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must undoubtedly be measured by their tendency to make men wiser, better, and happier; and in this view Geology must be content to rank after religion, morals, legislation, political economy, and indeed after many branches of physics, such as astronomy and chemistryIt may, however, be safely classed with botany and zoology-like them it has produced many incidental advantages, such as an improved system of mining, and a knowledge of the situations in which the several metals and their ores are likely to occur, by which many abortive and costly speculations have been prevented: so much it has already done-what the effect may be of its future progress, nobody can say. But beside the pleasure which Geology affords in the excitement and gratification of a laudable curiosity, it possesses a great advantage over many other scientific pursuits, in the effect which its investigations produce upon those who pursue it. Its labours are performed in the open air; it requires and encourages a habit of taking exercise, which is so necessary to persons of all ages, but so peculiarly indispensable to the young. Like Botany it gives zest to what has been formerly passed by, without awakening any pleasurable emotions: as the former enables us to take interest in every flower that adorns the fields, so does the latter induce us to notice every pebble, even the sand which we trample under foot. Under this point of view it may be reckoned peculiarly useful to the female sex."

N. B. Our Geological papers will in future be illustrated by plates-in the introductory Conversation none was required.

SERIES OF FAMILIAR CONVERSATIONS

ON THE ANIMAL KINGDOM.

CLASS IV. ZOOPHYTES.

ORDER 1. Echinodermata.... Star Fish, Sea Urchin

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ANNA: Look, Papa! what a large piece of sea-weed I have found!

PAPA. It is not sea-weed, my love.

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ANNA. Not sea-weed, Papa! What then?

PAPA. It is an animal substance, the residence of a species of Polype.

ANNA. But it looks just like a vegetable.

PAPA.-It resembles a vegetable very much in appearance certainly; and so do all the Corallines; but it is really the nest of the little animals that formed it. Do not you perceive that its surface is regularly disposed into a number of minute cells, scarcely big enough to admit the point of a pin? Each of these has had its inhabitant; and some of them, as you might perceive by the microscope, are still occupied. This flustra, as it is called, belongs to the class of Zoophytes; a class which forms a sort of intermediate link between the animal and vegetable creation. It has, as you observe, the form of a vegetable, but its properties are those of an animal; which we will prove, when we go home, by burning a piece of it: you will find that it smells like burnt bone. There are, I believe, more than thirty species of Corallines; most of them so much resembling vegetables, that it is

often very difficult to distinguish them in any other way than by burning them.

HENRY. I think the Sea-tamarisk and the Seacypress are among them, are they not?

PAPA. Yes, they are. Here is a Cockle-shell, Anna, which has been washed up by the tide with a piece of Sea-cypress adhering to it; you would not have supposed, I dare say, that this is not a vegetable.

ANNA. No indeed, Papa, I should not: it looks very much like some species of grass, or fennel, only it is not that colour.

PAPA. You see how delicately fine it is.

ANNA. Is not Sponge an animal substance too, Papa?

PAPA.-Yes; Sponge is classed among the Polypi; but, I believe, naturalists have not quite decided whether it is an animal or the residence of animals. Mr. Ellis, who took a great deal of pains to discover its nature, concluded, from its inspiring and expiring the water, that it is itself an animal. If it is, however, it has not the power of locomotion; for it is generally found firmly fixed to the rocks at the depth of several fathoms below the surface of the water. There are at least, fifty different kinds of Sponge, ten of which belong to our own coasts.

HENRY.-The sponge we generally use comes, I believe, from Greece.

PAPA.-Yes; Sponge is an article of commerce in the Mediterranean and in several of the islands of the Grecian Archipelago. The poor inhabitants dive to an immense depth to gather it. Of all the species of Polypi, the Coral-polype is the most wonderful in the effects it produces. Do you know, Anna, that these minute creatures are known to block up harbours and to form islands?

ANNA. Indeed, Papa! you surprise me.

PAPA. I assure you, my dear, it is true. There is a reef of coral rocks, extending from New Guinea to New

Holland, nearly nine hundred miles in length, which has been entirely made by them; they have also blocked up the harbour of Bantam with their productions, have destroyed the navigation of the Red Sea, and are believed to have formed all the tropical low islands in the Pacific ocean.

ANNA.-Do you mean to say, Papa, that the islands which Captain Cook visited were formed by these little animals?

PAPA.-Yes, my dear; it is believed that most, if not all of them were. That navigator, in his different voyages, observed the gradual increase of some of them; and no doubt, I believe, remains as to the manner of their formation. These little creatures build up a rocky structure from the bottom of the sea till it nearly reaches the surface; it then becomes a receptacle for various substances floating on the water: and by that means a soil is gradually formed, which supports vegetation, and finally becomes the abode of animal existences.

HENRY.-There is a very interesting account in Cuvier's "Theory of the Earth" of Coral islands, which I would advise you to read, Anna.

ANNA. I will; but I am curious to know what sort of a creature this wonderful little island-builder is.

PAPA. The Coral Polype, my dear, is a white, soft, and semitransparent animalcule, with eight tentacula or feelers, surrounding the orifice opening to the stomach. I might remark that this is a very general arrangement in the Zoophyte class: most of them have their organs of motion and sensation symmetrically disposed around a common centre.

HENRY. That is the reason they are also called radiated animals, I suppose?

PAPA. It is. I should add to my description of the Coral-polype, that it does not live in the stony part of the Coral, but in a gelatinous substance with which that structure is invested.

ANNA. Perhaps, Papa, the island of Great Britain

was formed by these little creatures: do you think it likely?

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PAPA. No, my dear. No Coral rocks have been found in the Atlantic ocean, excepting those in the West Indies. Great Britain, with most of the larger islands, was probably formed by the Deluge; and many of the smaller, perhaps, owe their origin to volcanic eruptions. HENRY.-The Madrepore, Anna, which lies in the study, is a substance of the same nature with Coral.

ANNA. I thought that was a stone: I understood Mamma that it is called Brain-stone.

PAPA. So it is, from its resemblance in figure to the brain; but it is really the work of minute Polypi. I should never have done were I to enumerate all the different kinds of lithophytes which the little animals of this genera have formed. They are the most unobserved and industrious little workmen in the universe.

ANNA. And yet I suppose they are the lowest species of animals.

PAPA. I do not know: the Infusoria, or Animalcules of infusions, are perhaps lower; but they are all so extremely minute as to be invisible to us without the assistance of a microscope of high magnifying powers; we can therefore determine little respecting them.

HENRY. It is astonishing what wonders the microscope has discovered. It has shewn us that

"Where the pool

Stands mantled o'er with green invisible
Amid the floating verdure millions stray;

and that

"Not the stream

Of purest crystal, nor the lucid air,

Though one transparent vacancy it seem,
Is void of unseen people."

ANNA. I have often been delighted with reading the "Wonders of the Microscope," which Mamma gave me. HENRY.-The Pennatula, or Sea-pen, of which there are several species in the ocean from the coast of Nor

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