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.