the thickening of the cells, as in wood, without
which the existence of such massive
structures as trees would be impossible,
should not interfere with the free diffusion of
nutritive fluid. Since the plant cell receives
its nourishment by the continued absorption
and elimination of fluid through its cell-walls,
it is evident that in thickening and hardening,
these walls, in order to acquire stability and
power of resistance, it is at the same time
shutting itself off from a due supply of
nourishment. But in the economy of the
cell-architecture nothing is forgotten; and
although compelled to erect these solid
buttresses, the cell does not the less remember
to leave here and there a small spot at which
the walls retain their original delicacy and
remain easily permeable by fluids. So minute
are these depressions that they are with
difficulty perceived, even when magnified a
thousand fold: nevertheless, they always
exist to a greater or less extent. There is
nothing in the whole range of the plant
architecture more admirable than the
arrangement of these dottings. Inconceivably
minute as they are, and apparently formed
on chance positions in the cell-wall, they are
yet found to bear a determinate relation to
similar depressions in other neighbouring
cells; so that, by their exact opposition, a
communication is established between a
succession of cells, and a channel is opened for
the nutritive fluid, which extends to the
external layers of the plant. This impervious
tissue of external cells bears no less important
a relation to the nourishment of the plant
than to its protection from foreign injury and
isolation from external influences. Without
its aid the processes of nutrition could not be
carried on—the action of the sun would
produce universal exhalation from the whole
surface. The sap, which is the life-blood,
would be rapidly dried up, and the plant
would perish. On the other hand, if the
special provision were not made for the
support of continued expiration of vapour,
death would be no less inevitable; we may be
sure, therefore, that the plant architect has
not forgotten to make such a provision in
preparing the plans for the construction of
this noble edifice. The passages which have
just been described, as being formed between
the cells, communicate with little openings—
mouths the botanists call them—existing in
great numbers on the under surface of leaves
especially: along these passages the vapours
creep, passing through cell-wall after cell-wall
until they reach the external atmosphere.
So rapid is the exhalation of these mouths,
so efficient is the provision for the respiration
of the plant, that an acre of plants have been
ascertained to eliminate during the period
of vegetation, about two million pounds of
vapour.

In the construction of the plant mansion,
due care is ever taken to provide secret
chambers and store rooms for the various
secretions of the vegetable organism. In
these chambers we see the most diverse
forms and arrangements according to the
nature of the substance to be lodged. In
one we see a fit receptacle for air, in another
for oil globules, for starch, for sugar, for
granules of green, yellow, red, or blue
pigment, for bunches of crystals. It is
impossible to conceive anything more varied
than the view presented by a section of a
plant seen under the microscope.

If now we review the whole internal
economy of the structure of the plant, we
can hardly express adequately our wonder
and admiration at the multiform perfection
of its arrangements. It is not only that the
plant, like the bee-hive, may be
mathematically proved to be erected on faultless
scientific principles. It is not only that it
combines lightness with strength and exquisite
beauty with solid utility. But as we
survey the actions of the plant we rise to the
perception that this perfect edifice so
complete in its oneness of purpose and development
consists in an union of individuals:
that it is a mass of separate and widely
differing mansions. The stones which so
perfectly fulfilled their part in the entire
structure, are no longer stones: they are
themselves complete chemical manufactories,
carrying on the most diverse processes, and
elaborating the most various products.
Unlike the stones in any other mansion, they
have entirely distinct and separate existences;
they are different in function, and
must therefore possess some characteristic
peculiarities of construction, imperceptible
though they be to the human eye, aided by
all the appliances of science. Nevertheless,
they all combine in a consentaneous effort
for the well-being of the whole plant, aiding
to perform the processes of general nutrition.
Hence they seem to hold a double relation—
aptly typifying our own position; since
like us they have both an individual existence,
(in respect to which they are only concerned
in performing their own duties and exercising
their own special functions,) and a social
position which calls upon them to aid in
operations that aim at the general good.
Thus the whole plant-mansion is supplied
with food without the aid of pump or engine,
and its inimitable chemical operations are
carried on without scale or balance. But,
sooner or later death enters also into this
paradise. In the very centre of this lovely
temple, one stone after another yields to
inevitable decay: even while its green
banners float proudly or joyously on the
breeze, the canker-worm eats its way within.
Soon the girders and cross-beams fail—
column after column falls—at last the very
corner-stones give way, and the ruins of the
noble edifice lies shattered in the dust.

A ray of light pierces the gloom of this dark
scene, sketched by Goethe with a master's
hand. A consolation still remains for us,