Chapter XVI: Introduction (11)

The galleries and chambers which are roofed in as thus described are very similar to those of the mason-ants, being partly excavated in the earth, and partly built with the clay thence procured. It is in these they pass the night, and also the colder months of the winter, when they become torpid, or nearly so, and of course require not the winter granaries of corn with which the ancients fabulously furnished them.

Carpenter-Ants.

The ants that work in wood perform much more extensive operations than any of the other carpenter insects which we have mentioned. Their only tools, like those of bees and wasps, are their jaws or mandibles; but though these may not appear so curiously constructed as the ovipositor file of the tree-hopper (_Cicada_), or the rasp and saw of the saw-flies (_Tenthredinidæ_), they are no less efficient in the performance of what is required. Among the carpenter-ants, the emmet or jet-ant (_F. fuliginosa_) holds the first rank, and is easily known by being rather less in size than the wood-ant, and by its fine shining black colour. It is less common in Britain than some of the preceding, though its colonies may occasionally be met with in the trunks of decaying oak or willow trees in hedges.

"The labourers," says Huber, "of this species work always in the interior of trees, and are desirous of being screened from observation: thus every hope on our part is precluded of following them in their several occupations. I tried every expedient I could devise to surmount this difficulty; I endeavoured to accustom these ants to live and work under my inspection, but all my efforts were unsuccessful; they even abandoned the most considerable portion of their nest to seek some new asylum, and spurned the honey and sugar which I offered them for nourishment. I was now, by necessity, limited to the inspection only of their edifices: but, by decomposing some of the fragments with care, I hoped to acquire some knowledge of their organization.

"On one side I found horizontal galleries, hidden in great part by their walls, which follow the circular direction of the layers of the wood; and on another, parallel galleries, separated by extremely thin partitions, having no communication except by a few oval apertures. Such is the nature of these works, remarkable for their delicacy and lightness.

"In other fragments I found avenues which opened laterally, including portions of walls and transverse partitions, erected here and there within the galleries, so as to form separate chambers. When the work is further advanced, round holes are always observed, encased, as it were, between two pillars cut out in the same wall. These holes in course of time become square, and the pillars, originally arched at both ends, are worked into regular columns by the chisel of our sculptors. This, then, is the second specimen of their art. This portion of the edifice will probably remain in this state.

"But in another quarter are fragments differently wrought, in which these same partitions, pierced now in every part, and hewn skilfully, are transformed into colonnades, which sustain the upper stories, and leave a free communication throughout the whole extent. It can readily be perceived how parallel galleries, hollowed out upon the same plan, and the sides taken down, leaving only from space to space what is necessary to sustain their ceilings, may form an entire story; but as each has been pierced separately, the flooring cannot be very level: this, however, the ants turn to their advantage, since these furrows are better adapted to retain the larvæ that may be placed there.

"The stories constructed in the great roots offer greater irregularity than those in the very body of the tree, arising either from the hardness and interlacing of the fibres, which renders the labour more difficult, and obliges the labourers to depart from their accustomed manner, or from their not observing in the extremities of their edifice the same arrangement as in the centre: whatever it be, horizontal stories and numerous partitions are still found. If the work be less regular, it becomes more delicate; for the ants, profiting by the hardness and solidity of the materials, give to their building an extreme degree of lightness. I have seen fragments of from eight to ten inches in length, and of equal height, formed of wood as thin as paper, containing a number of apartments, and presenting a most singular appearance. At the entrance of these apartments, worked out with so much care, are very considerable openings; but in place of chambers and extensive galleries, the layers of the wood are hewn in arcades, allowing the ants a free passage in every direction. These may be regarded as the gates or vestibules conducting to the several lodges."[DD]

It is a singular circumstance in the structures of these ants, that all the wood which they carve is tinged of a black colour, as if it were smoked; and M. Huber was not a little solicitous to discover whence this arose. It certainly does not add to the beauty of their streets, which look as sombre as the most smoke-dyed walls in the older lanes of the metropolis. M. Huber could not satisfy himself whether it was caused by the exposure of the wood to the atmosphere, by some emanation from the ants, or by the thin layers of wood being acted upon or decomposed by the formic acid.[DE] But if any or all of these causes operated in blackening the wood, we should be ready to anticipate a similar effect in the case of other species of ants which inhabit trees; yet the black tint is only found in the excavations of the jet-ant.

We are acquainted with several colonies of the jet-ants (_Formica fuliginosa_)--one of which, in the roots and trunk of an oak on the road from Lewisham to Sydenham, near Brockley, in Kent, is so extremely populous, that the numbers of its inhabitants appeared to us beyond any reasonable estimate. None of the other colonies of this species which we have seen appear to contain many hundreds. On cutting into the root of the before-mentioned tree, we found the vertical excavations of much larger dimensions, both in width and depth, than those represented by Huber in the preceding cut (page 302). What surprised us the most was to see the tree growing vigorously and fresh, though its roots were chiseled in all directions by legions of workers, while every leaf, and every inch of the bark, was also crowded by parties of foragers. On one of the low branches we found a deserted nest of the white-throat (_Sylvia cinerea_, Temminck), in the cavity of which they were piled upon one another as close as the unhappy negroes in the hold of a slave-ship; but we could not discover what had attracted them hither. Another dense group, collected on one of the branches, led us to the discovery of a very singular oak gall, formed on the bark in the shape of a pointed cone, and crowded together. It is probable that the juice which they extracted from these galls was much to their taste. (J. R.)

Beside the jet-ant, several other species exercise the art of carpentry,--nay, what is more wonderful still, they have the ingenuity to knead up, with spider's-web for a cement, the chips which they chisel out into a material with which they construct entire chambers. The species which exercise this singular art are the Ethiopian (_Formica nigra_) and the yellow ant (_F. flava_).[DF]

We once observed the dusky ants (_F. fusca_) at Blackheath, in Kent, busily employed in carrying out chips from the interior of a decaying black poplar, at the root of which a colony was established; but, though it thence appears that this species can chisel wood if they choose, yet they usually burrow in the earth, and by preference, as we have remarked, at the root of a tree, the leaves of which supply them with food.

* * * * *

Among the foreign ants we may mention a small yellow ant of South America, described by Dampier, which seems, from his account, to construct a nest of green leaves. "Their sting," he says, "is like a spark of fire; and they are so thick among the boughs in some places, that one shall be covered with them before he is aware. These creatures have nests on great trees, placed on the body between the limbs: some of their nests are as big as a hogshead. This is their winter habitation; for in the wet season they all repair to these their cities, where they preserve their eggs. In the dry season, when they leave their nests, they swarm all over the woodlands, for they never trouble the savannahs. Great paths, three or four inches broad, made by them, may be seen in the woods. They go out light, but bring home heavy loads on their backs, all of the same substance, and equal in size. I never observed anything besides pieces of green leaves, so big that I could scarcely see the insect for his burthen; yet they would march stoutly, and so many were pressing forward that it was a very pretty sight, for the path looked perfectly green with them."

Ants observed in New South Wales, by the gentlemen in the expedition under Captain Cook, are still more interesting. "Some," we are told, "are as green as a leaf, and live upon trees, where they build their nests of various sizes, between that of a man's head and his fist. These nests are of a very curious structure: they are formed by bending down several of the leaves, each of which is as broad as a man's hand, and gluing the points of them together, so as to form a purse. The viscous matter used for this purpose is an animal juice which nature has enabled them to elaborate. Their method of first bending down the leaves we had no opportunity to observe; but we saw thousands uniting all their strength to hold them in this position, while other busy multitudes were employed within in applying this gluten that was to prevent their returning back. To satisfy ourselves that the leaves were bent and held down by the efforts of these diminutive artificers, we disturbed them in their work; and as soon as they were driven from their stations, the leaves on which they were employed sprang up with a force much greater than we could have thought them able to conquer by any combination of their strength. But, though we gratified our curiosity at their expense, the injury did not go unrevenged; for thousands immediately threw themselves upon us, and gave us intolerable pain with their stings, especially those which took possession of our necks and hair, from whence they were not easily driven. Their sting was scarcely less painful than that of a bee; but, except it was repeated, the pain did not last more than a minute.

"Another sort are quite black, and their operation and manner of life are not less extraordinary. Their habitations are the inside of the branches of a tree, which they contrive to excavate by working out the pith almost to the extremity of the slenderest twig, the tree at the same time flourishing as if it had no such inmate. When we first found the tree we gathered some of the branches, and were scarcely less astonished than we should have been to find that we had profaned a consecrated grove, where every tree, upon being wounded, gave signs of life; for we were instantly covered with legions of these animals, swarming from every broken bough, and inflicting their stings with incessant violence.

"A third kind we found nested in the root of a plant, which grows on the bark of trees in the manner of mistletoe, and which they had perforated for that use. This root is commonly as big as a large turnip, and sometimes much bigger. When we cut it we found it intersected by innumerable winding passages, all filled with these animals, by which, however, the vegetation of the plant did not appear to have suffered any injury. We never cut one of these roots that was not inhabited, though some were not bigger than a hazel-nut. The animals themselves are very small, not more than half as big as the common red ant in England. They had stings, but scarcely force enough to make them felt: they had, however, a power of tormenting us in an equal, if not in a greater degree; for the moment we handled the root, they swarmed from innumerable holes, and running about those parts of the body that were uncovered, produced a titillation more intolerable than pain, except it is increased to great violence."[DG]

The species called sugar-ants in the West Indies are particularly destructive to the sugar-cane, as well as to lime, lemon, and orange-trees, by excavating their nests at the roots, and so loosening the earth that they are frequently uprooted and blown down by the winds. If this does not happen, the roots are deprived of due nourishment, and the plants become sickly and die.[DH]

[One or two examples of foreign ants are well worthy of notice. The first of them is an insect whose habits bear strongly upon the familiar passage in Proverbs, ch. vi. v. 6:--

"Go to the ant, thou sluggard; consider her ways, and be wise:
Which having no guide, overseer, or ruler,
Provideth her meat in the summer, and gathereth her food in the harvest."

This passage is one that has been often mentioned as a proof that the Bible is not to be implicitly trusted. Judging from all the species of ants known to entomologists, some writers argue that the author of the proverb in question was ignorant of the real history of the ant, and was taking up a popular fallacy.

[Still, although the ants of the old world are chiefly carnivorous, or feed on soft substances, and in consequence have not the least idea of hoarding food for the winter, there is one species of Brazilian ant which absolutely builds houses, prepares ground, sows seed, reaps the grain, and stores it away for future consumption. It is the Agricultural Ant, _Atta malefaciens_, first described by Dr. Lincecum, who watched the insect for twelve years before publishing an account that he knew would at first be received with incredulity. The following abstract of his paper appeared in the Journal of the Linnæan Society.

"The species which I have named 'Agricultural' is a large brownish ant. It dwells in what may be termed paved cities, and like a thrifty, diligent, provident farmer, makes suitable and timely arrangements for the changing seasons. It is, in short, endowed with skill, ingenuity, and untiring patience, sufficient to enable it successfully to contend with the varying exigencies which it may have to encounter in the life conflict.

"When it has selected a situation for its habitation, if on ordinary dry ground, it bores a hole, around which it raises the surface three and sometimes six inches, forming a low circular mound, having a very gentle inclination from the centre to the outer border, which on an average is three or four feet from the entrance. But if the location is chosen on low, flat, wet land, liable to inundation, though the ground may be perfectly dry at the time the ant sets to work, it nevertheless elevates the mound, in the form of a pretty sharp cone, to the height of fifteen or twenty inches or more, and makes the entrance near the summit. Around the mound, in either case, the ant clears the ground of all obstructions, and levels and marks the surface to the distance of three or four feet from the gate of the city, giving the space the appearance of a handsome pavement, as it really is.

"Within this paved area not a blade of any green thing is allowed to grow, except a single species of grain-bearing grass. Having planted this crop in a circle around, and two or three feet from the centre of the mound, the insect tends and cultivates it with constant care, cutting away all other grasses and weeds that may spring up amongst it, and all around outside the farm circle to the extent of one or two feet more. The cultivated grass grows luxuriantly, and produces a heavy crop of small, white, flinty seeds, which under the microscope very closely resemble ordinary rice. When ripe, it is carefully harvested and carried by the workers, chaff and all, into the granary cells, where it is divested of the chaff and packed away. The chaff is taken out and thrown beyond the limits of the paved area.

"During protracted wet weather it sometimes happens that the provision-stores become damp, and are liable to sprout and spoil. In this case, on the first fine day, the ants bring out the damp and damaged grain, and expose it to the sun till it is dry, when they carry it back and pack away all the sound seeds, leaving those that had sprouted to waste.

"In a peach orchard not far from my house is a considerable elevation, on which is an extensive bed of rock. In the sand-beds overlying portions of this rock are five cities of the agricultural ants, evidently very ancient. My observations on their manners and customs have been limited to the last twelve years, during which time the inclosure surrounding the orchard has prevented the approach of cattle to the ant-farms. The cities which are outside the inclosure, as well as those protected in it, are at the proper season invariably planted with the ant-rice. The crop may accordingly always be seen springing up within the circle about the 1st of November every year. Of late years, however, since the number of farms and cattle has greatly increased, and the latter are eating off the grass much closer than formerly, thus preventing the ripening of the seeds, I notice that the agricultural ant is placing its cities along the turn-rows in the fields, walks in gardens, inside about the gates, &c., where they can cultivate their farms without molestation from the cattle.

"There can be no doubt that the particular species of grain-bearing grass mentioned above is intentionally planted. In farmer-like manner the ground upon which it stands is carefully divested of all other grasses and weeds during the time it is growing. When it is ripe, the grain is taken care of, the dry stubble cut away and carried off, the paved area being left unencumbered until the ensuing autumn, when the same ant-rice reappears within the same circle, and receives the same agricultural attention as was bestowed upon the previous crop--and so on, year after year, as I _know_ to be the case, in all situations where the ants' settlements are protected from granivorous animals."

This interesting account is simply the result of twelve years' patient investigation on the part of Dr. Lincecum, who took special care not to invent a theory and to twist facts in accordance with it, but watched the entire proceedings of the insects for a series of years.

The preceding illustration represents the rather remarkable nest of an Australian ant, belonging to the genus Crematogaster. This word signifies "hanging-belly," and the name has been applied to the ant in consequence of the manner in which its abdomen is held up in the air, so that it overhangs the back.

As may be seen, the nest is of considerable size, and might from its external appearance be mistaken for that of a wasp. The interior of it, however, is even more elaborate, being full of little covered passages interlacing with each other in a most intricate manner, but all leading to the internal galleries.

The two nests which are shown in the next illustration are, if possible, still more remarkable.

The upper one is found in Cayenne, and is made by an insect called the fungus ant (_Polyrachis bispinosa_), because the nest looks as if it were made of fungus. It is not, however, composed of that material, but of the fibre of the cotton-tree (_Bombax ceiba_).

The fibre is in itself very short, barely exceeding an inch in length, but it is cut very much shorter by the ant, who contrives to felt it together in a most curious manner, so that it is hardly possible to trace the course of any one fibre. The size of the nest is, on an average, about eight or nine inches in diameter. The insect itself is given in the preceding illustration, but very much enlarged. If the reader will look at the centre of the body, he will see the projections which have given it the name of _bispinosa_, or two-spined.

The lower figure represents the nest of another species of ant belonging to the same genus, and called scientifically, _Polyrachis textor_. The nest is most ingeniously made of little pieces of wood and tendrils, put together so as to form a kind of open net-work, through which the interior of the nest is plainly visible. This insect inhabits Malacca.]

_CHAPTER XVI_.

STRUCTURES OF WHITE ANTS, OR TERMITES.

When we look back upon the details which we have given of the industry and ingenuity of numerous tribes of insects, both solitary and social, we are induced to think it almost impossible that they could be surpassed. The structures of wasps and bees, and still more those of the wood-ant (_Formica rufa_), when placed in comparison with the size of the insects, equal our largest cities compared with the stature of man. But when we look at the buildings erected by the white ants of tropical climates, all that we have been surveying dwindles into insignificance. Their industry appears greatly to surpass that of our ants and bees, and they are certainly more skilful in architectural contrivances. The elevation, also, of their edifices is more than five hundred times the height of the builders. Were our houses built according to the same proportions, they would be twelve or fifteen times higher than the London Monument, and four or five times higher than the pyramids of Egypt, with corresponding dimensions in the basements of the edifices. These statements are, perhaps, necessary to impress the extraordinary labours of ants upon the mind; for we are all more or less sensible to the force of comparisons. The analogies between the works of insects and of men are not perfect; for insects are all provided with instruments peculiarly adapted to the end which they instinctively seek, while man has to form a plan by progressive thought, and upon the experience of others, and to complete it with tools which he also invents.

The termites do not stand above a quarter of an inch high, while their nests are frequently twelve feet, and Jobson mentions some which he had seen as high as twenty feet; "of compass," he adds, "to contain a dozen men, with the heat of the sun baked into that hardness, that we used to hide ourselves in the ragged tops of them when we took up stands to shoot at deer or wild beasts."[DI] Bishop Heber saw a number of these high ant-hills in India, near the principal entrance of the Sooty or Moorshedabad river. "Many of them," he says, "were five or six feet high, and probably seven or eight feet in circumference at the base, partially overgrown with grass and ivy, and looking at a distance like the stumps of decayed trees. I think it is Ctesias, among the Greek writers, who gives an account alluded to by Lucian in his 'Cock,' of monstrous ants in India, as large as foxes. The falsehood probably originated in the stupendous fabrics which they rear here, and which certainly might be supposed to be the work of a much larger animal than their real architect."[DJ] Herodotus has a similar fable of the enormous size and brilliant appearance of the ants of India.

Nor is it only in constructing dwellings for themselves that the termites of Africa and of other hot climates employ their masonic skill. Though, like our ants and wasps, they are almost omnivorous, yet wood, particularly when felled and dry, seems their favourite article of food; but they have an utter aversion to feeding in the light, and always eat their way with all expedition to the interior. It thence would seem necessary for them either to leave the bark of a tree, or the outer portion of the beam or door of a house, undevoured, or to eat in open day. They do neither; but are at the trouble of constructing galleries of clay, in which they can conceal themselves, and feed in security. In all their foraging excursions, indeed, they build covert ways, by which they can go out and return to their encampment.[DK]

Others of the species (for there are several), instead of building galleries, exercise the art of miners, and make their approaches under ground, penetrating beneath the foundation of houses or areas, and rising again either through the floors, or by entering the bottom of the posts that support the building, when they follow the course of the fibres, and make their way to the top, boring holes and cavities in different places as they proceed. Multitudes enter the roof, and intersect it with pipes or galleries, formed of wet clay, which serve for passages in all directions, and enable them more readily to fix their habitations in it. They prefer the softer woods, such as pine and fir, which they hollow out with such nicety, that they leave the surface whole, after having eaten away the inside. A shelf or plank attacked in this manner looks solid to the eye, when, if weighed, it will not out-balance two sheets of pasteboard of the same dimensions. It sometimes happens that they carry this operation so far on stakes in the open air, as to render the bark too flexible for their purpose; when they remedy the defect by plastering the whole stick with a sort of mortar which they make with clay, so that, on being struck, the form vanishes, and the artificial covering falls in fragments on the ground. In the woods, when a large tree falls from age or accident, they enter it on the side next the ground, and devour it at leisure, till little more than the bark is left. But in this case they take no precaution of strengthening the outward defence, but leave it in such a state as to deceive an eye unaccustomed to see trees thus gutted of their insides: and "you may as well," says Mr. Smeathman, "step upon a cloud." It is an extraordinary fact, that when these creatures have formed pipes in the roof of a house, instinct directs them to prevent its fall, which would ensue from their having sapped the posts on which it rests; but as they gnaw away the wood, they fill up the interstices with clay, tempered to a surprising degree of hardness, so that, when the house is pulled down, these posts are transformed from wood to stone. They make the walls of their galleries of the same composition as their nests, varying the materials according to their kind; one species using the red clay, another black clay, and the third a woody substance, cemented with gums, as a security from the attacks of their enemies, particularly the common ant, which, being defended by a strong, horny shell, is more than a match for them, and when it can get at them, rapaciously seizes them, and drags them to its nest for food for its young brood. If any accident breaks down part of their walls, they repair the breach with all speed. Instinct guides them to perform their office in the creation, by mostly confining their attacks to trees that are beginning to decay, or such timber as has been severed from its roots for use, and would decay in time. Vigorous, healthy trees do not require to be destroyed, and accordingly, these consumers have no taste for them.[DL]

M. Adanson describes the termites of Senegal as constructing covert ways along the surface of wood which they intend to attack; but though we have no reason to distrust so excellent a naturalist, in describing what he saw, it is certain that they more commonly eat their way into the interior of the wood, and afterwards form the galleries, when they find that they have destroyed the wood till it will no longer afford them protection.

But it is time that we should come to their principal building, which may, with some propriety, be called a city; and, according to the method we have followed in other instances, we shall trace their labours from the commencement. We shall begin with the operations of the species which may be appropriately termed the Warrior (_Termes fatalis_, Linn.; _T. bellicosus_, Smeath.).

We must premise, that though they have been termed white _ants_, they do not belong to the same order of insects with our ants; yet they have a slight resemblance to ants in their form, but more in their economy. Smeathman, to whom we owe our chief knowledge of the genus, describes them as consisting of kings, queens, soldiers, and workers, and is of opinion that the workers are larvæ, the soldiers nymphæ, and the kings and queens the perfect insects. In this opinion he coincides with Sparrmann[DM] and others; but Latreille is inclined to think, from what he observed in a European species (_Termes lucifugus_) found near Bordeaux, that the soldiers form a distinct race, like the neuter workers among bees and ants, while the working termites are larvæ,[DN] which are furnished with strong mandibles for gnawing; when they become nymphs, the rudiments of four wings appear, which are fully developed in the perfect insects.

[It is now known that the differences of form among the termites are accounted for as follows. The winged specimens are the fully developed males and females, popularly called kings and queens. These crawl to the aperture of their house and take flight, retiring to earth after a short time. When a male and female meet each other, they cast off their wings exactly as do the ants of our own country, and become the founders of a new colony. Their soldiers are undeveloped males, and the workers are undeveloped females.]

In the winged state, they migrate to form new colonies, but the greater number of them perish in a few hours, or become the prey of birds, and even of the natives, who fry them as delicacies. "I have discoursed with several gentlemen," says Smeathman, "upon the taste of the white ants, and on comparing notes, we have always agreed that they are most delicious and delicate eating. One gentleman compared them to sugared marrow, another to sugared cream and a paste of sweet almonds."[DO]

Mr. Smeathman's very interesting paper affords us the most authentic materials for the further description of these wonderful insects; and we therefore continue partly to extract from, and partly to abridge, his account.

The few pairs that are so fortunate as to survive the various casualties that assail them, are usually found by workers (larvæ), which, at this season, are running continually on the surface of the ground, on the watch for them. As soon as they discover the objects of their search, they begin to protect them from their surrounding enemies, by inclosing them in a small chamber of clay, where they become the parents of a new community, and are distinguished from the other inhabitants of the nest by the title of king and queen. Instinct directs the attention of these labouring insects to the preservation of their race, in the protection of this pair and their offspring. The chamber that forms the rudiment of a new nest is contrived for their safety, but the entrances to it are too small to admit of their ever leaving it; consequently, the charge of the eggs devolves upon the labourers, who construct nurseries for their reception. These are small, irregularly-shaped chambers, placed at first round the apartment of the king and queen, and not exceeding the size of a hazel-nut; but in nests of long standing they are of great comparative magnitude, and distributed at a greater distance. The receptacles for hatching the young are all composed of wooden materials, apparently joined together with gum, and, by way of defence, cased with clay. The chamber that contains the king and queen is nearly on a level with the surface of the ground; and as the other apartments are formed about it, it is generally situated at an equal distance from the sides of the nest, and directly beneath its conical point. Those apartments which consist of nurseries and magazines of provisions, form an intricate labyrinth, being separated by small, empty chambers and galleries, which surround them, or afford a communication from one to another. This labyrinth extends on all sides to the outward shells, and reaches up within it to two-thirds or more of its height, leaving an open area above, in the middle, under the dome, which reminds the spectator of the nave of an old cathedral. Around this are raised three or four large arches, which are sometimes two or three feet high, next the front of the area, but diminish as they recede further back, and are lost amidst the innumerable chambers and nurseries behind them.

Every one of these buildings consists of two distinct parts, the exterior and the interior. The exterior is one large shell, in the manner of a dome, large and strong enough to inclose and shelter the interior from the vicissitudes of the weather, and the inhabitants from the attacks of natural or accidental enemies. It is always, therefore, much stronger than the interior building, which is the habitable part, divided, with a wonderful kind of regularity and contrivance, into an amazing number of apartments for the residence of the king and queen, and the nursing of the numerous progeny; or for magazines, which are always found well filled with stores and provisions. The hills make their first appearance above ground by a little turret or two, in the shape of sugar-loaves, which are run a foot high or more. Soon after, at some little distance, while the former are increasing in height and size, they raise others, and so go on increasing their number, and widening them at the base, till their works below are covered with these turrets, of which they always raise the highest and largest in the middle, and by filling up the intervals between each turret, collect them into one dome. They are not very curious or exact in the workmanship, except in making them very solid and strong; and when, by their joining them, the dome is completed, for which purpose the turrets answer as scaffolds, they take away the middle ones entirely, except the tops, which, joined together, make the crown of the cupola, and apply the clay to the building of the works within, or to erecting fresh turrets for the purpose of raising the hillock still higher; so that some part of the clay is probably used several times, like the boards and posts of a mason's scaffold.

When these hills are little more than half their height, it is a common practice of the wild bulls to stand as sentinels on them, while the rest of the herd are ruminating below. They are sufficiently strong for that purpose, and at their full height answer excellently well as places of look-out; and Mr. Smeathman has been, with four more, on the top of one of these hillocks, to watch for a vessel in sight. The outward shell, or dome, is not only of use to protect and support the interior buildings from external violence and the heavy rains, but to collect and preserve a regular degree of the warmth and moisture necessary for hatching the eggs and cherishing the young. The royal chamber occupied by the king and queen appears to be, in the opinion of this little people, of the most consequence, being always situated as near the centre of the interior building as possible. It is always nearly in the shape of half an egg, or an obtuse oval, within, and may be supposed to represent a long oven. In the infant state of the colony it is but about an inch in length; but in time will be increased to six or eight inches, or more, in the clear, being always in proportion to the size of the queen, who, increasing in bulk as in age, at length requires a chamber of such dimensions.

Its floor is perfectly horizontal, and in large hillocks, sometimes more than an inch thick of solid clay. The roof, also, which is one solid and well-turned oval arch, is generally of about the same solidity; but in some places it is not a quarter of an inch thick on the sides where it joins the floor, and where the doors or entrances are made level with it, at nearly equal distances from each other. These entrances will not admit any animal larger than the soldiers or labourers; so that the king and the queen (who is, at full size, a thousand times the weight of a king) can never possibly go out, but remain close prisoners.

[There is a good series of the queen cells of the Termite in the British Museum, and the reader is strongly recommended to go and examine them. Some of them are as large as cocoa-nuts. Around the cell are a number of small holes, looking as if they had been bored with a bradawl. Now, if the cell be carefully opened, a most curious arrangement will be seen. Each of the little holes serves as an opening into a passage which communicates with the interior of the cell. The apartment, if we may so call it, which contains the queen, is only just large enough to hold her, and there is no door or opening for her egress. This, however, is not required, as her enormous size prevents her from moving. Through these passages runs incessantly a stream of worker termites, some of them carrying eggs which the queen has just laid, and others returning to the royal chamber for a fresh supply.]

The royal chamber, if in a large hillock, is surrounded by a countless number of others, of different sizes, shapes, and dimensions; but all of them arched in one way or another--sometimes elliptical or oval. These either open into each other, or communicate by passages as wide as, and are evidently made for, the soldiers and attendants, of whom great numbers are necessary, and always in waiting. These apartments are joined by the magazines and nurseries. The former are chambers of clay, and are always well filled with provisions, which, to the naked eye, seem to consist of the raspings of wood, and plants which the termites destroy, but are found by the microscope to be principally the gums or inspissated juices of plants. These are thrown together in little masses, some of which are finer than others, and resemble the sugar about preserved fruits; others are like tears of gum, one quite transparent, another like amber, a third brown, and a fourth quite opaque, as we see often in parcels of ordinary gums. These magazines are intermixed with the nurseries, which are buildings totally different from the rest of the apartments; for these are composed entirely of wooden materials, seemingly joined together with gums. Mr. Smeathman calls them the nurseries because they are invariably occupied by the eggs and young ones, which appear at first in the shape of labourers, but white as snow. These buildings are exceedingly compact, and divided into many very small irregular-shaped chambers, not one of which is to be found of half an inch in width. They are placed all round, and as near as possible to the royal apartments.

When the nest is in the infant state, the nurseries are close to the royal chambers; but as, in process of time, the queen enlarges, it is necessary to enlarge the chamber for her accommodation; and as she then lays a greater number of eggs, and requires a greater number of attendants, so it is necessary to enlarge and increase the number of the adjacent apartments; for which purpose the small nurseries which are first built are taken to pieces, rebuilt a little further of a size larger, and the number of them increased at the same time. Thus they continually enlarge their apartments, pull down, repair, or rebuild, according to their wants, with a degree of sagacity, regularity, and foresight, not even imitated by any other kind of animals or insects.

All these chambers, and the passages leading to and from them, being arched, they help to support each other; and while the interior large arches prevent them from falling into the centre, and keep the area open, the exterior building supports them on the outside. There are, comparatively speaking, few openings into the great area, and they, for the most part, seem intended only to admit into the nurseries that genial warmth which the dome collects. The interior building, or assemblage of nurseries, chambers, &c., has a flattish top or roof, without any perforation, which would keep the apartments below dry, in case through accident the dome should receive any injury, and let in water; and it is never exactly flat and uniform, because the insects are always adding to it by building more chambers and nurseries; so that the division or columns between the future arched apartment resemble the pinnacles on the fronts of some old buildings, and demand particular notice, as affording one proof that for the most part the insects project their arches, and do not make them by excavation. The area has also a flattish floor, which lies over the royal chamber, but sometimes a good height above it, having nurseries and magazines between. It is likewise waterproof, and contrived to let the water off if it should get in, and run over by some short way into the subterraneous passages, which run under the lowest apartments in the hill in various directions, and are of an astonishing size, being wider than the bore of a great cannon. One that Mr. Smeathman measured was perfectly cylindrical, and thirteen inches in diameter. These subterraneous passages, or galleries, are lined very thick with the same kind of clay of which the hill is composed, and ascend the inside of the outward shell in a spiral manner; and winding round the whole building up to the top, intersect each other at different heights, opening either immediately in the dome in various places, and into the interior building, the new turrets, &c., or communicating with them by other galleries of different diameters, either circular or oval.

From every part of these large galleries are various small covert ways, or galleries leading to different parts of the building. Under ground there are a great many that lead downward by sloping descents, three and four feet perpendicular among the gravel, whence the workers cull the finer parts, which, being kneaded up in their mouths to the consistence of mortar, become that solid clay or stone of which their hills and all their buildings, except their nurseries, are composed. Other galleries again ascend, and lead out horizontally on every side, and are carried under ground near to the surface a vast distance: for if all the nests are destroyed within a hundred yards of a house, the inhabitants of those which are left unmolested farther off will still carry on their subterraneous galleries, and, invading it by sap and mine, do great mischief to the goods and merchandise contained in it.

It seems there is a degree of necessity for the galleries under the hills being thus large, since they are the great thoroughfares for all the labourers and soldiers going forth or returning, whether fetching clay, wood, water, or provisions; and they are certainly well calculated for the purposes to which they are applied by the spiral slope which is given them; for if they were perpendicular the labourers would not be able to carry on their building with so much facility, as they ascend a perpendicular with great difficulty, and the soldiers can scarcely do it at all. It is on this account that sometimes a road like a ledge is made on the perpendicular side of any part of the building within their hill, which is flat on the upper surface and half an inch wide, and ascends gradually like a staircase, or like those winding roads which are cut on the sides of hills and mountains, that would otherwise be inaccessible; by which and similar contrivances they travel with great facility to every interior part.

This, too, is probably the cause of their building a kind of bridge of one great arch, which answers the purpose of a flight of stairs from the floor of the area to some opening on the side of one of the columns that support the great arches. This contrivance must shorten the distance exceedingly to those labourers who have the eggs to carry from the royal chamber to some of the upper nurseries, which in some hills would be four or five feet in the straightest line, and much more if carried through all the winding passages leading through the inner chambers and apartments. Mr. Smeathman found one of these bridges, half an inch broad, a quarter of an inch thick, and ten inches long, making the side of an elliptic arch of proportionable size; so that it is wonderful it did not fall over or break by its own weight before they got it joined to the side of the column above.

It was strengthened by a small arch at the bottom, and had a hollow or groove all the length of the upper surface, either made purposely for the inhabitants to travel over with more safety, or else, which is not improbable, worn by frequent treading.

Turret-building White Ants.

Apparently more than one species smaller than the preceding, such as the _Termes mordax_ and _T. atrox_ of Smeathman, construct nests of a very different form, the figures of which resemble a pillar, with a large mushroom for a capital. These turrets are composed of well-tempered black earth, and stand nearly three feet high. The conical mushroom-shaped roof is composed of the same material, and the brims hang over the column, being three or four inches wider than its perpendicular sides. Most of them, says Smeathman, resemble in shape the body of a round windmill, but some of the roofs have little elevation in the middle. When one of these turrets is completed, the insects do not afterwards enlarge or alter it; but if it be found too small for them, they lay the foundation of another at a few inches' distance. They sometimes, but not often, begin the second before the first is finished, and a third before they have completed the second. Five or six of these singular turrets in a group may be seen in the thick woods at the foot of a tree. They are so very strongly built, that in case of violence, they will sooner tear up the gravel and solid heart of their foundation than break in the middle. When any of them happen to be thus thrown down, the insects do not abandon them; but, using their overturned column as a basis, they run up another perpendicularly from it to the usual height, fastening the under part at the same time to the ground, to render it the more secure.

The interior of a turret is pretty equally divided into innumerable cells, irregular in shape, but usually more or less angular, generally quadrangular or pentagonal, though the angles are not well defined. Each shell has at least two entrances; but there are no galleries, arches, nor wooden nurseries, as in the nests of the warrior (_T. bellicosus_). The two species which build turret nests are very different in size, and the dimensions of the nests differ in proportion.

The White Ants of Trees.

Latreille's species of white ant (_Termes lucifugus_, Rossi), formerly mentioned as found in the south of Europe, appear to have more the habits of the jet-ant, described page 301, than their congeners of the tropics. They live in the interior of the trunks of trees, the wood of which they eat, and form their habitations of the galleries which they thus excavate. M. Latreille says they appear to be furnished with an acid for the purpose of softening the wood, the odour of which is exceedingly pungent. They prefer the part of the wood nearest to the bark, which they are careful not to injure, as it affords them protection. All the walls of their galleries are moistened with small globules of a gelatinous substance, similar to gum Arabic. They are chiefly to be found in the trunks of oak and pine trees, and are very numerous.[DP]

Another of the species (_Termes arborum_), described by Smeathman, builds a nest on the exterior of trees, altogether different from any of the preceding. These are of a spherical or oval shape, occupying the arm or branch of a tree sometimes from seventy to eighty feet from the ground, and as large, in a few instances, as a sugar-cask. The composition used for a building material is apparently similar to that used by the warriors for constructing their nurseries, being the gnawings of wood in very small particles, kneaded into a paste with some species of cement or glue, procured, as Smeathman supposes, partly from gummiferous trees, and partly from themselves; but it is more probable, we think, that it is wholly secreted, like the wax of bees, by the insects themselves. With this cement, whatever may be its composition, they construct their cells, in which there is nothing very wonderful except their great numbers. They are very firmly built, and so strongly attached to the trees, that they will resist the most violent tornado. It is impossible, indeed, to detach them, except by cutting them in pieces, or sawing off the branch, which is frequently done to procure the insects for young turkeys. (See engraving, p. 324, for a figure of this nest.)

This species very often, instead of selecting the bough of a tree, builds in the roof or wall of a house, and unless observed in time, and expelled, occasions considerable damage. It is easier, in fact, to shut one's door against a fox or a thief, than to exclude such insidious enemies, whose aversion to light renders it difficult to trace them even when they are numerous.

[There are also termites in Europe, and the city of La Rochelle has suffered terribly from them. They eat the trees in the gardens, and not a stake can be driven into the ground, or even a plank left for twenty-four hours, without being attacked. They also enter the houses and utterly ruin them by eating every bit of timber that is used in them. In one instance, where a room had been repaired, the stalactitic galleries of the termites showed themselves the very day after the workmen had left the room.

They invaded the prefecture, and did exceeding damage, one of their feats of voracity being so extraordinary as to deserve mention. The archives of the department were left in boxes, and privately inspected. One day, when a paper was needed, the whole of the documents fell to pieces, and were metamorphosed as if by magic into a heap of clay. The termites had got into the boxes by boring through the wainscot of the room, and had then penetrated among the papers. They consumed every particle of them except the uppermost sheet and the edges, supplying their place with clay. The consequence was, that although the heap of documents seemed to be correct, there was nothing but a mass of clay galleries and a single sheet of paper at the top.

So voracious are they, that even a piece of paper wrapped round a bottle was eaten, the termites building a gallery of clay in order to reach it under cover.]

If we reflect on the prodigious numbers of those insects, and their power and rapidity of destroying, we cannot but admire the wisdom of Providence in creating so indefatigable and useful an agent in countries where the decay of vegetable substances is rapid in proportion to the heat of the climate. We have already remarked that they always prefer decaying or dead timber; and it is indeed a very general law among insects which feed on wood to prefer what is unsound; the same principle holds with respect to fungi, lichens, and other parasitical plants.