WOUNDS 29 



Notwithstanding the above, pruning is sometimes necessary, 

 even on a large scale, as in the case of trees growing in streets, 

 etc., and it is important that it should be performed in a 

 manner incurring the minimum of risk of infection by fungus 

 spores, or of decay of the wounded portion through wet. 



A general rule is that a branch should be cut as close as 

 possible, and the cut should be parallel to the part from which 

 the branch is removed. This method of operation is most 

 favourable for the quick development of a callus, provided 

 the edge of the bark surrounding the wound is not crushed or 

 torn in removing the branch. As soon as possible after the 

 removal of a branch, the wounded surface should be thor- 

 oughly covered with a coat of gas-tar. 



Pruning should always be done during the autumn or winter 

 months, if undertaken in spring or summer the gas-tar fails to 

 enter the wood, and does not prevent the entrance of spores 

 and wet into the tissues through cracks that form in the wood 

 during drying. 



Mr. J. Bean, assistant curator, Kew Gardens, has recently 

 published a valuable article on pruning, illustrating right and 

 wrong methods, in the Gardeners' Chronicle. 



Bean, Card. Chron. (1905). 



Hartig, Diseases of Trees (Engl. ed.) 5 p. 257 (1894). 



Schlich, Manual of Forestry, 3, p. 283. 



Injuries caused by man. As previously stated, grass-cutting 

 machines do a great amount of injury to the exposed roots 

 and bases of trees when carelessly handled. Such injuries 

 are usually either altogether ignored, or simply covered with 

 soil to hide the injury. 



During the planting of young trees the collar of the stem 

 is often more or less barked or bruised by the boots of the 

 workmen stamping the soil down round the root. 



In both these instances the wounds made serve as openings 

 for the attack of wound fungi, and when young larches are 

 injured in planting, larch canker too frequently follows in due 

 course. 



Injuries caused by wind, snow, etc. Too frequently limbs 

 of trees are broken by wind or by the weight of snow resting 

 on the branch. When such accidents happen to trees it is 

 desirable to preserve, the wound made should be carefully 



