SECT. IV. DECOMPOSITE ORGANS. 251 



SUBSECTION II. 



The Stem. The stem, like the root, or at least Mode of 



. . augmenta- 



the stem of woody plants, is also augmented in tion. 

 width by the addition of an annual layer, and in 

 length by the addition of an annual shoot bursting 

 from the terminating bud. Is the developement of 

 the shoot issuing from the stem effected in the same 

 manner also ? The developement of the shoot from The new 



shoots aug- 



the stem is not effected in the same manner as that mented by 

 of the root by additions to the extremity only susceptkm 



but by the intro-susception of additional particles 

 throughout its whole extent, at least in its soft and out its 



. whole ex- 



SUCCulent state: the longitudinal extension dimi-tent; 



nishing in proportion as the shoot acquires solidity, 



and ceasing entirely when the wood is perfectly 



formed ; though often continuing at the summit 



after it has ceased at the base. Du Hamel divided 



a shoot of the Horse-chesnut into several equal 



parts, distinguished by coloured varnish ; and on 



inspecting it some time afterwards, found that all the 



marks were removed from one another to a greater 



distance than at first ; but on inspecting it after a 



second interval, he found that the upper marks only 



had continued to increase in distance. Hales made 



a number of similar experiments on shoots of the 



Vine, and obtained similar results ; from which it 



seems to follow, as Du Hamel had observed, that 



the extension of the shoot is inversely as the indura- 





