126 



of gaseous fluids/ The fact is, that the roots are much 

 rather to be regarded as the mouths of plants, selecting what 

 is useful to nourishment, and rejecting what is yet in a crude 

 and indigestible state ; the larger portion of it also serving to 

 fix the plant in the soil, and to convey to the trunk the nom*- 

 ishnient absorbed by the smaller fibres, which, ascending by 

 the tubes of the alburnum, is thus conveyed to the leaves.t 

 Roots, moreover, by their vigour and numbers, must previ- 

 ously stretch out under ground, before the branches can ex- 

 tend themselves in the air ; and the progress of the latter 

 development will, of course, be in proportion to that of the 

 former. By the curious and beautiful way, in which almost 

 every part of a tree modifies and determines the existence of 

 every other part, as above noticed, the roots, in their turn, 

 receive vigour and extension from the advancement of the 

 branches. 



It appears, that roots and fibres are found more or less 

 extensive, in the ratio of the exposure or shelter, in which a 

 tree is placed. In open situations, they are always strong 

 and numerous, and they extend to a wide distance from 

 the plant. This is indispensably necessary, notwithstanding 

 the short and powerful stem, which a tree so situated usually 

 displays, in order to enable it to resist the elements, and to 

 provide sustenance for the great expansion of top, with 

 which such a tree is sure to be furnished. Hence may be 

 seen the great importance of numerous roots and fibres, in 

 removing trees of any magnitude. It is supposed by some, 

 that the roots of trees so placed, if of considerable age, after 

 having exhausted, before their maturity, all the pabulum in 

 their immediate neighbourhood, will at length be found 

 searching for food, at a distance from the trunk, equal to the 

 height of the trees themselves. At all events we are aware. 



• Note III. 



\ Kpith, Vol. IT. p. 24fi. Also pp. 90. 250. 



