In the deep places, the water beetle dives, carrying with him his reserves of breath: an air bubble at the tip of the wing cases and, under the chest, a film of gas that gleams like a silver breastplate; on the surface, the ballet of those shimmering pearls, the whirligigs, turns and twists about; hard by there skims the unsubmersible troop of the pond skaters, who glide along with side strokes similar to those which the cobbler makes when sewing.

Here are the water boatmen, who swim on their backs with two oars spread cross-wise, and the flat water scorpions; here, squalidly clad in mud, is the grub of the largest of our dragonflies, so curious because of its manner of progression: it fills its hinder parts, a yawning funnel, with water, spurts it out again and advances just so far as the recoil of its hydraulic cannon.

The mollusks abound, a peaceful tribe. At the bottom, the plump river snails discreetly raise their lid, opening ever so little the shutters of their dwelling; on the level of the water, in the glades of the aquatic garden, the pond snails—Physa, Limnaea and Planorbis—take the air. Dark leeches writhe upon their prey, a chunk of earthworm; thousands of tiny, reddish grubs, future mosquitoes, go spinning around and twist and curve like so many graceful dolphins.

Yes, a stagnant pool, though but a few feet wide, hatched by the sun, is an immense world, an inexhaustible mine of observation to the studious man and a marvel to the child who, tired of his paper boat, diverts his eyes and thoughts a little with what is happening in the water. Let me tell what I remember of my first pond, at a time when ideas began to dawn in my seven-year-old brain.

How shall a man earn his living in my poor native village, with its inclement weather and its niggardly soil? The owner of a few acres of grazing land rears sheep. In the best parts, he scrapes the soil with the swing plow; he flattens it into terraces banked by walls of broken stones. Pannierfuls of dung are carried up on donkey-back from the cowshed. Then, in due season, comes the excellent potato, which, boiled and served hot in a basket of plaited straw, is the chief stand-by in winter.

Should the crop exceed the needs of the household, the surplus goes to feed a pig, that precious beast, a treasure of bacon and ham. The ewes supply butter and curds; the garden boasts cabbages, turnips and even a few hives in a sheltered corner. With wealth like that one can look fate in the face.

But we, we have nothing, nothing but the little house inherited by my mother and its adjoining patch of garden. The meager resources of the family are coming to an end. It is time to see to it and that quickly. What is to be done? That is the stern question which father and mother sat debating one evening.

Hop-o'-my-Thumb, hiding under the woodcutter's stool, listened to his parents overcome by want. I also, pretending to sleep, with my elbows on the table, listen not to blood curdling designs, but to grand plans that set my heart rejoicing. This is how the matter stands: at the bottom of the village, near the church, at the spot where the water of the large roofed spring escapes from its underground weir and joins the brook in the valley, an enterprising man, back from the war, has set up a small tallow factory. He sells the scrapings of his pans, the burnt fat, reeking of candle grease, at a low price. He proclaims these wares to be excellent for fattening ducks.

"Suppose we bred some ducks," says mother. "They sell very well in town. Henri would mind them and take them down to the brook."

"Very well," says father, "let's breed some ducks. There may be difficulties in the way; but we'll have a try."

That night, I had dreams of paradise: I was with my ducklings, clad in their yellow suits; I took them to the pond, I watched them have their bath, I brought them back again, carrying the more tired ones in a basket.

A month or two after, the little birds of my dreams were a reality. There were twenty-four of them. They had been hatched by two hens, of whom one, the big, black one, was an inmate of the house, while the other was borrowed from a neighbor.

To bring them up, the former is sufficient, so careful is she of her adopted family. At first, everything goes perfectly: a tub with two fingers' depth of water serves as a pond. On sunny days, the ducklings bathe in it under the anxious eye of the hen.

A fortnight later, the tub is no longer enough. It contains neither cresses crammed with tiny shellfish nor worms and tadpoles, dainty morsels both. The time has come for dives and hunts amid the tangle of the water weeds; and for us the day of trouble has also come. True, the miller, down by the brook, has fine ducks, easy and cheap to bring up; the tallow smelter, who has extolled his burnt fat so loudly, has some as well, for he has the advantage of the waste water from the spring at the bottom of the village; but how are we, right up there, at the top, to procure aquatic sports for our broods? In summer, we have hardly water to drink!

Near the house, in a freestone recess, a scanty source trickles into a basin made in the rock.. Four or five families have, like ourselves, to draw their water there with copper pails. By the time that the schoolmaster's donkey has slaked her thirst and the neighbors have taken their provision for the day, the basin is dry. We have to wait for four-and-twenty hours for it to fill. No, this is not the hole in which the ducks would delight nor indeed in which they would be tolerated.

There remains the brook. To go down to it with the troop of ducklings is fraught with danger. On the way through the village, we might meet cats, bold ravishers of small poultry; some surly mongrel might frighten and scatter the little band; and it would be a hard puzzle to collect it in its entirety. We must avoid the traffic and take refuge in peaceful and sequestered spots.

On the hills, the path that climbs behind the chateau soon takes a sudden turn and widens into a small plain beside the meadows. It skirts a rocky slope whence trickles, level with the ground, a streamlet, forming a pond of some size. Here profound solitude reigns all day long. The ducklings will be well off; and the journey can be made in peace by a deserted footpath.

You, little man, shall take them to that delectable spot. What a day it was that marked my first appearance as a herdsman of ducks! Why must there be a jar to the even tenor of such joys? The too frequent encounter of my tender skin with the hard ground had given me a large and painful blister on the heel. Had I wanted to put on the shoes stowed away in the cupboard for Sundays and holidays, I could not. There was nothing for it but to go barefoot over the broken stones, dragging my leg and carrying high the injured heel.

Let us make a start, hobbling along, switch in hand, behind the ducks. They too, poor little things, have sensitive soles to their feet; they limp, they quack with fatigue. They would refuse to go any farther if I did not, from time to time, call a halt under the shelter of an ash.

We are there at last. The place could not be better for my birdlets; shallow, tepid water, interspersed with muddy knolls and green eyots. The diversions of the bath begin forthwith. The ducklings clap their beaks and rummage here, there and everywhere; they sift each mouthful, rejecting the clear water and retaining the good bits. In the deeper parts, they point their sterns into the air and stick their heads under water. They are happy; and it is a blessed thing to see them at work. We will let them be. It is my turn to enjoy the pond.

What is this? On the mud lie some loose, knotted, soot-colored cords. One could take them for threads of wool like those which you pull out of an old ravelly stocking. Can some shepherdess, knitting a black sock and finding her work turn out badly, have begun all over again and, in her impatience, have thrown down the wool with all the dropped stitches? It really looks like it.

I take up one of those cords in my hand. It is sticky and extremely slack; the thing slips through the fingers before they can catch hold of it. A few of the knots burst and shed their contents. What comes out is a black globule, the size of a pin's head, followed by a flat tail. I recognize, on a very small scale, a familiar object: the tadpole, the frog's baby. I have seen enough. Let us leave the knotted cords alone.

The next creatures please me better. They spin round on the surface of the water and their black backs gleam in the sun. If I lift a hand to seize them, that moment they disappear, I know not where. It's a pity: I should have much liked to see them closer and to make them wriggle in a little bowl which I should have put ready for them.

Let us look at the bottom of the water, pulling aside those bunches of green string whence beads of air are rising and gathering into foam. There is something of everything underneath. I see pretty shells with compact whorls, flat as beans; I notice little worms carrying tufts and feathers; I make out some with flabby fins constantly flapping on their backs. What are they all doing there? What are their names? I do not know. And I stare at them for ever so long, held by the incomprehensible mystery of the waters.

At the place where the pond dribbles into the adjoining field are some alder trees; and here I make a glorious find. It is a scarab—not a very large one, oh no! He is smaller than a cherry-stone, but of an unutterable blue. The angels in paradise must wear dresses of that color. I put the glorious one inside an empty snail-shell, which I plug up with a leaf. I shall admire that living jewel at my leisure, when I get back. Other distractions summon me away.

The spring that feeds the pond trickles from the rock, cold and clear. The water first collects into a cup, the size of the hollow of one's two hands, and then runs over in a stream. These falls call for a mill: that goes without saying. Two bits of straw, artistically crossed upon an axis, provide the machinery; some flat stones set on edge afford supports. It is a great success: the mill turns admirably. My triumph would be complete, could I but share it. For want of other playmates, I invite the ducks.

Everything palls in this poor world of ours, even a mill made of two straws. Let us think of something else: let us contrive a dam to hold back the waters and form a pool. There is no lack of stones for the brickwork. I pick the most suitable; I break the larger ones. And, while collecting these blocks, suddenly I forget all about the dam which I meant to build.

On one of the broken stones, in a cavity large enough for me to put my fist in, something gleams like glass. The hollow is lined with facets gathered in sixes which flash and glitter in the sun. I have seen something like this in church, on the great saints' days, when the light of the candles in the big chandelier kindles the stars in its hanging crystal.

We children, lying, in summer, on the straw of the threshing floor, have told one another stories of the treasures which a dragon guards underground. Those treasures now return to my mind: the names of precious stones ring out uncertainly but gloriously in my memory. I think of the king's crown, of the princesses' necklaces. In breaking stones, can I have found, but on a much richer scale, the thing that shines quite small in my mother's ring? I want more such.

The dragon of the subterranean treasures treats me generously. He gives me his diamonds in such quantities that soon I possess a heap of broken stones sparkling with magnificent clusters. He does more: he gives me his gold. The trickle of water from the rock falls on a bed of fine sand which it swirls into bubbles. If I bent over towards the light, I see something like gold filings whirling where the fall touches the bottom. Is it really the famous metal of which twenty-franc pieces, so rare with us at home, are made? One would think so, from the glitter.

I take a pinch of sand and place it in my palm. The brilliant particles are numerous, but so small that I have to pick them up with a straw moistened in my mouth. Let us drop this: they are too tiny and too bothersome to collect. The big, valuable lumps must be farther on, in the thickness of the rock. We'll come back later; we'll blast the mountain.

I break more stones. Oh, what a queer thing has just come loose, all in one piece! It is turned spiral-wise, like certain flat snails that come out of the cracks of old walls in rainy weather. With its gnarled sides, it looks like a little ram's horn. Shell or horn, it is very curious. How do things like that find their way into the stone?

Treasures and curiosities make my pockets bulge with pebbles. It is late and the little ducklings have had all they want to eat. Come along, youngsters, let's go home. My blistered heel is forgotten in my excitement. The walk back is a delight. A voice sings in my ear, an untranslatable voice, softer than any language and bewildering as a dream. It speaks to me for the first time of the mysteries of the pond; it glorifies the heavenly insect which I hear moving in the empty snail shell, its temporary cage; it whispers the secrets of the rock, the gold filings, the faceted jewels, the ram's horn turned to stone.

Poor simpleton, smother your joy! I arrive. My parents catch sight of my bulging pockets, with their disgraceful load of stones. The cloth has given way under the rough and heavy burden.

"You rascal!" says father, at sight of the damage. "I send you to mind the ducks and you amuse yourself picking up stones, as though there weren't enough of them all round the house! Make haste and throw them away!"

Broken hearted, I obey. Diamonds, gold dust, petrified ram's horn, heavenly beetle are all flung on a rubbish heap outside the door.

Mother bewails her lot: "A nice thing, bringing up children to see them turn out so badly! You'll bring me to my grave. Green stuff I don't mind: it does for the rabbits. But stones, which ruin your pockets; poisonous animals, which'll sting your hand: what good are they to you, silly? There's no doubt about it: some one has thrown a spell over you!"

Yes, my poor mother, you were right, in your simplicity: a spell had been cast upon me; I admit it today. When it is hard enough to earn one's bit of bread, does not improving one's mind but render one more meet for suffering? Of what avail is the torment of learning to the derelicts of life?

A deal better off am I, at this late hour, dogged by poverty and knowing that the diamonds of the duck pool were rock crystal, the gold dust mica, the stone horn an Ammonite and the sky-blue beetle a Hoplia! We poor men would do better to mistrust the joys of knowledge: let us dig our furrow in the fields of the commonplace, flee the temptations of the pond, mind our ducks and leave to others, more favored by fortune, the job of explaining the world's mechanism, if the spirit moves them.

And yet no! Alone among living creatures, man has the thirst for knowledge; he alone pries into the mysteries of things. The least among us will utter his whys and his wherefores, a fine pain unknown to the brute beast. If these questionings come from us with greater persistence, with a more imperious authority, if they divert us from the quest of lucre, life's only object in the eyes of most men, does it become us to complain? Let us be careful not to do so, for that would be denying the best of all our gifts.

Let us strive, on the contrary, within the measure of our capacity, to force a gleam of light from the vast unknown; let us examine and question and, here and there, wrest a few shreds of truth. We shall sink under the task; in the present ill ordered state of society, we shall end, perhaps, in the workhouse. Let us go ahead for all that: our consolation shall be that we have increased by one atom the general mass of knowledge, the incomparable treasure of mankind.

As this modest lot has fallen to me, I will return to the pond, notwithstanding the wise admonitions and the bitter tears which I once owed to it. I will return to the pond, but not to that of the small ducks, the pond aflower with illusions: those ponds do not occur twice in a lifetime. For luck like that, you must be in all the new glory of your first breeches and your first ideas.

Many another have I come upon since that distant time, ponds very much richer and, moreover, explored with the ripened eye of experience. Enthusiastically I searched them with the net, stirred up their mud, ransacked their trailing weeds. None in my memories comes up to the first, magnified in its delights and mortifications by the marvelous perspective of the years.

Nor would any of them suit my plans of today. Their world is too vast. I should lose myself in their immensities, where life swarms freely in the sun. Like the ocean, they are infinite in their fruitfulness. And then any assiduous watching, undisturbed by passers by, is an impossibility on the public way. What I want is a pond on an extremely reduced scale, sparingly stocked in my own fashion an artificial pond standing permanently on my study table.

A louis has been overlooked in a corner of the drawer. I can spend it without seriously jeopardizing the domestic balance. Let me make this gift to science, who, I fear, will be none too much obliged to me. A gorgeous equipment may be all very well for laboratories wherein the cells and fibers of the dead are consulted at great expense; but such magnificence is of doubtful utility when we have to study the actions of the living. It is the humble makeshift, of no value, that stumbles on the secrets of life.

What did the best results of my studies of instinct cost me? Nothing but time and, above all, patience. My extravagant expenditure of twenty francs, therefore, will be a risky speculation if devoted to the purchase of an apparatus of study. It will bring me in nothing in the way of fresh views, of that I am convinced. However, let us try.

The blacksmith makes me the framework of a cage out of a few iron rods. The joiner, who is also a glazier on occasion—for, in my village, you have to be a Jack-of-all-trades if you would make both ends meet—sets the framework on a wooden base and supplies it with a movable board as a lid; he fixes thick panes of glass in the four sides. Behold the apparatus, complete, with a bottom of tarred sheet iron and a trap to let the water out.

The makers express themselves satisfied with their work, a singular novelty in their respective shops, where many an inquisitive caller has wondered what use I intend to make of my little glass trough. The thing creates a certain stir. Some insist that it is meant to hold my supplies of oil and to take the place of the receptacle in general use in our parts, the urn dug out of a block of stone. What would those utilitarians have thought of my crazy mind, had they known that my costly gear would merely serve to let me watch some wretched animals kicking about in the water!

Smith and glazier are content with their work. I myself am pleased. For all its rustic air, the apparatus does not lack elegance. It looks very well, standing on a little table in front of a window visited by the sun for the greater part of the day. Its holding capacity is some ten or eleven gallons. What shall we call it? An aquarium? No, that would be too pretentious and would, very unjustly, suggest the aquatic toy filled with rock work, waterfalls and goldfish beloved of the dwellers in suburbia. Let us preserve the gravity of serious things and not treat my learned trough as though it were a drawing room futility. We will call it the glass pond.

I furnish it with a heap of those limy incrustations wherewith certain springs in the neighborhood cover the dead clump of rushes. It is light, full of holes and gives a faint suggestion of a coral reef. Moreover, it is covered with a short, green, velvety moss, a downy sward of infinitesimal pond weed. I count on this modest vegetation to keep the water in a reasonably wholesome state, without driving me to frequent renewals which would disturb the work of my colonies. Sanitation and quiet are the first conditions of success. Now the stocked pond will not be long in filling itself with gases unfit to breathe, with putrid effluvia and other animal refuse; it will become a sink in which life will have killed life. Those dregs must disappear as soon as they are formed, must be burnt and purified; and from their oxidized ruins there must even rise a perfect life-giving gas, so that the water may retain an unchangeable store of the breathable element. The plant effects this purification in its sewage farm of green cells.

When the sun beats upon the glass pond, the work of the water weeds is a sight to behold. The green-carpeted reef is lit up with an infinity of scintillating points and assumes the appearance of a fairy lawn of velvet, studded with thousands of diamond pin's heads. From this exquisite jewelry pearls break loose continuously and are at once replaced by others in the generating casket; slowly they rise, like tiny globes of light. They spread on every side. It is a constant display of fireworks in the depths of the water.

Chemistry tells us that, thanks to its green matter and the stimulus of the sun's rays, the weeds decompose the carbonic acid gas wherewith the water is impregnated by the breathing of its inhabitants and the corruption of the organic refuse; it retains the carbon, which is wrought into fresh tissues; it exhales the oxygen in tiny bubbles. These partly dissolve in the water and partly reach the surface, where their froth supplies the atmosphere with an excess of breathable gas. The dissolved portion keeps the colonists of the pond alive and causes the unhealthy products to be oxidized and disappear.

Old hand though I be, I take an interest in this trite marvel of a bundle of weeds perpetuating hygienic principles in a stagnant pool; I look with a delighted eye upon the inexhaustible spray of spreading bubbles; I see in imagination the prehistoric times when seaweed, the first-born of plants, produced the first atmosphere for living things to breathe at the time when the silt of the continents was beginning to emerge. What I see before my eyes, between the glass panes of my trough, tells me the story of the planet surrounding itself with pure air.



CHAPTER VIII. THE CADDIS WORM

Whom shall I lodge in my glass trough, kept permanently wholesome by the action of the water weeds? I shall keep caddis worms, those expert dressers. Few of the self-clothing insects surpass them in ingenious attire. The ponds in my neighborhood supply me with five or six species, each possessing an art of its own. Today, but one of these shall receive historical honors.

I obtain it from the muddy bottomed, stagnant pools crammed with small reeds. As far as one can judge from the habitation merely, it should be, according to the specialists, Limnophilus flavicornis, whose work has earned for the whole corporation the pretty name of Phryganea, a Greek term meaning a bit of wood, a stick. In a no less expressive fashion, the Provencal peasant calls it lou portofais, lou porto-caneu. This is the little grub that carries through the still waters a faggot of tiny fragments fallen from the reeds.

Its sheath, a travelling house, is a composite and barbaric piece of work, a megalithic pile wherein art, retires in favor of amorphous strength. The materials are many and sundry, so much so that we might imagine that we had the work of dissimilar builders before our eyes, if frequent transitions did not tell us the contrary.

With the young ones, the novices, it starts with a sort of deep basket in rustic wicker-work. The twigs employed present nearly always the same characteristics and are none other than bits of small, stiff roots, long steeped and peeled under water. The grub that has made a find of these fibers saws them with its mandibles and cuts them into little straight sticks, which it fixes one by one to the edge of its basket, always crosswise, perpendicular to the axis of the work.

Picture a circle surrounded by a bristling mass of tangents, or rather a polygon with its sides extended in all directions. On this assemblage of straight lines we place repeated layers of others, without troubling about similarity of position, thus obtaining a sort of ragged fascine, whose sticks project on every side. Such is the bastion of the child grub, an excellent system of defense, with its continuous pile of spikes, but difficult to steer through the tangle of aquatic plants.

Sooner or later, the worm forsakes this kind of caltrop which catches on to everything. It was a basket maker, it now turns carpenter; it builds with little beams and joists—that is to say, with round bits of wood, browned by the water, often as wide as a thick straw and a finger's-breadth long, more or less—taking them as chance supplies them.

For the rest, there is something of everything in this rag bag: bits of stubble, fag ends of rushes, scraps of plants, fragments of some tiny twig or other, chips of wood, shreds of bark, largish grains, especially the seeds of the yellow iris, which were red when they fell from their capsules and are now black as jet.

The heterogeneous collection is piled up anyhow. Some pieces are fixed lengthwise, others across, others aslant. There are angles in this direction and angles in the other, resulting in sharp little turns and twists; the big is mixed with the little, the correct rubs shoulders with the shapeless. It is not an edifice, it is a frenzied conglomeration. Sometimes, a fine disorder is an effect of art. This is not so here: the work of the Caddis worm is not a masterpiece worth signing.

And this mad heaping up follows straight upon the regular basket work of the start. The young grub's fascine did not lack a certain elegance, with its dainty laths, all stacked crosswise, methodically; and, lo and behold, the builder, grown larger, more experienced and, one would think, more skilful, abandons the orderly plan to adopt another which is wild and incoherent! There is no transition stage between the two systems. The extravagant pile rises abruptly from the original basket. But that we often find the two kinds of work placed one above the other, we would not dare ascribe to them a common origin. The fact of their being joined together is the only thing that makes them one, in spite of the incongruity.

But the two storeys do not last indefinitely. When the worm has grown slightly and is housed to its satisfaction in a heap of joists, it abandons the basket of its childhood, which has become too narrow and is now a troublesome burden. It cuts through its sheath, lops off and lets go the stern, the original work. When moving to a higher and roomier flat, it understands how to lighten its portable house by breaking off a part of it. All that remains is the upper floor, which is enlarged at the aperture, as and when required, by the same architecture of disordered beams.

Side by side with these cases, which are mere ugly faggots, we find others just as often of exquisite beauty and composed entirely of tiny shells. Do they come from the same workshop? It takes very convincing proofs to make us believe this. Here is order with its charm, there disorder with its hideousness; on the one hand a dainty mosaic of shells, on the other a clumsy heap of sticks. And yet it is all produced by the same laborer.

Proofs abound. On some case which offends the eye with the want of arrangement in its bits of wood, patches are apt to appear which are quite regular and made of shells; in the same way, it is not unusual to see a horrid tangle of joists braced to a masterpiece of shell work. One feels a certain annoyance at seeing the pretty sheath so barbarously spoilt.

This mixed construction tells us that the rustic stacker of wooden beams excels, when occasion offers, in making elegant shell pavements and that it practices rough carpentry and delicate mosaic work indifferently. In the latter instance, the scabbard is made, above all, of Planorbes, selected among the smaller of these pond snails and laid flat. Without being scrupulously regular, the work, at its best, does not lack merit. The pretty, close-whorled spirals, placed one against the other on the same level, have a very pleasing general effect. No pilgrim returning from Santiago de Compostella ever slung handsomer tippet from his shoulders.

But only too often the caddis worm dashes ahead, regardless of proportion. The big is joined to the small, the exaggerated suddenly stands out, to the great detriment of order. Side by side with tiny Planorbes, each at most the size of a lentil, others are fixed as large as one's fingernail; and these cannot possibly be fitted in correctly. They overlap the regular parts and spoil their finish.

To crown the disorder, the caddis worm adds to the flat spirals any dead shell that comes handy, without distinction of species, provided it be not excessively large. I notice, in its collection of bric-a-brac, the Physa, the Paludina, the Limnaea, the Amber snail [all pond snails] and even the Pisidium [a bivalve], that little twin-valved casket.

Land shells, swept into the ditches by the rains after the inmate's death, are accepted quite as readily. In the work made of the Mollusk's cast-off clothing, I find encrusted the spindle shell of the Clausilium, the key shell of the pupa, the spiral of the smaller Helix, the yawning volute of the Vitrina, or glass snail, the turret shell of the Bulimus [all land snails], denizens all of the fields. In short, the caddis worm builds with more or less everything that comes from the plant or the dead mollusk. Among the diversified refuse of the pond, the only materials rejected are those of a gravelly nature. Stone and pebble are excluded from the building with a care that is very rarely absent. This is a question of hydrostatics to which we will return presently. For the moment, let us try to follow the construction of the scabbard.

In a tumbler small enough to allow of easy and precise observation, I install three or four caddis worms, extracted this moment from their sheaths with every possible precaution. After a number of attempts which have at last shown me the right road, I place at their disposal two kinds of materials, possessing opposite qualities; the supple and the firm, the soft and the hard. On the one hand, we have a live aquatic plant, such as watercress, for instance, or ombrelle d'eau, having at its base a tufty bunch of fine white roots about as thick as a horsehair. In these soft tresses, the caddis worm, which observes a vegetarian diet, will find at one and the same time the wherewithal to build and eat. On the other hand, we have a little faggot of bits of wood, very dry, equal in length and each possessing the thickness of a good sized pin. The two sorts of building material lie side by side, mingling their threads and sticks. The animal can make its choice from the lump.

A few hours later, having recovered from the shock of losing its sheath, the caddis worm sets to work to manufacture a new one. It settles across a bunch of tangled rootlets, which are brought together by the builder's legs and more or less arranged by the undulating movement of the hinder part. This gives a kind of incoherent and ill defined suspended belt, a narrow hammock with a number of loose catches; for the various bits of which it is made up are respected by the teeth and extended from place to place beyond the main cords of the roots. Here, without much trouble, is the support, suitably fixed by natural moorings. A few threads of silk, casually distributed, make the frail combination a trifle more secure.

And now to the work of building. Supported by the suspended belt, the caddis worm stretches itself and thrusts out its middle legs, which, being longer than the others, are the grapnels intended to seize things at a distance. It meets a bit of root, fastens on to it, climbs above the point gripped, as though it were measuring the piece to a requisite length, and then, with the fine scissors of its mandibles, cuts the string.

There is at once a brief recoil, which brings the animal back to the level of the hammock. The bit detached lies across the worm's chest, held in its forelegs, which turn it, twist it, wave it about, lay it down, lift it up, as though trying for the best position. Those forelegs make admirably dexterous arms. Being less long than the other two pairs, they are brought into immediate contact with those primordial implements, the mandibles and the spinneret. Their delicate terminal jointing, with a movable and crooked finger, is the caddis worm's equivalent of our hand. They are the working legs. The second pair, which are exceptionally long, serve to spear distant materials and to give the worker a firm footing when measuring a piece and cutting it with the pliers. Lastly, the hind legs, of medium length, afford a support when the others are busy.

The caddis worm, I was saying, with the piece which it has removed held crosswise to its chest, retreats a little way along its suspended hammock until the spinneret is level with the support furnished by the close tangle of rootlets. With a quick movement, it shifts its burden, gets it as nearly by the middle as it can, so that the two ends stick out equally on either side, and chooses the spot to place it, whereupon the spinneret sets to work at once, while the little fore legs hold the scrap of root motionless in its transversal position. The soldering is effected with a touch of silk in the middle of the bit and along a certain distance to the right and left, as far as the bending of the head permits.

Without delay, other sticks are speared in like manner at a distance, cut off and placed in position. As the immediate neighborhood is stripped, the material is gathered at a yet greater distance and the caddis worm bends even farther from its support, which now holds only its last few segments. It is a curious gymnastic display, that of this soft, hanging spine turning and swaying, while the grapnels feel in every direction for a thread.

All this labor results in a sort of casing of little white cords. The work lacks firmness and regularity. Nevertheless, judging by the builder's methods, I can see that the building would not be devoid of merit if the materials gave it a better chance. The caddis worm estimates the size of its pieces very fairly; it cuts them all to nearly the same length; it always arranges them crosswise on the margin of the case; it fixes them by the middle.

Nor is this all: the manner of working helps the general arrangement considerably. When the bricklayer is building the narrow shaft of a factory chimney, he stands in the center of his turret and turns round and round while gradually laying new rows. The caddis worm acts in the same way. It twists round in its sheath; it adopts without inconvenience whatever position it pleases, so as to bring its spinneret full face with the point to be gummed. There is no straining of the neck to left or right, no throwing back of the head to reach points behind. The animal has constantly before it, within the exact range of its implements, the place at which the bit is to be fixed. When the piece is soldered, the worm turns a little aside, to a length equal to that of the last soldering, and here, along an extent which hardly ever varies, an extent determined by the swing which its head is able to give, it fixes the next piece.

These several conditions ought to result in a geometrically ordered dwelling, having a regular polygon as an opening. Then how comes it that the cylinder of bits of root is so confused, so clumsily fashioned? The reason is this: the worker possesses talent, but the materials do not lend themselves to accurate work. The rootlets supply stumps of very uneven shape and thickness. They include big and small ones, straight and bent, simple and ramified. To combine all these dissimilar pieces into an orderly whole is hardly possible, all the more so as the caddis worm does not appear to attach very much importance to its cylinder, which is a temporary work, hurriedly constructed to afford a speedy shelter. Matters are urgent; and very soft fibers, clipped with a bite of the mandibles, are more quickly gathered and more easily put together than joists, which require the patient work of the saw. The inaccurate cylinder, in short, held in position by numerous guy ropes, is a base upon which a solid and definite structure will rise before long. Soon, the original work will crumble to ruins and disappear, whereas the new one, a permanent structure, will even outlast the owner.

The insects reared in a tumbler show yet another method of building the first dwelling. This time, the caddis worm is given a few very leafy stalks of pond weed (Potamogeton densum) and a bundle of small dry twigs. It perches on a leaf, which the nippers of the mandibles cut half across. The portion left untouched will act as a lanyard and give the necessary steadiness to the early operations.

From an adjoining leaf a section is cut out entirely, an angular and good sized piece. There is plenty of material and no need for economy. The piece is soldered with silk to the strip which was not wholly cut off. The result of three or four similar operations is to surround the Caddis worm with a conical bag, whose wide mouth is scalloped with pointed and very irregular notches. The work of the nippers continues; fresh pieces are fixed, from one to another, inside the funnel, not far from the edge, so that the bag lengthens, tapers and ends by wrapping the animal in a light and floating drapery.

Thus clad for the time being, either in the fine silk of the pond weed or in the linsey-woolsey supplied by the roots of the watercress, the caddis worm begins to think of building a more solid sheath. The present casing will serve as a foundation for the stronger building. But the necessary materials are seldom near at hand: you have to go and fetch them, you have to move your position, an effort which has been avoided until now. With this object, the caddis worm cuts its moorings, that is to say, the rootlets which keep the cylinder fixed, or else the half-severed leaf of pond weed on which the cone-shaped bag has come into being.

The worm is now free. The smallness of the artificial pond, the tumbler, soon brings it into touch with what it is seeking. This is a little faggot of dry twigs, which I have selected of equal length and of slight thickness. Displaying greater care than it did when treating the slender roots, the carpenter measures out the requisite length on the joist. The distance to which it has to extend its body in order to reach the point where the break will be made tells it pretty accurately what length of stick it wants.

The piece is patiently sawn off with the mandibles; it is next taken in the fore legs and held crosswise below the neck. The backward movement which brings the caddis worm home also brings the bit of twig to the edge of the tube. Thereupon, the methods employed in working with the scraps of root are renewed in precisely the same manner. The sticks are scaffolded to the regulation height, all alike in length, amply soldered in the middle and free at either end.

With the picked materials provided, the carpenter has turned out a work of some elegance. The joists are all arranged crosswise, because this way is the handiest for carrying the sticks and putting them in position; they are fixed by the middle, because the two arms that hold the stick while the spinneret does its work require an equal grasp on either side; each soldering covers a length which is seen to be practically invariable, because it is equal to the width described by the head in bending first to this side and then to that when the silk is emitted; the whole assumes a polygonal shape, not far removed from a rectilinear pentagon, because, between laying one piece and the next, the caddis worm turns by the width of an arc corresponding with the length of a soldering. The regularity of the method produces the regularity of the work; but it is essential, of course, that the materials should lend themselves to precise coordination.

In its natural pond, the caddis worm does not often have at its disposal the picked joists which I give it in the tumbler. It comes across something of everything; and that something of everything it employs as it finds it. Bits of wood, large seeds, empty shells, stubble stalks, shapeless fragments are used in the building for better or for worse, just as they occur, without being trimmed by the saw; and this jumble, the result of chance, results in a shockingly faulty structure.

The caddis worm does not forget its talents; but it lacks choice pieces. Give it a proper timber yard and it at once reverts to correct architecture, of which it carries the plans within itself. With small, dead pond snails, all of the same size, it fashions a splendid patchwork scabbard; with a cluster of slender roots, reduced by rotting to their stiff, straight, woody axis, it manufactures pretty specimens of wicker work which could serve as models to our basket makers.

Let us watch it at work when it is unable to use its favorite joist. There is no point in giving it clumsy building stones; that would only bring us back to the uncouth sheaths. Its propensity to make use of soaked seeds, those of the iris, for instance, suggests that I might try grains. I select rice, which, because of its hardness, will be tantamount to wood and, because of its clean whiteness and its oval shape, will lend itself to artistic masonry.

Obviously, my denuded caddis worms cannot start their work with bricks of this kind. Where would they fix their first layer? They must have a foundation, quick and easy to build. This is once more supplied by a temporary cylinder of watercress roots. On this support follow the grains of rice, which, grouped one atop the other, straight or slanting, end by giving a magnificent turret of ivory. Next to the sheaths made of tiny snail shells, this is the prettiest thing with which the caddis worm's industry has furnished me. A fine sense of order has returned, because the materials, regular and of identical character, have cooperated with the correct method of the worker.

The two demonstrations are enough. Sticks and grains of rice make it plain that the caddis worm is not the bungler that one would expect from the monstrous buildings in the pond. Those Cyclopean piles, those mad conglomerations, are the inevitable results of chance finds, which are used for the best because there is no choice. The water carpenter has an art of its own, has method and rules of symmetry. When well served by fortune, it is quite able to turn out good work; when ill-served, it acts like others: the work which it turns out is bad. Poverty makes for ugliness.

There is another matter wherein the caddis worm deserves our attention. With a perseverance which repeated trials do not tire, it makes itself a new tube when I strip it. This is opposed to the habits of the generality of insects, which do not recommence the thing once done, but simply continue it according to the usual rules, taking no account of the ruined or vanished portions. The caddis worm is a striking exception: it starts again. Whence does it derive this capacity?

I begin by learning that, given a sudden alarm, it readily leaves its scabbard. When I go fishing for caddis worms, I put them in tin boxes, containing no other moisture than that wherewith my catches are soaked. I heap them up loosely, to avoid any grievous tumult and to fill the space at my disposal as best I may. I take no further precaution. This is enough to keep the caddis worms in good condition during the two or three hours which I devote to fishing and to walking home.

On my return, I find that a number of them have left their houses. They are swarming naked among the empty scabbards and those still occupied by their inhabitants. It is a pitiful sight to see these evicted ones dragging their bare abdomens and their frail respiratory threads over the bristling sticks. There is no great harm done, however; and I empty the whole lot into the glass pond.

Not one resumes possession of an unoccupied sheath. Perhaps it would take them too long to find one of the exact size. They think it better to abandon the old clouts and to manufacture cases new from top to bottom. The process is a rapid one. By the next day, with the materials wherein the glass trough abounds—bundles of twigs and tufts of watercress—all the denuded worms have made themselves at least a temporary home in the form of a tube of rootlets.

The lack of water, combined with the excitement of the crowding in the boxes, has upset my captives greatly; and, scenting a grave peril, they have made off hurriedly, doffing the cumbersome jacket, which is difficult to carry. They have stripped themselves so as to flee with greater ease. The alarm cannot have been due to me: there are not many simpletons like myself who are interested in the affairs of the pond; and the caddis worm has not been cautioned against their tricks. The sudden desertion of the crib has certainly some other reason than man's molestations.

I catch a glimpse of this reason, the real one. The glass pond was originally occupied by a dozen Dytisci, or water beetles, whose diving performances are so curious to watch. One day, meaning no harm and for want of a better receptacle, I fling among them a couple of handfuls of caddis worms. Blunderer that I am, what have I done! The corsairs, hiding in the rugged corners of the rock work, at once perceive the windfall. They rise to the surface with great strokes of their oars; they hasten and fling themselves upon the crowd of carpenters. Each pirate grabs a sheath by the middle and strives to rip it open by tearing off shells and sticks. While this ferocious enucleation continues with the object of reaching the dainty morsel contained within, the caddis worm, close pressed, appears at the mouth of the sheath, slips out and quickly decamps under the eyes of the Dytiscus, who appears to notice nothing.

I have said before that the trade of killing can dispense with intelligence. The brutal ripper of sheaths does not see the little white sausage that slips between his legs, passes under his fangs and madly flees. He continues to tear away the outer case and to tug at the silken lining. When the breach is made, he is quite crestfallen at not finding what he expected.

Poor fool! Your victim went out under your nose and you never saw it. The worm has sunk to the bottom and taken refuge in the mysteries of the rock work. If things were happening in the large expanse of a pond, it is clear that, with their system of expeditious removals, most of the lodgers would escape scot-free. Fleeing to a distance and recovering from the sharp alarm, they would build themselves a new scabbard and all would be over until the next attack, which would be baffled afresh by the selfsame trick.

In my narrow trough, things take a more tragic turn. When the sheaths are done for, when the caddis worms that are too slow in making off have been eaten up, the Water beetles return to the rockery at the bottom. Here, sooner or later, there are lamentable happenings. The naked fugitives are discovered and, succulent morsels that they are, are forthwith torn to pieces and devoured. Within twenty-four hours, not one of my band of caddis worms is left alive. In order to continue my studies, I had to lodge the water beetles elsewhere.

Under natural conditions, the caddis worm has its persecutors, the most formidable of whom appears to be the Water beetle. When we consider that, to thwart the brigand's attacks, it has invented the idea of quitting its scabbard with all speed, its tactics are certainly most appropriate; but, in that case, an exceptional condition becomes obligatory, namely, the capacity for recommencing the work. This most unusual gift of recommencing it possesses in a high measure. I am ready to see its origin in the persecutions of the Dytiscus and other pirates. Necessity is the mother of industry.

Certain caddis worms, of the Sericostoma and Leptocerus species, clothe themselves in grains of sand and do not leave the bed of the stream. On a clear bottom, swept by the current, they walk about from one bank of verdure to the other and do not think of coming to the surface to float and sail in the sunlight. The collectors of sticks and shells are more highly privileged. They can remain on the level of the water indefinitely, with no other support than their skiff, can rest in unsubmersible flotillas and can even shift their place by working the rudder.

To what do they owe this privilege? Are we to look upon the bundle of sticks as a sort of raft whose density is less than that of the water? Can the shells, which are always empty and able to contain a few bubbles of air in their spiral, he floats? Can the big joists, which break in so ugly a fashion the none too great regularity of the work, serve to buoy up the over-heavy raft? In short, is the caddis worm versed in the laws of equilibrium and does it choose its pieces, now lighter and now heavier as the case may be, so as to constitute a whole that is capable of floating? The following facts are a refutation of any such hydrostatic calculations in the animal.

I remove a number of caddis worms from their sheaths and submit these, as they are, to the test of water. Whether formed wholly of fibrous remnants or of mixed materials, not one of them floats. The scabbards made of shells go to the bottom with the swiftness of a bit of gravel; the others sink gently. I experiment with the separate materials one by one. No shell remains on the surface, not even among the Planorbes, which a many-whorled spiral ought, one would think, to keep afloat. The fibrous remnants must be divided into two categories. The first, darkened by time and soaked with moisture, sink to the bottom. These are the most plentiful. The second, considerably fewer in number, of more recent date and less saturated with water, float very well. The general result is immersion, as in the case of the intact scabbards. I may add that the animal, when removed from its tube, is also unable to float.

Then how does the caddis worm manage to remain on the surface without the support of the grasses, considering that itself and its sheath are both heavier than water? Its secret is soon revealed. I place a few high and dry on a sheet of blotting paper, which will absorb the excess of liquid unfavorable to successful observation. Outside its natural environment, the animal moves about violently and restlessly. With its body half out of the scabbard, this time composed entirely of fibrous matter, it clutches with its feet at the supporting plane. Then, contracting itself, it draws the scabbard towards it, half-raising it and sometimes even making it assume a vertical position. Even so do the Bulimi move along, lifting their shell as they complete each crawling step.

After a couple of minutes in the free air, I replace the caddis worm in the water. This time, it floats, but like a cylinder with too much weight below. The sheath remains vertical, with its hinder orifice level with the water. Soon, an air bubble escapes from the orifice. Deprived of this buoy, the skiff at once goes down.

The result is the same with the caddis worms in shell casings. At first, they float, straight up on end, and then dip under and sink, faster than the others, after sending out an air bubble or two through the back window.

That is enough: the secret is out. When cased in wood or in shells, the caddis worms, which are always heavier than water, are able to keep on the surface by means of a temporary air balloon which decreases the density of the whole structure.

This apparatus works in the simplest manner. Consider the rear of the sheath. It is truncated, wide open and supplied with a membranous partition, the work of the spinneret. A round hole occupies the center of this screen. Beyond it lies the interior of the scabbard, which is smoothly lined and wadded with satin, however rough the exterior may be. Armed at the stern with two hooks which bite into the silky lining, the animal is able to move backwards and forwards at will inside the cylinder, to fix its grapnels at whatever point it pleases and thus to keep a hold on the cylinder while the six legs and the fore part are outside.

When at rest, the body remains indoors entirely and the grub occupies the whole of the tube. But let it contract ever so little towards the front, or, better still, let it stick out a part of its body: a vacuum is formed behind this sort of piston, which may be compared with that of a pump. Thanks to the rear window, a valve without a plug, this vacuum at once fills, thus renewing the aerated water around the gills, a soft fleece of hairs distributed over the back and belly.

The piston stroke affects only the work of breathing; it does not alter the density, makes hardly any change in that which is heavier than water. To lighten the weight, the caddis worm must first rise to the surface. With this object, it scales the grasses of one support after the other; it clambers up, sticking to its purpose in spite of the drawback of its faggot dragging through the tangle. When it has reached the goal, it lifts the rear end a little above the water and gives a stroke of the piston. The vacuum thus obtained fills with air. That is enough: skiff and boatman are in a position to float. The now useless support of the grasses is abandoned. The time has come for evolutions on the surface, in the glad sunlight.

The caddis worm possesses no great talent as a navigator. To turn round, to tack about, to shift its place slightly by a backward movement is all that it can do; and even that it does very clumsily. The front part of the body, sticking out of the case, acts as a rudder. Three or four times over, it rises abruptly, bends, comes down again and strikes the water. These paddle strokes, repeated at intervals, carry the unskilled oarsman to fresh latitudes. It becomes a voyage on the right seas when the crossing measures a hand's breadth.

However, tacking on the surface of the water affords the caddis worm no pleasure. It prefers to twitter in one spot, to remain stationary in flotillas. When the time comes to return to the quiet of the mud bed at the bottom, the animal, having had enough of the sun, draws itself wholly into its sheath again and, with a piston stroke, expels the air from the back room. The normal density is restored and it sinks slowly to the bottom.

We see, therefore, that the caddis worm has not to trouble about hydrostatics when building its scabbard. In spite of the incongruity of its work, in which the bulky and less dense portions seem to balance the more solid, concentrated part, it is not called upon to contrive an equipoise between the light and the heavy. It has other artifices whereby to rise to the surface, to float and to dive down again. The ascent is made by the ladder of the water weeds. The average density of the sheath is of no importance, so long as the burden to be dragged is not beyond the animal's strength. Besides, the weight of the load is greatly reduced when moved in the water.

The admission of a bubble of air into the back chamber, which the animal ceases to occupy, allow it, without further to-do, to remain for an indefinite period on the surface. To dive down again, the caddis worm has only to retreat entirely into its sheath. The air is driven out; and the canoe, resuming its mean density, a greater specific density than that of water, goes under at once and descends of its own accord.

There is, therefore, no choice of materials on the builder's part, no nice calculation of equilibrium, save for one condition, that no stony matter be admitted. That apart, everything serves, large and small, joist and shell, seed and billet. Built up at haphazard, all these things make an impregnable wall. One point alone is essential: the weight of the whole must slightly exceed that of the water displaced; if not, there could be no steadiness at the bottom of the pond, without a perpetual anchorage struggling against the pull of the water. In the same manner, quick submersion would be impossible at times when the surface became dangerous and the frightened creature wanted to leave it.

Nor does this important heavier-than-water question call for lucid discernment, seeing that almost the whole of the sheath is constructed at the bottom of the pond, whither all the materials picked up at random, having descended once before, are likely to descend again. In the sheaths, the parts capable of floating are very rare. Without taking their specific levity into account, simply so as not to remain idle, the caddis worm fixed them to its bundle when sporting on the surface of the water.

We have our submarines, in which hydraulic ingenuity displays its highest resources. The caddis worms have theirs, which emerge, float on the surface, dip down and even stop at mid-depth by releasing gradually their surplus air. And this apparatus, so perfectly balanced, so skilful, requires no knowledge on the part of its constructor. It comes into being of itself, in accordance with the plans of the universal harmony of things.



CHAPTER IX. THE GREENBOTTLES

I have wished for a few things in my life, none of them capable of interfering with the common weal. I have longed to possess a pond, screened from the indiscretion of the passers by, close to my house, with clumps of rushes and patches of duckweed. Here, in my leisure hours, in the shade of a willow, I should have meditated upon aquatic life, a primitive life, easier than our own, simpler in its affections and its brutalities. I should have watched the unalloyed happiness of the mollusk, the frolics of the Whirligig, the figure-skating of the Hydrometra [a water bug known as the Pond skater], the dives of the Dytiscus beetle, the veering and tacking of the Notonecta [the water boatman], who, lying on her back, rows with two long oars, while her short forelegs, folded against her chest, wait to grab the coming prey. I should have studied the eggs of the Planorbis, a glairy nebula wherein focuses of life are condensed even as suns are condensed in the nebulae of the heavens. I should have admired the nascent creature that turns, slowly turns in the orb of its egg and describes a volute, the draft, perhaps, of the future shell. No planet circles round its center of attraction with greater geometrical accuracy.

I should have brought back a few ideas from my frequent visits to the pond. Fate decided otherwise: I was not to have my sheet of water. I have tried the artificial pond, between four panes of glass. A poor shift! Our laboratory aquariums are not even equal to the print left in the mud by a mule's hoof, when once a shower has filled the humble basin and life has stocked it with its marvels.

In spring, with the hawthorn in flower and the crickets at their concerts, a second wish often came to me. Along the road, I light upon a dead mole, a snake killed with a stone, victims both of human folly. The mole was draining the soil and purging it of its vermin. Finding him under his spade, the laborer broke his back for him and flung him over the hedge. The snake, roused from her slumber by the soft warmth of April, was coming into the sun to shed her skin and take on a new one. Man catches sight of her: 'Ah, would you?' says he. 'See me do something for which the world will thank me!'

And the harmless beast, our auxiliary in the terrible battle which husbandry wages against the insect, has its head smashed in and dies.

The two corpses, already decomposing, have begun to smell. Whoever approaches with eyes that do not see turns away his head and passes on. The observer stops and lifts the remains with his foot; he looks. A world is swarming underneath; life is eagerly consuming the dead. Let us replace matters as they were and leave death's artisans to their task. They are engaged in a most deserving work.

To know the habits of those creatures charged with the disappearance of corpses, to see them busy at their work of disintegration, to follow in detail the process of transmutation that makes the ruins of what has lived return apace into life's treasure house: these are things that long haunted my mind. I regretfully left the mole lying in the dust of the road. I had to go, after a glance at the corpse and its harvesters. It was not the place for philosophizing over a stench. What would people say who passed and saw me!

And what will the reader himself say, if I invite him to that sight? Surely, to busy one's self with those squalid sextons means soiling one's eyes and mind? Not so, if you please! Within the domain of our restless curiosity, two questions stand out above all others: the question of the beginning and the question of the end. How does matter unite in order to assume life? How does it separate when returning to inertia? The pond, with its Planorbis eggs turning round and round, would have given us a few data for the first problem; the Mole, going bad under conditions not too repulsive, will tell us something about the second: he will show us the working of the crucible wherein all things are melted to begin anew. A truce to nice delicacy! Odi profanum vulgus et arceo; hence, ye profane: you would not understand the mighty lesson of the rag tank.

I am now in a position to realize my second wish. I have space, air and quiet in the solitude of the harmas. None will come here to trouble me, to smile or to be shocked at my investigations. So far, so good; but observe the irony of things: now that I am rid of passers by, I have to fear my cats, those assiduous prowlers, who, finding my preparations, will not fail to spoil and scatter them. In anticipation of their misdeeds, I establish workshops in midair, whither none but genuine corruption agents can come, flying on their wings. At different points in the enclosure, I plant reeds, three by three, which, tied at their free ends, form a stable tripod. From each of these supports, I hang, at a man's height, an earthenware pan filled with fine sand and pierced at the bottom with a hole to allow the water to escape, if it should rain. I garnish my apparatus with dead bodies. The snake, the lizard, the toad receive the preference, because of their bare skins, which enable me better to follow the first attack and the work of the invaders. I ring the changes with furred and feathered beasts. A few children of the neighborhood, allured by pennies, are my regular purveyors. Throughout the good season, they come running triumphantly to my door, with a snake at the end of a stick, or a lizard in a cabbage leaf. They bring me the rat caught in a trap, the chicken dead of the pip, the mole slain by the gardener, the kitten killed by accident, the rabbit poisoned by some weed. The business proceeds to the mutual satisfaction of sellers and buyer. No such trade had ever been known before in the village nor ever will be again.

April ends; and the pans rapidly fill. An ant, ever so small, is the first arrival. I thought I should keep this intruder off by hanging my apparatus high above the ground: she laughs at my precautions. A few hours after the deposit of the morsel, fresh still and possessing no appreciable smell, up comes the eager picker-up of trifles, scales the stems of the tripod in processions and starts the work of dissection. If the joint suits her, she even goes to live in the sand of the pan and digs herself temporary platforms in order to work the rich find more at her ease.

All through the season, from start to finish, she will always be the promptest, always the first to discover the dead animal, always the last to beat a retreat when nothing more remains than a heap of little bones bleached by the sun. How does the vagabond, passing at a distance, know that, up there, invisible, high on the gibbet, there is something worth going for? The others, the real knackers, wait for the meat to go bad; they are informed by the strength of the effluvia. The ant, gifted with greater powers of scent, hurries up before there is any stench at all. But, when the meat, now two days old and ripened by the sun, exhales its flavor, soon the master ghouls appear upon the scene: Dermestes [bacon beetles, small flesh-eating beetles] and Saprini [exceedingly small flesh-eating beetles], Silphae [carrion beetles] and Necrophori [burying beetles], flies and Staphylini [rove beetles], who attack the corpse, consume it and reduce it almost to nothing. With the ant alone, who each time carries off a mere atom, the sanitary operation would take too long; with them, it is a quick business, especially as certain of them understand the process of chemical solvents.

These last, who are high class scavengers, are entitled to first mention. They are flies, of many various species. If time permitted, each of those strenuous ones would deserve a special examination; but that would weary the patience of both the reader and the observer. The habits of one will give us a summary notion of the habits of the rest. We will therefore confine ourselves to the two principal subjects, namely, the Luciliae, or greenbottles, and the Sarcophagae, or grey flesh flies.

The Luciliae—flies that glitter—are magnificent flies known to all of us. Their metallic luster, generally a golden green, rivals that of our finest beetles, the Rosechafers, Buprestes and leaf beetles. It gives one a shock of surprise to see so rich a garb adorn those workers in putrefaction. Three species frequent my pans: Lucilia Caesar, LIN., L. cadaverina, LIN., and L. cuprea, ROB. The first two, both of whom are gold-green, are plentiful; the third, who sports a coppery luster, is rare. All three have red eyes, set in a silver border.

Lucilia Caesar is larger than L. cadaverina and also more forward in her business. I catch her in labor on the 23rd of April. She has settled in the spinal canal of a neck of mutton and is laying her eggs on the marrow. For more than an hour, motionless in the gloomy cavity, she goes on packing her eggs. I can just see her red eyes and her silvery face. At last, she comes out. I gather the fruit of her labor, an easy matter, for it all lies on the marrow, which I extract without touching the eggs.

A census would seem important. To take it at once is impracticable: the germs form a compact mass, which would be difficult to count. The best thing is to rear the family in a jar and to reckon by the pupae buried in the sand. I find a hundred and fifty-seven. This is evidently but a minimum; for Lucilia Caesar and the others, as the observations that follow will tell me, lay in packets at repeated intervals. It is a magnificent family, promising a fabulous legion to come.

The greenbottles, I was saying, break up their laying into sections. The following scene affords a proof of this. A Mole, shrunk by a few days' evaporation, lies spread upon the sand of the pan. At one point, the edge of the belly is raised and forms a deep arch. Remark that the Greenbottles, like the rest of the flesh eating flies, do not trust their eggs to uncovered surfaces, where the heat of the sun's rays might endanger the existence of the delicate germs. They want dark hiding places. The favorite spot is the lower side of the dead animal, when this is accessible.

In the present case, the only place of access is the fold formed by the edge of the belly. It is here and here alone that this day's mothers are laying. There are eight of them. After exploring the piece and recognizing its good quality, they disappear under the arch, first this one, then that, or else several at a time. They remain under the Mole for a considerable while. Those outside wait, but go repeatedly to the threshold of the cavern to take a look at what is happening within and see whether the earlier ones have finished. These come out at last, perch on the animal and wait in their turn. Others at once take their place in the recesses of the cave. They remain there for some time and then, having done their business, make room for more mothers and come forth into the sunlight. This going in and out continues throughout the morning.

We thus learn that the laying is effected by periodical emissions, broken with intervals of rest. As long as she does not feel ripe eggs coming to her oviduct, the greenbottle remains in the sun, hovering to and fro and sipping modest mouthfuls from the carcass. But, as soon as a fresh stream descends from her ovaries, quick as lightning she makes for a propitious site whereon to deposit her burden. It appears to be the work of several days thus to divide the total laying and to distribute it at different points.

I carefully raise the animal under which these things are happening. The egg laying mothers do not disturb themselves; they are far too busy. Their ovipositor extended telescope fashion, they heap egg upon egg. With the point of their hesitating, groping instrument, they try to lodge each germ, as it comes, farther into the mass. Around the serious, red-eyed matrons, the Ants circle, intent on pillage. Many of them make off with a greenbottle egg between their teeth. I see some who, greatly daring, effect their theft under the ovipositor itself. The layers do not put themselves out, let the ants have their way, remain impassive. They know their womb to be rich enough to make good any such larceny.

Indeed, what escapes the depredations of the ants promises a plenteous brood. Let us come back a few days later and lift the mole again. Underneath, in a pool of sanies, is a surging mass of swarming sterns and pointed heads, which emerge, wriggle and dive in again. It suggests a seething billow. It turns one's stomach. It is horrible, most horrible. Let us steel ourselves against the sight: it will be worse elsewhere.

Here is a fat snake. Rolled into a compact whorl, she fills the whole pan. The greenbottles are plentiful. New ones arrive at every moment and, without quarrel or strife, take their place among the others, busily laying. The spiral furrow left by the reptile's curves is the favorite spot. Here alone, in the narrow space between the folds, are shelters against the heat of the sun. The glistening Flies take their places, side by side, in rows; they strive to push their abdomen and their ovipositor as far forward as possible, at the risk of rumpling their wings and cocking them towards their heads. The care of the person is neglected amid this serious business. Placidly, with their red eyes turned outwards, they form a continuous cordon. Here and there, at intervals, the rank is broken; layers leave their posts, come and walk about upon the snake, what time their ovaries ripen for another emission, and then hurry back, slip into the rank and resume the flow of germs. Despite these interruptions, the work of breeding goes fast. In the course of one morning, the depths of the spiral furrow are hung with a continuous white bark, the heaped up eggs. They come off in great slabs, free of any stain; they can be shoveled up, as it were, with a paper scoop. It is a propitious moment if we wish to follow the evolution at close quarters. I therefore gather a profusion of this white manna and lodge it in glass tubes, test tubes and jars, with the necessary provisions.

The eggs, about a millimeter long, are smooth cylinders, rounded at both ends. They hatch within twenty-four hours. The first question that presents itself is this: how do the greenbottle grubs feed? I know quite well what to give them, but I do not in the least see how they manage to consume it. Do they eat, in the strict sense of the word? I have reasons to doubt it.

Let us consider the grub grown to a sufficient size. It is the usual fly larva, the common maggot, shaped like an elongated cone, pointed in front, truncated behind, where two little red spots show, level with the skin: these are the breathing holes. The front, which is called the head by stretching a word—for it is little more than the entrance to an intestine—the front is armed with two little black hooks, which slide in a translucent sheath, project a little way outside and go in turn by turn. Are we to look upon these as mandibles? Not at all, for, instead of having their points facing each other, as would be required in a real mandibular apparatus, the two hooks work in parallel directions and never meet. What they are is ambulatory organs, grapnels assisting locomotion, which give a purchase on the plane and enable the animal to advance by means of repeated contractions. The maggot walks with the aid of what a superficial examination would pronounce to be a machine for eating. It carries in its gullet the equivalent of the climber's alpenstock.

Let us hold it, on a piece of flesh, under the lens. We shall see it walking about, raising and lowering its head and, each time, stabbing the meat with its pair of hooks. When stationary, with its crupper at rest, it explores space with a continual bending of its fore part; its pointed head pokes about, jabs forward, goes back again, producing and withdrawing its black mechanism. There is a perpetual piston play. Well, look as carefully and conscientiously as I please, I do not once see the weapons of the mouth tackle a particle of flesh that is torn away and swallowed. The hooks come down upon the meat at every moment, but never take a visible mouthful from it. Nevertheless, the grub waxes big and fat. How does this singular consumer, who feeds without eating, set about it? If he does not eat, he must drink; his diet is soup. As meat is a compact substance, which does not liquefy of its own accord, there must, in that case, be a certain recipe to dissolve it into a fluid broth. Let us try to surprise the maggot's secret.

In a glass tube, sealed at one end, I insert a piece of lean flesh, the size of a walnut, which I have drained of its juices by squeezing it in blotting paper. On the top of this, I place a few slabs of greenbottle eggs collected a moment ago from the snake in my earthen pan. The number of germs is, roughly, two hundred. I close the tube with a cotton plug, stand it upright, in a shady corner of my study, and leave things to take their course. A control tube, prepared like the first, but not stocked with maggots, is placed beside it.

As early as two or three days after the hatching, I obtain a striking result. The meat, which was thoroughly drained by the blotting paper, has become so moist that the young vermin leave a wet mark behind them as they crawl over the glass. The swarming brood creates a sort of mist with the crossing and criss-crossing of its trails. The control tube, on the contrary, keeps dry, proving that the moisture in which the worms move is not due to a mere exudation from the meat.

Besides, the work of the maggot becomes more and more evident. Gradually, the flesh flows in every direction like an icicle placed before the fire. Soon, the liquefaction is complete. What we see is no longer meat, but fluid Liebig's extract. If I overturned the tube, not a drop of it would remain.

Let us clear our minds of any idea of solution by putrefaction, for in the second tube a piece of meat of the same kind and size has remained, save for color and smell, what it was at the start. It was a lump and it is a lump, whereas the piece treated by the worms runs like melted butter. Here we have maggot chemistry able to rouse the envy of physiologists when studying the action of the gastric juice.

I obtain better results still with hard-boiled white of egg. When cut into pieces the size of a hazel nut and handed over to the greenbottle's grubs, the coagulated albumen dissolves into a colorless liquid which the eye might mistake for water. The fluidity becomes so great that, for lack of a support, the worms perish by drowning in the broth; they are suffocated by the immersion of their hind part, with its open breathing holes. On a denser liquid, they would have kept at the surface; on this, they cannot.

A control tube, filled in the same way, but not colonized, stands beside that in which the strange liquefaction takes place. The hardboiled white of egg retains its original appearance and consistency. In course of time, it dries up, if it does not turn moldy; and that is all.

The other quaternary compounds performing the same functions as albumen—the gluten of cereals, the fibrin of blood, the casein of cheese and the legumin of chickpeas—undergo a similar modification, in varying degrees. Fed, from the moment of leaving the egg, on any one of these substances, the worms thrive very well, provided that they escape drowning when the gruel becomes too clear; they would not fare better on a corpse. And, as a general rule, there is not much danger of going under: the matter only half liquefies; it becomes a running pea soup, rather than an actual fluid.

Even in this imperfect case, it is obvious that the greenbottle grubs begin by liquefying their food. Incapable of taking solid nourishment, they first transform the spoil into running matter; then, dipping their heads into the product, they drink, they slake their thirst, with long sups. Their dissolvent, comparable in its effects with the gastric juice of the higher animals, is, beyond a doubt, emitted through the mouth. The piston of the hooks, continually in movement, never ceases spitting it out in infinitesimal doses. Each spot touched receives a grain of some subtle pepsin, which soon suffices to make that spot run in every direction. As digesting, when all is said, merely means liquefying, it is no paradox to assert that the maggot digests its food before swallowing it.

These experiments with my filthy, evil smelling tubes have given me some delightful moments. The worthy Abbe Spallanzani must have known some such when he saw pieces of raw meat begin to run under the action of the gastric juice which he took, with pellets of sponge, from the stomachs of crows. He discovered the secrets of digestion; he realized in a glass tube the hitherto unknown labors of gastric chemistry. I, his distant disciple, behold once more, under a most unexpected aspect, what struck the Italian scientist so forcibly. Worms take the place of the crows. They slaver upon meat, gluten, albumen; and those substances turn to fluid. What our stomach does within its mysterious recesses the maggot achieves outside, in the open air. It first digests and then imbibes.

When we see it plunging into the carrion broth, we even wonder if it cannot feed itself, at least to some extent, in a more direct fashion. Why should not its skin, which is one of the most delicate, be capable of absorbing? I have seen the egg of the sacred beetle and other dung beetles growing considerably larger—I should like to say, feeding—in the thick atmosphere of the hatching chamber. Nothing tells us that the grub of the greenbottle does not adopt this method of growing. I picture it capable of feeding all over the surface of its body. To the gruel absorbed by the mouth it adds the balance of what is gathered and strained through the skin. This would explain the need for provisions liquefied beforehand.

Let us give one last proof of this preliminary liquefaction. If the carcass—mole, snake or another—left in the open air have a wire gauze cover placed over it, to keep out the flies, the game dries under a hot sun and shrivels up without appreciably wetting the sand on which it lies. Fluids come from it, certainly, for every organized body is a sponge swollen with water; but the liquid discharge is so slow and restricted in quantity that the heat and the dryness of the air disperse it as it appears, while the underlying sand remains dry, or very nearly so. The carcass becomes a sapless mummy, a mere bit of leather. On the other hand, do not use the wire gauze cover, let the flies do their work unimpeded; and things forthwith assume another aspect. In three or four days, an oozing sanies appears under the animal and soaks the sand to some distance.

I shall never forget the striking spectacle with which I conclude this chapter. This time, the dish is a magnificent Aesculapius' snake, a yard and a half long and as thick as a wide bottleneck. Because of its size, which exceeds the dimensions of my pan, I roll the reptile in a double spiral, or in two storeys. When the copious joint is in full process of dissolution, the pan becomes a puddle wherein wallow, in countless numbers, the grubs of the greenbottle and those of Sarcophaga carnaria, the Grey or checkered flesh fly, which are even mightier liquefiers. All the sand in the apparatus is saturated, has turned into mud, as though there had been a shower of rain. Through the hole at the bottom, which is protected by a flat pebble, the gruel trickles drop by drop. It is a still at work, a mortuary still, in which the Snake is being drawn off. Wait a week or two; and the whole will have disappeared, drunk up by the sun: naught but the scales and bones will remain on a sheet of mud.

To conclude: the maggot is a power in this world. To give back to life, with all speed, the remains of that which has lived, it macerates and condenses corpses, distilling them into an essence wherewith the earth, the plant's foster mother, may be nourished and enriched.



CHAPTER X. THE GREY FLESH FLIES

Here the costume changes, not the manner of life. We find the same frequenting of dead bodies, the same capacity for the speedy liquefaction of the fleshy matter. I am speaking of an ash-gray fly, the greenbottle's superior in size, with brown streaks on her back and silver gleams on her abdomen. Note also the blood-red eyes, with the hard look of the knacker in them. The language of science knows her as Sarcophaga, the flesh eater; in the vulgar tongue she is the grey flesh fly, or simply the flesh fly.

Let not these expressions, however accurate, mislead us into believing for a moment that the Sarcophagae are the bold company of master tainters who haunt our dwellings, more particularly in autumn, and plant their vermin in our ill-guarded viands. The author of those offences is Calliphora vomitoria, the bluebottle, who is of a stouter build and arrayed in darkest blue. It is she who buzzes against our windowpanes, who craftily besieges the meat safe and who lies in wait in the darkness for an opportunity to outwit our vigilance. The other, the grey fly, works jointly with the greenbottles, who do not venture inside our houses and who work in the sunlight. Less timid, however, than they, should the outdoor yield be small, she will sometimes come indoors to perpetrate her villainies. When her business is done, she makes off as fast as she can, for she does not feel at home with us.

At this moment, my study, a very modest extension of my open air establishments, has become something of a charnel house. The grey fly pays me a visit. If I lay a piece of butcher's meat on the windowsill, she hastens up, works her will on it and retires. No hiding place escapes her notice among the jars, cups, glasses and receptacles of every kind with which my shelves are crowded.

With a view to certain experiments, I collected a heap of wasp grubs, asphyxiated in their underground nests. Stealthily she arrives, discovers the fat pile and, hailing as treasure trove this provender whereof her race perhaps has never made use before, entrusts to it an installment of her family. I have left at the bottom of a glass the best part of a hard-boiled egg from which I have taken a few bits of white intended for the greenbottle maggots. The grey fly takes possession of the remains, recks not of their novelty and colonizes them. Everything suits her that falls within the category of albuminous matters: everything, down to dead silkworms; everything, down to a mess of kidney-beans and chick-peas.