PRUNING. 



37 



during its growth, must still be looked to after it is 

 felled, since, if neglected, there being no longer any 

 check to its development, fresh moisture" will be 

 absorbed, decay will be accelerated, 

 and the whole log soon destroyed. 

 To guard against this, it would be 

 proper, as soon as the log is ap- 

 propriated for any purpose, to take 

 out and completely remove the 

 affected part, substituting in its 

 place a piece of sound wood. 



Again, the damage done by the 

 breaking of a branch from a tree is 

 often very serious, as illustrated in 

 Fig. 13. The wound was of very 

 old standing, and entirely healed 

 over, but the decay had never- 

 theless made steady progress. It 

 was found, by counting the con- 

 centric layers, that the branch was 

 broken when the tree was fifty-six 

 years old; that in twenty-three 

 years more the annual layers had 

 completely covered the broken 

 part, while outside this twenty- 

 third layer there were twenty-seven 

 years' growth of duramen or heart- 

 wood, and twenty-six years' growth 

 of alburnum or sap, the tree having 

 been about 132 years old at the 

 time of its being felted. 



Pruning closely, except in the case of very young 

 trees, where the branches are small, and the wound is 

 certain to be soon healed over, will, as before shown, 



FIG. 14. 



