184 THE GYPSY MOTH. 



they break down and split off a portion of the trunk, which 

 in such case is frequently hollow. The removal of such 

 limbs in time may prevent injury to the trunk. These am- 

 putations when necessary are merely a question of surgery ; 

 and if they are performed at the right season and in the 

 proper manner, and the wound is properly treated, there is 

 little danger of injury to an otherwise sound tree. Where 

 injury to such a tree results from the process, it is usually 

 from ignorance of correct methods or carelessness in their 

 use. Still, it is well to bear in mind that when a surgical 

 operation is to be performed, the result depends not only on 

 the skill of the operator but also on the age and vigor of the 

 subject. 



The death of old decaying trees is sometimes hastened by 

 the amputation of large and hollow branches. The shock 

 caused by the removal of several large branches, together 

 with the reduction of leaf surface, which makes it difficult 

 for the tree to heal the wounds, will often kill such trees.* 

 The proper method for treating the cavities of such trees will 

 be spoken of later. 



Removing Large Limbs. In this process great caution 

 must be exercised : (1) not to injure the tree by the unneces- 

 sary removal of too many large branches in one season ; (2) 

 to avoid injury of the tree by the breaking down or falling 

 of the branch; (3) to guard against accidents to work- 

 men. The old rule for removing large branches was to 

 cut the stump across its diameter near its base, never mak- 

 ing a cut larger than the diameter of the branch. This 

 practice has already been shown to be pernicious, as the 

 tree has great difficulty in covering the lower part of the 

 wound with a new growth of bark. Where a large limb 

 is removed in this manner, the lower part of the stump 

 never becomes entirely covered, and finally decays. In saw- 

 ing off a branch the first cut should never be made from 

 above, as the limb is likely to split and tear away from 

 the trunk. The result of such an accident as is shown in 



* If an old tree with sound trunk whose branches appear to be dying is " headed 

 down" by the removal of most or all of its large branches, it may revive, throw out 

 shoots and form a smaller and more vigorous head. 



