Page images
PDF
EPUB
[graphic]

water. Their food principally consists of tadpoles. When first hatched they have only one eye, four oar-like legs, with whorls of hairs, the second pair being the largest: the body has then no tail, and the shell only covers the front half of the body: the other organs are gradually developed during succeeding moultings. These creatures are the common food of the Wagtails. We give the species Apus productus as an example.

AQUILA. [See EAGLE.]

ARACHNIDA. A class of Articulated animals, including Spiders, Mites, and Scorpions, all ranked by Linnæus under Insects; but though having a great analogy with them, and being equally fitted to live in the air, are distinguished from them by their number of limbs, their internal structure, and habits. All the Arachnida are destitute of antenna, and have the head united with the thorax: they have generally eight legs, though some species have six, and others ten; they have no wings; most of them breathe by means of air-sacs, instead of by prolonged trachea; and in the greater part there is a complete circulatory system. Most of the Arachnida are carnivorous, and are furnished with appropriate organs for their predatory life; but in general they confine themselves to sucking the juices of insects; and in order to enable them to capture and subdue animals otherwise capable of effectual resistance, Nature has furnished them with a poisonous apparatus. SPIDER.]

[graphic]
[graphic]

D

having the extremities of each armed with two small claws, which assist the insect in climbing. The body is of a brown chesnut colour, shining like glass, and covered with extremely fine hair. From this formation, it would appear, the Ant seems bolder and more active than any other creature of the insect tribe of the same size; and, indeed, it possesses sufficient intrepidity to attack an animal many times larger than itself.

The nests of Ants are differently constructed in the different species, but all are very curiously and regularly arranged. "If an Ant-hill," says Mr. Broderip," be examined any time after Midsummer up to the close of Autumn, there may be seen mixed with the wingless workers a number of both males and females furnished with white glistening wings. These, however, are neither kings nor queens in the state, at least so far as freedom of action is concerned, for they are not allowed to move without a guard of workers to prevent their leaving the boundaries; and if one straggles away unawares, it is for the most part dragged back by the vigilant sentinels, three or four of whom may, in such cases, be seen hauling along a single deserter by the wings and limbs. The workers, so far from ever facilitating the exit, much less the departure of the winged ones, more particularly the females, guard them most assiduously in order to prevent it, and are only forced to acquiesce in it when the winged ones become too numerous to be either guarded or fed. There seems, indeed, to be a uniform disposition in thewinged ones to desert their native colony; and as they never return after pairing, it would soon become depopulated in the absence of females. The actual pairing does not seem to take place within the ant-hill, and we have observed scouts posted all around ready to discover and carry back to the colony as many fertile females as they could meet with. It is probable that, soon after pairing, the males die, as do the males of bees and other insects; for, as the workers never bring any of them back, nor take any notice of them after leaving the ant-hill, they must perish, being entirely defenceless, and destitute both of a sting and of mandibles to provide for their subsistence. The subsequent proceedings of females are very different, and of curious interest. It was supposed by the ancients that all Ants, at a certain age, acquired wings; but it was reserved for the younger Huber, in particular, by means of his artificial formicaries, to trace the development of the wings in the female from the first commencement, till he saw them stript off and laid aside like cast clothes."

"Having directed my close attention to the eggs of ants," says Huber, "I remarked that they were of different sizes, shades, and forms. The smallest were white, opaque, and cylindrical; the largest transparent, and slightly arched at both ends; while those of a middle size were semi-transparent. On holding them up to the light, I observed a sort of white oblong cloud; in some, a transparent point might be remarked at the superior extremity; in others, a clear zone above and underneath the little cloud. There

were some whose whole body was so remarkably clear as to allow of my very distinctly observing the rings. On fixing attention more closely upon the latter, I observed the egg open, and the grub appear in its place. Having compared these eggs with those just laid, I constantly found the latter of a milky whiteness, completely opaque, and smaller by one half, so that I had no reason to doubt of the eggs of ants receiving a very considerable increase in size; that in elongating they become transparent, but do not at this time disclose the form of the grub, which is always arched." When the eggs are at length hatched, the young grubs are fed either by the neuters (called also nurse-ants and workers) when any of these are in the colony, and by the mother when she is alone, by a liquid disgorged from the stomach, as is done in a similar way by wasps, humble-bees, and certain birds.

"When the larvæ have attained their full growth they spin a silken covering, called by entomologists a cocoon : in this they completely enclose themselves, and remain perfeetly quiescent without receiving any nutriment, awaiting the final change when they are to assume the form of Ants. This stage of its existence is the pupa, but is commonly though very erroneously called the egg. Ants' eggs, as they are vulgarly called, are a favourite food for partridges and pheasants, and are eagerly sought after by persons who rear these birds from the egg. The cocoon containing the pupa is of a long cylindrical form, of a dirty white colour, and perfectly without motion. The pupa within the cocoon has now attained the form which it will finally possess; its limbs are distinct, but want strength and consistence, and are covered by a skin which has yet to be cast. In colour it changes from white to a pale yellow, then to red, and finally becomes almost black; its wings, if a male or female, are distinctly visible, but do not assume the shape, size, or character, they are hereafter destined to bear."- Newman's Hist. of Insects.

In England, ant-hills appear formed and arranged with very little regard to order or regularity; but in the more southern parts of Europe they are constructed with amazing ingenuity. They are generally formed in the vicinity of some large tree on the bank of a river; the former for the purpose of securing food, and the latter for supplying them with that abundant moisture which is requisite for the use of these insects. The ant-hill is of a conical shape, and is composed of leaves, bits of wood, sand, earth, stubble, gum, and grains of corn; all united into a compact body, perforated with galleries down to the bottom, and having a variety of tunnels or passages throughout the interior, the number of these avenues depending entirely on the population and extent of the nest. At its commencement the nest is simply an excavation made in the earth; a number of the labourers wander about in quest of materials suitable for the superstructure; others carry out particles of earth from the interior, and these particles, interspersed with the fragments of wood and leaves brought in continually from every

quarter, give a kind of stability to the edifice: it daily increases in size, the Ants taking care to leave the spaces required for the galleries which lead to the exterior; while the dome contains a number of spacious chambers or recesses, which communicate with each other by means of galleries constructed in a similar manner. Thus we see that although the exterior of the hillock always presents the appearance of a dome, and appears but a careless heap, it is in reality a most ingenious device for keeping out water, for evading the effects of the wind, and the attacks of enemies; and yet more especially for receiving and husbanding the heat of the sun. There are external apertures, to permit free egress to the multitude of labourers of which the commonwealth is composed; and from the commencement of the warm season they are constantly employed, till the unpropitious winter again suspends their exertions, and terminates their annual industry.

The working Ants are not only employed in sustaining the idlers at home, but in providing sufficient food for themselves. They subsist on various provisions, both animal and vegetable; killing and devouring all weaker insects, as well as in seeking ripe fruits and whatever appears to contain saccharine matter. When they are unable to eat the whole of the substance they have found, they devour what they can; and, tearing the rest in pieces, load themselves with the spoil. When they meet with an insect which they are singly incapable of mastering, several of them join in the attack; its destruction generally follows, each Ant assisting in carrying away a portion of the booty. When a single Ant chances to make a fortunate discovery, it immediately communicates the information to others, and the whole republic soon appear in motion. But while they are thus busied in feeding abroad, and carrying in provisions for the use of those which continue inactive at home, they are by no means unmindful of posterity. The female Ants soon begin to lay their eggs, which are immediately carried to the safest situation, at the bottom of the hill, where they are assiduously defended by the labourers, who always display the fondest attachment to the rising progeny, either attending to the safety of the larva, or in feeding the newly born insects. Who, indeed, has not seen them, when the gardener or some formidable enemy has demolished their whole habitation, affectionately solicitous of their offspring, and running wildly about, each loaded with a young one, not unfrequently as large as itself.

For some time the new born Ants remain under the careful superintendence of the labourers: they are attended in all their wanderings about the nest, and are made acquainted with all its galleries and chambers: the wings of the males and females, previously folded together, are extended, and this is always accomplished with such skill and tenderness, that these delicate members are never injured by the operation: in fine, these founders of future colonies are in all respects served with unremitting at

tention until their final departure from the nest.

In the autumn, says Mr. Newman, we frequently observe one of their hillocks closely covered with a living mass of winged Ants, which continue to promenade, as it were, over its entire surface: they mount on every plant in the vicinity of their nest, and the labourers (for now the entire population of the nest has turned out) accompany them as closely as possible, following them to the extreme tip of every blade of grass; and when at length those possessed of wings spread them in preparation for flight, the labourers will often hold them back, as if loath to trust them alone. . . . When the air is warm and still they rise in thousands, and sailing, or rather floating on the atmosphere, leave for ever the scene of their former existence. Each female, immediately on alighting from her aerial voyage, examines the situation in which chance has placed her, and if she find it adapted to her purpose, she turns her head back over her shoulders, and with her sharp mandibles tears off the wings which bore her from the place of her nativity. Strange as this propensity may seem, it is dictated by an unerring instinct, for the object for which wings were given her is now accomplished, and henceforth they would prove an incumbrance, and retard rather than assist, the performance of her duties. Sometimes a few workers, wandering at this period of excitement far from their home, may happen to meet with her, and if so, they unite their labours with hers in excavating a small and humble dwelling in the earth, which serves as the nucleus of a future colony in all operations the female, now a queen, takes a most energetic part, and continues to labour until she has laid eggs, when the conduct of the workers undergoes a great change, for they now treat her with the most marked respect, and consider her worthy the honours of a sovereign.

The ingenious author we before quoted gives a very curious account of what he terms the Slave Ants, which in substance is as follows: The most remarkable fact connected with the history of Ants, is the propensity possessed by certain species to kidnap the workers of other species, and compel them to labour for the benefit of the community, thus using them completely as slaves; and, as far as we yet know, the kidnappers are red or pale-coloured Ants, and the slaves, like the ill-treated natives of Africa, are of a jet black. The time for capturing slaves extends over a period of about ten weeks, and never commences until the male and female Ants are about emerging from the pupa state, and thus the ruthless marauders never interfere with the continuation of the species. This appears to be a special adaptation of their peculiar instinct; for if the attacks were made on the nests of the Negro Ants, before those by whom the race is propagated are ready to issue forth, it must speedily become extinct. When the Red Ants are about to sally forth on a marauding expedition, they send scouts to ascertain the exact position in which a colony of negroes may be found; these

« PreviousContinue »