component part of the spine, the unit of the
animal body. The vertebra is the type of the
spine, which is formed by heaping vertebra
on vertebra; and in the transformation of
the vertebra lies the secret of the animal
structure. At the extremity of the spine,
nature projects modified parts of vertebræ, as
arms; at the end of these, she puts forth new
modifications, as hands. Below, the process
is repeated in the development of legs and
feet. At the summit of the column, the
vertebra assumes its highest form; three
vertebræ, arched over, form the chamber for
the reception of the governing brain of man.
As the leaf moves upward from stage to
stage, ending at last with the flower and the
seed, so the vertebra, rising in the nobility of
its use, envelopes first stomach, then heart,
closing with the head, in which are concentrated
the boundless powers of the human
intellect.

It is thus that the plant is built up.
The marvels of its construction throw into
shade all that has been imagined by the most
daring romancist, or realised by the most
successful architect. The fairy dwelling of
Aladdin, and the no less fairy palace of Paxton
sink into insignificance. For the building of
this floral palace no complex instruments, no
multiplied combinations of lever, wheel and
pulley are employed. Stone by stone the fairy
fabric rises, while the unseen architect works
on unweariedly, not alone planning but
executing, not alone skilfully disposing the
materials, but itself preparing them. This
architect—under the Great Architect of all—
is the vegetable cell, which, in its varying
forms of activity, purifies the air we breathe
by absorbing the poisonous products of
respiration, provides for the sustenance of animal
life the materials of food, and clothes the
earth with a rich mantle of beauteous forms.
Working under fixed and invariable laws this
almost invisible globule evolves unaided the
whole structure of the plant. It is by the
help of the microscope that we have learnt to
appreciate the beautiful and effective
simplicity of the plant architecture, and have
traced out with tolerable accuracy the plan
of the designer.

The stones of which the edifice is
constructed are throughout the same;
everywhere we recognise this marvellous organism
of the vegetable cell; but it is so modified in
each situation as to meet the special requirements
of its position. First let us examine
the external walls of the plant mansion, and
here, on the very threshold, we are compelled
to pause and admire the perfection of the
architectural arrangement. It is impossible
to conceive any more excellently devised
roofing than that which is formed by the
outer layer of flattened cells, which serve to
protect the plant from injurious external
influences. Firmly united so that they may be
frequently stripped off as a continuous layer,
they secrete a thin resinous coating, which
renders them alike impervious to rain or dust.
We can hardly boast of having been equally
successful in protecting our most gorgeous
palaces from the destructive effects of these
foreign agencies. It is curiously illustrative
of the economy of nature, whose precautions
are never in excess, although always sufficient,
that this outer protective layer is not
developed in aquatic plants, where it would be
unnecessary. In the interior of the plant
palace we see equally faultless results
produced by no less simple means. The same
vegetable cell which by assuming a flattened
form, constituted so efficient a protective
wall, is here employed to attain other objects.
Perhaps, strength and power of resistance are
desired; a solid mansion is to be erected,
which will defy the force of the angry winds,
and deride the impotent fury of the elements
through centuries of time. And now the cell
is elongated, its walls are thickened, and
spiral fibres are deposited within it. It is no
longer a delicate vesicle: it is metamorphosed
into a strong hollow column, a cylinder or a
prism. It assumes a thousand varying forms,
but everywhere it so harmonises with
surrounding shapes, so thoroughly dovetails with
its neighbours, that no unnecessary chink is
left throughout the solid masonry. Each cell
appears to be accurately measured, and
carefully fitted into its precise situation. No
adaptation by mechanical means could be
more perfect; the plumb-line would have
failed to produce a more complete contiguity
of parts. Each stone in the edifice is adapted
to every elevation or depression on the
neighbouring parts. Columns and cylinders
bevelled off at either extremity leave small
interspaces, into which fit accurately other
elementary forms; and although unnumbered
millions of cells are included in the structure,
no one is misplaced or carelessly inserted.

The same faultless perfection in the
architectural arrangements is evinced in the
varying degrees of consolidation to which the
cells attain. If the giant oak is to lift its
sturdy form, a large amount of intercellular
substance, the hard cement of the plant, is
deposited, the cell-wall is greatly thickened,
the cell-cavity is considerably diminished,
perhaps completely obliterated, and thus a
firm unyielding structure is built up, against
which the boisterous winds will vainly spend
their force. But if the graceful lily is to rear
its slender stalk, the still tender cells build
up a delicate structure which yields to the
slightest impulse, and bends before the blast
I dare not brave.

In examining the architecture of the plant,
however, we are reminded that it is not a
mere inert mass, but a living organism
ceaselessly employed in the accomplishment
of important chemical actions, equally essential
to its own existence and to the preservation
of the balance of organic nature. Gases
and fluids are to be absorbed and expired in
an altered form, and it becomes essential that