sulphur-hued flowers expand their broad bosoms to the sun, and the
swelling fruit beneath is already putting on its lovely blush of
crimson. How curious are the leafless but leaf-like dilatations of the
stem--these flat oval plates of parenchyma, studded with clusters of
woody and most acute spines!--Every one of these expansions is an
expression of time, as they are of course successive, though several may
be formed in a single season; and not only so, but the tufts of spines,
which grow at the points of intersection of crossing lines, in a network
pattern, are all successive, appearing in turn as the expanded joint of
the stem grows out.
The jointed dilatations themselves are, however, transitory; in the slow
lapse of years the common woody axis enlarges, and the interspaces
between the oval plates become gradually filled up with cellular tissue,
and thus are obliterated; the stem, as may be seen in the central part
of this spreading thicket, becoming round, almost smooth, and of dense
woody texture. "This condition is the result of many years," you say.
It is so, in the ordinary course of nature; but in the case before us,
it has been educed in a totally different manner, and by a totally
different energy, viz. prochronically, by the omnipotent fiat of the
Creator.
We have emerged from the forest glooms, and are come within the light
and the music of the sparkling sea. And here at its margin, washed by
its wavelets, there has been suddenly created a Mangrove tree
(_Rhizophora_), destined to be, doubtless, the fruitful parent of a
grove, which by and by will fringe this flat and muddy shore for miles,
shutting out the light and air which now freely play over the beach, and
keeping in, beneath a long canopy of dense and leathery foliage, the
murky vapours which will rise from the decomposition of its successive
exuviations.
As yet it is a single tree, but in its perfection of maturity. And see
how characteristically we find here that singular structure, or rather
habit, which in Mangroves of normal development would be the effect of
age. The trunk springs from the union of a number of slender arches,
each forming the quadrant of a circle, whose extremities penetrate into
the muddy soil. These are the roots of the tree--there are no
others--that shoot out in this arched form from the base, or "crown" of
the stem, taking a very regular curve of six feet or more in length
before they dip into the mud. The larger arches send out secondary
shoots from their sides, which take the same curved form, but in a
direction at right angles to the former; and thus a complex array of
vaulted lines is formed, which, to the crabs that run beneath--if they
were only able to institute the comparison, must be like the roof-groins
of some Gothic church, supposing the interspaces to be open to the sky.
Now, normally, it would require a lapse of several years from the first
dip of the radicle of the seed into the soft soil, to form these arches,
and to lift the axis of the tree a foot or eighteen inches above the
surface. But here the same result is achieved in a moment, by the
exercise of creative power.
Look at this _Eriodendron_. What a magnificent accumulation of vegetable
cells is here! Its colossal trunk rises in naked majesty, a massive
column, to the height of a hundred feet, without a branch. And then what
branches! Those limbs themselves are of the bulk of ordinary forest
trees; they break out, three or four on the same plane, and radiate
horizontally to a vast distance, supporting a noble flat "roof of
inwoven shade."
[Illustration: SILK-COTTON TREE.]
Perhaps the most remarkable feature of this majestic tree is found at
the foot of the trunk, which sends out vast spurs, radiating in all
directions, and extending to a circle of seventy or eighty feet in
diameter. These spurs take the form of perpendicular walls of timber,
commonly not more than six or eight inches thick, pretty equal in their
thickness throughout, and varying in height from fifteen or twenty feet,
where they spring from the trunk, to the point where they enter the
soil.
Now the Silk-cotton tree has not had this form through its life. When
young, say up to twenty or thirty years old, there was no appearance of
spurs; the trunk was covered with a green bark, and was studded with
great triangular low spines, an inch in diameter. And, what had a
curious effect, the middle of the stem swelled into an ovate form, quite
symmetrical on all sides. But, as years passed, the ventricose form of
the trunk was gradually lost; the bark became of a hoary grey hue or
even almost white; the three-sided prickles disappeared from the bole,
and were retained only on the upper surfaces of the limbs; and the great
lateral buttresses began to fill up the angles which had hitherto
existed between the trunk and the main horizontal and superficial roots.
I called the noble tree before us an accumulation of vegetable cells.
And viewed in that aspect, what an irresistible evidence of the lapse of
time does this vast organism present to us! since the whole of this
immense structure originated in a single cell, which, by repeated acts
of self-division[59] (or, possibly, other modes of reproduction), has
gradually built up the mass.
Yet such a retrospect would be most fallacious in the case before us,
since the plant, as a perfect compound organism, with its parts--root,
trunk, limbs and leaves, and its tissues--cellular, fibrous, and
vascular, has been produced by the instantaneous putting forth of the
Divine volition.
Once again. More gigantic even than the towering Ceiba, this immense
Locust-tree (_Hymenaea_) appears to penetrate the very sky with its crowd
of foliage, which is so remote from the earth, that our eyes cannot
avail to discern the forms of the leaves. The straight columnar trunk,
like some triumphal monument in the midst of a great metropolis, is of
so vast a bulk that a dozen of such men as you and I could scarcely
embrace it with stretched arms and joined hands.[60]
Can our friend, the vegetable physiologist, help us here to form a
notion of the time which would be required for the production of this
tree in the ordinary way? It is the last favour we will ask of him
to-day. Come, Sir, give us your thoughts on the matter.
_The Botanist._--"There is a principle which, in trees of this
character, namely, such as are of exogenous structure, will determine
the age with very close accuracy. Each generation of leaves sends down
woody fibres, which unite into a cylinder on the outside of the wood
previously formed, and beneath the bark."
"Now, as these cylinders are in general sufficiently distinct, in those
trees which renew their leaves but once in a year, it will be enough to
count the concentric circles which appear on a transverse section of the
trunk, and we shall obtain the number of years during which the tree has
existed. In the case of this great Locust, the rule, to be sure, is
rather difficult of application in that way; a transverse section of
this trunk would cost a little labour. But with this circular saw,
which I always carry about with me for investigations of this sort, I
can take out a horizontal cylinder on each of two or three sides of the
tree, by counting the layers in which I can form a tolerably accurate
estimate of the number in the whole diameter.
[Illustration: SECTION OF EXOGENOUS TREE.]
"See; in these cylinders, which do not materially differ, there are
seventy-two layers in a foot, that is, each layer is one-sixth of an
inch wide. The trunk is, at the part I have tested, about fifty feet in
diameter, or twenty-five feet in radius; which would therefore contain
just eighteen hundred such layers. As the deposition of new wood,
however, is generally more abundant in youth and middle life than in
age, the layers are probably a little wider, that is, fewer in a given
space, as we approach the centre. For this we must make allowance, and
may conjecture that this tree is probably not less than one thousand
five hundred years old."
Now whether the premises of the botanist will bear out this conclusion
or not, is not a vital question. For the question at issue is, not, _How
long_ it has lived, but, _Whether it has lived at all_, before the
present moment. It is enough for our point that the tree does, in its
concentric zones, afford ocular evidence of successive epochs of growth.
And the proof of this would be equally good, if ten layers were
deposited in a year, or if one deposit were made every ten years;
equally good, if there were fifteen hundred zones, or if there were but
five. It would be easy to confirm the testimony of the zones by that of
other parts of the structure. The dimensions of the tree itself bear a
fixed and, to a certain extent, recognisable ratio to its age; every
leaf on a given twig has been successively developed from a leaf-bud,
the opening of which and its elongation into a twig occupied, normally,
a definite period; each bough, each of those mighty limbs, was once a
twig, was once an undeveloped leaf-bud, whose expansion to its present
condition was a process, of which time was an inseparable and, within
certain limits, a mensurable element.
If, then, we were precluded from examining any other organism, as it
proceeded from the formative hand of its Creator, than this single tree,
we should be amply warranted in inferring a past existence (be it longer
or shorter, which is no matter) from the phenomena of its structure,
which inference the fact of its creation would flatly contradict.
VIII.
PARALLELS AND PRECEDENTS.
(_Invertebrate Animals._)
"There is a kind of character in thy life
That to th' observer doth thy history
Fully unfold.----" (_Shakspeare._)
Leaving the vegetable kingdom, those organisms which, though beautiful
indeed and instructive, are yet inanimate, let us seek others which are
endowed with a higher style of life, a life which is distinguished by a
measure of consciousness of the exterior world, and a perception of
relations to it. Let us look for animals.
We retrace our steps to the verge of the rippling sea, where the belt of
umbrageous Mangroves fringes its margin. Beneath the arching roots of
these are now reposing in the warm sunlit shallows many creatures which
number this as the first day of their existence. It is their natal, or
rather (to make a word) their _creatal_ day.
Here is a specimen of the Sea-pen (_Pennatula_), closely resembling a
rather thick and fleshy feather, with its quill-end inserted in the
tenacious marl which constitutes the floor of the sea along this shore,
and with the greater part of its body, including all the pinnated
portion, erect, and waving lightly in the gentle swell of the bay. Its
central stem is beset on each side with about twenty-five horizontal
purple pinnae, and each pinna bears from five to fifteen polypes with
eight tentacles each.
Let us wade out to yonder reef. See this great mass of Millepore,
growing in thin irregular perpendicular plates, which join each other at
various angles, so as to form a large open honeycomb-like structure,
much resembling the second stomach of an ox. It is covered with what
appears a thin stratum of fawn-coloured jelly, but this consists of
innumerable disks, which protrude from myriads of orifices not larger
than those produced by the punctures of a fine needle; as we may discern
by touching the soft slimy surface, when the whole retires, and leaves
apparent only the white stony surface dotted with numberless holes,
within which the disks have disappeared, and whence they will again
presently re-appear.
Here too is a massive shrub of stone, a noble example of the Muricated
Madrepore. It consists of a great multitude of short tranches, which
are themselves branched and branched again, every part covered with
little mammillary warts, and pierced with innumerable holes in which
stand radiating plates of the common stone. Out of these plated
orifices, especially those towards the tips of the branches, for the
older ones are empty and dead, we see perpetually peeping forth,
expanding for an instant, and then coyly withdrawing, lovely little
green disks, surrounded with thread-like tentacles; and from the extreme
end of each branch there protrudes one exactly similar to the rest in
all respects, except that it is nearly twice as large. Here then are the
living architects; these have secreted within their gelatinous membranes
the calcareous atoms, whose aggregate forms the stony shrub before us.
Shall we try to estimate the number of polypes that have been occupied
in building this tree? There are about a hundred branches, which, taken
one with another, and followed along the sinuous course of their many
branchlets, we may estimate to average a continuous length of eight feet
each; that is, 800 feet of branch in all. Now we may consider these
branches as averaging a thickness of two inches and a half in
circumference, which gives us a surface of 24,000 square inches.
Finally, there are about ten polype-cells in each square inch; and thus
there are or have been in this coral-mass, nearly a quarter of a million
of polype inhabitants.
[Illustration: MURICATED MADREPORE.]
But look at this dark crimson edifice of many stories, tier above tier,
each horizontal floor of red stone sustained by a multitude of slender
cylindrical pillars. When we look closely at them, we see that the
pillars are tubes, perforating one or more of the floors, from the
lowest tier to the uppermost.
Have we any clue to the age of these corals, or to that of either of
them, supposing we did not know that they have been created to-day? Not
definitely, perhaps; but indefinitely we have, certainly. In the case of
the Sea-pen, the polypes have all been formed in succession; as also in
that of the stony Millepore and Madrepore, with this addition, that
every newly formed polype deposited an increase to the stony substance,
which thus went on increasing till the great foliated or ramified mass
that we see was formed.[61] And so, with this series of floors and
pillars, which is the solid portion of another coral-polype, the
Organ-pipe (_Tubipora musica_).
[Illustration: ORGAN-PIPE.]
Every one of these stories has been formed in succession. From the tips
of some of the tubes we see protruding an elegant polype of an
emerald-green hue, having eight starry tentacles, and giving off from
its base an enveloping membrane, which spreads over the rim of the tube
and descends on the outside to the floor. By means of this vascular
membrane, both tube and floor have been formed. Calcareous particles,
deposited, one by one, in its substance, gradually built up the tube of
the primary polype, or probably the tubes of the first series, the
basement or ground-floor. When these tubes had arrived at a certain
height, all simultaneously began to develope the fleshy membrane
horizontally, which expanded until that from each touched that from its
neighbour, with which it united. Meanwhile the calcareous deposition
went on in this horizontal layer, and thus the first floor was made.
Now from the living vascular upper surface of this layer sprang up at
certain spots buds,[62] offshoots of the common flesh, which soon rose
into columns, and, by a process of calcareous deposition, became tubes
with terminal polypes, which in turn spread out a horizontal layer, and
thus the second floor was built. Hence a new race of polypes budded,
which by and by formed the third floor; and so on in succession, until
the series had attained the height which we see.
If we assume one of these stories to be the growth of a year,[63] we
have ocular evidence in this specimen of six years' age, for here are
six successive floors. But no: for it was created complete, as we see
it, this very hour.
Yonder goes a _Medusa_, pumping its way laboriously, yet not
ineffectively, just beneath the surface of the clear wave. It is a
great affair, nearly a foot in diameter. Have we, from merely examining
its appearance and structure, any criterion by which we can guess
whether it has lived an hour, or a year, or ten years? Surely we have;
for this mass of clear jelly is composed, like all other organic bodies,
of cells, which have been gradually generated, by nutrition and
assimilation, from the embryo.[64] This process must have occupied many
months, if not several years; but the history of this Medusa did not
begin when it took its present umbrella-like form. Shall we trace it
back a little farther?
At some time back, then, this creature detached itself as the terminal
one of many little saucer-like bodies, which had been for some time
previously forming by the gradual constriction of a thick fleshy stem.
Before the constriction began to be visible, this stem was the body of a
white Hydraform polype, affixed by its base, and furnished at its free
extremity with thirty-two tentacles. It had lived several years in this
form, developing many Hydroid polypes, just like itself, by successive
gemmations. Before it took this shape, which it assumed gradually, its
tentacles being developed in geometrical progression, 32 from 16, from
8, from 4,--it was a soft ovoid planule clothed with vibratile cilia,
which swam freely in the sea, like an _Infusorium_.
Thus the physiologist would confidently assign to this Medusa an
existence of several years, as an independent organism; _nor could his
conclusions be controverted_, except by the knowledge of the fact that
the Medusa _has been but just now created_.
We pass on. Here is an _Echinus_. Let it be borne in mind still, that we
have, _in idea_, the power of pursuing our researches on each creature
at the moment which follows that of its creation; and that, when that
actually was is of no consequence to our investigation.
Here then is this new-made _Echinus sphaera_, a somewhat conical globe of
three inches diameter, which is covered with a forest of spines,
pedicellariae, and suckers, and which glides majestically along, with an
even but slow progress, over rock and reef. Its vitals are enclosed in a
hollow box of calcareous shell, which is built up of nearly a thousand
pieces. This specimen, which is rather below than above the average
size, is formed of ten meridional rows of large plates (the
interambulacral), and ten of small (the ambulacral). The former series
are each composed of thirty-two plates, making in all three hundred and
twenty; the latter have just double that number, making six hundred and
forty; thus this Urchin's box is built up of nine hundred and sixty
plates; every one of which is of definite shape and angle, and fits into
the angles of its fellows with the accuracy of the most skilfully
constructed cabinet-work.
Now every one of these plates is an eloquent witness to the past
life-history of the Sea-urchin. For the reason why the enclosing box is
made of so many pieces is, that it might gradually expand and enlarge
its capacity with the ever increasing requirements of the soft organs
within. Every plate is enveloped by a vascular flesh, from which the
calcareous particles are deposited in a constant and perfectly uniform
ratio; and thus all the constituent plates are continually enlarged by
additions to both the internal and external surfaces (increasing their
strength), and to their sutural margins (increasing their combined
capacity), until the adult dimensions are attained.
The size of the new-born Echinus is not nearly equal to that of one of
these plates, and the progressive increase of the plates by deposition
on their edges has certainly taken several years to accomplish.[65]
The same result is inferrible from the structure of the spines with
which every plate is armed. Each of these is a very long cone of
calcareous matter, arranged in minute oval chambers, divided by thin
glassy walls, and deposited particle by particle from the thin stratum
of living flesh with which each has been invested from its first
embryonic development.
But of this _Echinus_, as of the _Medusa_ before, we find a history
anterior to either box or spines. Its first appearance in this stage of
existence was as a barely-visible circular disk, constructed on the
outside of the stomach of a singular transparent organism, much like a
Medusa, but of a domular form with four or six legs, stiffened by
calcareous rods, and a crowning pinnacle. For some undefined time this
gelatinous dome had been gliding with a stately movement through the
open sea, before there was the least trace of the disk, which afterwards
grew to the _Echinus_. In its earliest condition the dome itself was a
soft, spherical, mulberry-like _Infusorium_, covered with vibratile
cilia; this altered its form to that of a three-sided pyramid, and this
to the vaulted dome.
Clearly, therefore, we have a right to infer a past history of the
Urchin, and that of not a few distinct stages. But no; the specimen has
commenced its history within an hour!
Yonder Feather-star (_Comatula_) notice; which, having just now started
into mature life at the almighty fiat of its Creator, goes careering
joyously through the sea, expanding and contracting its many-jointed and
feathery arms, as if it had been accustomed to the alternation for a
long life, and ever and anon settling itself by grasping the points of
rock with its dorsal claws. You would hardly think that those flexible
and slender arms were made of stone: yet they are; every joint of the
stems and of their pinnae is a vertebra of stone (precious stones, you
will say--topaz and ruby--from their brilliant hues), which has been
formed and deposited atom by atom, by the slow and gradual process of
secretion of calcareous matter; the lime having been primarily collected
from the sea-water which held it in solution. At least, such is the
physiological deduction.
[Illustration: COMATULA AND YOUNG.]
But there was a period in the _Comatula's_ history when it was not a
free-swimming star, but a lily-like flower of ten slender fringed
petals, seated at the summit of a long stalk, with a central columnar
axis of stone. Before that, the flower-head had a bud-like figure, and
the petals were minute and destitute of lateral fringes; and earlier
still, it was a tiny gelatinous club without any development of stone,
affixed by a spreading base, and shooting forth from the top a few
pellucid processes. Earlier still, it was, no doubt, an infusory-like
gemmule, clothed with cilia.
Through all these successive stages, which, of course, occupied a
considerable period of time, we should certainly affirm the Feather-star
to have passed, did we not know that it has this very hour burst into
existence.
That Panther, whose tawny fur studded with black rosettes appeared so
beautiful as he bounded with agile grace from glade to glade just as we
emerged from the forest, contains within his intestines, though you
cannot see it, a mature Tapeworm. The body of this parasite consists of
some hundreds of square flattened segments, each of which includes a
complicated generative apparatus, equal to the production of thousands
of fertile ova. Is not this an evidence of age? For, first of all,
consider that the formation of each of these hundreds of joints has been
a work of development from the anterior parts; and therefore they record
as many distinct and successive processes as there are segments. And,
secondly, remember that the _Taenia_ did not commence existence as a
_Taenia_, nor in the conditions in which it now exists, within the bowels
of the Panther. It looks back to another form, and to another living
_nidus_.
There was a time when this parasitic creature had no ribbon-like body of
flattened generative segments. There was, indeed, the same curious head,
a tiny globose knob at the extremity of a slender neck, furnished with
the same array as now, of rows of hooks and sucking disks. But in place
of the segments, the neck merged into a membranous bladder distended
with clear fluid. It was not a _Taenia_ then, but a _Cysticercus_.
Its home was at that time the interior of a living animal on whose
vitalized juices it was sustained, but that animal was widely different
from its present patron. It was an Antelope, that cropped the wiry grass
and aromatic shrubs of the arid plain.