PRUNING TREES 



165 



covering all wounds with coal tar cannot be overstated. 

 If the wound is not tarred, the exposed wood cracks, .as in 

 Fig. 115, providing suitable quarters for disease germs 

 that will eventually destroy the body of the tree. Coal tar 



FIG. 115. Result of a Wound not Covered with Coal Tar. 

 The exposed wood cracked and decay set in. 



is by far preferable to paint and other substances for covering 

 the wound. The tar penetrates the exposed wood, pro- 

 ducing an antiseptic as well as a protective effect. Paint 

 only forms a covering, which may peel off in course of time 

 and which will later protrude from the cut, thus forming, 

 between the paint and the wood, a suitable breeding place 



