OF OCEAN-WEEDS
“Have hung
My dank and dripping weeds.”--Trans. HORACE.
“The tide is full, the moon lies fair
Upon the Straits; on the French Coast the light
Gleams, and is gone; the Cliffs of England stand,
Glimmering and vast, out in the tranquil bay.”
MATTHEW ARNOLD.
Scattered through the vast Chalk-beds of Great Britain and the
Continent are thousands of layers of FLINT, such layers as any of us
may have seen intersecting the smooth white face of Chalk Cliffs. And
as with Chalk, so with Flint--we at once find ourselves upon the track
of Life.
Not indeed always of animal life. Sometimes vegetable life takes its
place. Though the highest Vegetables stand on a lower level than the
lowest Animals, they too have Life, and thereby they are entirely apart
from the whole world of inanimate Nature.
Widely distinct are the Animal Kingdom and the Vegetable Kingdom; yet
on the borderland between the two is found a hazy belt of uncertainty.
So gently does the one glide into the other that, though a line of
demarcation does exist, it is not always easily made out. But the
transition from the lowest form of that which _lives_ to any and every
form of that which has no Life is abrupt, absolute, precipitous.
Here we see no quiet sliding of the one into the other, no wavering
hesitancy as to whether a certain something may belong to this or that
side of the dividing parapet.
The term “Vegetables,” used scientifically about Land Vegetation,
includes all manner of growths, from the lichen to the forest tree.
But by that word, used in connection with the Ocean, is meant, _not_
cabbages and cauliflowers, _not_ garden-plants or forest-trees, but an
enormous variety of Sea-Weeds.
And among ocean-vegetables of humblest form, flourishing in salt water,
is that of Diatoms--Flint-makers.
It need not be imagined that the manufacture of Flint is a monopoly of
the Diatom tribe. That would be a mistake.
We have had to do in the last chapter with small carbonate-of-lime
building jelly-specks. We shall have to do in the next chapter with
carbonate-of-lime building jelly-polyps. But there are also little
vegetable-growths in the sea which form carbonate-of-lime, and some of
these add their quota to the work of rearing Coral-reefs.
We have to do in the present chapter with small flint-building
vegetable-growths. But there are also little animal jelly-specks in the
sea which form flint.
So neither Carbonate-of-lime nor Flint can be spoken of as belonging
_only_ to Animal or _only_ to Vegetable Life. They must both be
described in general terms as the outcome of that which Lives.
Among other Flint-builders in the ocean are the Radiolarians; living
jelly-specks, and makers of the most exquisite shells, so tiny in size
that millions of them may be packed into one cubic inch. These belong
to the Animal Kingdom. They rank with the Foraminifera, differing from
them chiefly in the fact that their shells or skeletons are formed of
silica, not carbonate-of-lime.
But in this chapter we are concerned with the Vegetable Life of the
ocean, and we must therefore let the wonderful Radiolarians alone.
Properly the chapter on Vegetables ought to have come before any
chapter on Animals, since we have been climbing upward from inanimate
Nature, and since all vegetables rank below all animals. When on the
topic of Ocean-building, however, the subject of Chalk seemed to follow
naturally after that of Sandstone. And this little volume makes no
pretensions to stiff classification.
No surprise need be felt at vegetables being able to make or “secrete”
flint and chalk. This making is, as we have seen, an unconscious work.
The living jelly-speck secretes automatically, not with intention.
Such secreting is not confined to ocean vegetables. Trees and plants
on land manufacture a host of substances--sweet oil, cocoa-nut milk,
indiarubber, and countless others.[2] Forest trees in like manner grow
their own framework of hard wood, which may be said to take the place
with them of a skeleton.
[2] The spicules of silica may be seen on coarse grass, secreted by the
grass.
All this is a part of LIFE. Inanimate rocks and stones may lie for
centuries unchanged, except through friction with other rocks and
stones, or with running water. But where Life reigns, though it be of
the simplest kind, there growth and development must follow.
Life, from its very nature, cannot mean stagnation, or standing still.
It must always be assimilating. It must always be expanding. It must
always be doing. When these things cease, death has begun.
So much alike are the lower forms of life in the two classes, that
many an animal has been for a time mistakenly called a vegetable, and
many a vegetable has been for a while supposed to be an animal. The
foraminifera were once ranked as vegetables, and the diatoms were
ranked as animals.
In deep-sea regions, dark and cold, no vegetable life can possibly
exist, not even the almost ubiquitous diatoms. But their remains are
present in vast multitudes. As the tiny plant-life dies out, the little
hard vegetable-cases sink to the ocean-bed, there to mingle with
gathering muds and oozes--there, too, in the course of ages, to be
transformed into Flint.
Diatoms flourish on land as well as in the ocean; in cold climates
as well as in warm. On the whole they prefer the colder regions,
therein differing from the warmth-loving foraminifera. Sometimes
immense floating banks of these microscopic plants are found, reaching
through many miles. A net, lowered into such a bank and then drawn up,
is filled with a “brown-coloured slimy and felt-like mass,” made up
chiefly of uncountable myriads of diatoms.
Such masses are held together by a kind of sticky jelly, and if the
hand is passed through it a very slight roughness may be perceptible,
caused by the flinty diatom shells or cases.
Mere specks indeed they are, individually too minute to be seen by a
human eye, unaided. Yet how marvellous in their make!
A Diatom plant or vegetable or sea-weed, whichever we choose to call
it, is like a Foraminifer of the simplest possible structure. It
consists of a single cell, with an outside flinty coating or inclosure,
answering to the wood of a tree or the skeleton of an animal.
This flint casing, though infinitely small and delicate, is yet firm
enough to prevent the passage of water through it; and also it is
practically indestructible by ordinary forces. Diatom-cases, dropping
to the ocean-bed, may lie there for ages.
[Illustration: DIATOM CASES (ARACHNOIDISCUS JAPONICUS)
_Reproduced by permission of Messrs. R. and J. Beck, Ltd., and Messrs.
J. and A. Churchill, publishers of Carpenter’s “The Microscope”_
_Face page 154_
]
The living cell is inclosed in the said “case,” which is a kind of box,
consisting of two halves or “frustules,” neatly joined together by a
ring or girdle.
Diatoms increase in numbers, like many of the Foraminifera, by simply
dividing into two. When the living cell thus parts, each half takes as
its share one side of the box, and each then makes another side, or
“frustule,” to complete itself. For this operation, the tiny ring or
hoop doubles into a pair of hoops, one of which clings to each half of
the case.
Perhaps in all the world no greater marvels are to be seen than these
extraordinary minute vegetable-cases.
[Illustration: PART OF DIATOM CASE (PLEUROSIGMA ANGULATUM)
Magnified 4,900 diams.
_From a photo-micrograph by Dr. R. Zeiss_
_Reproduced by permission of Messrs. C. Zeiss and Co. and Messrs. J.
and A. Churchill, publishers of Carpenter’s “The Microscope”_
_Face page 156_
]
Minute! Yes. A mass of millions upon millions, held together, may be
perceived and felt. But let a light scattering of them be dropped upon
a slip of glass in broad daylight, and let a man of keen eyesight set
himself to examine them. He will see--nothing! Not even an appearance
of delicate dust. The diatoms are to him as if they did not exist.
Then let him put that fine scattering under a good microscope, changing
lens after lens, to higher powers. A world of beauty, of finish, of
originality, of unbounded variety in construction, will open out before
him.
Each little shell is exquisitely shaped, exquisitely put together,
exquisitely ornamented. Though thousands, nay, millions, of them might
be packed into a cubic inch, yet there has been no carelessness, no
scamping, in the work, no saying, “Nobody will see, so anything will
do.”
The different kinds of Diatoms are innumerable; and each kind, each
species, even each variety, has its own especial form, its own complex
design, followed out and faithfully reproduced in hundreds of millions
of individuals.
Pattern-markings, by which each variety is distinguished, formed of an
infinitude of delicate lines and dots, arranged in every imaginable
fashion, vary to an extent almost beyond conception. There are cases
round, triangular, lengthy, many-sided, chain-like--but to picture them
in words is hopeless. They have to be studied in their own wonderful
minuteness and delicacy, complexity, and loveliness, before they can be
known.
In all this again we surely find unmistakable evidence of a MIND,
hidden, out of sight, inventing and designing.
Not the mind of the vegetable-speck, which for a brief space is
sheltered in the ornate little flint-box, but of a Higher
Intelligence--whether that of the Creator Himself directly, or whether,
as may seem to some more probable, the mind of some intermediate
Worker, Divinely appointed to the task.
Why should not Angelic or other beings, in the Unseen World, be allowed
to exercise their powers in such wise, even as man upon Earth is
allowed to think, to plan, to discover, to devise, to invent, according
to his mental gifts?
Some such possibility may well suggest itself to a thoughtful
imagination, as the variety of developments in these tiny sea-shells
or cases becomes apparent. All the more, because the developments are
not found scattered, haphazard, in single specimens, but--as above
stated--are accurately followed out by the multitudes belonging to each
variety.
It seems that every individual of every separate kind has power to form
certain shapes, with certain markings, and no more. It is as if upon
each minute speck of vegetable life had been originally impressed its
own--not _individual_ character, but _class_ character. This character
unconsciously expresses itself in such and such a form of shell, just
as with men the individual character expresses itself in such and such
outlines of face. The same may be said of Foraminifera and Radiolarian
shells.
Some Diatoms have a singular power of movement; and from this sprang
early mistakes, through which they were wrongly classed as animals.
Many of them grow, like ordinary plants, fixed in one spot. But
many others are in continuous and regular motion. Careful study
has, however, made it clear that the movements of Diatoms are
purely mechanical, purely involuntary, like those of some sensitive
land-plants. It is probably due to the working of food, taken into the
little organism, and not obedient to any _Will_ on its part.
It may be that herein lies the great difference between a Diatom and
a Foraminifer. The one exists, but has no approach to consciousness;
or, at least, probably no approach to any power of choice. The other,
though of the very lowest and feeblest type of Animal-life, may yet
be supposed in its infinitesimal measure to have a _wish_, and to be
able to act upon that wish. But here we do not get beyond conjecture.
Where Life exists, it _may_ be that in all cases some dim form of
consciousness exists also, which _may_ involve some faint power of
choice.
Flint-making, like Chalk-making, is not only an old-world and long-past
operation, but a present one. Diatoms lived and died in ages gone by,
and their remains are found hardened into flint. Diatoms live and die
in these days; and their remains may yet, in centuries to come, be
transformed into the same substance.
From Diatoms one might range upward through an enormous variety of
Ocean-weeds, of all kinds and descriptions.
Though they are the “last and lowest of all the tribes of plants,” yet
it is a wide step from the undermost to the uppermost of even this
humble Vegetable Tribe.
At least five or six thousand species of Sea-weeds are known to
Naturalists. Each ocean, each lesser sea, has its own particular
vegetation, largely affected by the varying degrees of saltness, the
warmth or coldness of the water, and the faster or slower currents
which happen there to prevail.
Sea-weeds of all sizes are found, from the invisible diatoms to
enormous growths in Pacific waters, reaching to yards upon yards in
length, with solid trunk-like stems, and huge fronds like those of a
tropical palm.
Near Tierra del Fuego immense growths have been seen, with stems
between three and four hundred feet in length. Great sub-ocean forests
of kelp are there, and floating fucus-islands, with leaves or fronds
seven or eight feet from base to tip, covered with living animals, and
having air-vessels several inches long.
In the matter of colour no great variety exists. Sea-weeds are
generally either grass-green, olive-brown, or red. The green are
usually close to land, and they never grow beyond touch with direct
sunlight. The olive-brown are the more abundant; and the red belong,
perhaps, more often to deep water.
A large majority grow attached either to stones or to the shallow
sea-bottom, but some kinds float unattached. To this last class belong
the masses of weed in the Sargasso Sea--the centre of the North
Atlantic currents.
Round that huge collection of weeds and drift, which reaches over
something like two hundred and sixty thousand square miles, the
entire North Atlantic slowly revolves. And of these weeds--called
“Sargassum”--none are attached to rock or ground, but all float
loosely in mid-ocean. They seem to flourish thus, though the fact that
fructification is not found upon them points to a somewhat unusual
condition of things.
Sea-weeds more often multiply by means of spores, which is a form of
vegetable-growth inferior to that of seeds. All spore-growing plants,
whether on land or in the sea, take a lower rank than seed-growing
plants.
A still lower and humbler method has been earlier described--that of
simply dividing into half.
There is yet another way by which ocean-weeds increase, and it reminds
one curiously of the gardener’s plan of growth by cuttings.
In rough weather, on shallow reaches not far from land, the waves tear
quantities of sea-weed fronds from their moorings, and carry them to
shore or to rocky parts, where they become entangled, and are held fast.
There, if later waves do not again dislodge them, and if other
circumstances are favourable, the wandering fronds settle down, attach
themselves, and become fresh plants. So in this case the waves act as
gardeners, and make cuttings of ocean-plants.
While plant-life in the ocean is plentiful in amount and abundant in
variety, it is confined within limits. By far the greater part of
Sea-weed existence is contained in the Hundred-fathom limit--that is,
within six hundred feet of the surface. Not many kinds, indeed, can
grow in anything like as much depth as five or six hundred feet.
Sea-weeds in abundance are found on shallow shores, near continents and
islands; on the zone between high and low tides; and on gently-shelving
slopes beyond that zone. Floating unattached sea-weeds, of the type
which belongs to the Sargasso Sea, may be anywhere, over the deepest
depths of the ocean. These, however, are not found living and growing
very far beneath the surface: and Ocean’s depths are without any kind
of vegetable-life, except probably bacteria.