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LETTERS ON TREES. 



leaves. But the effect of the mutilation, on their 

 Cambium, cannot be owing merely to this privation, — 

 because nothing need hinder it from drawing the 

 needful supplies from the adjoining branches. It is 

 easy, however, to understand it on the supposition 

 that the Cambium is only an extension of the buds 

 and the matrix of the roots of the plants that issue 

 from the buds. Take away the buds, or take away 

 the young plants themselves : you deprive the Cam- 

 bium of the only office it has to serve ; and, doing this, 

 you destroy its capacity of growth. 



7. One thing I must add, not to qualify what has 

 just been said, but to obviate misapprehension. It 

 might chance to happen that from the sides and 

 through the bark of a branch thus mutilated, shoots 

 would sprout, and the Cambium-layer be in con- 

 sequence more or less transformed into wood. But 

 this would be an instance not of the Cambium exerting 

 independent powers of growth, but of buds inter- 

 spersed here and there through its substance pushing 

 out. The Cambium-layer of many kinds of trees, the 

 Elm in particular, is thus furnished with buds over its 

 whole extent. Under ordinary circumstances these 

 buds commonh remain " latent " or dormant," — - 

 and that because of the divergent influence resulting 

 from the development and growth of the proper buds. 

 Independently of this, in some trees, these Cambium- 

 buds push out every season, concurrently with the 



