The Western World Part 29

This curious monster, concealing itself among the reeds on the bank, lies in wait for its prey, darting forward its long neck, and seizing with its sharp beak any pa.s.sing fish, reptile, or water-fowl; or, should they not come near enough, it swims at a great rate after its prey.

PART THREE, CHAPTER FIFTEEN.

WONDERS OF INSECT LIFE.

TERMITES, OR WHITE ANTS.

The great ant-eater, dozing during the hot hours of the day within the shady coverts of the forest, sallies forth in the cool of the evening to search for its insect prey on the open Campos. The surface of the ground is there, in many districts, raised into conical hillocks, some five feet in height, and streaked by lines which differ in colour from the surrounding earth, and lead in all directions, over decayed timber and the roots of herbage, from one hillock to the other. These hillocks are the habitations of those curious small pale-coloured and soft-bodied insects called termites, or white ants. They differ very greatly from the true ants in their mode of growth, or metamorphosis, though similar to them in their habits.

The true ant, when emerging from the egg, is a footless grub, and remains in the pupa, or quiescent stage, inclosed in a membrane, till its limbs are developed. The termites at once possess the form they are to bear through life, except that the s.e.xual individuals, during the latter stages of their growth, gradually acquire eyes and wings. They belong, indeed, to two very dissimilar orders of insects. The ant-bear, however, never troubles himself about this matter; but, sc.r.a.ping away with his powerful claws, soon breaks open the citadel which the industrious insects have formed during days of unremitting toil.

The mounds of the termites differ in composition. Some, consisting of earth, are worked into a substance as hard as stone. The coloured lines on the ground mark the covered ways which lead from the places where the insects obtain their food, or the materials for their habitations. The mounds exhibit no openings for egress or ingress. They are often formed by several distinct species of termites, each of which keeps to its own portion of the mounds, and uses different materials. Within the fortress exist a vast number of chambers, with galleries connecting them, composed sometimes of particles of earth, and at others of vegetable matter, cemented by the saliva of the insects. As they live on dry food, and in regions where no water is found, it is supposed that they may possess the power of combining, by vital force, the oxygen and hydrogen of their vegetable food, and thus form water. This supposition, if correct, accounts for the large amount of liquid which they employ in the construction of their cells. The inhabitants of these structures consist of differently formed insects, employed in various distinct occupations. The most numerous are the labourers, who have to toil for the benefit of the community. They are s.e.xless and blind; yet, without the power of sight, they are ceaselessly employed in the construction of these curious mounds, or in taking care of the young, and in collecting and bringing in food for the support of the population. Then come the soldiers, who defend the fortress, or, as more frequently happens, sacrifice themselves for the protection of the rest. The two most important personages of the community are the king and queen, who are the parents of future colonies. These are always found in every perfect termitarium. There are also a large number of winged termites, male and female, who, at a certain period of the year-- generally at the commencement of the rainy season--issue forth from the hive into the world. Although a large number are destroyed, a few escape, and, pairing, become the parents of fresh colonies. The formation of a new citadel or colony takes place somewhat in the following manner:--On a mound becoming overstocked, a party of workers, guarded by a body of soldiers, issue forth, and commence a fresh edifice at a distance from the old one. Here they form a large cell in the centre, surrounded by numerous galleries leading to smaller cells. From thence they run their covered ways, in suitable directions, towards spots whence they can obtain their necessary supplies of food and building materials. This being accomplished, they go in search of a royal pair; whom, when they have found, under a leaf or clod of earth, they conduct into the interior cell, where they are installed in due state. The newly-married couple, who have by this time got rid of their wings, are considerably larger than the rest of the population, but are helpless individuals, having neither the power of working nor fighting.

The king soon dies; but his consort, instead of pining for his loss, sets herself to work for the benefit of posterity, by laying a countless number of eggs. As soon as these are deposited the workers carry them off, and place them in the cells, where they watch over them with the most vigilant care, supplying the larvae with food as soon as they are hatched; and when the nursery becomes full, carrying some off in their mouths to another cell. While some are thus employed, others increase the size of their abode by running fresh corridors round the edifice, and forming new cells; while other parties, protected by soldiers, are foraging far and wide for food for the ever-increasing population.

In process of time--always within twelve months--the numberless progeny of the queen become full-grown. Some become developed into labourers, with smooth, rounded heads, and mouths adapted for carrying loads and working up the materials for the construction of their abodes; others-- the fighting cla.s.s--have heads of large size, provided with pointed weapons of defence of various shapes, resembling, in different species, horns, pikes, rams; while others are furnished with powerful jaws, resembling either sabres, swords, or sickles. A third cla.s.s appear with eyes, and long, delicate wings--gay, happy creatures, far better formed, it would seem, to enjoy existence than their hard-working brethren.

These are the males and females of the community. When they are prepared to issue forth from their birth-place, the labourers busily set to work to clear a pa.s.sage to allow of their speedy egress. This takes place generally on a damp, close evening or cloudy morning. Countless numbers issue forth at intervals, till the whole progeny of males and females have emerged from their pupa state. They make a loud rustling noise as they fly through the air in all directions; but they are immediately set upon by numberless enemies,--goatsuckers, lizards, spiders, and ants,--who greedily eat them up. On reaching the ground they immediately divest themselves of their wings; and the few pairs which escape from their foes seek safety in some hollow beneath a leaf or lump of earth, where they await the arrival of the faithful labourers, who now come forth in search of them, and conduct them, as has before been said, to the newly-formed abode prepared for their reception. And thus the wonderful process goes forward year after year.

So utterly helpless are these males and females, that, were it not for the a.s.sistance of other individuals, the race would speedily become extinct. The warrior termites are utterly regardless of personal safety. When their castle is attacked, they appear in vast numbers at the breach, to cover the retreat of the labourers. As the long tongue of the ant-eater is projected among them, they throw themselves on it; and no sooner is one regiment swallowed up than another rushes out to take its place--thus, by the sacrifice of themselves, enabling the rest of the community to seek safety in flight.

SAUBA ANTS.

Of the numerous true ants which exist in all parts of Tropical America, the sauba is one of the most remarkable. In all parts of the country-- as well near the abodes of man as in the distant wilds--large mounds are seen, two feet in length, and often upwards of forty yards in circ.u.mference, and distinguished from the surrounding soil by the difference of colour. Yet these mounds are merely the domes or upper works of the vast subterranean galleries which run for enormous distances and to great depths below the surface. Unlike the termites, the armies go forth in open daylight in vast hordes, to obtain food or materials for the construction of their wonderful habitations.

Sometimes, many hundred yards away from these mounds, the whole ground seems covered with animated leaves, each of the size of a sixpence, moving at a steady pace over the ground. Each leaf is held vertically in the mandibles of an ant, which is conveying it for the purpose of thatching the domes which cover the entrance to its subterranean abode; the roof thus formed protecting the cells beneath, rilled with young, from the heavy rains. Going in the direction whence the army is seen coming, we may find a tree covered by innumerable mult.i.tudes employed in cutting off leaves. Here the labourers are protected by the warrior cla.s.s, who appear also to perform the duties of overlookers, and keep them to their tasks. Each ant, on gaining a leaf, commences with its scissor-like jaws to make a semicircular incision on the upper side. It then takes it into its jaws, and detaches it by a sharp jerk. Having done this, it descends to the ground, and joining its comrades, who have been similarly employed, they return with their loads to the colony.

Frequently, however, while an ant is up the tree, the piece of leaf falls to the ground, when it sets to work to cut off another; while fresh labourers appear, to carry away the pieces which have thus acc.u.mulated.

The sauba ants are greatly dreaded by the inhabitants, as they frequently attack their coffee and orange-trees, and utterly destroy them. Sometimes, indeed, plantations have to be abandoned in consequence of the inroads of these persevering insects.

The body of the sauba ant is of a pale reddish-brown colour, and of a solid consistency. The head is armed with a pair of sharp spines, while the thorax has three pairs of the same character.

There appear to be three orders of workers among them, greatly differing in size. One order has an enormously large head; the head of another is very highly polished; while that of a third is opaque--to enable it, apparently, to perform the duties of a subterranean labourer. The earth of which the domes of the sauba ants are composed is brought up from a considerable depth below. There are numerous entrances leading to the galleries, but, under ordinary circ.u.mstances, they are kept closed. The smaller galleries lead, at a depth of several feet, to a broad, elaborately-worked tunnel of four or five inches in diameter, which conducts downwards to the centre chamber; the abode of the royal pair, on whom devolves--as is the case with the termites--the duty of propagating the species. Here they are guarded much in the same way by the labourers, who deposit the eggs in the cells, and finally a.s.sist in the exit of the winged males and females--which fly forth to be destroyed in vast numbers, the few who remain becoming the parents of other families.

The female winged ants are of considerable size, measuring fully two and a quarter inches across the wings. The male is very much smaller.

The royal chamber is curiously constructed. As soon as the newly-wedded pair are conducted within, the workers, who are themselves much smaller, so diminish the size of the entrance that it is impossible for the king and queen to escape. Round it are numerous exits and entrances, through which the workers convey the eggs when laid. The queen, after the death of her consort, lives for two or three years, employed during the whole of the time in laying eggs, at the rate of fifty in a minute. This will give some idea of the rapid increase of the population.

The workers vary somewhat in size and appearance. While a large number are employed in bringing in leaves and granules of earth for thatching their domes, as well as various sorts of provision, others are engaged in tending the royal chamber--carrying the eggs to the cells, and watching over the young. There is another cla.s.s, whose heads are covered with hairs, and who appear to be employed entirely below ground, probably as excavators or tunnellers.

Like the Cyclops, they have in the centre of their forehead a single eye, very different in structure to the compound eyes on the sides of their head. The other workers do not possess this peculiar frontal eye, nor is it found in any other species of ant.

It is wonderful what extensive tunnels these ants will form. Near Rio de Janeiro a tunnel was discovered, excavated by the creatures under the River Parahiba, as broad as the Thames at London Bridge. Near Para they, on one occasion, pierced the embankment of a large reservoir to such an extent as to allow the escape of a vast body of water before the damage could be repaired. In the same neighbourhood an attempt was made to destroy their colonies, by blowing fumes of sulphur down the galleries by means of bellows. Mr Bates relates, that he saw smoke issuing from a vast number of outlets, one of which was seventy yards distant from the place where the bellows were used.

They wander to a great distance in search of plunder, and enter houses for the purpose of carrying off the farina or mandioca meal. The same naturalist relates that he was one night awoke by his servant telling him that rats were robbing the farina baskets. On listening, he was certain that the noise was unlike that made by rats. On going to the storeroom he there found a broad column of sauba ants, consisting of thousands of individuals, pa.s.sing to and fro between the door and his baskets of meal. Most of those pa.s.sing outwards were loaded each with a grain of farina, larger and many times heavier than the bodies of the carriers. The baskets, which were on a high table, were entirely covered with ants, many hundreds of whom were employed in snipping the dry leaves which served as a lining; and this had produced the rustling sound which had disturbed him. He and his servant in vain attempted to exterminate them by killing them with their wooden clogs. Fresh hosts came on to take the place of the slain. The next night they returned, when he attempted to get rid of them by laying trains of gunpowder along their line to blow them up. Not, however, till he had repeated this operation several times, did the survivors of the daring depredators retreat.

THE AMPHISBAENA.

A curious snake, with something the character of the English slow-worm, the amphisbaena--called by the natives Mai das Saubas, or the mother of the saubas--is frequently found in these mounds. The natives believe that the ants treat it with great affection, and will, if the snake is removed, leave the spot. It is probable, however, that the amphisbaena takes up its abode in the nest for the convenience of devouring the inhabitants, whenever unable to procure other food.

Some of the American ants are of great size. One species (the Dinoponera grandis) is an inch and a quarter in length, and proportionally stout. It is seen marching in single file through the forest; but though of considerable size, its sting is not severe, while there is nothing particularly interesting about its habits.

ECITONS.

There are, however, several species of foraging ants, called ecitons, which move in vast bodies through the forest in search of prey. They are carnivorous, and attack not only insects and grubs of all sorts, but even other ants,--a.s.saulting their citadels and carrying off the slaughtered inhabitants. The natives, when they meet them in the forest, hurry out of their way, to avoid their fierce attacks. Their communities appear to be composed, besides males and females, of two cla.s.ses of workers, one with head and jaws very much larger than the others.

One species of these foraging ants is known as the Eciton rapax, the larger workers among which are half an inch in length.

The two common species of ecitons are, Eciton hamata and Eciton drepanophora, which are very similar in their habits and appearance.

They are of the most pugnacious character, and a person incautiously getting in their midst finds himself furiously attacked. They climb up his legs, and, holding on by their pincer-like jaws, double in their tails, and sting with all their might. The natives, on seeing them, cry out, "Tauoca"--the name which they give to the ecitons--and scamper off to a distance. The only way of getting rid of them is to pluck them out one by one; but so securely do they fasten themselves to the skin, that their head and jaws are left sticking to it.

As they advance through the forest, the creatures on which they prey endeavour to get out of their way; but vast numbers of maggots, caterpillars, larvae, and ants of other species fall victims to their ferocity. They advance in a long column live or six deep, while thinner columns forage on either flank, till they arrive at a ma.s.s of rotten wood abounding in insect larvae, when they surround it, and do not again move forward till every particle of food has been carried off!

When they discover a wasp's nest, they attack the papery covering to get at the larvae pupae and newly-hatched wasps. In spite of the rage of the parents, who vainly keep flying about them, they carry off their spoil in fragments; the carriers having their loads apportioned to their size--the dwarfs taking the smaller pieces, and the stronger fellows the heavier portions. Sometimes two ants join in carrying one piece.

ROBBER ECITONS.

Another species (the Eciton legionis) has been known to attack other ants' nests for the sake of plunder. Mr Bates saw an army of them employed on the face of an inclined bank of earth. They were excavating mines to get at the nest of a larger species of ant of the genus Formica. Some were rus.h.i.+ng into the pa.s.sages, others were seen a.s.sisting their comrades to lift out the bodies of the formicae, while others were tearing them in pieces--their weight being too great for that of a single eciton. A number of carriers then seized each a fragment and carried it down the slope. When the naturalist dug into the earth with a small trowel, the eager freebooters rushed in as fast as he excavated, and carried off the ants, so rapidly tearing them in pieces that he had great difficulty in rescuing a few entire specimens.

The little ecitons seemed to be divided into parties, some excavating, others carrying away the grains of earth. When the shafts became rather deep, the mining parties had to climb up the sides each time they wished to cast out a pellet of earth; but their work was lightened by their comrades, who stationed themselves at the mouth of the shaft and relieved them of their burdens, carrying the particles to a sufficient distance from the edge of the hole to prevent them rolling in again.

All the work seemed thus to be performed by intelligent co-operation among the host of eager little creatures. Still, there was not a rigid division of labour; for some of them, whose proceedings he watched, acted at one time as carriers of pellets, and at another as miners, and all shortly afterwards a.s.sumed the office of conveyers of the spoil. In about two hours, all the nests of the formicae were rifled.

He frequently saw these little creatures engaged apparently in play, in the neighbourhood of their homes. Some were walking slowly about, others were brus.h.i.+ng their antennae with their fore-feet; but the drollest sight was to see them cleaning one another. Here and there an ant was seen stretching forth first one leg, then another, to be brushed or washed by one or more of its comrades; who performed the task by pa.s.sing the limb between the jaw and the tongue, finis.h.i.+ng by giving the antennae a friendly wipe.

There are two species of blind ecitons--which, however, go on foraging expeditions, and even attack the nests of other stinging species; but, avoiding the light, they move always under leaves and fallen branches: when the columns have to pa.s.s a cleared s.p.a.ce, the ants form covered ways with granules of earth, arched over and holding together mechanically.

BLIND ANTS.

Two other species--Eciton vastator, and Eciton erratica--both of which are blind, move entirely under covered ways in search of promising hunting-grounds. Their arcades are sometimes two hundred yards in length, the grains of earth being taken from the soil over which the column is pa.s.sing, and fitted together without cement. In this they are distinguished from the covered ways made by the termites, who use a glutinous saliva for cementing their edifices. These blind ecitons build up the side of their convex arcade, and in a wonderful manner contrive so to fit in the key-stones, without allowing the loose uncemented structure to fall to pieces. Whenever a breach is made in any of their covered ways, the workers remain behind to repair the damage, while the soldiers issue forth in a menacing manner, rearing their heads, and snapping their jaws with an expression of fiercest rage and defiance.

The above account will give some idea of the vast numbers and varieties of the termites and ants of this region, and of the wonderful way in which Providence has furnished them with the means of sustaining existence, and taking their part in the economy of nature. Science is deeply indebted to Mr Bates, for his persevering efforts and acute observation in making known the varieties and habits of these curious insects.

CENTIPEDS--c.o.c.kROACHES--FIRE-ANTS.

Although the rest of the animal creation is small compared with the creatures of the Eastern world, insects and reptiles attain a size which will vie with those of any portion of the globe. Here we have a centiped nearly a foot in length, with innumerable legs, and two horns or feelers, which it protrudes with the most venomous expression. These animals are not only hideous to look on, but their bite is _very_ painful, though not dangerous.

c.o.c.kroaches swarm everywhere; but the fire-ant is, for its size, probably the most terrible of created beings. Its bite produces the most acute pain; and where they swarm, on the dry sandy sh.o.r.es of the streams, they frequently compel the natives to desert their villages.

Mrs Aga.s.siz mentions having on one occasion hung some towels to dry on the cord of her hammock, and was about to remove them, when suddenly her hand and arm seemed plunged into fire. She dropped the towels as if they were hot coals, which for the moment they literally seemed to be.

She then saw that her arm was covered with little brown ants. A native brushed them off in all haste; and an army of them was found pa.s.sing over the hammock, and out of the window, near which it hung. He said they were on their way somewhere, and if left undisturbed would be gone in an hour or so.

INSECTS--FIRE-FLIES.

Of those diamonds of the night, the fire-flies and fire-beetles, there are numerous species. One of the most abundant--and of much larger dimensions than the rest of the elaters or beetles--pyrophorus noctilucus, called by the natives cocuja, displays both red and green light. On the upper surface of the thorax there are two oval tubercles, hard and transparent, like bull's-eye lights let into a s.h.i.+p's deck.

These are windows out of which s.h.i.+ne a vivid green luminousness, which appears to fill the interior of the chest. Then on the under surface of the body, at the base of the abdomen, there is a transverse orifice in the sh.e.l.ly skin, covered with a delicate membrane, which glows with a strong ruddy light; visible, however, only when the wing-cases are expanded. It is about an inch and a half long, of a brown colour, and has a strong spine situated beneath the thorax, which fits at pleasure into a small cavity on the upper part of the abdomen. By means of this machine it can, when placed on its back, spring up a couple of inches, and regain its feet. When preparing to do this it moves its head and thorax backwards, so that the pectoral spine is drawn out and rests on the edge of the sheath. The same backward movement being continued, the spine, by the full action of the muscles, is bent like a spring, and the insect at this moment rests on the extremity of its head and wing cases.

The effort being suddenly relaxed, the head and thorax fly up, and in consequence the base of the wing-cases strike the supporting surface with such force that the insect by the reaction is jerked upward, while the projecting points of the thorax and the sheath of the spine serve to steady the whole body.

So brilliant is the light of these creatures, that even one moved over the print of a book wall enable a person to read by it, while eight or ten placed in a clear gla.s.s bottle serve the purpose of a lamp. The Brazilian ladies ornament their dresses with these fire-beetles, by securing them so as not to injure the creatures; while they frequently wear several in the braids of their dark hair, which, when they walk abroad in the evening, has a curious and beautiful effect. [Gosse and Darwin.]