Page images
PDF
EPUB

in order to take them, drive a number of wild horses into the pool, on which the eels first expend their electric power. Humboldt describes a scene of this kind, which we abridge: "The Indians told us they would 'fish with horses,' of which we found it difficult to form an idea; but we soon saw our guides return from the savannah, which they had been scouring for wild horses and mules. They brought about thirty with them, which they forced to enter the pool. The extraordinary noise caused by the horses' hoofs, makes the fish issue from the mud, in which they bury themselves, and excites them to combat; they swim on the surface of the water, and crowd under the bellies of the horses and mules. The Indians, provided with harpoons and long slender reeds, surround the pool closely, and prevent the horses from running away. The eels, stunned by the noise, defend themselves by the repeated discharge of their electric power, and during a long time they seem to prove victorious. Several horses sink beneath the violence of the invisible strokes which they receive from all sides, and stunned by the force and frequency of the shocks, disappear under the water. Others, panting, with mane erect, and haggard eyes expressing anguish, raise themselves, and endeavour to flee from the storm by which they are overtaken. In less than five minutes two horses were drowned. The horses are probably only stunned, not killed, but they are drowned from the impossibility of rising, amid the prolonged struggles between the other horses and the eels. At last the mules and horses appeared less frightened; their manes no longer bristled, and their eyes expressed less dread. The eels, which require a long rest and abundant nourishment to repair what they have lost of galvanic force, approach timidly the edge of the marsh, where they are taken by means of small harpoons, fastened to long cords." Humboldt afterwards states,-" If by chance you receive a stroke before the fish is wounded, or wearied by long pursuit, the pain and numbness are so violent, that it is impossible to describe the nature of the feeling they excite. I do not remember having ever received from the stroke of an electrical machine, a more dreadful shock than that which I experienced by imprudently placing both my feet on an eel just taken out of the water.

was affected the rest of the day with a violent pain in the knees, and in almost every joint."

XVIII.-Insects.

INSECTS are very small animals, having their heads furnished with antennæ or horns,-their bodies, which are without blood, bones, or cartilages, covered with a kind of bony substance instead of skin,—and a row of spiracles, or breathing holes, running along each side of the body. Their horns are jointed, and moveable in every part, being organs of sense to their owners. The antennæ must be carefully distinguished from the palpi or feelers, which are situated on each side of the mouth. They are generally in pairs, and some kinds have four, and others six. They, like the antennæ, are jointed and moveable, but are always short, and destitute of the crustaceous coating with which the antennæ are covered.

Insects are numerous beyond conception-the whole earth literally teeming with them. Indeed, there is not a plant, not a leaf, not a grain, but supports living creatures that even the microscope can scarcely make visible to our eyes. They far surpass the classes of animals already noticed, in the beauty of their colouring, in variety, and singularity of structure,-in the mode of constructing their abodes, and many other particulars; and small and insignificant as they may appear to the thoughtless, yet they form a very important part in the economy of nature. They supply a large portion of the food of many of the feathered tribes, and no inconsiderable portion of that of several species of fish; and if some of them seem a nuisance to man, others contribute largely to his comfort and support. We may mention as instances, the Bee, the Silk-worm, the Gall Fly, the Cochineal Insect, and the Spanish Fly.

All the winged and some of the wingless insects pass through three distinct states of existence. From the egg, and let it be remembered that most of the insect tribes are oviparous, comes forth the larva, which is called by the

different names of caterpillar, maggot, or grub. In this state the creature is a very soft substance, extremely voracious of its own peculiar food, and usually possesses a great many feet. Having attained its full size it passes into the pupa state. In some kinds of insects there is but little difference between the larva and pupa state; in others the difference is very great. The Butterfly affords a beautiful instance of the latter, and its pupa is called a chrysalis. From the chrysalis proceeds the perfectly formed insect, furnished with antennæ, which, having fluttered about in its gorgeous apparel for a few days, or weeks, lays its eggs, the seeds of a future progeny, and dies.

The Tree-Beetle, or Cock-Chaffer, which inhabits Britain and the northern parts of Europe, is the most mischievous of European insects. The grub is soft and grey, with testaceous head and legs, remains in the earth three years before it is transformed into the perfect insect, and devours the roots of corn and other vegetables, sometimes laying waste a large tract of country. The Beetle sticks to the tree whose leaves it feeds upon, and is eagerly sought after and devoured by swine, bats, crows, and poultry.

The Fire-Fly tribe contains many remarkable insects. We may mention the Glow-worm, which inhabits the woods and meadows of Britain. The female is larger than the male, and emits a beautiful phosphoric light for the purpose of attracting her mate. But though many of the English species are very elegant insects, they are far inferior both in size and splendour to the foreign ones, some of which are upwards of two inches in length.

The Great Lantern-Fly of Surinam, is one of the most curious of nature's productions. It is about three inches long, and upwards of five in expanse of wing: the ground colour is an elegant yellow, beautifully variegated with stripes and spots of different colours: and during the night it emits so strong a phosphoric light from its head or lantern, that a person may see to read by it, and travellers sometimes use it as a torch or lantern.

The Dragon-Fly is a beautiful insect, about three inches long, and rather more in expanse of wing. It is of all colours, blue, green, scarlet, and white, and in the sum

mer months it may frequently be scen hovering over stagnant waters or slow flowing streams, in which the larvæ also reside. They are two years in passing through the larva and pupa state, and when arrived at maturity are exceedingly rapacious, preying upon aquatic insects, which they seize very dexterously on the wing with a pair of jointed forceps wherewith the head is armed..

The Ephemera, or Day-Fly, is one of the most shortlived of animals, and is every where found about waters during summer. They seldom live above a day-some of the species not a single hour; yet in this, their brief life, they seem to enjoy all the happiness of which irrational creatures are capable,-perform all the functions of life, and die after propagating their species. The larva is sixfooted, active, furnished with a tail, resides in the water, possesses lateral processes or fins, and is greedily devoured by trout and other fish. The pupa resembles the larva, but has the rudiments of wings.

The Lion-Ant, which is considerably smaller than the Dragon-Fly, preys with the most savage ferocity upon ants and smaller insects. For the purpose of ensnaring them it sinks itself into the sand, and forms a kind of funnel or pit, in which it lies buried up to the head. Such insects as come near this trap are sure to tumble into it, and not being able to scramble up the sides of a projecting sand bank, are seized and devoured by the Lion-Ant. But if the sides of the pit should not give way, and the unlucky captive seems likely to escape, its merciless enemy instantly sends up from his broad flat head, which he uses as a shovel, such showers of sand as speedily cause it to tumble down, and then its doom is sealed.

XIX.-Insects continued.

Or the Bee there are nearly three hundred different kinds, thirty of which inhabit Great Britain. Most of the species are gregarious, living in considerable communities, but some of them are solitary. The Honey-Bee, which is a perfect model of industry, lives in large societies, composed of males or drones, females or queens, and neuters or working bees. The drone lives a life of indo

lence and gluttony, as neither his proboscis nor feet are formed for collecting honey or wax. The sole business of their life seems to be attending on the Queen; and the number is usually about a hundred. The Queen is easily distinguished by her great size and short wings. After having destroyed all the females in the larva or pupa state, the working bees take the queen under their particular protection, feed her, and attend upon her wherever she goes. In the brief period of about two months she lays between three and four thousand eggs. When the community have become too numerous to feel comfortable in their abode, the queen becomes agitated, and communicates her agitation to her faithful subjects. She then rushes out in quest of a new settlement, the working bees accompanying her in immense swarms, and wherever she alights they cling round her and guard her with the utmost care. The owner of the bees takes care to observe the spot where the swarm has settled, and loses no time in supplying them with a new habitation. This he places right over the cluster into which they have gathered, and they instantly take possession of it. This done, "they form themselves into companies, generally of four, one of which traverses the fields for materials, another is employed in laying out the bottoms and partitions of the cells, the third finishes the cells and smooths the insides, and the fourth either brings food for the rest, or relieves those who return with their burdens. The same bees, however, do not always continue in the same employ, but change occasionally. In one day's time they will construct cells enough for three thousand bees, allowing one cell for each bee. These cells are perfect hexagons, those in each honeycomb being double, opening on each side and closing at the bottom.

Meantime those that remain in their old abode, and did not migrate with the queen, are without a ruler. This deficiency the working bees speedily supply, by setting another queen at liberty from the pupa state, and all the operations of the community proceed as before. It sometimes happens that the young queen has made her appearance before the departure of the old one, and in this case that portion of the community that do not mean to emigrate keep their young sovereign in confinement, and

« PreviousContinue »