VERMES--ZOOPHYTA. (_Worms and Zoophytes_).
_Worms._
The worm of worms, the one you know best, is the earthworm: so he shall
have the honor of representing his group.
He will not take much time to describe. He is, in brief, a tube, open
at both ends, so as to allow food to come in and go out. That is all.
I talked to you before about the ruminants, those food-manufacturers
who are employed in cooking victuals for the stomach, and in disengaging
albumen from the coarse materials among which it is apparently lost,
so as to give it out again in a more acceptable form. The ruminant has
other workmen under him, whom I keep in store for you as the last of
the eaters, and who prepare the raw material for him*. These are the
vegetables, who seek out the elements of albumen in earth, water, and
air, those final sources of all alimentation. The earthworm also is
a _preparer_, but in a peculiar way. Look along the garden-walks
in summer-time, after rainy weather: you will see here and there,
little heaps of earth moulded into small sticks, like dough which has
been passed through a tube. [Footnote: M. Mace's account of the
earthworm's life seems founded on the assumption that it extracts its
nourishment from the earth itself, i.e., from inorganic matter, as
_vegetables_ do, to use his own words. But this notion is so
entirely at variance with present received opinions, and also with the
fact that the animal possesses a gizzard for digesting, as well as an
intestinal canal, that it has been necessary to make considerable
alterations in the description. To dismiss his theory of the primitive
animal, etc., altogether, was, however, impossible, without omitting
the whole chapter; but as young heads are not likely to trouble
themselves about it, and it is very innocent in itself, it will do no
harm; subject to this warning, that M. Macé has taken the earthworm
for a more simply organised creature than it really is.--TR.] This is
the damp soil which the worm has passed through his tube, after
extracting from it, during its passage, the various elements of
fertility he requires for the support of his life. This is what makes
him so particularly fond of garden soil, because it is richer in animal
and vegetable matter than common earth, and proves therefore more
nourishing food. The worm, then, feeds on the fat of the earth, which
he converts into azotic aliment for the use of moles, hens and Chinese.
It only figures, it is true, for want of something better, in Chinese
cookery, so profusely hospitable for all that; but the hen doats upon
it, and you do not despise it yourself when it comes back to you in
the form of a chicken's wing, that second transformation of the matter
of which the soil of your garden is composed. It is told of certain
savage tribes, the victims of constant scarcity, that they swallow
little balls of clay in order to keep down their hunger; and during
the great famines in India the distracted inhabitants may, we are told,
be seen digging up the banks of the rivers to feed on the fertile clay
in which the splendid vegetation of their country is developed. This
is a desperate trial of that primeval system of alimentation which
answers perfectly with the worm, but becomes a cruel mockery in the
case of an organisation as exacting as that of man. Let us examine a
little more closely, then, this wonderful tube.
At first sight one notices, to begin with, that it is composed of
perfectly distinct rings, all quite alike. Inside as well as out each
of these rings is an exact repetition of the other. They are all formed
of circular muscles, enclosed between two coats, which extend from one
to the other. A series of ganglions, arranged in the form of a necklace
along the whole length of the body, set in motion the muscular system
of the rings, each of which possesses its local centre of impulsion.
Each feeds itself in its place from the nourishing juices with which
it is in contact, the interior coat enjoying the double property of
distilling digestive juices and absorbing digested ones. These juices
pass through the muscular partition, and proceed to bathe the outer
coat, which plays, at the same time, the part of coat and lung, and
affords a passage to the air through its soft, damp surface, like that
of gills. From all this results a fine red blood, such as we have not
met with since we left the reptiles, and which is manufactured in all
parts of the body at once.
Each of these rings, then, the worm's only organs, is a little eating
machine to and for itself, and at the same time a little movement
machine also; in fact, a complete animal. Each one could, if necessary,
nourish itself and live apart; and this is what he really does. Learn
hence, to despise nothing in nature. One tramples an earthworm under
foot, and there below one's heel lies a little revealer of secrets,
whose organisation throws the most unexpected light upon one of the
greatest mysteries in our own life.
I said to you before, and I felt at the time that it was rather beyond
you, that "each one of our organs is a distinct being, which has its
particular nature and special office, its separate life consequently;
and our individual life is the sum total of all these lesser lives,
independent one of the other, but which nevertheless blend together,
by a mysterious combination, into one common life, which is diffused
everywhere, but can be apprehended nowhere in particular."
The study of the worm admirably explains this out-of-the-way sentence.
And here observe my adjective--my out-of-the-way--for it is a case in
point. We may call it a literary worm; a worm of four rings, each
perfect in itself, but yet compounded together into a whole with its
own idea.
That which makes this idea of life most difficult to comprehend is,
that one cannot prove it by a direct experiment, since there is not
one of our organs which could exist separately from the others. Although
independent in their special action, yet these multiplied lives are
nevertheless in a state of absolute and mutual dependence, from the
imperative need they have of each other to make them act, each having
for its share only one particular function, the effect of which extends
to all the others. This is called the division of labor; and if you
still do not understand me clearly, I will explain it in another way.
The heart sends to all the organs--does it not?--the blood, without
which they could not live: separated from the heart, the lungs would
die immediately. It is to the lungs the blood goes to find the air,
without which it could not maintain life. Separated from the lungs,
the heart would die immediately. There is nothing belonging to us which
can avoid the inexorable requirements of blood and air;
consequently, there is nothing which can live an isolated life.
I will borrow a simile from human society which you will understand
at once. In civilised countries, where division of labor is established,
the tailor makes clothes, the mason makes houses, and the baker makes
bread. If you could throw them each alone by himself into a wood, the
mason would not be able to dress himself, the baker would sleep in the
open air, and the tailor would not know how to make bread. Or rather,
as not one of them can carry on his trade without the co-operation of
a multitude of hands, they could none of them do anything at all. Each
completely independent in his work, yet each dependent upon the others,
both for living, and even for being able to work, our workmen can only
act when they remain bound in close union with the vast society of
which they form a part; and our organs--those other laborers whom you
have seen working for so long--our organs are just in the same
predicament. But in the primitive societies, among savage tribes, where
each man can make his clothes, his house, his bread (when he has any),
and everything else for himself, you might take such an individual if
you liked, and separate him from the rest of the tribe, and he would
go on living as before. And so with the rings of the worm, that
primitive society of organs. Each of them is a universal workman, who
knows how to make everything. Separate him from his fellows, it will
not disturb him at all, and he will go on living as if nothing was
thematter.
I still remember some profound reflections I indulged in one day some
years ago whilst leaning on my spade and looking at a worm that I had
just cut in two, and whose two halves were walking off one on each
side.
"There was only one creature here just now," I said to myself, "and
now there are two! Have I had power, then, to create one with a stroke
of the spade?"
I had not then got hold of the key which I now give you, and to which
no possible objection can be raised. If there are two beings after the
stroke of the spade it is because there were two before. Nay, there
were even many more, if we may trust to the "Manual of Zoology" by
Milne Edwards, a very good book, excellent for an old scholar like
myself, and which I have found very useful in my country-home, as it
has enabled me to relate to you one after another the mysterious wonders
of life.
He says that, "if one cuts an earthworm across into two, three, ten,
or even twenty morsels, each of these morsels will go on living in the
same way as the whole, and will form a new individual."
Twenty! that seems to me a great many, because, as far as I can trust
to my brief observations as a gardener, it is necessary that some of
the rings should remain united together and afford each other mutual
support, in order to succeed in repairing the bleeding breaches; but
I would much rather believe it than try the operation. My mind is easy
when I am defending the plants that I have sown in my garden from the
gluttonous worm who would rob them of their food; but it would not be
so if I were cutting them up on my table to learn something about them.
Besides, there is no need of an operation to convince oneself of the
particular life of each ring. There is one worm, well known by name
at least, though happily not to be met with every day, and that is the
tape-worm, who establishes himself in the intestine of man, and lives
on the chyme, as the other worm does on garden-mould. They call him
the _Solitary_ worm in France; and if ever one might suppose a
creature appropriately named, it would surely be him; for certainly
there is not much society to be looked for in the dwelling he chooses
for himself! But it happens that this pretended _solitary_ worm,
with his unlimited chain of rings, is only a long row of perfectly
distinct beings, so distinct indeed that, from time to time, some of
the rings let themselves go, fall off like ripe fruit, and go away to
live elsewhere, ready to become the nucleus of a new set, if a happy
accident carries them into another intestine, the only place favorable
to their development.
At last, then, here is a corner of the curtain raised; here we see the
associated organs which constitute an animal, living for once a life
positively and in all respects their own. We are now satisfied about
this; and when at another time we find them bound together in the
chains of a union too ingenious to be severed with impunity--which we
shall discover by seeing their action stop at the moment of
separation--we shall know the cause.
Do not think, my dear child, that a wretched earthworm can prove nothing
as regards other creatures. The worm is the starting-point of all the
organisations which come after him. Of what is he composed? Of a
tubewhich is itself composed of rings. Well, it is upon this very tube
that the whole animal machine has been founded: and these rings, as
they expand and modify themselves in a thousand different ways, give
birth to all those varieties of being which drive classifiers to
despair, because they will not understand that there ought only to be
one animal, since there is only one Creator of animals. Now, this
animal is a digestive tube served by organs; it is a worm, _i.e.,_
which goes on constantly embellishing itself. I said to you long ago,
and at a time when you scarcely knew anything, "Have you ever observed
a worm or a leech in motion? You see a successive swelling up of the
whole surface of its body as the creature gradually pushes forward,
as if there was something in its inside rolling along from the tail
to the head. Such is precisely the appearance which the oesophagus
would present to you as the food passes down it, if you had the
opportunity of seeing it in action; and this has been called the
_vermicular_ movement, in consequence of its resemblance to the
movement of a worm."
And afterwards, in speaking of the intestine:
"If your body were made of glass, so that you could look through it
to watch the intestine at work, it would appear to you like an enormous
worm, coiled up into a bundle, heaving and moving with all its rings
at once."
You have now got hold of the secret, namely, that from the beginning
to the end of the digestive tube, its movements are those of a worm.
What a wonder! and that the worm is a digestive tube which can walk.
This worm, or this tube, whichever you please to call it, has never
ceased crawling under our eyes since we began this study. Lost sight
of in man in the midst of the riches he has picked up on his road,
invisible and coiled backward and forward in his palace like an Eastern
despot who leaves everything to be done by his slaves; behold him here
in his first stage naked, shivering in the air, forced to go off himself
and alone to his pasture--ground! But in the coarse earth with which
he fills himself I can already see the delicate chyme which his numerous
servants will prepare for him later on, and into which the heart-tree
will one day send down its roots--the chyliferous vessels.
A short time ago I called the oyster the primitive animal, but I was
in too great a hurry. The worm is the real primitive animal. He is to
be found in the oyster, as the oyster is to be found in us; and that
poor little beast is, by comparison, an animal of high pretension, who
would be shocked, I am sure, if he could understand what we are saying,
and heard us assert that he is nothing but an embellished worm.
_Zoophytes._
Two centuries ago it was believed that below the worm, animal life,
properly so called, ceased, and the creatures whom I am about to
introduce you to were supposed to be animated plants rather than living
organisms. Hence their name was especially chosen to express that
double nature by which they were thought to have a share in two kingdoms
at one time--viz., the animal and vegetable--_zoon_ in Greek
meaning animal, and _phuton_ a plant. Zoophytes were set down as
animal plants.
And although later discoveries have long ago established the fact of
the complete animality of zoophytes, the old name is still in general
use. But you must not let it deceive you. Zoophytes are animals every
inch of them, however low in the organic scale, and although many of
the compound ones imitate the growth of plants and shrubs so exactly
in their mode of spreading that it is only by the closest observation
we can persuade ourselves they do not belong to the vegetable kingdom.
Of these there are the delicate buff-colored, prettily-branched, horny
specimens found on the shore, which make so beautiful a variety in
seaweed pictures among the red and green colors of the real seaweed;
but of these also are those wonderful stony shrubs which grow on the
submerged rocks of islands in warm seas, and the material which you
know so well by the name of coral--the very coral of which the necklaces
and bracelets in the jeweller's window are composed.
In all cases of compound zoophytes, however, there is one great point
which they have in common with the worm, viz., that there is an
association of distinct lives acting unanimously; or, rather, to the
same end. Plainly as this is seen in the worm, it is still more obvious
in the zoophyte. There is no need here either of cutting them up
yourself or of taking other people's dissecting operations upon trust.
It is enough to use your eyes, with the help, it is true, now and then,
of the microscope's clearer sight.
You know the old oak-tree which stands on the outskirts of the wood,
and is called among the country folk _the patriarch_? Now, this
is clearly not an individual, but a nation. It is not a tree; it is
a forest. Nay, may I not call it a green field? For this trunk, so
truly venerable from ages of growth that one feels inclined to bow to
it as one goes by, is, in fact, a collection of structures, accumulated
by countless generations of fleeting herbs, _i.e.,_ leaves, not
one of which has lived for the space of a whole year round. Every
spring some thousands and thousands of buds open to the sun; each one,
therefore, affording a passage to a little green point; and this point
is an oak, who comes into the world, like the first oak, the grandfather
who formerly came forth from an acorn, under the form of an herb or
tender leaf, which a sheep might have browsed upon. Yet it is so
thoroughly an oak, that you have only to take out the bud carefully
before it has expanded and fasten it into another one's place upon a
tree of the same family, though of a different species, and it will
produce an oak of the same sort as its old companions, and which will,
as it progresses, look quite a stranger among the indigenous branches.
This is the secret of what the gardeners call _grafting_, and I
advise you to try the operation upon rose-trees, for nothing is more
amusing. When the autumnal frosts set in, all these troops of new
little oaks die, and deliver up their leaves to the wind; but they
leave behind, as their summer's work, a tiny morsel of new wood, upon
which, if you look carefully, you will see a fresh bud dawning--the
hope of the coming season. And thus the great life of the tree is
perpetuated from century to century by an uninterrupted succession of
transient lives, reminding one in all respects of the life of a nation;
and the similitude is complete in the evergreen trees, where the new
leaf makes its appearance before the old one has quitted the stem.
And such is the life of the great stone trees and shrubs of various
kinds which grow under tropical seas, and whose makers and inhabitants
are the coral polyps, the undoubted heads of the Zoophyte race.
But before considering the _polypidom,_ or external dwelling
(otherwise called the _coeneciun,_ or "common house"), you must
learn something of its originator, the little _polyp,_ who lives
inside, and belongs to a family so widely spread over the face of the
earth, that there are scarcely any waters, whether salt or fresh,
without them.
In your own neighborhood, if you know how to look for them, are to be
found on the banks of ponds, or along the borders of streams which lie
sleeping in roadside ditches, extraordinary beings which, a hundred
years and more ago, completely bewildered the good Dutch naturalist
Trembley, who had taken it into his head to study them. Picture to
yourself some very tiny bags made of a kind of jelly; gray, brown, or,
most commonly of all, green in color, always transparent, and fastened
by their base to the stalks of _carex,_ water-lentils, or the
confervas, which grow in still water. A hunter on the watch, this bag
shoots out on all sides a number of slender threads, like so many
whip-lashes, arranged within a circle round the edge of its opening
or mouth; and with these whip-lashes all the animalcules which come
within reach are entwined, stifled, and carried away to the ever-yawning
little gulf, where they are digested in less than no time. Whatever
will not digest comes out afterwards by the way it went in. Of what
becomes of the results of this digestion it is impossible to form an
idea. Were you to cut up the bag and put little morsels of it under
the best microscope possible, you would see positively nothing but
solid jelly, without the least sign of any organisation whatever. But
this is not all. Replace these morsels in the water, and come back
tolook at them at the end of five, twenty, or thirty hours. Each one of
them will have become a perfect bag, ready to multiply itself afresh
if you submit it to the same operation. Sometimes, on some part of the
original bag, there suddenly appears a little raised spot, like that
which came on your baby brother's arm the other day after he had been
vaccinated. What would you have said, if this ugly spot had grown
larger and larger without stopping; if it had assumed legs, arms, and
a head, and so become another baby, growing from the arm of the first
one? Yet this is just what the spots do which come on the bag I have
been telling you of; and people have come across bags of a larger
species still--between one and two inches in size, in fact--which in
this way carried twelve young ones on their backs, if one is allowed
to talk of stomachs having _backs_. You perceive at once that
this commencement of animal life is not even a digestive tube, and
that nothing in it can be found but a stomach, opening straight to the
air above and closed up below.
It was Réaumur, the originator of the famous thermometer, who gave a
name to the wonderful bags discovered by Trembley. Aristotle had
previously bestowed the title of _polypus_ (many feet) upon a
mollusk outwardly formed upon a similar model [Footnote: This is the
cuttle-fish, called _polypus_ by old naturalists. We shall speak
of it fully hereafter in the history of the movement machine.] with
large whips disposed regularly in a circle round the mouth, and intended
for a similar use, only that they have another function besides; that
of carrying the body along in the capacity of feet by clinging on to
the rocks with their suckers as they go. Réaumur transferred this name
to the newcomers, and called them fresh-water polyps, to the infinite
amusement of Voltaire, who had declared that they were only blades of
grass; a new proof, among many others, that in natural history all the
intellect in the world is not worth a pair of good eyes.
But it was soon found out that, in collecting these bits of living
jelly near the Hague, Trembley had laid his hands on little beings of
immense importance on the surface of the globe, and that he had
discovered under his microscope the explanation of a mystery which had
spread itself, setting human science at defiance, over some thousands
of square miles.
I talked to you just now of the jeweller's coral, of which ornaments
so becoming to dark-haired people are made. That is one of the stony
polypidoms I spoke of as stone trees found at the bottom of the sea,
where it grows attached to the rocks in the form of a charming little
shrub, stretching its red branches in all directions. The Greeks, who
were never at a loss, relate that Perseus one day laid down upon the
sea-shore the famous head of Medusa, the sight of which had the property
of turning everything to stone, and that the nymphs, in sport, showed
it to the coral shrubs; a fact which explained everything quite
naturally. Without exactly holding this mythological explanation,
modern philosophers had not got much farther, and coral was still a
puzzle to them, which they were not fond of troubling themselves about;
till, roused by Trembley's revelations, they examined it more carefully,
and discovered in its soft extremities (hitherto unnoticed) those same
living jelly-bags or sacs, with their circlets of legs, or rather arms,
charged with supplying them with food. These were marine polyps, which
grow, like those in fresh water, one upon another, but each in its own
crusty cell; and like the buds of the oak, these buds of the stony
tree form each its special deposit, which it bequeaths in dying to the
general mass. In short, as the tender shoot of the oak is filled by
degrees with the wood which forms within it, and hardens into a branch,
that goes on increasing by perpetually new growths, so the jelly polyp
of the polypidom hardens below into stone and dies incessantly at the
base, while it lives on indefinitely above in its constantly-renewed
summit.
Do not get tired of all this phantasmagoria, my dear pupil: it is a
matter of the highest interest. Here is the point of junction--the
bond, as it were, between the three kingdoms: an animal growing
vegetable-wise produces a mineral mass, extracted from the waters of
the sea by an infinity of little living crucibles, who carry on under
our eyes the work begun in the first ages of the globe, and quietly
manufacture continents for the use of future generations. This ought
to console you, my dear child, for being little. It is by little things
that God loves to effect what is truly great. He did not seek out the
elephant or the whale to form these worlds; He chose workmen no bigger
than a pin's head. I have spoken to you about jeweller's coral, which
is made into toys or presents for ladies to adorn themselves with; but
its brethren, the madrepores of the Pacific Ocean play a very different
part. They have formed in front of the shores of New Holland a barrier
of reefs three hundred leagues in extent and twenty wide. What are all
our buildings after this?--those pyramids and cathedrals which seem
so gigantic to us? This ever-increasing wave of coral polypidoms will
one day shut against navigators the entrance to one part of the sea's
tropical region; and lands not to be found on the map to-day will then
lie stretched out under the sun, covered with plants and animals; and
this in places where ships now plough the ocean. Know, also, that a
great portion of the soil which we tread under foot has no other origin.
It was manufactured formerly in the sea by infinite myriads of beings,
often infinitely small. Each one, whether polype or shell, produced
its grain of stone, and from all these grains God, who directed their
work, has made our country.
But it is time to bring this chattering to a close, for it will never
end if I do not force myself to stop. I leave it with regret; but all
these paths through which I have threaded my way one after another
without counting them, have already made a volume which may possibly
be considered too large for you. There are many other zoophytes besides
the coral polypes, and all of them beautiful and curious. They all
inhabit the fertile depths of the waters where God has deposited the
first germs of life. I cannot describe them to you now. But to make
amends, I will give you a piece of advice which will perhaps make some
people stare. Ask your papa to lend you Michelet's book, _The Sea_,
and look there for what is said about the mysterious animals which lie
hid beneath the waves. His book was not written for you as this one
is: and if, in spite of all my good intentions, I have not always
succeeded in being as comprehensible as I meant to be, Michelet, who
never thought about little people when he took up his pen, will
certainly startle you now and then. But do not be disheartened by a
word. You will find there, that which will be forever plain to you,
the poesy of nature, and children comprehend that better than learned
men.