72 SYLVA AMERICANA. 



position, and well propt up. Especially the cure may be 

 expected to succeed if the fracture happens in the spring ; but it 

 will not succeed if the fracture is accompanied with contusion, or 

 if the stem or branch is large ; and even where it succeeds, the 

 woody fibres do not contribute to the union, but the granular and 

 herbaceous substance only which exudes from between the wood 

 and liber, insinuating itself into all interstices, and finally becoming 

 indurated into wood. 



5. Pruning. Wounds are necessarily inflicted by the gar- 

 dener or forester in the pruning or lopping off of superfluous 

 branches, but this is seldom attended with any bad effects to the 

 health of the tree, if done by a skilful practitioner ; indeed no 

 further art is required merely for the protection of the tree, 

 beyond that of cutting the branch through in a sloping direction 

 so as to prevent the rain from lodging. In this case the wound 

 soon closes up by the induration of the exposed surface of the 

 section, and by the protrusion of a granular substance, forming a 

 sort of circular lip between the wood and bark; and hence the 

 branch is never elongated by the growth of the same vessels that 

 have been cut, but by the protrusion of new buds near the point 

 of section. 



6. Grafting. In this operation there is a wound both of the 

 stock and graft ; which are united not by the immediate adhesion 

 of the surfaces of the two sections, but by means of a granular 

 and herbaceous substance exuding from between the wood and 

 bark, and insinuating itself as a sort of cement into all open 

 spaces : new wood is finally formed within it, and the union is 

 complete. 



7. Felling. Felling is the operation of cutting down trees 

 close to the ground which many of them will yet survive, if the 

 stump is protected from the injuries of animals, and the root fresh 

 and vigorous. In this case the fibres of the wood are never 

 again regenerated, but a lip is formed as in the case of pruning ; 

 and buds, that spring up into new shoots, are protruded near the 

 section : so that from the old shoot, ten, twelve or even twenty 

 new stems may issue according to its size and vigor. The shoots 

 of the oak and ash will furnish good examples ; but there are 



