Imatges de pàgina
PDF
EPUB

Hamilton Smith relates that he once witnessed the destruction of a soldier by one of these immense rays, off the island of Trinidad. It appears that the soldier wished to desert, and, being a good swimmer, he had jumped into the sea from the vessel, which then lay at anchor near the entrance of the harbor. The circumstance occurHorned Ray, Sea Devil, or Ocean Vampire, Cephaloptera vampirus. red soon after daylight, and the man, being alarmed by the call of a sailor up aloft, endeavored to return to the ship; but the monster fish threw one of his fins over him, and he was never seen more.

6. In the Natural History of the State of New York we find it stated that this fish has been known "to seize the cable of a small vessel at anchor, and draw the vessel several miles with great velocity." The writer, Mr. De Kay, says: "An instance of this kind was related to me by a credible witness, as having occurred in the harbor of Charleston. A schooner lying at anchor was suddenly seen moving across the harbor with great rapidity, impelled by some unknown and mysterious power. Upon approaching the opposite shore, its course was changed so suddenly as nearly to capsize the vessel, when it again crossed the harbor with its former velocity, and the same scene was repeated when it reached the shore. These mysterious flights across the harbor were repeated several times, in the presence of hundreds of spectators." If this be a true fish story, even the Atlantic cable may have been torn from its moorings by some of these monsters of the deep.

7. Among the rays are a group of fish which possess electrical properties, and which are known as electric rays, or torpedoes. Although the torpedo is less powerfully electrical than the gymnotus or eel, it can benumb the arm of a person touching it; and this power it seems to exert at will, both as a means of defense and for the purpose of securing its prey. The angel-fish, or shark-ray, of which we have given a drawing, is classed by some among the sharks. It is more remarkable for the singularity of its form than for its beauty.

8. There is still another family of fishes of the cartilaginous division called Lampreys, resembling the eels in form. We have given drawings of several species. The sea-lamprey is esteemed by many as a delicious article of food. The lampreys occupy the lowest place, not only among fishes, but

[graphic]
[graphic][subsumed][subsumed][subsumed][merged small][subsumed][subsumed][subsumed]

THE LAMPREY FAMILY.-1. Glutinous Hag, or Myxine, Gastrobranchus cœcus. 2. The Pride, or Mud Lamprey, Ammocætes branchialis. 3. Common Lamprey, Pteromyzon marinus. 4. The Lancelot, Amphioxus lanceolatus.

among all vertebrated animals, showing the gradual approaches which one class of animals makes to another. Thus one species, the glutinous hag, is destitute of eyes. The lancelot, which has been classed among the lampreys, is the lowest link yet discovered in the scale of vertebrated life, as the skeleton is only a series of sacs, and there is a total want of brain, eye, and ear.

Here we close our description of the four great classes of vertebrate animals-mammalia, birds, reptiles, and fishes. In the sixth volume of this series we enter upon another great division of zoology-the Insect World-in which we shall find renewed evidence of that wisdom which has peopled every part of our globe with life adapted to the conditions for which it is destined. When we shall have arrived at those lowest links in the scale of animal life which connect the animal and vegetable kingdoms, we shall look with renewed interest upon the great whole of animated nature; and as we trace upward, from the dividing line, a gradual elevation, until we arrive at the most intelligent of the brute animals, and there find the chain suddenly broken, we shall more fully realize the beauty of the Christian idea, that man belongs to an entirely different and immeasurably higher order of being, although perhaps the lowest in a series that rises upward-upward-through angelic hosts, until it takes hold of the throne of the ETERNAL.

LES. XIV.-THE AQUARIA, OR DRAWING-ROOM FISH-PONDS.

[graphic]

1. DECIDEDLY the prettiest drawing-room ornament that has been invented of late years is the Aquarium, or ornamental fish-pond. This is usually a glass vessel, either circular or oblong, with a slate bottom, wooden or zinc pillars, and glass sides, and containing various kinds of sea-weed, fish, and marine animals of the lower organizations, all in the full vigor of life.

2. It is hard to say whether the process by which the present aquaria were developed, or that development itself, is the

more wonderful. Probably every body has seen gold-fish in the old conventional1 glass tureen.2 Their life was a series of spirals, and it was a relief to beholders as well as to themselves when they expired at last. Dazzled by the glare of the sunlight through the sides of their glass dwelling, the poor creatures spent their whole existence in trying to find out where they were and how they could get out: no moth near a candle ever suffered more agonizing perplexity than they. To keep them in some appearance of health for a few weeks, it was necessary to change the water frequently: every time this was done the poor little creatures died a thousand deaths -endured such agony as we should feel if we were plunged to the bottom of a river, and held there till we were senseless, every morning before breakfast.

3. It was found a difficult matter to rear, in this way, the hardy gold-fish, while almost every other description of fish would have perished in the glass tureen within a week. And for this simple reason: like all living creatures, fish emit carbonic acid gas; this, in a confined body of water, would soon be in excess, the water would become poisonous, and the fish would die. The only alternative-that of changing the water daily would frequently be fatal to the tender creatures that were compelled to submit to our handling.

4. At length, however-and it was only a few years agothe principle was discovered that, in water as in air, the prime function of plants is to evolve oxygen and to consume carbonic acid gas; in other words, to use for food the noxious vapor emitted by animals, and to supply them, in its stead, with the first necessary of animal life-pure air.

5. Starting with this principle, about the year 1850, a Mr. Warrington, an Englishman, set about breeding fish and mollusks3 in tanks, with the aid of marine plants. He succeeded admirably for a few days; but, after a time, a change came o'er his little worlds. Without apparent reason the water became suddenly impure, and his fish died. Here was a new agency at work. With the aid of the microscope, Mr. Warrington explored his tank for the poison which was evidently latent there. He soon discovered that some of his plants had reached maturity, and, obedient to the law of nature, had died and decayed. The decaying matter was the poison he was in search of. How was this to be counteracted?

6. In Nature's tanks, reflected Mr. Warrington-in seas, rivers, and ponds-plants must die and decay, yet the decay does not destroy animal life. We must see how Nature obviates

the evil. The experimentalist hastened to a pond in the vicinity, and explored its bottom with care. He found, as he had anticipated, abundance of decayed vegetable matter; but he likewise found swarms of water-snails doing duty as scavengers, and devouring the putrefying substances before they had time to taint the water. Here was the secret-so beautiful a contrivance that it is said Mr. Warrington, with the emotion of a true man of science, burst into tears when it flashed upon him.

7. He dried his eyes, however, quickly enough, pocketed some snails, and threw a handful of them into his little tank at home. In a single day the water was pure and clear. Fish launched into it throve and gamboled, grew and multiplied; the plants resumed their bright colors, and the snails not only rollicked in an abundance of decaying branches from the plants, but laid a profusion of eggs, on which the fish and mollusks dined sumptuously every day.

8. Thus the aquarium-the drawing-room fish-pond-became a possibility. Mr. Warrington communicated his discoveries to the Royal Society of London; they were taken up by half the scientific men of England, and a series of experiments was begun, to test the relative capacity of the various known kinds of marine plants, fish, and marine creatures of the lowest orders, for living in the limited area of a housetank. Those experiments have been so thorough that books are now published containing the most minute directions for the establishment of aquaria; and it is said that almost every great drawing-room in England is provided with one or more of them.

9. The most common kind of aquarium is the oblong box or the circular vase, like the one represented in the engraving. If all the sides are of glass, that which is nearest the light should be shaded with a curtain, as neither fish nor plants thrive unless the sunlight reaches them from the surface of the water. Nature must always be copied. If you would have fish in your aquarium, a siphon should be used to change the water occasionally, and a syringe to aerates it daily, unless a gentle stream can be made to flow in and out constantly. Perfectly still water is too slow for well-bred fish, although it may do for reptiles.

10. Having provided yourself with the aquarium, strew the bottom with clean sand and fine pebbles to the depth of some three inches; then build your rock-work. As trees were created before the creatures which bask in their shade, so you

« AnteriorContinua »