Social Life in the Insect World

At the sight of a great cricket, which thoughtlessly approaches along the wire-work of the cover, the Mantis, shaken by a convulsive start, suddenly assumes a most terrifying posture. An electric shock would not produce a more immediate result. The transition is so sudden, the mimicry so threatening, that the unaccustomed observer will draw back his hand, as though at some unknown danger. Seasoned as I am, I myself must confess to being startled on occasions when my thoughts have been elsewhere. The creature spreads out like a fan actuated by a spring, or a fantastic Jack-in-the-box.

The wing-covers open, and are thrust obliquely aside; the wings spring to their full width, standing up like parallel screens of transparent gauze, forming a pyramidal prominence which dominates the back; the end of the abdomen curls upwards crosier-wise, then falls and unbends itself with a sort of swishing noise, a pouf! pouf! like the sound emitted by the feathers of a strutting turkey-cock. One is reminded of the puffing of a startled adder.

Proudly straddling on its four hind-claws, the insect holds its long body almost vertical. The murderous fore-limbs, at first folded and pressed against one another on the thorax, open to their full extent, forming a cross with the body, and exhibiting the axillæ ornamented with rows of pearls, and a black spot with a central point of white. These two eyes, faintly recalling those of the peacock's tail, and the fine ebony embossments, are part of the blazonry of conflict, concealed upon ordinary occasions. Their jewels are only assumed when they make themselves terrible and superb for battle.

Motionless in its weird position, the Mantis surveys the acridian, its gaze fixed upon it, its head turning gently as on a pivot as the other changes place. The object of this mimicry seems evident; the Mantis wishes to terrorise its powerful prey, to paralyse it with fright; for if not demoralised by fear the quarry might prove too dangerous.

Does it really terrify its prey? Under the shining head of the Decticus, behind the long face of the cricket, who is to say what is passing? No sign of emotion can reveal itself upon these immovable masks. Yet it seems certain that the threatened creature is aware of its danger. It sees, springing up before it, a terrible spectral form with talons outstretched, ready to fall upon it; it feels itself face to face with death, and fails to flee while yet there is time. The creature that excels in leaping, and might so easily escape from the threatening claws, the wonderful jumper with the prodigious thighs, remains crouching stupidly in its place, or even approaches the enemy with deliberate steps.[2]

It is said that young birds, paralysed with terror by the gaping mouth of a serpent, or fascinated by its gaze, will allow themselves to be snatched from the nest, incapable of movement. The cricket will often behave in almost the same way. Once within reach of the enchantress, the grappling-hooks are thrown, the fangs strike, the double saws close together and hold the victim in a vice. Vainly the captive struggles; his mandibles chew the air, his desperate kicks meet with no resistance. He has met with his fate. The Mantis refolds her wings, the standard of battle; she resumes her normal pose, and the meal commences.

In attacking the Truxalis and the Ephippigera, less dangerous game than the grey cricket and the Decticus, the spectral pose is less imposing and of shorter duration. It is often enough to throw forward the talons; this is so in the case of the Epeirus, which is seized by the middle of the body, without a thought of its venomous claws. With the smaller crickets, which are the customary diet in my cages as at liberty, the Mantis rarely employs her means of intimidation; she merely seizes the heedless passer-by as she lies in wait.

When the insect to be captured may present some serious resistance, the Mantis is thus equipped with a pose which terrifies or perplexes, fascinates or absorbs the prey, while it enables her talons to strike with greater certainty. Her gins close on a demoralised victim, incapable of or unready for defence. She freezes the quarry with fear or amazement by suddenly assuming the attitude of a spectre.

The wings play an important part in this fantastic pose. They are very wide, green on the outer edge, but colourless and transparent elsewhere. Numerous nervures, spreading out fan-wise, cross them in the direction of their length. Others, transversal but finer, cut the first at right angles, forming with them a multitude of meshes. In the spectral attitude the wings are outspread and erected in two parallel planes which are almost in contact, like the wings of butterflies in repose. Between the two the end of the abdomen rapidly curls and uncurls. From the rubbing of the belly against the network of nervures proceeds the species of puffing sound which I have compared to the hissing of an adder in a posture of defence. To imitate this curious sound it is enough rapidly to stroke the upper face of an outstretched wing with the tip of the finger-nail.

In a moment of hunger, after a fast of some days, the large grey cricket, which is as large as the Mantis or larger, will be entirely consumed with the exception of the wings, which are too dry. Two hours are sufficient for the completion of this enormous meal. Such an orgy is rare. I have witnessed it two or three times, always asking myself where the gluttonous creature found room for so much food, and how it contrived to reverse in its own favour the axiom that the content is less than that which contains it. I can only admire the privileges of a stomach in which matter is digested immediately upon entrance, dissolved and made away with.

The usual diet of the Mantis under my wire cages consists of crickets of different species and varying greatly in size. It is interesting to watch the Mantis nibbling at its cricket, which it holds in the vice formed by its murderous fore-limbs. In spite of the fine-pointed muzzle, which hardly seems made for such ferocity, the entire insect disappears excepting the wings, of which only the base, which is slightly fleshy, is consumed. Legs, claws, horny integuments, all else is eaten. Sometimes the great hinder thigh is seized by the knuckle, carried to the mouth, tasted, and crunched with a little air of satisfaction. The swollen thigh of the cricket might well be a choice "cut" for the Mantis, as a leg of lamb is for us!

The attack on the victim begins at the back of the neck or base of the head. While one of the murderous talons holds the quarry gripped by the middle of the body, the other presses the head downwards, so that the articulation between the back and the neck is stretched and opens slightly. The snout of the Mantis gnaws and burrows into this undefended spot with a certain persistence, and a large wound is opened in the neck. At the lesion of the cephalic ganglions the struggles of the cricket grow less, and the victim becomes a motionless corpse. Thence, unrestricted in its movements, this beast of prey chooses its mouthfuls at leisure.

CHAPTER VI

THE MANTIS.—COURTSHIP

The little we have seen of the customs of the Mantis does not square very well with the popular name for the insect. From the term Prègo-Diéu we should expect a peaceful placid creature, devoutly self-absorbed; and we find a cannibal, a ferocious spectre, biting open the heads of its captives after demoralising them with terror. But we have yet to learn the worst. The customs of the Mantis in connection with its own kin are more atrocious even than those of the spiders, who bear an ill repute in this respect.

To reduce the number of cages on my big laboratory table, to give myself a little more room, while still maintaining a respectable menagerie, I installed several females under one cover. There was sufficient space in the common lodging and room for the captives to move about, though for that matter they are not fond of movement, being heavy in the abdomen. Crouching motionless against the wire work of the cover, they will digest their food or await a passing victim. They lived, in short, just as they lived on their native bushes.

Communal life has its dangers. When the hay is low in the manger donkeys grow quarrelsome, although usually so pacific. My guests might well, in a season of dearth, have lost their tempers and begun to fight one another; but I was careful to keep the cages well provided with crickets, which were renewed twice a day. If civil war broke out famine could not be urged in excuse.

At the outset matters did not go badly. The company lived in peace, each Mantis pouncing upon and eating whatever came her way, without interfering with her neighbours. But this period of concord was of brief duration. The bellies of the insects grew fuller: the eggs ripened in their ovaries: the time of courtship and the laying season was approaching. Then a kind of jealous rage seized the females, although no male was present to arouse such feminine rivalry. The swelling of the ovaries perverted my flock, and infected them with an insane desire to devour one another. There were threats, horrid encounters, and cannibal feasts. Once more the spectral pose was seen, the hissing of the wings, and the terrible gesture of the talons outstretched and raised above the head. The females could not have looked more terrible before a grey cricket or a Decticus. Without any motives that I could see, two neighbours suddenly arose in the attitude of conflict. They turned their heads to the right and the left, provoking one another, insulting one another. The pouf! pouf! of the wings rubbed by the abdomen sounded the charge. Although the duel was to terminate at the first scratch, without any more serious consequence, the murderous talons, at first folded, open like the leaves of a book, and are extended laterally to protect the long waist and abdomen. The pose is superb, but less terrific than that assumed when the fight is to be to the death.

Then one of the grappling-hooks with a sudden spring flies out and strikes the rival; with the same suddenness it flies back and assumes a position of guard. The adversary replies with a riposte. The fencing reminds one not a little of two cats boxing one another's ears. At the first sign of blood on the soft abdomen, or even at the slightest wound, one admits herself to be conquered and retires. The other refurls her battle standard and goes elsewhere to meditate the capture of a cricket, apparently calm, but in reality ready to recommence the quarrel.

Very often the matter turns out more tragically. In duels to the death the pose of attack is assumed in all its beauty. The murderous talons unfold and rise in the air. Woe to the vanquished! for the victor seizes her in her vice-like grip and at once commences to eat her; beginning, needless to say, at the back of the neck. The odious meal proceeds as calmly as if it were merely a matter of munching a grasshopper; and the survivor enjoys her sister quite as much as lawful game. The spectators do not protest, being only too willing to do the like on the first occasion.

Ferocious creatures! It is said that even wolves do not eat one another. The Mantis is not so scrupulous; she will eat her fellows when her favourite quarry, the cricket, is attainable and abundant.

These observations reach a yet more revolting extreme. Let us inquire into the habits of the insect at breeding time, and to avoid the confusion of a crowd let us isolate the couples under different covers. Thus each pair will have their own dwelling, where nothing can trouble their honeymoon. We will not forget to provide them with abundant food; there shall not be the excuse of hunger for what is to follow.

We are near the end of August. The male Mantis, a slender and elegant lover, judges the time to be propitious. He makes eyes at his powerful companion; he turns his head towards her; he bows his neck and raises his thorax. His little pointed face almost seems to wear an expression. For a long time he stands thus motionless, in contemplation of the desired one. The latter, as though indifferent, does not stir. Yet the lover has seized upon a sign of consent: a sign of which I do not know the secret. He approaches: suddenly he erects his wings, which are shaken with a convulsive tremor.

This is his declaration. He throws himself timidly on the back of his corpulent companion; he clings to her desperately, and steadies himself. The prelude to the embrace is generally lengthy, and the embrace will sometimes last for five or six hours.

Nothing worthy of notice occurs during this time. Finally the two separate, but they are soon to be made one flesh in a much more intimate fashion. If the poor lover is loved by his mistress as the giver of fertility, she also loves him as the choicest of game. During the day, or at latest on the morrow, he is seized by his companion, who first gnaws through the back of his neck, according to use and wont, and then methodically devours him, mouthful by mouthful, leaving only the wings. Here we have no case of jealousy, but simply a depraved taste.

I had the curiosity to wonder how a second male would be received by a newly fecundated female. The result of my inquiry was scandalous. The Mantis in only too many cases is never sated with embraces and conjugal feasts. After a rest, of variable duration, whether the eggs have been laid or not, a second male is welcomed and devoured like the first. A third succeeds him, does his duty, and affords yet another meal. A fourth suffers a like fate. In the course of two weeks I have seen the same Mantis treat seven husbands in this fashion. She admitted all to her embraces, and all paid for the nuptial ecstasy with their lives.

There are exceptions, but such orgies are frequent. On very hot days, when the atmospheric tension is high, they are almost the general rule. At such times the Mantis is all nerves. Under covers which contain large households the females devour one another more frequently than ever; under the covers which contain isolated couples the males are devoured more eagerly than usual when their office has been fulfilled.

I might urge, in mitigation of these conjugal atrocities, that the Mantis does not commit them when at liberty. The male, his function once fulfilled, surely has time to wander off, to escape far away, to flee the terrible spouse, for in my cages he is given a respite, often of a whole day. What really happens by the roadside and in the thickets I do not know; chance, a poor schoolmistress, has never instructed me concerning the love-affairs of the Mantis when at liberty. I am obliged to watch events in my laboratory, where the captives, enjoying plenty of sunshine, well nourished, and comfortably lodged, do not seem in any way to suffer from nostalgia. They should behave there as they behave under normal conditions.

Alas! the facts force me to reject the statement that the males have time to escape; for I once surprised a male, apparently in the performance of his vital functions, holding the female tightly embraced—but he had no head, no neck, scarcely any thorax! The female, her head turned over her shoulder, was peacefully browsing on the remains of her lover! And the masculine remnant, firmly anchored, continued its duty!

Love, it is said, is stronger than death! Taken literally, never has an aphorism received a more striking confirmation. Here was a creature decapitated, amputated as far as the middle of the thorax; a corpse which still struggled to give life. It would not relax its hold until the abdomen itself, the seat of the organs of procreation, was attacked.

The custom of eating the lover after the consummation of the nuptials, of making a meal of the exhausted pigmy, who is henceforth good for nothing, is not so difficult to understand, since insects can hardly be accused of sentimentality; but to devour him during the act surpasses anything that the most morbid mind could imagine. I have seen the thing with my own eyes, and I have not yet recovered from my surprise.

Could this unfortunate creature have fled and saved himself, being thus attacked in the performance of his functions? No. We must conclude that the loves of the Mantis are fully as tragic, perhaps even more so, than those of the spider. I do not deny that the limited area of the cage may favour the massacre of the males; but the cause of such butchering must be sought elsewhere. It is perhaps a reminiscence of the carboniferous period when the insect world gradually took shape through prodigious procreation. The Orthoptera, of which the Mantes form a branch, are the first-born of the insect world.

Uncouth, incomplete in their transformation, they wandered amidst the arborescent foliage, already flourishing when none of the insects sprung of more complex forms of metamorphosis were as yet in existence: neither butterflies, beetles, flies, nor bees. Manners were not gentle in those epochs, which were full of the lust to destroy in order to produce; and the Mantis, a feeble memory of those ancient ghosts, might well preserve the customs of an earlier age. The utilisation of the males as food is a custom in the case of other members of the Mantis family. It is, I must admit, a general habit. The little grey Mantis, so small and looking so harmless in her cage, which never seeks to harm her neighbours in spite of her crowded quarters, falls upon her male and devours him as ferociously as the Praying Mantis. I have worn myself out in trying to procure the indispensable complements to my female specimens. No sooner is my capture, strongly winged, vigorous and alert, introduced into the cage than he is seized, more often than not, by one of the females who no longer have need of his assistance and devoured. Once the ovaries are satisfied the two species of Mantis conceive an antipathy for the male; or rather they regard him merely as a particularly tasty species of game.

CHAPTER VII

The nest of the Praying Mantis may be found almost everywhere in places exposed to the sun: on stones, wood, vine stocks, the twigs of bushes, stems of dried grass, and even on products of human industry, such as fragments of brick, rags of heavy cloth, and pieces of old boots. Any support will suffice, so long as it offers inequalities to which the base of the nest may adhere, and so provide a solid foundation. The usual dimensions of the nest are one and a half inches long by three-quarters of an inch wide, or a trifle larger. The colour is a pale tan, like that of a grain of wheat. Brought in contact with a flame the nest burns readily, and emits an odour like that of burning silk. The material of the nest is in fact a substance similar to silk, but instead of being drawn into a thread it is allowed to harden while a mass of spongy foam. If the nest is fixed on a branch the base creeps round it, envelops the neighbouring twigs, and assumes a variable shape according to the accidents of support; if it is fixed on a flat surface the under side, which is always moulded by the support, is itself flat. The nest then takes the form of a demi-ellipsoid, or, in other words, half an egg cut longitudinally; more or less obtuse at one end, but pointed at the other, and sometimes ending in a short curved tail.

In all cases the upper face is convex and regular. In it we can distinguish three well-marked and longitudinal zones. The middle zone, which is narrower than the others, is composed of thin plates arranged in couples, and overlapping like the tiles of a roof. The edges of these plates are free, leaving two parallel series of fissures by which the young can issue when the eggs are hatched. In a nest recently abandoned this zone is covered with fine cast-off skins which shiver at the least breath, and soon disappear when exposed to the open air. I will call this zone the zone of issue, as it is only along this bell that the young can escape, being set free by those that have preceded them.

In all other directions the cradle of this numerous family presents an unbroken wall. The two lateral zones, which occupy the greater part of the demi-ellipsoid, have a perfect continuity of surface. The little Mantes, which are very feeble when first hatched, could not possibly make their way through the tenacious substance of the walls. On the interior of these walls are a number of fine transverse furrows, signs of the various layers in which the mass of eggs is disposed.

Let us cut the nest in half transversely. We shall then see that the mass of eggs constitutes an elongated core, of very firm consistency, surrounded as to the bottom and sides by a thick porous rind, like solidified foam. Above the eggs are the curved plates, which are set very closely and have little freedom; their edges constituting the zone of issue, where they form a double series of small overlapping scales.

The eggs are set in a yellowish medium of horny appearance. They are arranged in layers, in lines forming arcs of a circle, with the cephalic extremities converging towards the zone of issue. This orientation tells us of the method of delivery. The newly-born larvæ will slip into the interval between two adjacent flaps or leaves, which form a prolongation of the core; they will then find a narrow passage, none too easy to effect, but sufficient, having regard to the curious provision which we shall deal with directly; they will then reach the zone of issue. There, under the overlapping scales, two passages of exit open for each layer of eggs. Half the larvæ will issue by the right-hand passage, half by that on the left hand. This process is repeated for each layer, from end to end of the nest.

Let us sum up those structural details, which are not easily grasped unless one has the nest before one. Lying along the axis of the nest, and in shape like a date-stone, is the mass of eggs, grouped in layers. A protective rind, a kind of solidified foam, envelops this core, except at the top, along the central line, where the porous rind is replaced by thin overlapping leaves. The free edges of these leaves form the exterior of the zone of issue; they overlap one another, forming two series of scales, leaving two exits, in the shape of narrow crevices, for each layer of eggs.

The end of the abdomen, continually palpitating, rapidly closing and opening its valves, oscillates right and left like a pendulum. From each of these oscillations results a layer of eggs in the interior, and a transversal crevice on the exterior. As it advances in the arc described, suddenly, and at frequent intervals, it plunges deeper into the foam, as though burying something at the bottom of the frothy mass. Each time it does so an egg is doubtless deposited; but the operation is so rapid, and takes place under conditions so unfavourable for observation, that I have never once been enabled to see the oviduct at work. I can only judge of the advent of the eggs by the movements of the end of the abdomen, which is immersed more deeply with a sudden plunging movement.

At the same time the viscous composition is emitted in intermittent waves, and is beaten into a foam by the terminal valves. The foam thus obtained spreads itself over the sides and at the base of the layer of eggs, and projects through the meshes of the wire gauze as a result of the pressure of the abdomen. Thus the spongy envelope is progressively created as the ovaries are gradually emptied.

I imagine, although I cannot speak as the result of direct observation, that for the central core, where the eggs are surrounded by a material more homogeneous than that of the outer shell, the Mantis must employ her secretion as it emerges, without beating it into a foam. The layer of eggs once deposited, the two valves would produce the foam required to envelop the eggs. It is extremely difficult, however, to guess what occurs beneath the veil of foam-like secretion.

In a recent nest the zone of issue is surrounded by a layer of finely porous matter, of a pure matt, almost chalky white, which contrasts distinctly with the remainder of the nest, which is of a dirty white. It resembles the icing composition made by confectioners with whipped white of egg, sugar, and starch, for the ornamentation of cakes.

This snowy border is easily crumbled and easily detached. When it disappears the zone of issue is clearly defined, with its double series of leaves with free edges. Exposure to the weather, wind, and rain result in its disappearance, fragment by fragment, so that old nests preserve no trace of it.

At first sight one is tempted to regard this snowy substance as of a different material to the rest of the nest. But does the Mantis really employ two secretions? No. Anatomy, in the first place, assures us of the unity of the materials of the nest. The organ which secretes the substance of the nest consists of cylindrical tubes, having a curious tangled appearance, which are arranged in two groups of twenty each. They are all filled with a colourless, viscous fluid, which is precisely similar in appearance in all parts of the organ. There is no indication of any organ or secretion which could produce a chalky coloration.

Moreover, the method by which the snowy band is formed rejects the idea of a different material. We see the two caudal appendices of the Mantis sweeping the surface of the foamy mass, and skimming, so to speak, the cream of the cream, gathering it together, and retaining it along the hump of the nest in such a way as to form a band like a ribbon of icing. What remains after this scouring process, or what oozes from the band before it has set, spreads over the sides of the nest in a thin layer of bubbles so fine that they cannot be distinguished without the aid of a lens.

We often see a torrent of muddy water, full of clay in suspension, covered with great streaks and masses of foam. On this fundamental foam, so to call it, which is soiled with earthy matters, we see here and there masses of a beautiful white foam, in which the bubbles are much smaller. A process of selection results from variations in density, and here and there we see foam white as snow resting on the dirty foam from which it is produced. Something of the kind occurs when the Mantis builds her nest. The two appendices whip the viscous secretion of the glands into foam. The lightest portion, whose bubbles are of the greatest tenuity, which is white on account of its finer porosity, rises to the surface, where the caudal filaments sweep it up and gather it into the snowy ribbon which runs along the summit of the nest.

So far, with a little patience, observation is possible and yields a satisfactory result. It becomes impossible in the matter of the complex central zone, where the exits for the larvæ are contrived through the double series of overlapping leaves. The little I have been able to learn amounts to this: The end of the abdomen, deeply cleft in a horizontal direction, forms a kind of fork, of which the upper extremity remains almost motionless, while the lower continuously oscillates, producing the foam and depositing the eggs. The creation of the central zone is certainly the work of the upper extremity.

It is always to be seen in the continuation of this central zone, in the midst of the fine white foam gathered up by the caudal filaments. The latter delimit the zone, one working on either side, feeling the edges of the belt, and apparently testing it and judging its progress. These two filaments are like two long fingers of exquisite sensitiveness, which direct the difficult operation.

But how are the two series of scales obtained, and the fissures, the gates of exit which they shelter? I do not know; I cannot even imagine. I leave the end of the problem to others.

What a wonderful mechanism is this, that has the power to emit and to form, so quickly and methodically, the horny medium of the central kernel, the foam which forms the protective walls, the white creamy foam of the ribbon which runs along the central zone, the eggs, and the fecundating liquid, while at the same time it constructs the overlapping leaves, the imbricated scales, and the alternating series of open fissures! We are lost in the face of such a wonder. Yet how easily the work is performed! Clinging to the wire gauze, forming, so to speak, the axis of her nest, the Mantis barely moves. She bestows not a glance on the marvel which is growing behind her; her limbs are used only for support; they take no part in the building of the nest. The nest is built, if we may say so, automatically. It is not the result of industry and the cunning of instinct; it is a purely mechanical task, which is conditioned by the implements, by the organisation of the insect. The nest, complex though it is in structure, results solely from the functioning of the organs, as in our human industries a host of objects are mechanically fashioned whose perfection puts the dexterity of the fingers to shame.

From another point of view the nest of the Mantis is even more remarkable. It forms an excellent application of one of the most valuable lessons of physical science in the matter of the conservation of heat. The Mantis has outstripped humanity in her knowledge of thermic nonconductors or insulators.

The famous physicist Rumford was responsible for a very pretty experiment designed to demonstrate the low conductivity of air where heat other than radiant heat is concerned. The famous scientist surrounded a frozen cheese by a mass of foam consisting of well-beaten eggs. The whole was exposed to the heat of an oven. In a few minutes a light omelette was obtained, piping hot, but the cheese in the centre was as cold as at the outset. The air imprisoned in the bubbles of the surrounding froth accounts for the phenomenon. Extremely refractory to heat, it had absorbed the heat of the oven and had prevented it from reaching the frozen substance in the centre of the omelette.

Now, what does the Mantis do? Precisely what Rumford did; she whips her albumen to obtain a soufflée, a froth composed of myriads of tiny air-bubbles, which will protect the germs of life contained in the central core. It is true that her aim is reversed; the coagulated foam of the nest is a safeguard against cold, not against heat, but what will afford protection from the one will afford protection from the other; so that Rumford, had he wished, might equally well have maintained a hot body at a high temperature in a refrigerator.

Rumford understood the athermic properties of a blanket of air-cells, thanks to the accumulated knowledge of his predecessors and his own studies and experiments. How is it that the Mantis, for who knows how many ages, has been able to outstrip our physicists in this problem in calorics? How did she learn to surround her eggs with this mass of solidifying froth, so that it was able, although fixed to a bough or a stone without other shelter, to brave with impunity the rigours of winter?

The other Mantes found in my neighbourhood, which are the only species of which I can speak with full knowledge, employ or omit the envelope of solidifying froth accordingly as the eggs are or are not intended to survive the winter. The little Grey Mantis (Ameles decolor), which differs so widely from the Praying Mantis in that the wings of the female are almost completely absent, builds a nest hardly as large as a cherry-stone, and covers it skilfully with a porous rind. Why this cellular envelope? Because the nest of the Ameles, like that of the Praying Mantis, has to endure through the winter, fixed to a stone or a twig, and is thus exposed to the full severity of the dangerous season.

The Empusa pauperata, on the other hand (one of the strangest of European insects), builds a nest as small as that of the Ameles, although the insect itself is as large as the Praying Mantis. This nest is quite a small structure, composed of a small number of cells, arranged side by side in three or four series, sloping together at the neck. Here there is a complete absence of the porous envelope, although the nest is exposed to the weather, like the previous examples, affixed to some twig or fragment of rock. The lack of the insulating rind is a sign of different climatic conditions. The eggs of the Empusa hatch shortly after they are laid, in warm and sunny weather. Not being exposed to the asperities of the winter, they need no protection other than the thin egg-cases themselves.

Are these nice and reasonable precautions, which rival the experiment of Rumford, a fortuitous result?—one of the innumerable combinations which fall from the urn of chance? If so, let us not recoil before the absurd: let us allow that the blindness of chance is gifted with marvellous foresight.

The Praying Mantis commences her nest at the blunter extremity, and completes it at the pointed tail. The latter is often prolonged in a sort of promontory, in which the insect expends the last drop of glutinous liquid as she stretches herself after her task. A sitting of two hours, more or less, without interruption, is required for the total accomplishment of the work. Directly the period of labour is over, the mother withdraws, indifferent henceforth to her completed task. I have watched her, half expecting to see her return, to discover some tenderness for the cradle of her family. But no: not a trace of maternal pleasure. The work is done, and concerns her no longer. Crickets approach; one of them even squats upon the nest. The Mantis takes no notice of them. They are peaceful intruders, to be sure; but even were they dangerous, did they threaten to rifle the nest, would she attack them and drive them away? Her impassive demeanour convinces me that she would not. What is the nest to her? She is no longer conscious of it.

I have spoken of the many embraces to which the Praying Mantis submits, and of the tragic end of the male, who is almost invariably devoured as though a lawful prey. In the space of a fortnight I have known the same female to adventure upon matrimony no less than seven times. Each time the readily consoled widow devoured her mate. Such habits point to frequent laying; and we find the appearance confirmed, though not as a general rule. Some of my females gave me one nest only; others two, the second as capacious as the first. The most fruitful of all produced three; of these the two first were of normal dimensions, while the third was about half the usual size.

From this we can reckon the productivity of the insect's ovaries. From the transverse fissures of the median zone of the nest it is easy to estimate the layers of eggs; but these layers contain more or fewer eggs according to their position in the middle of the nest or near the ends. The numbers contained by the widest and narrowest layers will give us an approximate average. I find that a nest of fair size contains about four hundred eggs. Thus the maker of the three nests, of which the last was half as large as the others, produced no less than a thousand eggs; eight hundred were deposited in the larger nests and two or three hundred in the smaller. Truly a fine family, but a thought ungainly, were it not that only a few of its members can survive.

Of a fair size, of curious structure, and well in evidence on its twig or stone, the nest of the Praying Mantis could hardly escape the attention of the Provençal peasant. It is well known in the country districts, where it goes by the name of tigno; it even enjoys a certain celebrity. But no one seems to be aware of its origin. It is always a surprise to my rustic neighbours when they learn that the well-known tigno is the nest of the common Mantis, the Prègo-Diéu. This ignorance may well proceed from the nocturnal habits of the Mantis. No one has caught the insect at work upon her nest in the silence of the night. The link between the artificer and the work is missing, although both are well known to the villager.

No matter: the singular object exists; it catches the eye, it attracts attention. It must therefore be good for something; it must possess virtue of some kind. So in all ages have the simple reasoned, in the childlike hope of finding in the unfamiliar an alleviation of their sorrows.

By general agreement the rural pharmacopœia of Provence pronounces the tigno to be the best of remedies against chilblains. The method of employment is of the simplest. The nest is cut in two, squeezed and the affected part is rubbed with the cut surface as the juices flow from it. This specific, I am told, is sovereign. All sufferers from blue and swollen fingers should without fail, according to traditional usage, have recourse to the tigno.

Is it really efficacious? Despite the general belief, I venture to doubt it, after fruitless experiments on my own fingers and those of other members of my household during the winter of 1895, when the severe and persistent cold produced an abundant crop of chilblains. None of us, treated with the celebrated unguent, observed the swelling to diminish; none of us found that the pain and discomfort was in the least assuaged by the sticky varnish formed by the juices of the crushed tigno. It is not easy to believe that others are more successful, but the popular renown of the specific survives in spite of all, probably thanks to a simple accident of identity between the name of the remedy and that of the infirmity: the Provençal for "chilblain" is tigno. From the moment when the chilblain and the nest of the Mantis were known by the same name were not the virtues of the latter obvious? So are reputations created.

In my own village, and doubtless to some extent throughout the Midi, the tigno—the nest of the Mantis, not the chilblain—is also reputed as a marvellous cure for toothache. It is enough to carry it upon the person to be free of that lamentable affection. Women wise in such matters gather them beneath a propitious moon, and preserve them piously in some corner of the clothes-press or wardrobe. They sew them in the lining of the pocket, lest they should be pulled out with the handkerchief and lost; they will grant the loan of them to a neighbour tormented by some refractory molar. "Lend me thy tigno: I am suffering martyrdom!" begs the owner of a swollen face.—"Don't on any account lose it!" says the lender: "I haven't another, and we aren't at the right time of moon!"

We will not laugh at the credulous victim; many a remedy triumphantly puffed on the latter pages of the newspapers and magazines is no more effectual. Moreover, this rural simplicity is surpassed by certain old books which form the tomb of the science of a past age. An English naturalist of the sixteenth century, the well-known physician, Thomas Moffat, informs us that children lost in the country would inquire their way of the Mantis. The insect consulted would extend a limb, indicating the direction to be taken, and, says the author, scarcely ever was the insect mistaken. This pretty story is told in Latin, with an adorable simplicity.

CHAPTER VIII

I capture them and place them in the insectorium. The procession is quickly re-formed; the caterpillars, to the number of perhaps a hundred and fifty, move forward in an undulating line. They pass near the piece of board, one following the other like the pigs at Chicago. The moment is propitious. I cry Havoc! and let loose the dogs of war: that is to say, I remove the plank.

The sleepers immediately awake, scenting the abundant prey. One of them runs forward; three, four, follow; the whole assembly is aroused; those who are buried emerge; the whole band of cut-throats falls upon the passing flock. It is a sight never to be forgotten. The mandibles of the beetles are at work in all directions; the procession is attacked in the van, in the rear, in the centre; the victims are wounded on the back or the belly at random. The furry skins are gaping with wounds; their contents escape in knots of entrails, bright green with their aliment, the needles of the pine-tree; the caterpillars writhe, struggling with loop-like movements, gripping the sand with their feet, dribbling and gnashing their mandibles. Those as yet unwounded are digging desperately in the attempt to take refuge underground. Not one succeeds. They are scarcely half buried before some beetle runs to them and destroys them by an eviscerating wound.

If this massacre did not occur in a dumb world we should hear all the horrible tumult of the slaughter-houses of Chicago. But only the ear of the mind can hear the shrieks and lamentations of the eviscerated victims. For myself, I possess this ear, and am full of remorse for having provoked such sufferings.

Now the beetles are rummaging in all directions through the heap of dead and dying, each tugging and tearing at a morsel which he carries off to swallow in peace, away from the inquisitive eyes of his fellows. This mouthful disposed of, another is hastily cut from the body of some victim, and the process is repeated so long as there are bodies left. In a few minutes the procession is reduced to a few shreds of still palpitating flesh.

There were a hundred and fifty caterpillars; the butchers were twenty-five. This amounts to six victims dispatched by each beetle. If the insect had nothing to do but to kill, like the knackers in the meat factories, and if the staff numbered a hundred—a very modest figure as compared with the staff of a lard or bacon factory—then the total number of victims, in a day of ten hours, would be thirty-six thousand. No Chicago "cannery" ever rivalled such a result.

The speed of assassination is the more remarkable when we consider the difficulties of attack. The beetle has no endless chain to seize its victim by one leg, hoist it up, and swing it along to the butcher's knife; it has no sliding plank to hold the victim's head beneath the pole-axe of the knacker; it has to fall upon its prey, overpower it, and avoid its feet and its mandibles. Moreover, the beetle eats its prey on the spot as it kills. What slaughter there would be if the insect confined itself to killing!

What do we learn from the slaughter-houses of Chicago and the fate of the beetle's victims? This: That the man of elevated morality is so far a very rare exception. Under the skin of the civilised being there lurks almost always the ancestor, the savage contemporary of the cave-bear. True humanity does not yet exist; it is growing, little by little, created by the ferment of the centuries and the dictates of conscience; but it progresses towards the highest with heartbreaking slowness.

It was only yesterday that slavery finally disappeared: the basis of the ancient social organism; only yesterday was it realised that man, even though black, is really man and deserves to be treated accordingly.

What formerly was woman? She was what she is to-day in the East: a gentle animal without a soul. The question was long discussed by the learned. The great divine of the seventeenth century, Bossuet himself, regarded woman as the diminutive of man. The proof was in the origin of Eve: she was the superfluous bone, the thirteenth rib which Adam possessed in the beginning. It has at last been admitted that woman possesses a soul like our own, but even superior in tenderness and devotion. She has been allowed to educate herself, which she has done at least as zealously as her coadjutor. But the law, that gloomy cavern which is still the lurking-place of so many barbarities, continues to regard her as an incapable and a minor. The law in turn will finally surrender to the truth.

The abolition of slavery and the education of woman: these are two enormous strides upon the path of moral progress. Our descendants will go farther. They will see, with a lucidity capable of piercing every obstacle, that war is the most hopeless of all absurdities. That our conquerors, victors of battles and destroyers of nations, are detestable scourges; that a clasp of the hand is preferable to a rifle-shot; that the happiest people is not that which possesses the largest battalions, but that which labours in peace and produces abundantly; and that the amenities of existence do not necessitate the existence of frontiers, beyond which we meet with all the annoyances of the custom-house, with its officials who search our pockets and rifle our luggage.

Our descendants will see this and many other marvels which to-day are extravagant dreams. To what ideal height will the process of evolution lead mankind? To no very magnificent height, it is to be feared. We are afflicted by an indelible taint, a kind of original sin, if we may call sin a state of things with which our will has nothing to do. We are made after a certain pattern and we can do nothing to change ourselves. We are marked with the mark of the beast, the taint of the belly, the inexhaustible source of bestiality.

The intestine rules the world. In the midst of our most serious affairs there intrudes the imperious question of bread and butter. So long as there are stomachs to digest—and as yet we are unable to dispense with them—we must find the wherewithal to fill them, and the powerful will live by the sufferings of the weak. Life is a void that only death can fill. Hence the endless butchery by which man nourishes himself, no less than beetles and other creatures; hence the perpetual holocausts which make of this earth a knacker's yard, beside which the slaughter-houses of Chicago are as nothing.

But the feasters are legion, and the feast is not abundant in proportion. Those that have not are envious of those that have; the hungry bare their teeth at the satisfied. Then follows the battle for the right of possession. Man raises armies; to defend his harvests, his granaries, and his cellars, he resorts to warfare. When shall we see the end of it? Alas, and many times alas! As long as there are wolves in the world there must be watch-dogs to defend the flock.

This train of thought has led us far away from our beetles. Let us return to them. What was my motive in provoking the massacre of this peaceful procession of caterpillars who were on the point of self-burial when I gave them over to the butchers? Was it to enjoy the spectacle of a frenzied massacre? By no means; I have always pitied the sufferings of animals, and the smallest life is worthy of respect. To overcome this pity there needed the exigencies of scientific research—exigencies which are often cruel.

In this case the subject of research was the habits of the Carabus auratus, the little vermin-killer of our gardens, who is therefore vulgarly known as the Gardener Beetle. How far is this title deserved? What game does the Gardener Beetle hunt? From what vermin does he free our beds and borders? His dealings with the procession of pine-caterpillars promise much. Let us continue our inquiry.

On various occasions about the end of April the gardens afford me the sight of such processions, sometimes longer, sometimes shorter. I capture them and place them in the vivarium. Bloodshed commences the moment the banquet is served. The caterpillars are eviscerated; each by a single beetle, or by several simultaneously. In less than fifteen minutes the flock is completely exterminated. Nothing remains but a few shapeless fragments, which are carried hither and thither, to be consumed at leisure under the shelter of the wooden board. One well-fed beetle decamps, his booty in his jaws, hoping to finish his feast in peace. He is met by companions who are attracted by the morsel hanging from the mandibles of the fugitive, and audaciously attempt to rob him. First two, then three, they all endeavour to deprive the legitimate owner of his prize. Each seizes the fragment, tugs at it, commences to swallow it without further ado. There is no actual battle; no violent assaults, as in the case of dogs disputing a bone. Their efforts are confined to the attempted theft. If the legitimate owner retains his hold they consume his booty in common, mandibles to mandibles, until the fragment is torn or bitten through, and each retires with his mouthful.

As I found to my cost in bygone experiments, the pine-caterpillar wields a violently corrosive poison, which produces a painful rash upon the hands. It must therefore, one would think, form a somewhat highly seasoned diet. The beetles, however, delight in it. No matter how many flocks I provide them with, they are all consumed. But no one, that I know of, has ever found the Golden Gardener and its larva in the silken cocoons of the Bombyx. I do not expect ever to make such a discovery. These cocoons are inhabited only in winter, when the Gardener is indifferent to food, and lies torpid in the earth. In April, however, when the processions of larvæ are seeking a suitable site for burial and metamorphosis, the Gardener should profit largely by its good fortune should it by any chance encounter them.

The furry nature of the victim does not in the least incommode the beetle; but the hairiest of all our caterpillars, the Hedgehog Caterpillar, with its undulating mane, partly red and partly black, does seem to be too much for the beetle. Day after day it wanders about the vivarium in company with the assassins. The latter apparently ignore its presence. From time to time one of them will halt, stroll round the hairy creature, examine it, and try to penetrate the tangled fleece. Immediately repulsed by the long, dense palisade of hairs, he retires without inflicting a wound, and the caterpillar proceeds upon its way with undulating mane, in pride and security.

But this state of things cannot last. In a hungry moment, emboldened moreover by the presence of his fellows, the cowardly creature decides upon a serious attack. There are four of them; they industriously attack the caterpillar, which finally succumbs, assaulted before and behind. It is eviscerated and swallowed as greedily as though it were a defenceless grub.

According to the hazard of discovery, I provision my menagerie with various caterpillars, some smooth and others hairy. All are accepted with the utmost eagerness, so long as they are of average size as compared with the beetles themselves. If too small they are despised, as they would not yield a sufficient mouthful. If they are too large the beetle is unable to handle them. The caterpillars of the Sphinx moth and the Great Peacock moth, for example, would fall an easy prey to the beetle were it not that at the first bite of the assailant the intended victim, by a contortion of its powerful flanks, sends the former flying. After several attacks, all of which end by the beetle being flung back to some considerable distance, the insect regretfully abandons his prey. I have kept two strong and lively caterpillars for a fortnight in the cage of my golden beetles, and nothing more serious occurred. The trick of the suddenly extended posterior was too much for the ferocious mandibles.

The chief utility of the Golden Gardener lies in its extermination of all caterpillars that are not too powerful to attack. It has one limitation, however: it is not a climber. It hunts on the ground; never in the foliage overhead. I have never seen it exploring the twigs of even the smallest of bushes. When caged it pays no attention to the most enticing caterpillars if the latter take refuge in a tuft of thyme, at a few inches above the ground. This is a great pity. If only the beetle could climb how rapidly three or four would rid our cabbages of that grievous pest, the larva of the white cabbage butterfly! Alas! the best have always some failing, some vice.

To exterminate caterpillars: that is the true vocation of the Golden Gardener. It is annoying that it can give us but little or no assistance in ridding us of another plague of the kitchen-garden: the snail. The slime of the snail is offensive to the beetle; it is safe from the latter unless crippled, half crushed, or projecting from the shell. Its relatives, however, do not share this dislike. The horny Procrustes, the great Scarabicus, entirely black and larger than the Carabus, attacks the snail most valiantly, and empties its shell to the bottom, in spite of the desperate secretion of slime. It is a pity that the Procrustes is not more frequently found in our gardens; it would be an excellent gardener's assistant.

CHAPTER IX

It is generally recognized that the Carabus auratus is an active exterminator of caterpillars; on this account in particular it deserves its title of Gardener Beetle; it is the vigilant policeman of our kitchen-gardens, our flower-beds and herbaceous borders. If my inquiries add nothing to its established reputation in this respect, they will nevertheless, in the following pages, show the insect in a light as yet unsuspected. The ferocious beast of prey, the ogre who devours all creatures that are not too strong for him, is himself killed and eaten: by his fellows, and by many others.

Standing one day in the shadow of the plane-trees that grow before my door, I see a Golden Gardener go by as if on pressing business. The pilgrim is well met; he will go to swell the contents of my vivarium. In capturing him I notice that the extremities of the wing-covers are slightly damaged. Is this the result of a struggle between rivals? There is nothing to tell me. The essential thing is that the insect should not be handicapped by any serious injury. Inspected, and found to be without any serious wound and fit for service, it is introduced into the glass dwelling of its twenty-five future companions.

Next day I look for the new inmate. It is dead. Its comrades have attacked it during the night and have cleaned out its abdomen, insufficiently protected by the damaged wing-covers. The operation has been performed very cleanly, without any dismemberment. Claws, head, corselet, all are correctly in place; the abdomen only has a gaping wound through which its contents have been removed. What remains is a kind of golden shell, formed of the two conjoined elytra. The shell of an oyster emptied of its inmate is not more empty.

This result astonishes me, for I have taken good care that the cage should never be long without food. The snail, the pine-cockchafer, the Praying Mantis, the lob-worm, the caterpillar, and other favourite insects, have all been given in alternation and in sufficient quantities. In devouring a brother whose damaged armour lent itself to any easy attack my beetles had not the excuse of hunger.

Is it their custom to kill the wounded and to eviscerate such of their fellows as suffer damage? Pity is unknown among insects. At the sight of the desperate struggles of a crippled fellow-creature none of the same family will cry a halt, none will attempt to come to its aid. Among the carnivorous insects the matter may develop to a tragic termination. With them, the passers-by will often run to the cripple. But do they do so in order to help it? By no means: merely to taste its flesh, and, if they find it agreeable, to perform the most radical cure of its ills by devouring it.

It is possible, therefore, that the Gardener with the injured wing-covers had tempted his fellows by the sight of his imperfectly covered back. They saw in their defenceless comrade a permissible subject for dissection. But do they respect one another when there is no previous wound? At first there was every appearance that their relations were perfectly pacific. During their sanguinary meals there is never a scuffle between the feasters; nothing but mere mouth-to-mouth thefts. There are no quarrels during the long siestas in the shelter of the board. Half buried in the cool earth, my twenty-five subjects slumber and digest their food in peace; they lie sociably near one another, each in his little trench. If I raise the plank they awake and are off, running hither and thither, constantly encountering one another without hostilities.

The profoundest peace is reigning, and to all appearances will last for ever, when in the early days of June I find a dead Gardener. Its limbs are intact; it is reduced to the condition of a mere golden husk; like the defenceless beetle I have already spoken of, it is as empty as an oyster-shell. Let us examine the remains. All is intact, save the huge breach in the abdomen. So the insect was sound and unhurt when the others attacked it.

A few days pass, and another Gardener is killed and dealt with as before, with no disorder in the component pieces of its armour. Let us place the dead insect on its belly; it is to all appearances untouched. Place it on its back; it is hollow, and has no trace of flesh left beneath its carapace. A little later, and I find another empty relic; then another, and yet another, until the population of my menagerie is rapidly shrinking. If this insensate massacre continues I shall soon find my cage depopulated.

Are my beetles hoary with age? Do they die a natural death, and do the survivors then clean out the bodies? Or is the population being reduced at the expense of sound and healthy insects? It is not easy to elucidate the matter, since the atrocities are commonly perpetrated in the night. But, finally, with vigilance, on two occasions, I surprise the beetles at their work in the light of day.

Towards the middle of June a female attacks a male before my eyes. The male is recognisable by his slightly smaller size. The operation commences. Raising the ends of the wing-covers, the assailant seizes her victim by the extremity of the abdomen, from the dorsal side. She pulls at him furiously, eagerly munching with her mandibles. The victim, who is in the prime of life, does not defend himself, nor turn upon his assailant. He pulls his hardest in the opposite direction to free himself from those terrible fangs; he advances and recoils as he is overpowered by or overpowers the assassin; and there his resistance ends. The struggle lasts a quarter of an hour. Other beetles, passing by, call a halt, and seem to say "My turn next!" Finally, redoubling his efforts, the male frees himself and flies. If he had not succeeded in escaping the ferocious female would undoubtedly have eviscerated him.