74 The Care of Ornamental Timber 



if the operation is carefully conducted, disease is checked and the life 

 of the tree is very considerably prolonged. 



In the other cases, when from one or other cause a stump of a 

 branch has been left on the trunk, this stump will die if it does not 

 possess a sap-lifting bud. Ordinarily, if the branch were sawn 

 or cut off quite close to the trunk, the wound would gradually 

 heal over and so prevent the entrance of destructive organisms ; 

 but the protrusion of the dead branch prevents the occlusion of 

 the wound, so that the wood soon becomes infected, and rots ; 

 then the decay spreads down into the trunk as shown in Fig. 24. 



Fig. 24. Trunk of tree showing rot, due to broken or improperly- 

 pruned branches, and the method of treatment, (a), dead stump of 

 branch which prevents the occlusion of the bark at b.c., until the 

 decayed portion has spread into the trunk forming a cavity as d ; 

 (e), auger-hole made to drain the water from the cavity. 



The method of treatment is on similar lines to the above ; but in 

 this case, the dead stump must be sawn off flush with the trunk, all 

 dead wood cut out, the exposed wood treated with preservative, and 

 the cavity is filled up with cement, which must be finished off level 



