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versation about Polypes, particularly those that make Coral. I was quite astonished when Papa told me that these little creatures form islands, and block up harbours and seas.
MAMA. You were very much surprised at it, my dear, I dare say; and indeed it is exceedingly wonderful. One thing it may teach you, Anna, and that is, the importance of little things. The minute efforts of one of these Animalcules would be thought of no consequence, and would perhaps be scarcely perceived; yet see what they effect altogether.
ANNA.-Ah, Mama! I know what you are thinking of; but indeed I do mean for the future to pay more attention to what I call trifles.
MAMA. Well, my love, I hope you will-they are, I assure you, of far more importance than young people are generally willing to allow. It is the trifling and unobserved actions of each day that form habits; and habits, you know, form character.
HENRY. I fancy few of you young ladies were aware that you are indebted for your ornaments to such little creatures.
ANNA. No, indeed, Henry-I am sure I was not. Where is the Coral we wear brought from?
HENRY. I believe most that is used in Europe is fished up by divers on the shores of the Mediterranean. ANNA. I hope, Papa, you have not forgotten what you promised when you were here last.
PAPA. That I would give you some account of the Hydra, or fresh water Polype? O no; I have not forgotten it.
ANNA. You said you should surprise me very much, you know, Papa.
PAPA. And I still think I shall: what would you say of a creature that might be turned inside out like a glove, and would continue, notwithstanding, to live and act as before; and if cut into several pieces, would become so many distinct and perfect animals?
ANNA. Are you really serious, Papa?
PAPA. Yes, my dear-I assure you that this is the case with the Hydra, or fresh water Polype. It may be cut either length-ways or transversely into two, three, or more pieces, and each piece will quickly be furnished with a head and tail, and will perform all the functions of life; or it may be turned inside out, so that the lining of the stomach form the outer skin, and what was before the outer skin, the lining of the stomach; it will still eat, and live, and act as vigorously as ever.
HENRY. And I think you told me, Father, that if we slit a Polype length-ways through the head or tail to the middle of the body, we may form a monster with two heads or tails; and by slitting these again in like manner, we may form one with as many heads or tails as we please.
PAPA. Yes, that is the case. Indeed every part of these creatures is so strongly endowed with the principle of life, that a new animal will be produced, even from a small portion of the skin of an old one. Linnæus, you know, called them Hydra, on account of their remarkable power of reproduction. A still more surprising property of these animals is, that they may be grafted together. If the truncated portions of two Polypes be placed end to end, and gently pushed together, they will unite into a single one. Thus we may form Polypes, not only from portions of the same, but of different animals: we may fix the head of one to the body of another, and the compound animal will grow, and eat, and multiply, as if it had never been divided.
ANNA.-Well, Papa, this is certainly the most wonderful thing I ever heard: pray what sort of a creature is the Hydra, and where is it found?
PAPA. They are frequently to be found in ditches and ponds, adhering to pieces of wood, stones, leaves, or weeds, especially to the common duck-weed. I have often observed them when the sun has been shining powerfully, in a pond which is at the bottom of a pasture we
shall cross on our way home. Their appearance when at rest, is that of little transparent lumps of jelly, about the size of a pea, and flattened upon one side. These little crcatures consist, properly speaking, of merely a skin, or bag, with a large opening at one end, while the other end is firmly fixed to the substance to which they adhere. Around the large opening which may be termed the head, are a set of arms, or feelers, similar to those I mentioned in the Coral-Polype; when they are hungry, they spread these arms, or tentacula, as they are called, in a kind of circle to a considerable extent, enclosing within them, as in a net, every worm or insect that has the misfortune to come within the circumference. The moment any thing touches one of these arms, it is caught and swallowed.
MAMA.--The voracity of these creatures is astonishing. I believe every portion of a Polype is capable of destroying insects as soon as it is cut off.
PAPA.-Yes; and they will swallow them, even if they are two or three times as big as themselves. Most of the insects on which they feed bear the same proportion to their mouths that an apple, the size of a man's head, would bear to his mouth.
HENRY.-It is remarkable that their prey dies almost the moment that they catch it.
PAPA.-The Abbé Fontana, you know, supposes that they contain a very strong poison, which occasions instant death in insects the moment they are brought to the Polype's mouth.
ANNA.-Well, Papa, pray let us return by the pasture, and examine the pond you spoke of, to see if we can find any of these little monsters.
HENRY.-The quickness of feeling of these creatures very remarkable, Father; they contract themselves in a moment when they are touched. It seems to me to prove that they have nerves, though we cannot discover them; for if they had not, I cannot conceive how they could be so extremely sensitive.
PAPA.-True: nerves are the instruments of feeling, and without them it is difficult to imagine how the sense can exist. It is probable, I think, that polypes have them; but that they are so mixed up and confounded with the general substance of the body, that they are quite imperceptible to the anatomist.
MAMA. I believe there is no animal altogether destitute of the sense of feeling.
PAPA. No: every animal has that sense, how deficient soever it may be in all the others.
The contractile power of polypes is truly astonishing. When fully extended, they are often an inch or an inch and a half long; but they can shrink so that they would not measure more than one-tenth part of an inch. The green polype, which was the first discovered by Mr. Trembley, sometimes appears, at the approach of danger, scarcely bigger than a grain of sand.
ANNA. Can these polypes move at all, Papa?
PAPA. Yes, they can move slowly their motion is performed by their power of dilating and contracting their bodies. When about to move, they bend down their heads and arms, lay hold, by means of them, of some substance to which they design to fasten themselves, then loosen the tail and draw it towards the head, and so on till they have travelled as far as they wish.
HENRY.-I should like to see some of the congregated polypes.
PAPA. They are very curious compilations of animal existences. A number of polypes, Anna, each possessing distinct organs, are sometimes found growing on one parent stem, to the maintenance of which they all contribute. Every one appears to live for the community as much as for itself; for if any fail in procuring sustenance, the rest support it.
HENRY.-There are several varieties of fresh-water polypes, are there not?
PAPA.-I believe there are six.
The Actinia, Auna, or Sea-anemous, is another
zoophyte, that possesses the same power of re-production as the hydra.
HENRY. It is not of the same order, is it, Father?
PAPA.-No; it belongs to the Acalephæ. Scarcely any thing more is requisite to produce as many seaanemones as you please, than to cut a single one into as many pieces.
HENRY. And if any of the tentacula were destroyed, others would spring in their place.
ANNA. Why are they called anemones, Papa?
PAPA. From the resemblance of their tentacula, which are disposed in regular circles, and tinged with a variety of beautiful colours, to the petals of the anemone. Do not you remember our finding some on the rocks a few weeks ago?
ANNA. O yes! and I recollect your saying that they have been called "living barometers."
PAPA.-Very probably I did; for some have been of opinion that when they close the mouth, it indicates bad weather, and when they open it fine weather. It has even been said that they are more to be depended on than the most accurately-constructed barometer: but sensible as they may be to changes in the atmosphere, I am very much disposed to doubt whether they may be relied on as a criterion of the approaching state of the weather.
ANNA. I was astonished to see them eat: one of them swallowed two muscles in their shells, and the other a crab as large as a hen's egg.
PAPA. The crab was nearly as large as the anemone. You recollect that a day or two after, they returned from the mouth the shells of their prey, perfectly cleared of the meat.
ANNA. Yes; the muscle shells were quite whole, with the two shells joined together, but entirely empty.
PAPA.-The anemones, like the hydræ, are very voracious animals; but they can, nevertheless, bear long fasting. They may be preserved alive in a vessel of salt