 

 same spot, a proceeding that always injures the crop, 

 and becomes a very difficult task for the forest 

 officer, it is advisable to divide the forest into a 

 certain number of compartments, five to ten, each 

 of which is taken in its turn successively. 



In order to render the yield of each year as nearly 

 equal as possible, these compartments should be 

 made either equal in area or equal in fertility. Too 

 much importance, however, is not to be attached to 

 this point, and a certain approximation will be 

 quite sufficient. 



From each of these compartments, timber that is 

 deemed exploitable will be removed, that is to say, 

 in the case of imperishable proprietors (the State, 



