CHAPTER IX. 



THE HEALING OF WOUNDS BY OCCLUSION. 



IF we pass through a forest of oaks, beeches, pines, 

 and other trees, it requires but a glance here and there 

 to see that various natural processes are at work to 

 reduce the number of branches as the trees become 

 older. Every tree bears more buds than develop into 

 twigs and branches, for not only do some of the buds at 

 a very early date divert the food-supplies from others, 

 and thus starve them off, but they are also exposed to 

 the attacks of insects, squirrels, &c., and to dangers 

 arising from inclement weather, and from being struck 

 by falling trees and branches, &c., and many are thus 

 destroyed. Such causes alone will account in part for 

 the irregularity of a tree, especially a Conifer, in which 

 the buds may have been developed so regularly that 

 if all came to maturity the tree would be symmetrical. 

 But ^that this is not the whole of the case, can be 



