No. 4.] 



TREE SURGERY. 



447 



weather. If the tree be vigorous, it may make a determined 

 eftbrt to cover this snag Avith new wood and bark. Such an 

 effort is illustrated in Fig. 8. - Here the callus or new 

 growth has been })ushed out on the stub for two or three 

 inches. It has alread}^ made })rogress enough to have 

 entirely covered the Avound, had the branch been cut off 

 close to the trunk at the time of the accident. If Ave leave 

 nature to herself, the stub may persist for many years. 

 The bark can ncA^er groAV o\'er it, as the farther it groAvs 

 from the main trunk, the farther it gets from the direct iioAV 

 of the current of elaborated sap supplied by the cambium. 

 Unless the branch rots off, or is broken off again close to 

 the tree, the Avound can ncA^er heal. One or the other of 

 these alternatives is sure to foUoAv in the course of years ; 

 but, even if the Avound heals, the trunk of the tree may 

 have become alread}" diseased or cA'en hollow by its intimate 

 connection Avith the dead branches. 



This sort of natural pruning no doubt tends toAvard the 

 destruction of the Aveaker trees and the survival of the fit- 

 test. In the forest, this is best ; but for man, w^io Avishes 

 to cultivate and perpetuate certain characteristics in trees, 

 to follow such a course of pruning, and so destroy his 

 selected trees, is pure foil}'. XcA'er- 

 theless, this is precisely Avhat many 

 of us do to-day in this 

 Commonwealth . 



enlightened 



Poor Pruning. 

 The citizen, desiring to remove a 

 branch, climbs into the tree and be- 

 gins to saw dowuAvard throuo-h the 

 limb at a point from six inches to a 

 foot from the trunk. When the limb 



becomes so Aveakened by the saAv cut that it can no longer 

 support its branches, its outer end falls to the ground, splin- 

 tering and tearing the stump Avhich remains, perhaps even 

 tearing a part of the trunk in its fall (Fig. 9). The ragged 

 stump is then left to decay, and begin the destruction of the 

 tree. Some pruners do better than this, by sawing off the 



Fig. 9. — Limb breaking 

 dowu from cut ■svronglj- 

 made. 



