180 TREE WOUNDS AND DISEASES 



and diseased branches either wholly removed 

 or cut back to such an extent that their safety 

 is assured. But even with the most minute 

 and careful examination it by no means follows 

 that accidents will not occur, for the simple 

 reason that it is often impossible to detect 

 flaws and diseases which are not revealed out- 

 side the bark. This is especially the case 

 with the branches of old elm trees, the diseased 

 centres of which often defy the most careful 

 examination of the experienced woodman. 



Apart altogether from disease or injury, a 

 branch may, for the sake of safety, require to 

 be pruned or lightened. Upright-growing 

 branches are not so dangerous, but such as 

 hang downwards from the horizontal and 

 extend to a considerable distance from the 

 main stem require judicious pruning. This 

 should be carried out in such a manner that 

 the general appearance of the tree is not 

 damaged, the heavy branches being neatly 

 cut back at the point where the operation 

 will be least readily detected. Here again a 

 careful smoothing of the branch surface at the 

 point where amputation took place is all- 



