« ElőzőTovább »
animals, it feels an evident pleasure in musical sounds, and, therefore, when fatigue comes upon it, the driver sings some cheering snatch of his Arabian melodies, and the delighted creature toils forward with a brisker step till the hour of rest arrives, when it again kneels down to have the load removed for a little while.
The camel is often referred to in Scripture; and it constituted an important branch of patriarchal wealth. The patriarch Job had at first 3,000 camels, and after the days of his adversity had passed away, he had 6,000; and the Midianites and the Amalekites, against whom Gideon went forth to battle with his handful of warriors, had “ camels without number as the sand by the sea-side."
The Camel-Leopard or Giraffe is spotted like the leopard, and has a long neck like the camel. If height alone constituted precedency among quadrupeds, the giraffe would undoubtedly claim the first rank, measuring, when full grown, near seventeen feet from the hoofs of the fore-feet to the top of the head. Its fore legs are much longer than those behind, so that its back inclines like the roof of a house. Its head is surmounted by two protuberances resembling short horns, which, however, are found to be merely a prolongation of the bone of the skull, covered with a soft velvety skin, and surmounted at the top by strong bristly hairs. It is a ruminating animal with cloven hoofs, like those of the ox; it feeds on herbage, and especially on the leaves of trees, which its long neck enables it to reach at a great height. The skin is of a warm cream colour, and the spots, which are large, are of a yellow or reddish tinge, and of a square form. The giraffe is gentle and harmless, and is found chiefly to the south of the great desert of Africa. They are sometimes seen in small groups six or seven, and when discovered, run off with great swiftness.
Some insects never have wings, but creep about till they die. These are produced from eggs, and when once they break the shell,
further change of form, but continue to row larger till they perish. The spider and scorpion are instances of this kind. The insects which have wings, are of two sorts. Some, when produced from the egg, have their wings cased up in such a manner as not to appear; and it is not till the case has burst, and the wings have a power of expanding, that the animal arrives at full perfection. The grasshopper, the dragon-fly, and the locust, are examples of this sort. Others proceed from the egg in the form of a caterpillar, which eats food for a few days, then becomes sick and casts its skin; this is repeated two or three times; and having changed its slough for the last time, it assumes a new covering, called an aurelia or crysalis, in which it continues hidden till it issues forth a perfect moth or butterfly. The silk-worm, with the various tribes of moths and butterflies, are instances of this kind.
When winter has disrobed the trees of their foliage, nature seems to have lost her insects. Thousands that were swarming in the summer's sun then entirely disappear. They almost all perish during the autumn, leaving behind them the seeds of a future progeny, either in the form of an egg or of an aurelia. In this state they remain during the winter, torpid and apparently lifeless, yet preserving, during all the rigours and humidity of the climate, the latent principle of life, to be exerted at the approach of spring. The same power that pushes forth the budding leaf and the opening flower, impels the insect into animation; and nature seems to furnish at once the guest and the banquet. Of the almost endless variety of insects, we shall here describe only two, the one remarkable for its usefulness, the other for its destructiveness.
The Silk-worm is the most serviceable not only of all insects, but, perhaps, even of all animals ; since from the produce of its labours, and the manufacture attending it, a great portion of the human race are clothed, adorned, and supported. The cone which it spins is formed for covering it while it remains in its aurelia state ; and several of these, properly wound off, and united together, form those strong and beautiful threads which we call silk. The feeding these worms, the gathering, the winding, the twisting, and the weaving of their silk, is one of the principal manufactures of Europe.
The silk-worm, at the time it bursts the shell, is like the egg from which it is hatched, extremely small, scarcely larger than a mustard seed, and of a black colour, but in a few days it begins to turn whitish, or of an ash-coloured grey. The skin soon begins to grow too rigid, or the animal is stinted within it, when it ceases to eat for two days, and then with various writhings throws off the skin, and appears clothed anew; it then becomes larger and much whiter. After some days it again leaves off eating, and having slept for two days, casts off its skin a second time; after another interval it does the same a third time; and all these changes being accomplished in three or four weeks, it is now a large caterpillar with twelve feet. It then sets about spinning a silken case or cone, in which it buries itself, till it assumes its winged form. This cone or ball is spun from two bags that lie above the intestines, and are filled with a gummy fluid of a marigold colour. This is the substance of which the threads are made, one seeming to proceed from each bag, and uniting as they issue from the animal's body, The thread composing the cone is not rolled round, but lies
upon it in a very irregular manner, so that it winds off now from one side of the cone, and now from the other. The whole thread, if measured, will be found about three hundred yards long, and so very fine, that eight or ten of them are generally rolled off into one by the manufacturers. The cone, when completed, is in form and size like a pigeon's egg, and more pointed at one end than the other. In about a fortnight or three weeks, the insect bursts from its aurelia skin, a winged moth, that seems produced for no other purpose than to transmit a future brood. The male dies immediately after separation from his mate, and she only survives him till she has laid her eggs, which are not hatched
into worms till the ensuing spring. Few, however, of these animals are allowed to leave their cone, as their bursting through destroys the silk. The manufacturers, therefore, take care to kill the aurelia by exposing it to the sun before the moth comes to perfection. This done, they take off the floss, which is a rough cotton-like substance, that forms the outer covering of the cone; they then throw the cones into warm water, stirring them till the first thread offers them a clue for winding all off.
In China, Tonquin, and other hot countries, the worms remain at liberty on the mulberry trees where they are hatched. In Europe, where the animal is artificially propagated, they are supplied every morning with fresh mulberry leaves, or, failing these, with the leaves of lettuce.
The Locust, that scourge of every country which it visits, is one of those insects, which, when they come from the egg, have their wings confined by a sheath that covers the whole body, and it is not till after a space of twenty days or more, that the animal bursts the covering, and its wings expand. No animal in creation breeds so fast, if the climate be warm, and the soil in which the eggs are deposited be dry. Their great numbers, therefore, and their destructive habits, render them the terror of those countries in which they breed. They often fly in such numerous bodies as to darken the sun like a thick cloud; one flight has been known to occupy three or four hours in its passage over a certain spot. It is related, that at the end of last century, there was an army of locusts in South Africa, so great as to cover thickly a space of two thousand square miles. They perished at last in the sea, and the dead bodies that were thrown upon the coast, formed a bank three or four feet high, and nearly fifty English miles in length. They make a loud rustling noise with their wings, and a harsh sound, like that made by a saw, when nibbling the corn, or grass, or leaves, on which they feed.
The locust is of a brownish colour, sometimes varied with blue. It is about three inches in length; its hind legs are very long, and like those of the grasshopper; and of its four wings, the upper pair are long and narrow, of a brown colour, with small dusky spots ; the under pair more transparent, of a light brown tinctured with green.
These destructive insects seem chiefly to come from Africa. Europe has been at times visited by them. At different periods, they have overspread Poland and Russia ; and in the year 1748, some of them were seen in England, which excited the utmost alarm among the people. But northern climates are too cold for them. When they attack the countries of Europe, the havoc they make is terrible, because they not only eat up every thing that vegetates, but the crops which they consume cannot be renewed till the following year, so that scarcity, if not famine, must be the consequence; whereas, the rapid growth which takes place in warm countries, soon repairs the damage that has been sustained. One of the plagues that God sent on Pharaoh and his people, for refusing to let the children of Israel leave Egypt, was the dreadful plague of locusts, of which an account is given in the tenth chapter of the book of Exodus.
XVI.-ON THE PLANTS WHICH FORM THE LINK BETWEEN THE ANIMAL AND VEGETABLE KINGDOMS. What a near approach do some plants make to that superior order of creation immediately above them in the scale of existence! The Sensitive Plant, when slightly touched, evinces something like the timidity of our harmless animals. The Hedysarum gyrans, or moving plant of the east, exhibits an incessant and spontaneous movement of its leaves during the day, in warm and clear weather ; but in the night season, and in the absence of light and heat, its motions cease, and it remains in a state of quiescence. The Venus Fly-trap of America, like an animal of prey, seems to lie in wait to catch the unwary insect. The leaves of this plant are jointed, and furnished with two rows of prickles. Their surfaces are covered with a number of minute glands, which secrete a sweet liquor, and allure the approach of flies. When these parts are touched by the legs of a fly, the two lobes