Nature^ Longevity^ and Size of Trees, 17 



tion, however, and its precise character, is unimportant. 

 Still, if it is genuine roots, as M. Thouars maintains, and as 

 Dr Lindley and Dr Carpenter agree with him in believing,* 

 it will at once follow that the growths in question have roots, 

 and that having these, they have no extraneous element 

 entering into their composition. And a positive and very 

 valuable fact wdll be added to the general body of evidence 

 already adduced in support of the view, that those growths 

 possess the character ascribed to them, 



II. Secondly, at the close of every year, the annual growths 

 or plants, with the exception, of course, of the newly-formed 

 buds, cease to be, and never afterwards become, the seat of 

 any vital action, i, e.^ they die, and never afterwards live. 



This is sufficiently obvious as regards the leaves and flowers, 

 which wither, fall off, and completely disappear. It is equally 

 true, however, of what remains of the other parts of the 

 plants, i. e., of the roots and the woody stems or shoots. 



But on what grounds are we entitled to say that these parts 

 then die, and never again live 1 



1. In the first place, because after the fall of the leaves, 

 and during subsequent years, no growth or increase of the 

 organic matter composing them takes place, as should be 

 exhibited in an increase of their length and thickness, and 

 produced in the way that the leaflet of spring is gradually 

 developed into the full gi'own leaf of summer. They appear, 

 indeed, to elongate and become thicker, i. e., to grow in length 

 and breadth. This growth, however, is not a real extension 

 of the parts in question, as it is in the leaflet ; it is a new 

 and independent formation at their extremities, and either 

 around or within them, and may, by examination, be seen to 



* " The most consistent account of its development is that given by Du Petit 

 Thouars, who, followed by Lindley, regards the fibrous [woody] tissue as formed 

 in the leaves, and growing downwards into the cambium, just as roots are pro- 

 longed into the soil. This view would liken the woody fibres to the roots of 

 the buds ; and such a comparison, though at first sight improbable, is fully 

 borne out by facts." — Ca.rj^enter, Principles of General and Comparative Physiology, 

 1st Ed., p. 278. 



VOL. Xm. NO. LXXXUI.^JANUARY 1847. B 



