The Glow-worm
萤火虫
让－亨利·法布尔 Jean-Henri Fabre（1823–1915）
译者：Alexander Teixeira de Mattos（1865–1921），1919 年
法布尔晚年应译者之请用法文写成，供译成英文；先刊于《世纪杂志》，1918 年收入书中；这里是 1919 年的修订文本

冷冻图书馆 · 开架书库 · S-006204 · https://coldlibrary.com/s/006204
权利：作者法布尔卒于 1915 年。译者亚历山大·特谢拉·德·马托斯卒于 1921 年；他的译文 1918 年首次收入书中，这里的修订文本发表于 1919 年。已按澳大利亚、欧盟、英国、中国大陆和美国的规则核对（截至 2026 年 10 月 11 日）。仅供参考，不是法律意见。
来源：Project Gutenberg，https://www.gutenberg.org/cache/epub/27868/pg27868.txt（取于 2026-10-11）
中文译文：Claude（AI），2026 · CC0 1.0
生成于 2026-10-14，来自 https://coldlibrary.com/open-stacks/fabre-the-glow-worm

----

Few insects in our climes vie in popular fame with the Glow-worm, that curious little animal which, to celebrate the little joys of life, kindles a beacon at its tail-end. Who does not know it, at least by name? Who has not seen it roam amid the grass, like a spark fallen from the moon at its full? The Greeks of old called it λάμπουρις, meaning, the bright-tailed. Science employs the same term: it calls the lantern-bearer, *Lampyris noctiluca*, LIN. In this case, the common name is inferior to the scientific phrase, which, when translated, becomes both expressive and accurate.

In fact, we might easily cavil at the word "worm." The Lampyris is not a worm at all, not even in general appearance. He has six short legs, which he well knows how to use; he is a gad-about, a trot-about. In the adult state, the male is correctly garbed in wing-cases, like the true Beetle that he is. The female is an ill-favoured thing who knows naught of the delights of flying: all her life long, she retains the larval shape, which, for the rest, is similar to that of the male, who himself is imperfect so long as he has not achieved the maturity that comes with pairing-time. Even in this initial stage, the word "worm" is out of place. We French have the expression "Naked as a worm," to point to the lack of any defensive covering. Now the Lampyris is clothed, that is to say, he wears an epidermis of some consistency; moreover, he is rather richly coloured: his body is dark brown all over, set off with pale pink on the thorax, especially on the lower surface. Finally, each segment is decked at the hinder edge with two spots of a fairly bright red. A costume like this was never worn by a worm.

Let us leave this ill-chosen denomination and ask ourselves what the Lampyris feeds upon. That master of the art of gastronomy, Brillat-Savarin, said:

"Show me what you eat and I will tell you what you are."

A similar question should be addressed, by way of a preliminary, to every insect whose habits we propose to study, for, from the least to the greatest in the zoological progression, the stomach sways the world; the data supplied by food are the chief of all the documents of life. Well, in spite of his innocent appearance, the Lampyris is an eater of flesh, a hunter of game; and he follows his calling with rare villainy. His regular prey is the Snail.

This detail has long been known to entomologists. What is not so well-known, what is not known at all yet, to judge by what I have read, is the curious method of attack, of which I have seen no other instance anywhere.

Before he begins to feast, the Glow-worm administers an anaesthetic: he chloroforms his victim, rivalling in the process the wonders of our modern surgery, which renders the patient insensible before operating on him. The usual game is a small Snail hardly the size of a cherry, such as, for instance, *Helix variabilis*, DRAP., who, in the hot weather, collects in clusters on the stiff stubble and on other long, dry stalks, by the roadside, and there remains motionless, in profound meditation, throughout the scorching summer days. It is in some such resting-place as this that I have often been privileged to light upon the Lampyris banqueting on the prey which he had just paralyzed on its shaky support by his surgical artifices.

But he is familiar with other preserves. He frequents the edges of the irrigating-ditches, with their cool soil, their varied vegetation, a favourite haunt of the mollusc. Here, he treats the game on the ground; and, under these conditions, it is easy for me to rear him at home and to follow the operator's performance down to the smallest detail.

I will try to make the reader a witness of the strange sight. I place a little grass in a wide glass jar. In this I install a few Glow-worms and a provision of Snails of a suitable size, neither too large nor too small, chiefly *Helix variabilis*. We must be patient and wait. Above all, we must keep an assiduous watch, for the desired events come unexpectedly and do not last long.

Here we are at last. The Glow-worm for a moment investigates the prey, which, according to its habit, is wholly withdrawn in the shell, except the edge of the mantle, which projects slightly. Then the hunter's weapon is drawn, a very simple weapon, but one that cannot be plainly perceived without the aid of a lens. It consists of two mandibles bent back powerfully into a hook, very sharp and as thin as a hair. The microscope reveals the presence of a slender groove running throughout the length. And that is all.

The insect repeatedly taps the Snail's mantle with its instrument. It all happens with such gentleness as to suggest kisses rather than bites. As children, teasing one another, we used to talk of "tweaksies" to express a slight squeeze of the finger-tips, something more like a tickling than a serious pinch. Let us use that word. In conversing with animals, language loses nothing by remaining juvenile. It is the right way for the simple to understand one another.

The Lampyris doles out his tweaks. He distributes them methodically, without hurrying, and takes a brief rest after each of them, as though he wished to ascertain the effect produced. Their number is not great: half-a-dozen, at most, to subdue the prey and deprive it of all power of movement. That other pinches are administered later, at the time of eating, seems very likely, but I cannot say anything for certain, because the sequel escapes me. The first few, however—there are never many—are enough to impart inertia and loss of all feeling to the mollusc, thanks to the prompt, I might almost say, lightning methods of the Lampyris, who, beyond a doubt, instils some poison or other by means of his grooved hooks.

Here is the proof of the sudden efficacity of those twitches, so mild in appearance: I take the Snail from the Lampyris, who has operated on the edge of the mantle some four or five times. I prick him with a fine needle in the fore-part, which the animal, shrunk into its shell, still leaves exposed. There is no quiver of the wounded tissues, no reaction against the brutality of the needle. A corpse itself could not give fewer signs of life.

Here is something even more conclusive: chance occasionally gives me Snails attacked by the Lampyris while they are creeping along, the foot slowly crawling, the tentacles swollen to their full extent. A few disordered movements betray a brief excitement on the part of the mollusc and then everything ceases: the foot no longer slugs; the front-part loses its graceful swan-neck curve; the tentacles become limp and give way under their weight, dangling feebly like a broken stick. This conditions persists.

Is the Snail really dead? Not at all, for I am free to resuscitate the seeming corpse. After two or three days of that singular condition which is no longer life and yet not death, I isolate the patient and, although this is not really necessary to success, I give him a douche which will represent the shower so dear to the able-bodied mollusc. In about a couple of days, my prisoner, but lately injured by the Glow-worm's treachery, is restored to his normal state. He revives, in a manner; he recovers movement and sensibility. He is affected by the stimulus of a needle; he shifts his place, crawls, puts out his tentacles, as though nothing unusual had occurred. The general torpor, a sort of deep drunkenness, has vanished outright. The dead returns to life. What name shall we give to that form of existence which, for a time, abolishes the power of movement and the sense of pain? I can see but one that is approximately suitable: anaesthesia. The exploits of a host of Wasps whose flesh-eating grubs are provided with meat that is motionless though not dead have taught us the skilful art of the paralyzing insect, which numbs the locomotory nerve-centres with its venom. We have now a humble little animal that first produces complete anaesthesia in its patient. Human science did not in reality invent this art, which is one of the wonders of our latter-day surgery. Much earlier, far back in the centuries, the Lampyris and, apparently, others knew it as well. The animal's knowledge had a long start of ours; the method alone has changed. Our operators proceed by making us inhale the fumes of ether or chloroform; the insect proceeds by injecting a special virus that comes from the mandibular fangs in infinitesimal doses. Might we not one day be able to benefit by this hint? What glorious discoveries the future would have in store for us, if we understood the beastie's secrets better!

What does the Lampyris want with anaesthetical talent against a harmless and moreover eminently peaceful adversary, who would never begin the quarrel of his own accord? I think I see. We find in Algeria a Beetle known as *Drilus maroccanus*, who, though non-luminous, approaches our Glow-worm in his organization and especially in his habits. He too feeds on land molluscs. His prey is a Cyclostome with a graceful spiral shell, tight-closed with a stony lid which is attached to the animal by a powerful muscle. The lid is a movable door which is quickly shut by the inmate's mere withdrawal into his house and as easily opened when the hermit goes forth. With this system of closing, the abode becomes inviolable; and the Drilus knows it.

Fixed to the surface of the shell by an adhesive apparatus whereof the Lampyris will presently show us the equivalent, he remains on the look-out, waiting, if necessary, for whole days at a time. At last, the need of air and food oblige the besieged noncombatant to show himself; at least, the door is set slightly ajar. That is enough. The Drilus is on the spot and strikes his blow. The door can no longer be closed and the assailant is henceforth master of the fortress. Our first impression is that the muscle moving the lid has been cut with a quick-acting pair of shears. This idea must be dismissed. The Drilus is not well enough equipped with jaws to gnaw through a fleshy mass so promptly. The operation has to succeed at once, at the first touch: if not, the animal attacked would retreat, still in full vigour, and the siege must be recommenced, as arduous as ever, exposing the insect to fasts indefinitely prolonged. Although I have never come across the Drilus, who is a stranger to my district, I conjecture a method of attack very similar to that of the Glow-worm. Like our own Snail-eater, the Algerian insect does not cut its victim into small pieces: it renders it inert, chloroforms it by means of a few tweaks which are easily distributed, if the lid but half-opens for a second. That will do. The besieger thereupon enters and, in perfect quiet, consumes a prey incapable of the least muscular effort. That is how I see things by the unaided light of logic.

Let us now return to the Glow-worm. When the Snail is on the ground, creeping, or even shrunk into his shell, the attack never presents any difficulty. The shell possesses no lid and leaves the hermit's fore-part to a great extent exposed. Here, on the edges of the mantle contracted by the fear of danger, the mollusc is vulnerable and incapable of defence. But it also frequently happens that the Snail occupies a raised position, clinging to the tip of a grass-stalk or perhaps to the smooth surface of a stone. This support serves him as a temporary lid; it wards off the aggression of any churl who might try to molest the inhabitant of the cabin, always on the express condition that no slit show itself anywhere on the protecting circumference. If, on the other hand, in the frequent case when the shell does not fit its support quite closely, some point, however tiny, be left uncovered, this is enough for the subtle tools of the Lampyris, who just nibbles at the mollusc and at once plunges him into that profound immobility which favours the tranquil proceedings of the consumer.

These proceedings are marked by extreme prudence. The assailant has to handle his victim gingerly, without provoking contractions which would make the Snail let go his support and, at the very least, precipitate him from the tall stalk whereon he is blissfully slumbering. Now any game falling to the ground would seem to be so much sheer loss, for the Glow-worm has no great zeal for hunting-expeditions: he profits by the discoveries which good luck sends him, without undertaking assiduous searches. It is essential, therefore, that the equilibrium of a prize perched on the top of a stalk and only just held in position by a touch of glue should be disturbed as little as possible during the onslaught; it is necessary that the assailant should go to work with infinite circumspection and without producing pain, lest any muscular reaction should provoke a fall and endanger the prize. As we see, sudden and profound anaesthesia is an excellent means of enabling the Lampyris to attain his object, which is to consume his prey in perfect quiet.

What is his manner of consuming it? Does he really eat, that is to say, does he divide his food piecemeal, does he carve it into minute particles, which are afterwards ground by a chewing-apparatus? I think not. I never see a trace of solid nourishment on my captives' mouths. The Glow-worm does not eat in the strict sense of the word: he drinks his fill; he feeds on a thin gruel into which he transforms his prey by a method recalling that of the maggot. Like the flesh-eating grub of the Fly, he too is able to digest before consuming; he liquefies his prey before feeding on it.

This is how things happen: a Snail has been rendered insensible by the Glow-worm. The operator is nearly always alone, even when the prize is a large one, like the Common Snail, *Helix aspersa*. Soon a number of guests hasten up—two, three or more—and, without any quarrel with real proprietor, all alike fall to. Let us leave them to themselves for a couple of days and then turn the shell, with the opening downwards. The contents flow out as easily as would soup from an overturned saucepan. When the sated diners retire from this gruel, only insignificant leavings remain.

The matter is obvious: by repeated tiny bites, similar to the tweaks which we saw distributed at the outset, the flesh of the mollusc is converted into a gruel on which the various banqueters nourish themselves without distinction, each working at the broth by means of some special pepsine and each taking his own mouthfuls of it. In consequence of this method, which first converts the food into a liquid, the Glow-worm's mouth must be very feebly armed apart from the two fangs which sting the patient and inject the anaesthetic poison and, at the same time, no doubt, the serum capable of turning the solid flesh into fluid. These two tiny implements, which can just be examined through the lens, must, it seems, have some other object. They are hollow and in this resemble those of the Ant-lion, which sucks and drains its capture without having to divide it; but there is this great difference, that the Ant-lion leaves copious remnants, which are afterwards flung outside the funnel-shaped trap dug in the sand, whereas the Glow-worm, that expert liquefier, leaves nothing, or next to nothing. With similar tools, the one simply sucks the blood of its prey and the other turns every morsel of his to account, thanks to a preliminary liquefaction.

And this is done with exquisite precision, though the equilibrium is sometimes anything but steady. My rearing-glasses supply me with magnificent examples. Crawling up the sides, the Snails imprisoned in my apparatus sometimes reach the top, which is closed with a glass pane, and fix themselves to it by means of a speck of glair. This is a mere temporary halt, in which the mollusc is miserly with its adhesive product, and the merest shake is enough to loosen the shell and send it to the bottom of the jar.

Now it is not unusual for the Glow-worm to hoist himself to the top, with the help of a certain climbing-organ that makes up for his weak legs. He selects his quarry, makes a minute inspection of it to find an entrance-slit, nibbles it a little, renders it insensible and, without delay, proceeds to prepare the gruel which he will consume for days on end.

When he leaves the table, the shell is found to be absolutely empty; and yet this shell, which was fixed to the glass by a very faint stickiness, has not come loose, has not even shifted its position in the smallest degree: without any protest from the hermit gradually converted into broth, it has been drained on the very spot at which the first attack was delivered. These small details tell us how promptly the anaesthetic bite takes effect; they teach us how dexterously the Glow-worm treats his Snail without causing him to fall from a very slippery vertical support and without even shaking him on his slight line of adhesion.

Under these conditions of equilibrium, the operator's short, clumsy legs are obviously not enough; a special accessory apparatus is needed to defy the danger of slipping and to seize the unseizable. And this apparatus the Lampyris possesses. At the hinder end of the animal we see a white spot which the lens separates into some dozen short, fleshy appendages, sometimes gathered into a cluster, sometimes spread into a rosette. There is your organ of adhesion and locomotion. If he would fix himself somewhere, even on a very smooth surface, such as a grass-stalk, the Glow-worm opens his rosette and spreads it wide on the support, to which it adheres by its own stickiness. The same organ, rising and falling, opening and closing, does much to assist the act of progression. In short, the Glow-worm is a new sort of self-propelled cripple, who decks his hind-quarters with a dainty white rose, a kind of hand with twelve fingers, not jointed, but moving in every direction: tubular fingers which do not seize, but stick.

The same organ serves another purpose: that of a toilet-sponge and brush. At a moment of rest, after a meal, the Glow-worm passes and repasses the said brush over his head, back, sides and hinder-parts, a performance made possible by the flexibility of his spine. This is done point by point, from one end of the body to the other, with a scrupulous persistency that proves the great interest which he takes in the operation. What is his object in thus sponging himself, in dusting and polishing himself so carefully? It is a question, apparently, of removing a few atoms of dust or else some traces of viscidity that remain from the evil contact with the snail. A wash and brush-up is not superfluous when one leaves the tub in which the mollusc has been treated.

If the Glow-worm possessed no other talent than that of chloroforming his prey by means of a few tweaks resembling kisses, he would be unknown to the vulgar herd; but he also knows how to light himself like a beacon; he shines, which is an excellent manner of achieving fame. Let us consider more particularly the female, who, while retaining her larval shape, becomes marriageable and glows at her best during the hottest part of summer. The lighting-apparatus occupies the last three segments of the abdomen. On each of the first two, it takes the form, on the ventral surface, of a wide belt covering almost the whole of the arch; on the third, the luminous part is much less and consists simply of two small crescent-shaped markings, or rather two spots which shine through to the back and are visible both above and below the animal. Belts and spots emit a glorious white light, delicately tinged with blue. The general lighting of the Glow-worm thus comprises two groups: first, the wide belts of the two segments preceding the last; secondly, the two spots of the final segments. The two belts, the exclusive attribute of the marriageable female, are the part richest in light: to glorify her wedding, the future mother dons her brightest gauds; she lights her two resplendent scarves. But, before that, from the time of the hatching, she had only the modest rush-light of the stern. This efflorescence of light is the equivalent of the final metamorphosis, which is usually represented by the gift of wings and flight. Its brilliance heralds the pairing-time. Wings and flight there will be none: the female retains her humble larval form, but she kindles her blazing beacon.

The male, on his side, is fully transformed, changes his shape, acquires wings and wing-cases; nevertheless, like the female, he possesses, from the time when he is hatched, the pale lamp of the end segment. This luminous aspect of the stern is characteristic of the entire Glow-worm tribe, independently of sex and season. It appears upon the budding grub and continues throughout life unchanged. And we must not forget to add that it is visible on the dorsal as well as on the ventral surface, whereas the two large belts peculiar to the female shine only under the abdomen.

My hand is not so steady nor my sight so good as once they were, but, as far as they allow me, I consult anatomy for the structure of the luminous organs. I take a scrap of the epidermis and manage to separate pretty neatly half of one of the shining belts. I place my preparation under the microscope. On the skin, a sort of white-wash lies spread, formed of a very fine, granular substance. This is certainly the light-producing matter. To examine this white layer more closely is beyond the power of my weary eyes. Just beside it is a curious air-tube, whose short and remarkably wide stem branches suddenly into a sort of bushy tuft of very delicate ramifications. These creep over the luminous sheet, or even dip into it. That is all.

The luminescence, therefore, is controlled by the respiratory organs and the work produced is an oxidization. The white sheet supplies the oxidizable matter and the thick air-tube spreading into a tufty bush distributes the flow of air over it. There remains the question of the substance whereof this sheet is formed. The first suggestion was phosphorus, in the chemist's sense of the word. The Glow-worm has been calcined and treated with the violent reagents that bring the simple substances to light; but no one, so far as I know, has obtained a satisfactory answer along these lines. Phosphorus seems to play no part here, in spite of the name of phosphorescence which is sometimes bestowed upon the Glow-worm's gleam. The answer lies elsewhere, no one knows where.

We are better informed as regards another question. Has the Glow-worm a free control of the light which he emits? Can he turn it on or down or put it out as he pleases? Has he an opaque screen which is drawn over the flame at will, or is that flame always left exposed? There is no need for any such mechanism: the insect has something better for its revolving light.

The thick tube supplying the light-producing sheet increases the flow of air and the light is intensified; the same air-tube, swayed by the animal's will, slackens or even suspends the passage of air and the light grows fainter or even goes out. It is, in short, the mechanism of a lamp which is regulated by the access of air to the wick.

Excitement can set the attendant air-duct in motion. We must here distinguish between two cases: that of the gorgeous scarves, the exclusive ornament of the female ripe for matrimony, and that of the modest fairy-lamp on the last segment, which both sexes kindle at any age. In the second case, the extinction caused by a flurry is sudden and complete, or nearly so. In my nocturnal hunts for young Glow-worms, measuring about 5 millimetres long, I can plainly see the glimmer on the blades of grass; but, should the least false step disturb a neighbouring twig, the light goes out at once and the coveted insect becomes invisible. Upon the full-grown females, lit up with their nuptial scarves, even a violent start has but a slight effect and often none at all.

I fire a gun beside a wire-gauze cage in which I am rearing my menagerie of females in the open air. The explosion produces no result. The illumination continues, as bright and placid as before. I take a spray and rain down a slight shower of cold water upon the flock. Not one of my animals puts out its light; at the very most, there is a brief pause in the radiance; and then only in some cases. I send a puff of smoke from my pipe into the cage. This time, the pause is more marked. There are even some extinctions, but these do not last long. Calm soon returns and the light is renewed as brightly as ever. I take some of the captives in my fingers, turn and return them, tease them a little. The illumination continues and is not much diminished, if I do not press too hard with my thumb. At this period, with the pairing close at hand, the insect is in all the fervour of its passionate splendour; and nothing short of very serious reasons would make it put out its signals altogether.

All things considered, there is not a doubt but that the Glow-worm himself manages his lighting-apparatus, extinguishing and rekindling it at will; but there is one point at which the voluntary agency of the insect is without effect. I detach a strip of the epidermis showing one of the luminescent sheets and place it in a glass tube, which I close with a plug of damp wadding, to avoid too rapid an evaporation. Well, this scrap of carcass shines away merrily, although not quite as brilliantly as on the living body.

Life's aid is now superfluous. The oxidizable substance, the luminescent sheet, is in direct communication with the surrounding atmosphere; the flow of oxygen through an air-tube is not necessary; and the luminous emission continues to take place, in the same way as when it is produced by the contact of the air with the real phosphorus of the chemists. Let us add that, in aerated water, the luminousness continues as brilliant as in the free air, but that it is extinguished in water deprived of its air by boiling. No better proof could be found of what I have already propounded, namely, that the Glow-worm's light is the effect of a slow oxidization.

The light is white, calm and soft to the eyes and suggests a spark dropped by the full moon. Despite its splendour, it is a very feeble illuminant. If we move a Glow-worm along a line of print, in perfect darkness, we can easily make out the letters, one by one, and even words, when these are not too long; but nothing more is visible beyond a narrow zone. A lantern of this kind soon tires the reader's patience.

Suppose a group of Glow-worms placed almost touching one another. Each of them sheds its glimmer, which ought, one would think, to light up its neighbours by reflexion and give us a clear view of each individual specimen. But not at all: the luminous party is a chaos in which our eyes are unable to distinguish any definite form at a medium distance. The collective lights confuse the link-bearers into one vague whole.

Photography gives us a striking proof of this. I have a score of females, all at the height of their splendour, in a wire-gauze cage in the open air. A tuft of thyme forms a grove in the centre of their establishment. When night comes, my captives clamber to this pinnacle and strive to show off their luminous charms to the best advantage at every point of the horizon, thus forming along the twigs marvellous clusters from which I expected magnificent effects on the photographer's plates and paper. My hopes are disappointed. All that I obtain is white, shapeless patches, denser here and less dense there according to the numbers forming the group. There is no picture of the Glow-worms themselves; not a trace either of the tuft of thyme. For want of satisfactory light, the glorious firework is represented by a blurred splash of white on a black ground.

The beacons of the female Glow-worms are evidently nuptial signals, invitations to the pairing; but observe that they are lighted on the lower surface of the abdomen and face the ground, whereas the summoned males, whose flights are sudden and uncertain, travel overhead, in the air, sometimes a great way up. In its normal position, therefore, the glittering lure is concealed from the eyes of those concerned; it is covered by the thick bulk of the bride. The lantern ought really to gleam on the back and not under the belly; otherwise the light is hidden under a bushel.

The anomaly is corrected in a very ingenious fashion, for every female has her little wiles of coquetry. At nightfall, every evening, my caged captives make for the tuft of thyme with which I have thoughtfully furnished the prison and climb to the top of the upper branches, those most in sight. Here, instead of keeping quiet, as they did at the foot of the bush just now, they indulge in violent exercises, twist the tip of their very flexible abdomen, turn it to one side, turn it to the other, jerk it in every direction. In this way, the search-light cannot fail to gleam, at one moment or another, before the eyes of every male who goes a-wooing in the neighbourhood, whether on the ground or in the air.

It is very like the working of the revolving mirror used in catching Larks. If stationary, the little contrivance would leave the bird indifferent; turning and breaking up its light in rapid flashes, it excites it.

While the female Glow-worm has her tricks for summoning her swains, the male, on his side, is provided with an optical apparatus suited to catch from afar the least reflection of the calling-signal. His corselet expands into a shield and overlaps his head considerably in the form of a peaked cap or eye-shade, the object of which appears to be to limit the field of vision and concentrate the view upon the luminous speck to be discerned. Under this arch are the two eyes, which are relatively enormous, exceedingly convex, shaped like a skull-cap and contiguous to the extent of leaving only a narrow groove for the insertion of the antennae. This double eye, occupying almost the whole face of the insect and contained in the cavern formed by the spreading peak of the corselet, is a regular Cyclop's eye.

At the moment of the pairing, the illumination becomes much fainter, is almost extinguished; all that remains alight is the humble fairy-lamp of the last segment. This discreet night-light is enough for the wedding, while, all around, the host of nocturnal insects, lingering over their respective affairs, murmur the universal marriage-hymn. The laying follows very soon. The round, white eggs are laid, or rather strewn at random, without the least care on the mother's part, either on the more or less cool earth or on a blade of grass. These brilliant ones know nothing at all of family-affection.

Here is a very singular thing: the Glow-worm's eggs are luminous even when still contained in the mother's womb. If I happen by accident to crush a female big with germs that have reached maturity, a shiny streak runs along my fingers, as though I had broken some vessel filled with a phosphorescent fluid. The lens shows me that I am wrong. The luminosity comes from the cluster of eggs forced out of the ovary. Besides, as laying-time approaches, the phosphorescence of the eggs is already made manifest without this clumsy midwifery. A soft opalescent light shines through the skin of the belly.

The hatching follows soon after the laying. The young of either sex have two little rush-lights on the last segment. At the approach of the severe weather, they go down into the ground, but not very far. In my rearing-jars, which are supplied with fine and very loose earth, they descend to a depth of three or four inches at most. I dig up a few in mid-winter. I always find them carrying their faint stern-light. About the month of April, they come up again to the surface, there to continue and complete their evolution.

From start to finish, the Glow-worm's life is one great orgy of light. The eggs are luminous; the grubs likewise. The full-grown females are magnificent light-houses, the adult males retain the glimmer which the grubs already possessed. We can understand the object of the feminine beacon; but of what use is all the rest of the pyrotechnic display? To my great regret, I cannot tell. It is and will be, for many a day to come, perhaps for all time, the secret of animal physics, which is deeper than the physics of the books.

----

中文译文 · Claude（AI）译

在我们这个地区，很少有昆虫的名气能和萤火虫相比。这种奇特的小动物，为了庆祝生活中的小小欢乐，在尾巴上点起一盏灯。谁不知道它，至少知道它的名字呢？谁没有见过它在草丛中漫游，像一颗从满月上掉下来的火星呢？古希腊人称它为 λάμπουρις，意思是“尾巴发亮的”。科学也用同样的说法：它把这个提灯者叫作 *Lampyris noctiluca*（林奈）。在这里，俗名不如学名，学名翻译出来，既生动又准确。

其实，我们很容易对英文俗名 Glow-worm 里的“worm”（蠕虫）这个词吹毛求疵。萤火虫根本不是蠕虫，甚至在大体的样子上也不是。它有六条短腿，而且很会用；它是个到处乱跑、四处溜达的家伙。到了成虫阶段，雄虫规规矩矩地披上了鞘翅，正像它这真正的甲虫所应有的那样。雌虫是个丑陋的家伙，不懂得飞翔的乐趣：它一辈子都保持着幼虫的形状，而幼虫的形状，除此之外和雄虫的也差不多；雄虫在达到交配期带来的成熟之前，本身也是不完全的。即使在这最初的阶段，“蠕虫”这个词也用得不对。我们法国人有一个说法，“光溜溜的像条虫”，用来指没有任何防护的外衣。而萤火虫是穿着衣服的，也就是说，它有一层相当结实的表皮；此外，它的颜色还相当华丽：它的身体全是深棕色，胸部点缀着淡粉红色，尤其是在下面。最后，每一个体节的后缘都装饰着两个相当鲜红的斑点。蠕虫是从来不穿这样的衣服的。

让我们撇开这个起得不好的名称，问一问萤火虫吃什么。那位烹饪艺术的大师布里亚－萨瓦兰说过：

“告诉我你吃什么，我就能告诉你你是什么人。”

对于每一种我们打算研究其习性的昆虫，都应该先提出一个类似的问题，作为开场；因为在动物界的进阶中，从最低等的到最高等的，都是胃在支配着世界；食物提供的资料，是生命的一切文献中最主要的。那么，萤火虫尽管外表天真无邪，却是一个吃肉的，一个猎手；而且它干这一行的手段，邪恶得少见。它通常的猎物是蜗牛。

这个细节，昆虫学家早就知道了。还不那么为人所知的，根据我读过的东西来判断，可以说是完全不为人知的，是它奇特的攻击方法，这种方法我在别处从来没有见过第二个例子。

萤火虫开始大吃之前，先给它的受害者施行麻醉：它用氯仿麻醉它的猎物，在这个过程中，可以同我们现代外科的奇迹相媲美——现代外科在给病人动手术之前，先使他失去知觉。通常的猎物是一种小蜗牛，几乎只有樱桃那么大，比如说 *Helix variabilis*（德拉帕尔诺）；天热的时候，它们成群地聚集在硬硬的麦茬上，以及路边其他又长又干的茎秆上，在那里一动不动，深深地沉思，度过整个炎热的夏日。正是在这样的歇息之处，我常常有幸碰见萤火虫在大吃它刚刚在摇摇晃晃的支撑物上用它的外科手术麻痹了的猎物。

但是它也熟悉别的猎场。它常到灌溉沟渠的边上去，那里土壤凉爽，植物繁多，是软体动物喜爱出没的地方。在这里，它在地面上处置猎物；在这种条件下，我很容易在家里养它，并且把这位手术者的操作观察到最细微的地方。

我要试着让读者亲眼看看这奇异的景象。我在一只大玻璃瓶里放一点草。在里面安置几只萤火虫，以及一批大小合适、不太大也不太小的蜗牛，主要是 *Helix variabilis*。我们必须耐心地等待。最重要的是，我们必须勤勤恳恳地守着，因为我们想看的事情总是出其不意地发生，而且持续不了多久。

我们终于等到了。萤火虫先把猎物察看了一会儿；猎物按照它的习惯，全身缩在壳里，只有外套膜的边缘稍稍露在外面。于是猎手亮出了它的武器，一件非常简单的武器，但是不借助放大镜，是看不清楚的。它由两片大颚组成，大颚有力地向后弯成钩状，非常尖利，细得像一根头发。显微镜显示出，大颚上有一道细槽，贯穿全长。就这些。

这只昆虫用它的工具一再轻叩蜗牛的外套膜。这一切进行得那样温柔，使人想到的是亲吻，而不是咬啮。我们小时候互相逗着玩，常说“掐掐”，表示用指尖轻轻一捏，与其说是认真的掐，不如说是挠痒痒。我们就用这个词吧。在同动物交谈的时候，语言保持孩子气并不会有什么损失。这是单纯的人们互相理解的正确方式。

萤火虫把它的掐掐一下一下地分发出去。它有条不紊地分发，并不匆忙，每掐一次就稍稍休息一下，仿佛想要弄清楚产生了什么效果。掐的次数并不多：至多半打，就足以制服猎物，使它失去一切活动能力。后来在吃的时候还要再掐几下，看来很有可能，但我不能肯定地说什么，因为后面的情形我没能看到。不过，最初的几下——从来不多——就足以使这软体动物陷入不动和失去一切感觉，这要归功于萤火虫迅速的、我几乎可以说是闪电般的方法，它无疑是用它那带槽的钩子注入了某种毒液。

下面就是那些看来那么温和的轻掐有突然功效的证据：我把蜗牛从萤火虫那里拿走，萤火虫已经在它外套膜的边缘上动了四五次手术。我用一根细针刺它的前部，那是缩进壳里的动物仍然露在外面的部分。受伤的组织没有一点颤动，对针的粗暴没有一点反应。一具尸体也不会比它显出更少的生命迹象。

下面是更有说服力的事实：偶然的机会有时让我得到正在爬行时遭到萤火虫攻击的蜗牛，那时它的足在慢慢地爬，触角伸展到最长。这软体动物几下杂乱的动作，透露出它短暂的激动，然后一切都停止了：足不再蠕动；前部失去了它优美的天鹅颈似的弯曲；触角变软了，在自身的重量下垂下来，像一根折断的棍子那样无力地晃荡着。这种状态持续下去。

蜗牛真的死了吗？完全没有，因为我可以随意使这具表面上的尸体复活。在那种既不再是生、又还不是死的奇特状态中过了两三天之后，我把这个病人隔离开来，虽然这对于成功并不真正必要，我还给它冲了个淋浴，代替健壮的软体动物非常喜爱的阵雨。大约过了两天，我这个不久前受到萤火虫暗算的囚犯，就恢复了正常状态。它可以说是复活了；它恢复了运动和感觉。针的刺激会使它有反应；它挪动位置，爬行，伸出触角，好像什么不寻常的事都没有发生过。那种全身的麻木，一种深深的醉态，完全消失了。死者复生了。对于那种暂时取消了运动能力和痛觉的存在形式，我们该给它一个什么名称呢？我只能想到一个大致合适的名称：麻醉。许许多多的狩猎蜂，它们吃肉的幼虫得到的是不动却没有死的肉食，它们的功绩已经教会了我们麻痹型昆虫的高超技艺，它们用毒液麻痹运动神经中枢。现在我们又有了一种卑微的小动物，它首先使它的病人完全麻醉。人类的科学实际上并没有发明这种技艺，这是我们近代外科的奇迹之一。远在许多世纪以前，萤火虫，显然还有别的动物，就已经懂得了。动物的知识比我们的领先了很久；只是方法改变了。我们的手术者是让我们吸入乙醚或氯仿的气体；而昆虫则是注射一种特别的毒液，这种毒液以极微的剂量从大颚的尖牙里出来。难道我们有朝一日不能从这个启示中得益吗？如果我们更好地懂得了这小动物的秘密，未来会给我们准备多么光辉的发现啊！

萤火虫对付一个无害的、而且极其爱好和平的对手，一个决不会主动挑起争端的对手，要麻醉的本领做什么呢？我想我明白了。在阿尔及利亚，我们见到一种甲虫，叫作 *Drilus maroccanus*，它虽然不发光，在构造上、尤其是在习性上，却和我们的萤火虫相近。它也吃陆生的软体动物。它的猎物是一种圆口螺，有一个优美的螺旋形的壳，用一块石质的盖子紧紧地关着，盖子由一块有力的肌肉连在动物身上。这盖子是一扇活动的门，住户只要缩进屋里，门就迅速关上；隐士出门时，门又同样容易地打开。有了这种关闭的装置，住所就变得不可侵犯了；而 Drilus 是知道这一点的。

它用一种黏附装置固定在壳的表面上，这种装置的等价物，萤火虫马上就会给我们看到；它守在那里，必要的时候一连等上好几天。最后，对空气和食物的需要，迫使被围困的非战斗人员露面；至少，门开了一条小缝。这就够了。Drilus 就在现场，发动了攻击。门再也关不上了，攻击者从此成了堡垒的主人。我们的第一印象是，牵动盖子的肌肉被一把快剪刀剪断了。这个想法必须抛弃。Drilus 的颚长得不够好，不能这么快就咬断一块肉。手术必须立刻成功，第一下就成功：否则，被攻击的动物就会缩回去，仍然精力充沛，围攻就得重新开始，照旧艰难，使这只昆虫面临无限期延长的饥饿。虽然我从来没有遇到过 Drilus，它不是我这个地区的居民，我却推测它的攻击方法同萤火虫的非常相似。像我们这里吃蜗牛的昆虫一样，这种阿尔及利亚的昆虫并不把它的受害者切成小块：它使它不能动，用几下轻掐把它麻醉，只要盖子半开那么一秒钟，这几下就很容易分发出去。那就够了。于是围攻者走了进去，在十分安静中吃掉一个连最轻微的肌肉动作都做不出的猎物。这就是我单凭逻辑的光亮对事情的看法。

现在让我们回到萤火虫上来。当蜗牛在地上爬行，或者甚至缩在壳里时，攻击从来不会有什么困难。蜗牛壳没有盖子，隐士的前部很大一部分都露在外面。在这里，在因害怕危险而收缩的外套膜边缘，这软体动物是容易受伤的，不能自卫。但是也常常有这样的情形：蜗牛待在一个高处，附着在一根草茎的顶端，或者附着在一块石头的光滑表面上。这个支撑物给它充当了临时的盖子；它挡住了任何想骚扰这间小屋居民的粗汉的侵犯，但总有一个明确的条件：在起保护作用的圆周上，任何地方都不能露出缝隙。反过来，如果在常见的情况下壳同支撑物贴合得不十分紧密，留下了某一点没有遮住，不管多么微小，这就足以让萤火虫那些精巧的工具派上用场了，它只要咬一咬那软体动物，就立刻使它陷入深深的不动，这正有利于食客从容不迫地行事。

这种行事以极度的谨慎为特点。攻击者必须小心翼翼地处置它的受害者，不要引起收缩，那会使蜗牛松开它的支撑物，至少会使它从它正幸福地睡着的高高的草茎上掉下去。而任何掉到地上的猎物，似乎就是纯粹的损失，因为萤火虫对出猎并没有多大的热情：它利用好运送给它的发现，并不去作勤勉的搜寻。因此，必须使一个高踞在草茎顶端、只靠一点胶粘着的战利品，在进攻的时候尽可能少受扰动而失去平衡；攻击者必须以无限的谨慎去工作，不能引起疼痛，以免任何肌肉的反应引起坠落，危及这件战利品。正如我们看到的，突然而深度的麻醉，是使萤火虫达到它的目的的绝妙手段，它的目的就是十分安静地享用它的猎物。

它是以怎样的方式享用的呢？它真的吃吗？也就是说，它是否把食物一块一块地分开，把它切成微小的颗粒，然后用咀嚼器把它磨碎呢？我想不是。我从来没有在我的俘虏的嘴上看到固体食物的痕迹。萤火虫并不是严格意义上的吃：它是喝饱的；它靠一种稀粥过活，它用一种使人想起蛆的方法把猎物变成这种稀粥。像吃肉的蝇蛆一样，它也能先消化后进食；它在吃猎物之前，先把它液化。

事情是这样发生的：一只蜗牛被一只萤火虫弄得失去了知觉。手术者几乎总是单独的，即使猎物是一只大个子，像普通的庭园蜗牛 *Helix aspersa*。很快就有好几位客人赶来——两个、三个或更多——它们同真正的主人一点也不争吵，都一样地吃起来。让我们让它们自己待上两天，然后把壳翻过来，口朝下。里面的东西就像从打翻的锅里流出汤来一样容易地流出来。当吃饱了的食客们离开这锅稀粥时，只剩下一点微不足道的残渣。

事情很明显：通过反复的轻微啃咬，就像我们在开始时看到分发出去的那些轻掐一样，软体动物的肉被变成了一种稀粥，各位宴饮者都不加区别地以它为食，每一个都用某种特殊的胃蛋白酶来加工这汤，每一个都吃自己的那一口。由于这种先把食物变成液体的方法，萤火虫的嘴，除了那两只刺入病人、注射麻醉毒液、无疑同时也注射能把固体的肉变成液体的血清的尖牙以外，必定装备得很差。这两件刚刚能用放大镜看清楚的小工具，看来必定还有别的用途。它们是空心的，在这一点上像蚁狮的大颚，蚁狮吸干它的猎物，用不着把它分开；但是有这样一个很大的区别：蚁狮留下大量的残余，后来把它们扔到它在沙里挖的漏斗形陷阱外面去，而萤火虫，这位液化的专家，什么也不留下，或者几乎什么也不留下。用相似的工具，一个只吸猎物的血，另一个则由于预先的液化，把它的每一口都利用起来。

而且，这是以精妙的准确性完成的，尽管平衡有时一点也不稳。我的饲养瓶给我提供了绝好的例子。关在我的装置里的蜗牛，沿着瓶壁往上爬，有时爬到顶上，顶上盖着一块玻璃板，它们就用一点黏液把自己固定在上面。这只是一次临时的停留，软体动物对它的黏性分泌物很吝啬，只要轻轻一摇，壳就会松开，掉到瓶底去。

而萤火虫爬到顶上去，并不是什么稀罕事，它借助一种弥补它无力的腿的攀爬器官。它选好了猎物，仔细地察看一番，寻找一条可以进去的缝，稍稍咬它一下，使它失去知觉，然后毫不迟延地开始准备它将要接连几天享用的稀粥。

当它离开饭桌时，壳已经完全空了；然而这个只靠非常微弱的黏性固定在玻璃上的壳，并没有松开，甚至一点也没有移动它的位置：那个渐渐变成了汤的隐士没有任何抗议，它就在最初受到攻击的那个地点被吸干了。这些小小的细节告诉我们，麻醉的一咬生效得多么迅速；它们告诉我们，萤火虫处置它的蜗牛多么灵巧，既不使它从一个非常滑的垂直支撑物上掉下来，甚至也不使它在那条细弱的黏附线上晃动。

在这样的平衡条件下，手术者那又短又笨的腿显然是不够用的；需要一种特殊的辅助装置，才能不怕滑跌的危险，抓住那抓不住的东西。而萤火虫正拥有这种装置。在这动物的后端，我们看到一个白点，放大镜把它分辨成大约一打肉质的短附器，有时聚成一簇，有时散开成玫瑰花形。这就是它的黏附和运动器官。如果它想把自己固定在什么地方，即使是很光滑的表面，比如一根草茎上，萤火虫就打开它的玫瑰花，把它在支撑物上展开，靠它自身的黏性附着在上面。同一个器官，升起落下，张开合拢，对前进的动作也大有帮助。总之，萤火虫是一种新式的自动推进的跛子，它在后身装饰着一朵精致的白玫瑰，一种有十二根手指的手，手指没有关节，却能向各个方向活动：管状的手指，不是抓，而是粘。

这同一个器官还有另一个用途：当作梳洗用的海绵和刷子。在休息的时候，饭后，萤火虫用这把刷子来来回回地刷它的头、背、两侧和后部，这是由于它的脊柱很柔软才能做到的。它一点一点地刷，从身体的一端刷到另一端，那种一丝不苟的坚持，证明它对这项操作有很大的兴趣。它这样小心地擦洗自己、掸去灰尘、把自己擦亮，目的是什么呢？看来是要除去几粒灰尘，或者是同蜗牛恶心的接触后留下的一些黏液的痕迹。从处置了软体动物的那个澡盆里出来，洗一洗、刷一刷，并不是多余的。

如果萤火虫除了用几下像亲吻一样的轻掐来麻醉它的猎物以外，没有别的才能，那么一般人是不会知道它的；但是它还懂得把自己点得像一座灯塔；它发光，这是成名的绝妙方法。让我们特别来看看雌虫，它保持着幼虫的形状，到了可以婚配的年纪，在夏天最热的时候发出最亮的光。发光装置占据着腹部最后三节。在前两节上，它在腹面形成一条宽带，几乎覆盖着整个弧面；在第三节上，发光的部分要小得多，只是两个小小的新月形的斑纹，或者毋宁说是两个光点，光透到背面，从这动物的上面和下面都看得见。光带和光点发出一种灿烂的白光，微微带一点蓝色。这样，萤火虫的总体照明包括两组：第一组，是最后一节前面那两节上的宽光带；第二组，是最后几节上的两个光点。那两条光带，是可以婚配的雌虫独有的标志，是光最丰富的部分：为了给自己的婚礼增光，未来的母亲穿戴上她最鲜艳的饰物；她点亮她那两条光辉灿烂的披带。但是在那以前，从孵化的时候起，她只有尾部那盏简朴的灯芯草烛。这种光的绽放，相当于最后一次变态，那通常表现为获得翅膀和飞翔。它的光辉预告着交配期的到来。翅膀和飞翔是不会有的：雌虫保持着她卑微的幼虫形态，但是她点亮了她那火焰熊熊的灯塔。

雄虫这方面，则是完全变态了，改变了它的形状，获得了翅膀和鞘翅；不过，同雌虫一样，它从孵化的时候起，就有最后一节上的那盏淡淡的灯。尾部的这种发光的样子，是整个萤火虫族的特征，与性别和季节无关。它出现在刚刚孵出的幼虫身上，并且终生不变地延续下去。我们也不要忘了补充一点：它在背面和腹面都看得见，而雌虫所特有的那两条大光带，只在腹部下面发光。

我的手不像从前那么稳了，我的视力也不像从前那么好了，但是在它们允许的范围内，我借助解剖来了解发光器官的构造。我取下一小片表皮，设法相当利落地分离出一条发光带的一半。我把这件标本放在显微镜下。在皮上铺着一层白粉似的东西，由一种非常细的颗粒状物质构成。这无疑就是发光的物质。要把这白色的层再仔细地看一看，就不是我疲倦的眼睛所能做到的了。就在它旁边，有一根奇特的气管，它短而特别宽的主干，突然分出一丛灌木似的、非常纤细的分支。这些分支在发光的薄层上蔓延，甚至伸进它里面。就这些。

所以，发光是受呼吸器官控制的，所产生的作用是一种氧化。白色的薄层提供可以氧化的物质，而那根分成一丛灌木的粗气管，把气流分布到它上面。剩下的问题，是这个薄层是由什么物质构成的。最初的猜测是磷，化学家所说的那种磷。人们曾把萤火虫煅烧，用那些能显示出单质的猛烈试剂来处理它；但是据我所知，还没有人沿着这条路得到令人满意的答案。磷在这里似乎不起作用，尽管人们有时把萤火虫的光叫作磷光。答案在别处，没有人知道在哪里。

在另一个问题上，我们知道得多一些。萤火虫能自由控制它发出的光吗？它能随意把光开大、调小或者熄灭吗？它有没有一块不透光的屏，可以随意拉过来遮住火焰，还是那火焰总是暴露着？用不着任何这样的机械：对于它那旋转的灯，这昆虫有更好的办法。

供给发光薄层的那根粗管增加气流，光就增强；同一根气管，受动物意志的支配，放慢甚至停止空气的通过，光就变弱甚至熄灭。总之，这就是一盏灯的机制，它靠空气进入灯芯的多少来调节。

激动能使这附属的气管动作起来。这里我们必须区分两种情形：一种是那华丽的披带，到了婚龄的雌虫独有的装饰；一种是最后一节上那盏朴素的小仙灯，两性在任何年龄都会点亮。在第二种情形下，惊扰引起的熄灭是突然而完全的，或者几乎是完全的。在我夜间搜寻长约五毫米的幼小萤火虫时，我能清楚地看到草叶上的微光；但是，只要一个最小的失足惊动了附近的一根细枝，光就立刻熄灭，那只我想要的昆虫就看不见了。而在那些点亮了婚礼披带的成年雌虫身上，即使一次猛烈的惊吓，也只有轻微的效果，常常根本没有效果。

我在一个铁丝网笼子旁边开了一枪，我在露天里用这个笼子饲养我那一群雌虫。爆炸声没有产生任何结果。照明继续着，和先前一样明亮、平静。我拿一个喷雾器，给这一群洒下一阵冷水的细雨。我的动物没有一只熄灭它的光；至多是光辉短暂地停顿一下；而且只是在某些情况下。我从烟斗里往笼子里喷一口烟。这一次，停顿比较明显。甚至有一些熄灭了，但是并不持久。平静很快就恢复了，光又像以前一样明亮地重新燃起。我用手指拿起几只俘虏，把它们翻过来翻过去，逗弄它们一下。照明继续着，并没有减弱多少，只要我的拇指不压得太重。在这个时期，交配临近了，这昆虫正处在它热烈的光辉的全盛之中；不是非常严重的理由，不会使它完全熄灭它的信号。

考虑到所有这一切，毫无疑问，萤火虫自己管理着它的发光装置，随意把它熄灭、重新点亮；但是有一点，昆虫的意志作用是不起效的。我剥下一条带有一片发光薄层的表皮，把它放进一根玻璃管里，用一团湿棉花塞住管口，以免蒸发太快。结果呢，这一小片尸体愉快地亮着，虽然不像在活的身体上那么明亮。

现在已经用不着生命的帮助了。可氧化的物质，即发光的薄层，直接同周围的大气相通；氧气不必通过气管流进来；发光照样进行，就像化学家所说的真正的磷同空气接触时产生的发光一样。我们还要补充一点：在充气的水里，发光继续像在空气中一样明亮，但是在经过煮沸、除去了空气的水里，它就熄灭了。我前面提出的看法，即萤火虫的光是一种缓慢氧化的结果，再也找不到更好的证据了。

这光是白的，平静的，对眼睛很柔和，使人想到从满月上掉下来的一颗火星。尽管它很灿烂，却是一种非常微弱的照明。如果我们在完全的黑暗中，拿一只萤火虫沿着一行印刷的字移动，我们可以很容易地一个一个地认出字母，甚至认出不太长的单词；但是在一个狭窄的范围以外，就什么也看不见了。这样的灯笼，很快就会使读者失去耐心。

假设把一群萤火虫放在一起，几乎彼此挨着。每一只都放出它的微光，人们会以为，这光应该通过反射照亮它的邻居，使我们清楚地看到每一个个体。可是完全不是这样：这个发光的集体是一团混沌，在中等的距离上，我们的眼睛分辨不出任何确定的形状。集体的光把这些提灯者混成了一个模糊的整体。

摄影给了我们一个惊人的证明。我有二十来只雌虫，全都在它们光辉的顶峰，关在露天的一个铁丝网笼子里。一丛百里香在它们住所的中央形成一片小树林。夜幕降临时，我的俘虏们就爬到这个尖顶上去，努力向地平线上的每一点尽量炫耀它们发光的魅力，就这样沿着细枝形成了一串串奇妙的光簇，我原以为它们会在摄影的底片和相纸上产生壮丽的效果。我的希望落空了。我得到的只是一些白色的、没有形状的斑块，这里浓一些，那里淡一些，随组成光簇的数目而定。萤火虫本身没有留下任何影像；那丛百里香也没有一点痕迹。由于缺少令人满意的光，那灿烂的焰火被表现为黑底上一块模糊的白斑。

雌萤火虫的灯塔显然是婚礼的信号，是交配的邀请；但是请注意，它们是在腹部的下面点亮的，面朝地面，而被召唤的雄虫，飞行突然而飘忽，是在头顶上、在空中经过的，有时飞得很高。所以，在正常的姿势下，这闪闪发光的诱饵是对有关的人隐藏着的；它被新娘厚实的身躯遮住了。这盏灯笼确实应该在背上闪光，而不是在肚子下面；否则，这光就被藏在斗底下了。

这种反常被纠正得非常巧妙，因为每一个雌性都有她卖弄风情的小小诡计。每天晚上，夜幕降临时，我那些关在笼子里的俘虏，就向我体贴地布置在囚室里的那丛百里香走去，爬到上面的枝条顶上，最显眼的地方。在这里，它们不再像刚才在灌木脚下那样安安静静地待着，而是做起剧烈的运动来，扭动它们那非常柔软的腹部末端，把它转到一边，又转到另一边，向各个方向猛地一甩。这样，探照灯就不会不在这一刻或那一刻，在附近每一只来求偶的雄虫眼前闪亮，不管它是在地上还是在空中。

这很像捕云雀时用的旋转镜的作用。如果那小小的装置是静止的，鸟就会无动于衷；它旋转着，把光碎成一道道快速的闪光，就使鸟兴奋起来。

雌萤火虫有她召唤情郎的诡计，雄虫这方面，则配备了一种光学装置，适于从远处捕捉召唤信号的最微弱的反光。它的前胸扩展成一块盾，像一顶鸭舌帽或者一个眼罩一样，大大地盖过它的头，目的看来是限制视野，把视线集中在要辨认的那个光点上。在这个拱顶下面是两只眼睛，相对来说大得惊人，极其凸出，形状像一顶无边便帽，两只眼睛紧紧挨着，只留下一条窄槽插着触角。这双眼睛几乎占据了这昆虫的整个面部，藏在前胸伸展的帽檐所形成的洞穴里，真是一只库克罗普斯的独眼。

交配的时候，照明变得暗淡得多，几乎熄灭了；只剩下最后一节上那盏卑微的小仙灯还亮着。这盏小心谨慎的夜灯，足够婚礼之用了；而在四周，大群夜间的昆虫，流连于它们各自的事务，低声唱着普天下的婚礼颂歌。紧接着就产卵了。圆圆的白色的卵，被产下来，或者毋宁说是随便撒下来，母亲一点也不照料，或者撒在比较凉爽的泥土上，或者撒在一片草叶上。这些光辉灿烂的家伙，对家庭的温情一无所知。

有一件非常奇特的事：萤火虫的卵即使还在母亲的肚子里，也是发光的。如果我偶然压碎了一只怀着已经成熟的卵的雌虫，就会有一道发亮的条纹沿着我的手指流过，好像我打破了一只盛满磷光液体的容器似的。放大镜告诉我，我错了。发光来自从卵巢里挤出来的那一团卵。此外，随着产卵期的临近，即使没有这种笨拙的接生，卵的磷光也已经显露出来了。一种柔和的乳白色的光透过腹部的皮肤照出来。

产卵之后不久就孵化了。两种性别的幼虫在最后一节上都有两盏小小的灯芯草烛。严寒的天气临近时，它们钻进地下，但是钻得并不太深。在我的饲养瓶里，放着很细很松的土，它们至多下降到三四英寸深。我在隆冬挖出几只来。我发现它们总是带着它们尾部微弱的灯。大约在四月份，它们又回到地面上来，在那里继续并完成它们的发育。

从开始到结束，萤火虫的一生就是一场光的大狂欢。卵是发光的；幼虫也一样。成年的雌虫是壮丽的灯塔，成年的雄虫保留着幼虫就已经有的微光。我们能理解雌性的灯塔的目的；但是其余那一切烟火表演又有什么用呢？很遗憾，我说不出来。这是，而且在今后的许多日子里，也许永远，都将是动物物理学的秘密，它比书本上的物理学更深。