- quently, a few short fibres are sufficient. 
eee 
branches or leaves or scales in the manner of a 
stem; it never becomes green in its tissue by 
exposure to the action of air and light; and it 
comprises all the peints of the plant’s basal at- 
tachment, and also all the bibulous organs of the 
plant’s functions of nourishment. See the article 
AxssorPtion oF Prants. Some cryptogams, such 
as many of the conferve, have apparently no root 
whatever; a few cryptogams, such as the truffle, 
lock to be ail roct; many cryptogams, such as 
the lichens and the mosses, have rather rostels | 
than roots; some aquatic pheanogams, such as 
the duckweeds, have only such roots or absorb- 
ing organs as float in water; many phenogams, 
such as the tropical orchidacee and otker epi- 
phytes, have only such roots as live upon trees 
or other plants; and seme phenogams, such as 
many plants of the iris order,—and also some 
eryptogams, such as some of tke ferns,—have 
roots more or less of the character of prostrate, 
thickened, underground stems. But all other 
plants, comprising the enormous majority of all 
the known flora of the world, and absolutely 
all which have a comparatively perfect or well- 
developed phesnogamous character, possess true 
roots, or basal, compound organs of attachment 
and nourishment, such as we have defined. Yet 
these true roots present a wondrous diversity of 
structure and constitution and habits; and might 
be discussed threugh a long series of sections, in- 
vestigating their resemblances and differences 
and characters and myriads of most beautiful 
adaptations ; but, in the very limited space which 
we can allow to them, we must simply say, that 
they are usually classified into the fibrous, the 
bitten, the spindle-shaped, the bulbous, and the 
tuberous, 
“Tn all cases,” remarks Dr. Madden, “ an ob- 
vious relation may be perceived between the 
form of the root and the kind ef soil in which 
the plaat grows. Thus, if two specimens of the 
same plant—some of the grasses, for example— 
be found growing, the one in clayey, the other in 
a sandy soil, it will be seen on examination, that 
the root of the one growing in the sand is much 
more minutely subdivided, and contains many 
more small fibres, than the one which grew in 
clay; and the reason of this is obvious: the | 
spongicles are the only absorbent parts of the 
root,—they exist only at the extremities of the 
smallest fibres,—and moreover, they can take up | 
nothing but what is presented to them in the | 
form of solution. Mow, in the clayey soil, from | 
its retentive nature, the soluble parts are not al- 
lowed to drain away; and hence the pliant is 
supplied with food near at hand, and, conse- 
On 
the other hand, plants growing in sand are fre- 
quently deprived of all fluid near them, by the 
sinking of the soluble matters through the loosely | 
in which case the plant would | 
aggregated soil ; 
inevitably perish from starvation, were it not for 
the wise law of Nature, which provides against 
69 
such calamities, by endowing the roots of the 
plants, placed under such circumstances, with 
the power of shooting forth innumerable minute 
fibres in all directions, in order that advantage 
may be taken of every drop of moisture which 
falls in their neighbourhood. Nor is it merely 
in the number of minute fibres that the roots of 
plants growing in sand differ from those which 
inhabit the stiffer soils. The form of the body 
of the root is distinct ; thus, nearly all bulbous, 
and other large succulent roots—as the turnip, 
for example—require sandy soil ; and, moreover, 
some plants,—as the meadow, cat’s tail, or 
Timothy - grass, Phleum pratense,—change the 
form of the root, according to the soil they in- 
habit; thus, in stiff clays, the plant just men- 
tioned has a fibrous root, whereas in sand it 
becomes bulbous, and assumes all the characters 
of Phleum nodosum. The explanation here is as 
evident as in the former case. The bulbs of the 
roots act as reservoirs ef food for the plant ; thus, 
in very dry seasons, these bulbs shrivel up, their 
fluids being all needed by the rest of the plant, 
and hence withdrawn, -So beautifully do we per- 
ceive in this, as in all other cases, that design 
and adaptation of means to specific purposes, 
which must impress even the most sceptical with 
the abselute existence of a Great First Cause.” 
“ But what gives roots their chief interest to 
the agriculturist,” remarks Mr. J. G. Macvicar, 
“is the fact, that the cellular tissue, of which 
they are Bontroced: is capable of becoming a re- 
servoir of nutritious matter, which, though na- 
turally designed for the subsequent use of the 
plant, man and other animals find it convenient 
te consume. It does not appear that sap is fit 
for nourishing a plant until it has been elaborat- 
ed in the leaves ; but it frequently happens that 
more can be elaborated by them at one time 
than is necessary for the plant’ s immediate con- 
sumption, in which case it is conveyed back, and 
stored up for future consumption, at a season 
when the leaves not being in a state of activity, 
or the soil being exhausted, there is some objec- 
tion to the immediate formation of nutrient 
matter. In perennial plants, which form’ buds, 
this nutrient matter is usually deposited in the 
cellular tissue, about their roots or origin, and, 
when robbed by man, yields sago, and other nu- 
tritious articles of diet. When the plant is of 
that more perfect kind where many buds are 
formed, and the stem contains a decided pith, in 
it the nutrient grains and juices are stored, to 
be carried forward another season to the un- 
evolved bud, by the ascending sap, giving it the 
characters of elaborated sap, and thus rendering 
it fit for nourishing the young leaves. But al- 
though trees, shrubs, and many forms of plants 
admit of this supplementary nutriment being 
deposited, in many little magazines, at the base 
of the buds,—and though the palms, and the 
plants which yield sago, admit of its being in 
one great mass, at elevations in the atmosphere, 
BO a 
