314 ELEMENTS OF SYLVICULTUEE. 



whence they proceed is the medullary canal itself; 

 they are therefore of the same age as the part of 

 the trunk on which they are found. 



Hence, the shoots which are derived from adventi- 

 tious buds present themselves on the cut surface of 

 the stool, between the bark and the wood ; the other 

 class of shoots spring up below this section and 

 make their appearance after piercing through the 

 bark. These latter are by far the most numerous. 

 On their number, as well as their less or greater 

 vitality, depends for the most part the aptitude of a 

 tree to reproduce itself from the stool. The thick- 

 ness and hardness of the bark have nothing to do 

 with it. 



Besides these stool-shoots, a certain number of 

 trees also throw up suckers or shoots from the roots. 

 It is even remarkable that some of them, though 

 they coppice badly, produce suckers in abundance, 

 and are thus invaluable for keeping up the under- 

 wood. The fact is that suckers are rooted directly 

 in the soil, and are hence independent of the parent 

 stool from the very beginning, a circumstance which, 

 in the case of stool shoots, occurs only when they 

 are in contact with the soil. 



The trees which reproduce themselves most freely 

 from the stool are the oaks, the hornbeam, the elms, 

 the maples, the sweet chestnut, the common alder, 

 the ash, the willow, &c. 



The trees most apt to furnish suckers are the 

 holm, the Pyrenean and the cork oaks, the aspen, 

 the white alder, the lime, the willows, the birch, &c. 



A certain number throw up both shoots and 



