No. 4.] TREE SURGERY. 465 



lars from concealing themselves beneath the scales. When 

 this bark Avas shaved rather closely, it was noticed that in 

 many cases the trees were stimulated to vigorous growth. 

 This groAvth usuall}^ began the second year. With the trees 

 Avhich responded to this treatment the results seemed similar 

 to those caused b}' manm^ing and cultivation. Growth began 

 earlier, the leaves grew faster in the spring, were larger and 

 darker, the fruit was larger or more numerous, and the an- 

 nual wood growth considerably more than on similar trees 

 unscraped. Their trunks :ind limbs growing better and 

 larger, there was also in some cases a greater flow of callus 

 about the edges of wounds, so that healing progressed more 

 rapidh'. The reason for the improved condition of things 

 is not far to seek. 



'Wtv many trees become " bark bound." The old dead 

 bark does not shed fast enough and remains upon the tree, 

 pressing upon the circumference of the trunk like a barrel 

 hoop upon the staves, until it becomes so thick and strong 

 as to repress the annual formation of the wood ring and 

 check the growth of the trunk. Release the pressure early 

 in the spring, by either softening the bark, paring it down 

 thin or dividing it by longitudinal slits down the trunk, and 

 the ' ' bark-bound " tree immediately takes advantage of the 

 opportunity that ofl'ers for growth and development. 



If the tree in its weakened condition has already become 

 infested by bark beetles, the forerunners of death, it may 3'et 

 be able, with the pressure on its trunk released, to make 

 such a vigorous flow of sap as to destroy the beetles and 

 take a new lease of life. Some trees will not respond to 

 this treatment. In many cases little if any improvement in 

 the healing of wounds was noted. Possibly it maybe bene- 

 ficial only in the case of bark-bound trees. Nor can it be 

 expected to bring the dead to life. An old oak in Winches- 

 ter, which had been much injured by the attacks of the 

 gypsy moth, was pruned and scraped. Although apparently 

 nearly dead when treatment was begun, it made a most 

 remarkable growth soon afterward, healing over a large bare 

 space where the bark had fallen from the trunk ; two years 

 later the tree failed again, and finally died. Its death ap- 



