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I also unearthed some cocoons, slightly different in appearance, containing an adult inmate, likewise dead, in whom I recognized the Interrupted Scolia. The remnants of the provisions again consisted of the empty skin of a larva, also a Lamellicorn, but not the same as the one hunted by the first Scolia. And this was all. Now here, now there, I shifted a few cubic yards of soil, without managing to find fresh provisions with the egg or the young larva. And yet it was the right season, the egg-laying season, for the males, numerous at the outset, had grown rarer day by day until they disappeared entirely. My lack of success was due to the uncertainty of my excavations, in which I had nothing to guide me over the indefinite area covered.

If I could at least identify the Scarabaeidae whose larvae form the prey of the two Scoliae, the problem would be half solved. Let us try. I collect all that the luchet has turned up: larvae, nymphs and adult Beetles. My booty comprises two species of Lamellicorns: Anoxia villosa and Euchlora Julii, both of whom I find in the perfect state, usually dead, but sometimes alive. I obtain a few of their nymphs, a great piece of luck, for the larval skin which accompanies them will serve me as a standard of comparison. I come upon plenty of larvae, of all ages. When I compare them with the cast garment abandoned by the nymphs, I recognize some as belonging to the Anoxia and the rest to the Euchlora.

With these data, I perceive with absolute certainty that the empty skin adhering to the cocoon of the Interrupted Scolia belongs to the Anoxia. As for the Euchlora, she is not involved in the problem: the larva hunted by the Two-banded Scolia does not belong to her any more than it belongs to the Anoxia. Then with which Scarabaeid does the empty skin which is still unknown to me correspond? The Lamellicorn whom I am seeking must exist in the ground which I have been exploring, because the Two-banded Scolia has established herself there. Later--oh, very long afterwards!--I recognized where my search was at fault. In order not to find a network of roots beneath my luchet and to render the work of excavation lighter, I was digging the bare places, at some distance from the thickets of holm-oak; and it was just in those thickets, which are rich in vegetable mould, that I should have sought. There, near the old stumps, in the soil consisting of dead leaves and rotting wood, I should certainly have come upon the larva so greatly desired, as will be proved by what I have still to say.

Here ends what my earlier investigations taught me. There is reason to believe that the Bois des Issards would never have furnished me with the precise data, in the form in which I wanted them. The remoteness of the spot, the fatigue of the expeditions, which the heat rendered intensely exhausting, the impossibility of knowing which points to attack would undoubtedly have discouraged me before the problem had advanced a step farther. Studies such as these call for home leisure and application, for residence in a country village. You are then familiar with every spot in your own grounds and the surrounding country and you can go to work with certainty.

Twenty-three years have passed; and here I am at Serignan, where I have become a peasant, working by turns on my writing-pad and my cabbage-patch. On the 14th of August, 1880, Favier clears away a heap of mould consisting of vegetable refuse and of leaves stacked in a corner against the wall of the paddock. This clearance is considered necessary because Bull, when the lovers' moon arrives, uses this hillock to climb to the top of the wall and thence to repair to the canine wedding the news of which is brought to him by the effluvia borne upon the air. His pilgrimage fulfilled, he returns, with a discomfited look and a slit ear, but always ready, once he has had his feed, to repeat the escapade. To put an end to this licentious behaviour, which has cost him so many gaping wounds, we decided to remove the heap of soil which serves him as a ladder of escape.

Favier calls me while in the midst of his labours with the spade and barrow:

"Here's a find, sir, a great find! Come and look."

I hasten to the spot. The find is a magnificent one indeed and of a nature to fill me with delight, awakening all my old recollections of the Bois des Issards. Any number of females of the Two-banded Scolia, disturbed at their work, are emerging here and there from the depth of the soil. The cocoons also are plentiful, each lying next to the skin of the victim on which the larva has fed. They are all open but still fresh: they date from the present generation; the Scoliae whom I unearth have quitted them not long since. I learnt later, in fact, that the hatching took place in the course of July.

In the same heap of mould is a swarming colony of Scarabaeidae in the form of larvae, nymphs and adult insects. It includes the largest of our Beetles, the common Rhinoceros Beetle, or Oryctes nasicornis. I find some who have been recently liberated, whose wing-cases, of a glossy brown, now see the sunlight for the first time; I find others enclosed in their earthen shell, almost as big as a Turkey's egg. More frequent is her powerful larva, with its heavy paunch, bent into a hook. I note the presence of a second bearer of the nasal horn, Oryctes Silenus, who is much smaller than her kinswoman, and of Pentodon punctatus, a Scarabaeid who ravages my lettuces.

But the predominant population consists of Cetoniae, or Rosechafers, most of them enclosed in their egg-shaped shells, with earthen walls encrusted with dung. There are three different species: C. aurata, C. morio and C. floricola. Most of them belong to the first species. Their larvae, which are easily recognized by their singular talent for walking on their backs with their legs in the air, are numbered by the hundred. Every age is represented, from the new born grub to the podgy larva on the point of building its shell.

This time the problem of the victuals is solved. When I compare the larval slough sticking to the Scolia's cocoons with the Cetonia-larvae or, better, with the skin cast by these larvae, under cover of the cocoon, at the moment of the nymphal transformation, I establish an absolute identity. The Two-banded Scolia rations each of her eggs with a Cetonia-grub. Behold the riddle which my irksome searches in the Bois des Issards had not enabled me to solve. To-day, at my threshold, the difficult problem becomes child's play. I can investigate the question easily to the fullest possible extent; I need not put myself out at all; at any hour of the day, at any period that seems favourable, I have the requisite elements before my eyes. Ah, dear village, so poor, so countrified, how happily inspired was I when I came to ask of you a hermit's retreat, where I could live in the company of my beloved insects and, in so doing, set down not too unworthily a few chapters of their wonderful history!

According to the Italian observer Passerini, the Garden Scolia feeds her family on the larvae of Oryctes nasicornis, in the heaps of old tan-waste removed from the hot-houses. I do not despair of seeing this colossal Wasp coming to establish herself one day in my heaps of leaf-mould, in which the same Scarabaeid is swarming. Her rarity in my part of the country is probably the only cause that has hitherto prevented the realization of my wishes.

I have just shown that the Two-banded Scolia feeds in infancy on Cetonia-larvae and particularly on those of C. aurata, C. morio and C. floricola. These three species dwell together in the rubbish-heap just explored; their larvae differ so little that I should have to examine them minutely to distinguish the one from the other; and even then I should not be certain of succeeding. It seems probable that the Scolia does not choose between them, that she uses all three indiscriminately. Perhaps she even assails other larvae, inhabitants, like the foregoing, of heaps of rotting vegetable-matter. I therefore set down the Cetonia genus generally as forming the prey of the Two-banded Scolia.

Lastly, round about Avignon, the Interrupted Scolia used to prey upon the larva of the Shaggy Anoxia . At Serignan, which is surrounded by the same kind of sandy soil, without other vegetation than a few sparse seed-bearing grasses, I find her rationing her young with the Morning Anoxia . Oryctes, Cetoniae and Anoxiae in the larval state: here then is the prey of the three Scoliae whose habits we know. The three Beetles are Lamellicorns, Scarabaeidae. We shall have occasion later to consider the reason of this very striking coincidence.

For the moment, the business in hand is to move the heap of leaf-mould to some other place, with the wheelbarrow. This is Favier's work, while I myself collect the disturbed population in glass jars, in order to put them back into the new rubbish-heap with all the consideration which my plans owe to them. The laying-time has not yet set in, for I find no eggs, no young Scolia-larvae. September apparently will be the propitious month. But there are bound to be many injured in the course of this upheaval; some of the Scoliae have flown away who will perhaps have a certain difficulty in finding the new site; I have disarranged everything in the overturned heap. To allow tranquility to be restored and habit to resume its rounds, to give the population time to increase and replace the fugitives and the injured, it would be best, I think, to leave the heap alone this year and not to resume my investigations until the next. After the thorough confusion due to the removal, I should jeopardize success by being too precipitate. Let us wait one year more. I decide accordingly, curb my impatience and resign myself. We will simply confine ourselves to enlarging the heap, when the leaves begin to fall, by accumulating the refuse that strews the paddock, so that we may have a richer field of operations.

On the 2nd of September, I decide upon a search with my son Emile, who handles the fork and the shovel, while I examine the clods dug up. Victory! A magnificent result, finer than any that my fondest ambition would have dared to contemplate! Here is a vast array of Cetonia-larvae, all flaccid, motionless, lying on their backs, with a Scolia's egg sticking to the centre of their abdomen; here are young Scolia-larvae dipping their heads into the entrails of their victims; here are others farther advanced, munching their last mouthfuls of a prey which is drained dry and reduced to a skin; here are some laying the foundation of their cocoons with a reddish silk, which looks as if it had been dyed in Bullock's blood; here are some whose cocoons are finished. There is plenty of everything, from the egg to the larva whose period of activity is over. I mark the 2nd of September as a red-letter day; it has given me the final key to a riddle which has kept me in suspense for nearly half a century.

I place my spoils religiously in shallow, wide-mouthed glass jars containing a layer of finely sifted mould. In this soft bed, which is identical in character with the natal surroundings, I make some faint impressions with my fingers, so many cavities, each of which receives one of my subjects, one only. A pane of glass covers the mouth of the receptacle. In this way I prevent a too rapid evaporation and keep my nurselings under my eyes without fear of disturbing them. Now that all this is in order, let us proceed to record events.

The Cetonia-larvae which I find with a Scolia's egg upon their ventral surface are distributed in the mould at random, without special cavities, without any sign of some sort of structure. They are smothered in the mould, just as are the larvae which have not been injured by the Wasp. As my excavations in the Bois des Issards told me, the Scolia does not prepare a lodging for her family; she knows nothing of the art of cell-building. Her offspring occupies a fortuitous abode, on which the mother expends no architectural pains. Whereas the other Hunting Wasps prepare a dwelling to which the provisions are carried, sometimes from a distance, the Scolia confines herself to digging her bed of leaf-mould until she comes upon a Cetonia-larva. When she finds a quarry, she stabs it on the spot, in order to immobilize it; and, again on the spot, she lays an egg on the ventral surface of the paralysed creature. That is all. The mother goes in quest of another prey without troubling further about the egg which has just been laid. There is no effort of carting or building. At the very spot where the Cetonia-grub is caught and paralysed, the Scolia-larva hatches, grows and weaves its cocoon. The establishment of the family is thus reduced to the simplest possible expression.

The Scolia's egg is in no way exceptional in shape. It is white, cylindrical, straight and about four millimetres long by one millimetre thick. It is fixed, by its fore-end, upon the median line of the victim's abdomen, well to the rear of the legs, near the beginning of the brown patch formed by the mass of food under the skin.

I watch the hatching. The grub, still wearing upon its hinder parts the delicate pellicle which it has just shed, is fixed to the spot to which the egg itself adhered by its cephalic extremity. A striking spectacle, that of the feeble creature, only this moment hatched, boring, for its first mouthful, into the paunch of its enormous prey, which lies stretched upon its back. The nascent tooth takes a day over the difficult task. Next morning the skin has yielded; and I find the new-born larva with its head plunged into a small, round, bleeding wound.

In size the grub is the same as the egg, whose dimensions I have just given. Now the Cetonia-larva, to meet the Scolia's requirements, averages thirty millimetres in length by nine in thickness , whence follows that its bulk is six or seven hundred times as great as that of the newly-hatched grub of the Scolia. Here certainly is a quarry which, were it active and capable of wriggling and biting, would expose the nurseling to terrible attacks. The danger has been averted by the mother's stiletto; and the fragile grub attacks the monster's paunch with as little hesitation as though it were sucking the breast.

Day by day the young Scolia's head penetrates farther into the Cetonia's belly. To pass through the narrow orifice made in the skin, the fore-part of the body contracts and lengthens out, as though drawn through a die-plate. The larva thus assumes a rather strange form. Its hinder half, which is constantly outside the victim's belly, has the shape and fulness usual in the larvae of the Digger-wasps, whereas the front half, which, once it has dived under the skin of the exploited victim, does not come out again until the time arrives for spinning the cocoon, tapers off suddenly into a snake-like neck. This front part is moulded, so to speak, by the narrow entrance-hole made in the skin and henceforth retains its slender formation. As a matter of fact, a similar configuration recurs, in varying degrees, in the larvae of the Digger-wasps whose ration consists of a bulky quarry which takes a long time to consume. These include the Languedocian Sphex, with her Ephippiger, and the Hairy Ammophila, with her Grey Worm. There is none of this sudden constriction, dividing the creature into two disparate halves, when the victuals consist of numerous and comparatively small items. The larva then retains its usual shape, being obliged to pass, at brief intervals, from one joint in its larder to the next.

From the first bite of the mandibles, until the whole head of game is consumed, the Scolia-larva is never seen to withdraw its head and its long neck from inside the creature which it is devouring. I suspect the reason of this persistence in attacking a single point; I even seem to perceive the need for a special art in the manner of eating. The Cetonia-larva is a square meal in itself, one large dish, which has to retain a suitable freshness until the end. The young Scolia, therefore, must attack with discretion, at the unvarying point chosen by the mother on the ventral surface, for the entrance-hole is at the exact point where the egg was fixed. As the nurseling's neck lengthens and dives deeper, the victim's entrails are nibbled gradually and methodically: first, the least essential; next, those whose removal leaves yet a remnant of life; lastly, those whose loss inevitably entails death, followed very soon by putrefaction.

At the first bites we see the victim's blood oozing through the wound. It is a highly-elaborated fluid, easy of digestion, and forms a sort of milk-diet for the new-born grub. The little ogre's teat is the bleeding paunch of the Cetonia-larva. The latter will not die of the wound, at least not for some time. The next thing to be tackled is the fatty substance which wraps the internal organs in its delicate folds. This again is a loss which the Cetonia can suffer without dying then and there. Now comes the turn of the muscular layer which lines the skin; now, that of the essential organs; now, that of the nerve-centres and the trachean network, whereupon the last gleam of light is extinguished and the Cetonia reduced to a mere bag, empty but intact, save for the entrance-hole made in the middle of the belly. From now onwards, these remains may rot if they will: the Scolia, by its methodical fashion of consuming its victuals, has succeeded in keeping them fresh to the very last; and now you may see it, replete, shining with health, withdraw its long neck from the bag of skin and prepare to weave the cocoon in which its development will be completed.

It is possible that I may not be quite accurate as to the precise order in which the organs are consumed, for it is not easy to perceive what happens inside the exploited larva's body. The ruling feature in this scientific method of eating, which proceeds from the parts less to the parts more necessary to preserve a remnant of life, is none the less obvious. If direct observation did not already to some degree confirm it, a mere examination of the half-eaten larva would do so in the most positive fashion.

The Cetonia-larva is at first a plump grub. Drained by the Scolia's tooth, it gradually becomes limp and wrinkled. In a few days' time it resembles a shrivelled bit of bacon-fat and then a bag whose two sides have fallen in. Yet this bit of bacon and this bag have the same characteristic look of fresh meat as had the grub before it was bitten into. Despite the persistent nibbling of the Scolia, life continues, holding at bay the inroads of putrefaction until the mandibles have given their last bites. Does not this remnant of tenacious vitality in itself show that the organs of primary importance are the last to be attacked? Does it not prove that there is a progressive dismemberment passing from the less essential to the indispensable?

If a single stroke of my dagger, fashioned from the point of a needle, results in immediate death and early putrefaction; if the repeated bites of the Scolia gut the creature's body and reduce it almost to a skin without completely killing it, the striking contrast between these two results must be due to the relative importance of the organs injured. I destroy the nerve-centres and inevitably kill my larva, which is putrid by the following day; the Scolia attacks the reserves of fat, the blood, the muscles and does not kill its victim, which will provide it with wholesome food until the end. But it is clear that, if the Scolia were to set to work as I did, there would be nothing left, after the first few bites, but an actual corpse, discharging fluids which would be fatal to it within twenty-four hours. The mother, it is true, in order to assure the immobility of her prey, has injected the poison of her sting into the nerve-centres. Her operation cannot be compared with mine in any respect. She practises the method of the skilful physiologist who induces anaesthesia; I go to work like the butcher who chops, cuts and disembowels. The sting leaves the nerve-centres intact. Deprived of sensibility by the poison, they have lost the power of provoking muscular contractions; but who can say that, numbed as they are, they no longer serve to maintain a faint vitality? The flame is extinguished, but there is still a glowing speck upon the wick. I, a rough blunderer, do more than blow out the lamp: I throw away the wick and all is over. The grub would do the same if it bit straight into the mass of nerves.

Everything confirms the fact: the Scolia and the other Hunting Wasps whose provisions consist of bulky heads of game are gifted with a special art of eating, an exquisitely delicate art which saves a remnant of life in the prey devoured, until it is all consumed. When the prey is a small one, this precaution is superfluous. Consider, for instance, the Bembex-grubs in the midst of their heap of Flies. The prey seized upon is broached on the back, the belly, the head, the thorax, indifferently. The larva munches a given spot, which it leaves to munch a second, passing to a third and a fourth, at the bidding of its changing whims. It seems to taste and select, by repeated trials, the mouthfuls most to its liking. Thus bitton at several points, covered with wounds, the Fly is soon a shapeless mass which would putrefy very quickly if the meagre dish were not devoured at a single meal. Allow the Scolia-grub the same unlicensed gluttony: it would perish beside its corpulent victim, which should have kept fresh for a fortnight, but which almost from the beginning would be no more than a filthy putrescence.

This art of careful eating does not seem easy to practise: at least, the larva, if ever so little diverted from its usual courses, is no longer able to apply its talent as a capable trencherman. This will be proved by experiment. I must begin by observing that, when I spoke of my larva which turned putrid within twenty-four hours, I adopted an extreme case for the sake of greater clearness. The Scolia, taking its first bite, does not and cannot go to such lengths. Nevertheless it behooves us to enquire whether, in the consumption of the victuals, the initial point of attack is a matter of indifference and whether the rummaging through the entrails of the victim entails a determined order, without which success is uncertain or even impossible. To these delicate questions no one, I think, can reply. Where science is silent, perhaps the grub will speak. We will try.

I move from its position a Scolia-grub which has attained a quarter or a third of its full growth. The long neck plunged into the victim's belly is rather difficult to extract, because of the need of molesting the creature as little as possible. I succeed, by means of a little patience and repeated strokes with the tip of a paint-brush. I now turn the Cetonia-larva over, back uppermost, at the bottom of the little hollow made by pressing my finger in the layer of mould. Lastly, I place the Scolia on its victim's back. Here is my grub under the same conditions as just now, with this difference, that the back and not the belly of its victim is presented to its mandibles.

I watch it for a whole afternoon. It writhes about; it moves its little head now in this direction, now in that, frequently laying it on the Cetonia, but without fixing it anywhere. The day draws to a close; and still it has accomplished nothing. There are restless movements, nothing more. Hunger, I tell myself, will eventually induce it to bite. I am wrong. Next morning I find it more anxious than the day before and still groping about, without resolving to fix its mandibles anywhere. I leave it alone for half a day longer without obtaining any result. Yet twenty-four hours of abstinence must have awakened a good appetite, above all in a creature which, if left undisturbed, would not have ceased eating.

My Scolia-grubs would die of starvation if I left them on their victim's back. I therefore restore matters as they were, with the Cetonia-larva belly uppermost and the young Scolia on top. I might utilise the subjects of my previous experiments; but, as I have to take precautions against the disturbance which may have been caused by the test already undergone, I prefer to operate on new patients, a luxury in which the richness of my menagerie allows me to indulge. I move the Scolia from its position, extract its head from the entrails of the Cetonia-larva and leave it to its own resources on its victim's belly. Betraying every symptom of uneasiness, the grub gropes, hesitates, casts about and does not insert its mandibles anywhere, though it is now the ventral surface which it is exploring. It would not display greater hesitation if placed on the back of the larva. I repeat, who knows? On this side it might perhaps injure the nervous plexus, which is even more essential than the dorsal vessel. The inexperienced grub must not drive in its mandibles at random; its future is jeopardized if it gives a single ill-judged bite. If it gnaws at the spot where I myself operated with my needle wrought into a scalpel, its victuals will very soon turn putrid. Once more, then, we witness an absolute refusal to perforate the skin of the victim elsewhere than at the very point where the egg was fixed.

The mother selects this point, which is undoubtedly that most favourable to the future prosperity of the larva, though I am not able clearly to discern the reasons for her choice; she fixes the egg to it; and the place where the opening is to be made is henceforth determined. It is here that the grub must bite: only here, never elsewhere. Its invincible refusal to tackle the Cetonia in any other part, even though it should die of starvation, shews us how rigorous is the rule of conduct with which its instinct is inspired.

As it gropes about, the grub laid on the victim's ventral surface sooner or later rediscovers the gaping wound from which I have removed it. If this takes too long for my patience, I can myself guide its head to the place with the point of a paint-brush. The grub then recognizes the hole of its own making, slips its neck into it and little by little dives into the Cetonia's belly, so that the original state of affairs appears to be exactly restored. And yet its successful rearing is henceforth highly problematical. It is possible that the larva will prosper, complete its development and spin its cocoon; it is also possible--and the case is not unusual--that the Cetonia-larva will soon turn brown and putrid. We then see the Scolia itself turn brown, distended as it is with putrescent foodstuffs, and then cease all movement, without attempting to withdraw from the sanies. It dies on the spot, poisoned by its excessively high game.

What can be the meaning of this sudden corruption of the victuals, followed by the death of the Scolia, when everything appeared to have returned to its normal condition? I see only one explanation. Disturbed in its activities and diverted from its usual courses by my interference, the grub, when replaced on the wound from which I extracted it, was unable to rediscover the lode at which it was working a few minutes earlier; it thrust its way at random into the victim's entrails; and a few untimely bites extinguished the last sparks of vitality. Its confusion rendered it clumsy; and the mistake cost it its life. It dies poisoned by the rich food which, if consumed according to the rules, should have made it grow plump and lusty.

I was anxious to observe the deadly effects of a disturbed meal in another fashion. This time the victim itself shall disorder the grub's activities. The Cetonia-larva, as served up to the young Scolia by its mother, is profoundly paralysed. Its inertia is complete and so striking that it constitutes one of the leading features of this narrative. But we will not anticipate. For the moment, the thing is to substitute for this inert larva a similar larva, but one not paralysed, one very much alive. To ensure that it shall not double up and crush the grub, I confine myself to reducing it to helplessness, leaving it otherwise just as I extracted it from its burrow. I must also be careful of its legs and mandibles, the least touch of which would rip open the nurseling. With a few turns of the finest wire I fix it to a little slab of cork, with its belly in the air. Next, to provide the grub with a ready-made hole, knowing that it will refuse to make one for itself, I contrive a slight incision in the skin, at the point where the Scolia lays her egg. I now place the grub upon the larva, with its head touching the bleeding wound, and lay the whole on a bed of mould in a transparent beaker protected by a pane of glass.

Unable to move, to wriggle, to scratch with its legs or snap with its mandibles, the Cetonia-larva, a new Prometheus bound, offers its defenceless flanks to the little Vulture destined to devour its entrails. Without too much hesitation, the young Scolia settles down to the wound made by my scalpel, which to the grub represents the wound whence I have just removed it. It thrusts its neck into the belly of its prey; and for a couple of days all seems to go well. Then, lo and behold, the Cetonia turns putrid and the Scolia dies, poisoned by the ptomaines of the decomposing game! As before, I see it turn brown and die on the spot, still half inside the toxic corpse.

The fatal issue of my experiment is easily explained. The Cetonia-larva is alive in every sense. True, I have, by means of bonds, suppressed its outward movements, in order to provide the nurseling with a quiet meal, devoid of danger; but it was not in my power to subdue its internal movements, the quivering of the viscera and muscles irritated by its forced immobility and by the Scolia's bites. The victim is in possession of its full power of sensation; and it expresses the pain experienced as best it may, by contractions. Embarrassed by these tremors, these twitches of suffering flesh, incommoded at every mouthful, the grub chews away at random and kills the larva almost as soon as it has started on it. In a victim paralysed by the regulation sting, the conditions would be very different. There are no external movements, nor any internal movements either, when the mandibles bite, because the victim is insensible. The grub, undisturbed in any way, is then able, with an unfaltering tooth, to pursue its scientific method of eating.

These marvellous results interested me too much not to inspire me with fresh devices when I pursued my investigations. Earlier enquiries had taught me that the larvae of the Digger-wasps are fairly indifferent to the nature of the game, though the mother always supplies them with the same diet. I had succeeded in rearing them on a great variety of prey, without paying regard to their normal fare. I shall return to this subject later, when I hope to demonstrate its great philosophical significance. Let us profit by these data and try to discover what happens when we give the Scolia food which is not properly its own.

I select from my heap of garden-mould, that inexhaustible mine, two larvae of the Rhinoceros Beetle, Oryctes nasicornis, about one-third full-grown, so that their size may not be out of proportion to the Scolia's. It is in fact almost identical with the size of the Cetonia. I paralyse one of them by giving an injection of ammonia in the nerve-centres. I make a fine incision in its belly and I place the Scolia on the opening. The dish pleases my charge; and it would be strange indeed if this were not so, considering that another Scolia-grub, the larva of the Garden Scolia, feeds on the Oryctes. The dish suits it, for before long it has burrowed half-way into the succulent paunch. This time all goes well. Will the rearing be successful? Not a bit of it! On the third day, the Oryctes decomposes and the Scolia dies. Which shall we hold responsible for the failure, myself or the grub? Myself who, perhaps too unskilfully, administered the injection of ammonia, or the grub which, a novice at dissecting a prey differing from its own, did not know how to practise its craft upon a changed victim and began to bite before the proper time?

In my uncertainty, I try again. This time I shall not interfere, so that my clumsiness cannot be to blame. As I described when speaking of the Cetonia-larva, the Oryctes-larva now lies bound, quite alive, on a strip of cork. As usual, I make a small opening in the belly, to entice the grub by means of a bleeding wound and facilitate its access. I obtain the same negative result. In a little while, the Oryctes is a noisome mass on which the nurseling lies poisoned. The failure was foreseen: to the difficulties presented by a prey unknown to my charge was added the commotion caused by the wriggling of an unparalysed animal.

We will try once more, this time with a victim paralysed not by me, an unskilled operator, but by an adept whose ability ranks so high that it is beyond discussion. Chance favours me to perfection: yesterday, in a warm sheltered corner, at the foot of a sandy bank, I discovered three cells of the Languedocian Sphex, each with its Ephippiger and the recently laid egg. This is the game I want, a corpulent prey, of a size suited to the Scolia and, what is more, in splendid condition, artistically paralysed according to rule by a master among masters.

This result is eloquent. Had I left the egg of the Sphex to hatch, the larva coming out of it would have fed upon the Ephippiger; and for the hundredth time I should have witnessed an incomprehensible spectacle, that of an animal which, devoured piecemeal for nearly a fortnight, grows thin and empty, shrivels up and yet retains to the very end the freshness peculiar to living flesh. Substitute for this Sphex-larva a Scolia-larva of almost the same size; let the dish be the same though the guest is different; and healthy live flesh is promptly replaced by pestilent rotten flesh. That which under the mandibles of the Sphex would for a long while have remained wholesome food promptly becomes a poisonous liquescence under the mandibles of the Scolia.

It is impossible to explain the preservation of the victuals until finally consumed by supposing that the venom injected by the Wasp when she delivers her paralysing stings possesses antiseptic properties. The three Ephippigers were operated on by the Sphex. Able to keep fresh under the mandibles of the Sphex-larvae, why did they promptly go bad under the mandibles of the Scolia-larvae? Any idea of an antiseptic must needs be rejected: a liquid preservative which would act in the first case could not fail to act in the second, as its virtues would not depend on the teeth of the consumer.

Those of you who are versed in the knowledge attaching to this problem, investigate, I beg you, search, sift, see if you can discover the reason why the victuals keep fresh when consumed by a Sphex, whereas they promptly become putrid when consumed by a Scolia. For me, I see only one reason; and I very much doubt whether any one can suggest another.

Both larvae practise a special art of eating, which is determined by the nature of the game. The Sphex, when sitting down to an Ephippiger, the food that has fallen to its lot, knows thoroughly how to consume it and how to preserve, to the very end, the glimmer of life which keeps it fresh; but, if it has to browse upon a Cetonia-grub, whose different structure would confuse its talents as a dissector, it would soon have nothing before it but a heap of putrescence. The Scolia, in its turn, is familiar with the method of eating the Cetonia-grub, its invariable portion; but it does not understand the art of eating the Ephippiger, though the dish is to its taste. Unable to dissect this unknown species of game, its mandibles slash away at random, killing the creature outright as soon as they take their first bites of the deeper tissues of the victim. That is the whole secret.

One more word, on which I shall enlarge in another chapter. I observe that the Scoliae to which I give Ephippigers paralysed by the Sphex keep in excellent condition, despite the change of diet, so long as the provisions retain their freshness. They languish when the game goes high; and they die when putridity supervenes. Their death, therefore, is due not to an unaccustomed diet, but to poisoning by one or other of those terrible toxins which are engendered by animal corruption and which chemistry calls by the name of ptomaines. Therefore, notwithstanding the fatal outcome of my three attempts, I remain persuaded that the unfamiliar method of rearing would have been perfectly successful had the Ephippigers not gone bad, that is, if the Scoliae had known how to eat them according to the rules.

Before deciding this serious matter, I will ask you to reflect that the first Wasp, of whatever kind, that thought of feeding her progeny on a Cetonia-grub or on any other large piece of game demanding long preservation could necessarily have left no descendants unless the art of consuming food without causing putrescence had been practised, with all its scrupulous caution, from the first generation onwards. Having as yet learnt nothing by habit or by atavistic transmission, since it was making a first beginning, the nurseling would bite into its provender at random. It would be starving, it would have no respect for its prey. It would carve its joint at random; and we have just seen the fatal consequence of an ill-directed bite. It would perish--I have just proved this in the most positive manner--it would perish, poisoned by its victim, already dead and putrid.

To prosper, it would have, although a novice, to know what was permitted and what forbidden in ransacking the creature's entrails; nor would it be enough for the larva to be approximately in possession of this difficult secret: it would be indispensable that it should possess the secret completely, for a single bite, if delivered before the right moment, would inevitably involve its own demise. The Scoliae of my experiments are not novices, far from it: they are the descendants of carvers that have practised their art since Scoliae first came into the world; nevertheless they all perish from the decomposition of the rations supplied, when I try to feed them on Ephippigers paralysed by the Sphex. Very expert in the method of attacking the Cetonia, they do not know how to set about the business of discreetly consuming a species of game new to them. All that escapes them is a few details, for the trade of an ogre fed on live flesh is familiar to them in its general features; and these unheeded details are enough to turn their food into poison. What, then, happened in the beginning, when the larva bit for the first time into a luscious victim? The inexperienced creature perished; of that there is not a shadow of doubt, unless we admit an absurdity and imagine the larva of antiquity feeding upon those terrible ptomaines which so swiftly kill its descendants to-day.

Nothing will ever make me admit and no unprejudiced mind can admit that what was once food has become a horrible poison. What the larva of antiquity ate was live flesh and not putrescence. Nor can it be admitted that the chances of fortune can have led at the first trial to success in a system of nourishment so full of pit-falls: fortuitous results are preposterous amid so many complications. Either the feeding is strictly methodical at the beginning, in conformity with the organic exigencies of the prey devoured, and the Wasp established her race; or else it was hesitating, without determined rules, and the Wasp left no successor. In the first case we behold innate instinct; in the second acquired habit.

A strange acquisition, truly! An acquisition presumed to be made by an impossible creature; an acquisition supposed to develop in no less impossible successors! Though the snow-ball, slowly rolling, at last becomes an enormous sphere, it is still necessary that the starting-point shall not have been NIL. The big ball implies the little ball, as small as you please. Now, in harking back to the origin of these acquired habits, if I interrogate the possibilities I obtain zero as the only answer. If the animal does not know its trade thoroughly, if it has to acquire something, all the more if it has to acquire everything, it perishes: that is inevitable; without the little snow-ball the big snow-ball cannot be rolled. If it has nothing to acquire, if it knows all that it needs to know, it flourishes and leaves descendants behind it. But then it possesses innate instinct, the instinct which learns nothing and forgets nothing, the instinct which is steadfast throughout time.

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