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diff --git a/old/67110-0.txt b/old/67110-0.txt deleted file mode 100644 index db5883a..0000000 --- a/old/67110-0.txt +++ /dev/null @@ -1,8710 +0,0 @@ -The Project Gutenberg eBook of The Hunting Wasps, by Jean-Henri Fabre - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: The Hunting Wasps - -Author: Jean-Henri Fabre - -Translator: Alexander Teixeira de Mattos - -Release Date: January 5, 2022 [eBook #67110] - -Language: English - -Produced by: Jeroen Hellingman and the Online Distributed Proofreading - Team at https://www.pgdp.net/ for Project Gutenberg (This - file was produced from images generously made available by - The Internet Archive) - -*** START OF THE PROJECT GUTENBERG EBOOK THE HUNTING WASPS *** - - - - - - THE WORKS OF J. H. FABRE - - THE - HUNTING WASPS - - - BY - J. HENRI FABRE - - Translated by - ALEXANDER TEIXEIRA DE MATTOS, F.Z.S. - - - HODDER AND STOUGHTON - LONDON NEW YORK TORONTO - - - - - - - - -TRANSLATOR’S NOTE - - -Henri Fabre’s essays on Wasps will fill three volumes in all, of which -this is the first. The others will be entitled The Mason-Wasps and More -Hunting Wasps. The former will include the chapters on the Common or -Social Wasp. - -The first seventeen chapters of the present book appeared some years -ago, wholly or in part, in a version of vol. i. of the Souvenirs -Entomologiques prepared by the author of Mademoiselle Mori for Messrs. -Macmillan and Co., by arrangement with whom I am now permitted to -retranslate and republish them for the purpose of this collected and -definite edition of Fabre’s entomological works. Of the remainder, ‘The -Modern Theory of Instinct’ first saw the light in the English Review, -and ‘An Unknown Sense,’ in an abbreviated form, in the Daily Mail. - -It is a pleasure once more to express my thanks to Miss Frances -Rodwell, who, as usual, has rendered me much valuable assistance, and -to Mr. Geoffrey Meade-Waldo, of the Natural History Museum, who has -been kind enough to set me right on many an entomological point. - - - Alexander Teixeira de Mattos. - - Chelsea, 1916. - - - - - - - - -CONTENTS - - - PAGE - - TRANSLATOR’S NOTE V - - CHAPTER I - THE BUPRESTIS-HUNTING CERCERIS 1 - - CHAPTER II - THE GREAT CERCERIS 18 - - CHAPTER III - A SCIENTIFIC SLAUGHTERER 40 - - CHAPTER IV - THE YELLOW-WINGED SPHEX 58 - - CHAPTER V - THE THREE DAGGER-THRUSTS 75 - - CHAPTER VI - THE LARVA AND THE NYMPH 86 - - CHAPTER VII - ADVANCED THEORIES 107 - - CHAPTER VIII - THE LANGUEDOCIAN SPHEX 129 - - CHAPTER IX - THE WISDOM OF INSTINCT 149 - - CHAPTER X - THE IGNORANCE OF INSTINCT 174 - - CHAPTER XI - AN ASCENT OF MONT VENTOUX 196 - - CHAPTER XII - THE TRAVELLERS 215 - - CHAPTER XIII - THE AMMOPHILÆ 231 - - CHAPTER XIV - THE BEMBEX 251 - - CHAPTER XV - THE FLY-HUNT 271 - - CHAPTER XVI - A PARASITE OF THE BEMBEX. THE COCOON 284 - - CHAPTER XVII - THE RETURN TO THE NEST 305 - - CHAPTER XVIII - THE HAIRY AMMOPHILA 323 - - CHAPTER XIX - AN UNKNOWN SENSE 341 - - CHAPTER XX - THE MODERN THEORY OF INSTINCT 354 - - APPENDIX 379 - - - - - - - - -CHAPTER I - -THE BUPRESTIS-HUNTING CERCERIS - - -There are for each one of us, according to his turn of mind, certain -books that open up horizons hitherto undreamed of and mark an epoch in -our mental life. They fling wide the gates of a new world wherein our -intellectual powers are henceforth to be employed; they are the spark -which lights the fuel on a hearth doomed, without its aid, to remain -indefinitely bleak and cold. And it is often chance that places in our -hands those books which mark the beginning of a new era in the -evolution of our ideas. The most casual circumstances, a few lines that -happen somehow to come before our eyes, decide our future and plant us -in the appointed groove. - -One winter evening, when the rest of the household was asleep, as I sat -reading beside a stove whose ashes were still warm, my book made me -forget for a while the cares of the morrow: those heavy cares of a poor -professor of physics who, after piling up diplomas and for a quarter of -a century performing services of uncontested merit, was receiving for -himself and his family a stipend of sixteen hundred francs, or less -than the wages of a groom in a decent establishment. Such was the -disgraceful parsimony of the day where education was concerned; such -was the edict of our government red-tape: I was an irregular, the -offspring of my solitary studies. And so I was forgetting the poverty -and anxieties of a professor’s life, amid my books, when I chanced to -turn over the pages of an entomological essay that had fallen into my -hands I forget how. - -It was a monograph by the then father of entomology, the venerable -scientist Léon Dufour, [1] on the habits of a Wasp that hunted -Buprestis-beetles. Certainly, I had not waited till then to interest -myself in insects; from my early childhood I had delighted in Beetles, -Bees, and Butterflies; as far back as I can remember, I see myself in -ecstasy before the splendour of a Ground-beetle’s wing-cases or the -wings of Papilio machaon, the Swallowtail. The fire was laid; the spark -to kindle it was absent. Léon Dufour’s essay provided that spark. - -New lights burst forth: I received a sort of mental revelation. So -there was more in science than the arranging of pretty Beetles in a -cork box and giving them names and classifying them; there was -something much finer: a close and loving study of insect life, the -examination of the structure and especially the faculties of each -species. I read of a magnificent instance of this, glowing with -excitement as I did so. Some time after, aided by those lucky -circumstances which he who seeks them eagerly is always able to find, I -myself published an entomological article, a supplement to Léon -Dufour’s. This first work of mine won honourable mention from the -Institute of France and was awarded a prize for experimental -physiology. But soon I received a far more welcome recompense, in the -shape of a most eulogistic and encouraging letter from the very man who -had inspired me. From his home in the Landes the revered master sent me -a warm expression of his enthusiasm and urged me to go on with my -studies. Even now, at that sacred recollection, my old eyes fill with -happy tears. O fair days of illusion, of faith in the future, where are -you now? - -I am sure that my readers will welcome an extract from the essay that -formed the starting-point of my own researches, especially as this -extract is necessary for the due understanding of what follows. I will -therefore let the master speak for himself, abridging his words in -parts: [2] - - - ‘In all insect history, I can think of no more curious, no more - extraordinary fact than that which I am about to describe to you. - It concerns a species of Cerceris who feeds her family on the most - sumptuous species of the genus Buprestis. Allow me to make you - share the vivid impressions which I owe to my study of this - Hymenopteron’s habits. - - ‘In July 1839, a friend living in the country sent me two specimens - of Buprestis bifasciata, an insect at that time new to my - collection, informing me that a kind of Wasp that was carrying one - of these pretty Beetles had let it fall on his coat and that, a few - moments later, a similar Wasp had dropped another on the ground. - - ‘In July 1840, I was visiting my friend’s house professionally and - reminded him of his capture of the year before and asked for - details of the circumstances that accompanied it. The identity of - the season and place made me hope to make a similar capture myself; - but the weather that day was overcast and chilly; and therefore but - few Wasps had ventured out. Nevertheless, we made a tour of - inspection in the garden; and, seeing nothing coming, I thought of - looking on the ground for the homes of Burrowing Hymenoptera. - - ‘My attention was attracted by a small heap of sand freshly thrown - up and forming a sort of tiny mole-hill. On raking it, I saw that - it masked the opening of a shaft running some way down. With a - spade we carefully turned over the soil and soon saw the glittering - wing-cases of the coveted Buprestis lying scattered around. - Presently I discovered not only isolated and fragmentary - wing-cases, but a whole Buprestis, then three or four of them, - displaying their emerald and gold. I could not believe my eyes. - - ‘But this was only a prelude to the feast. In the chaos of rubbish - produced by the exhumation, a Wasp appeared and fell into my hands: - it was the kidnapper of the Buprestes, trying to escape from among - her victims. In this burrowing insect I recognized an old - acquaintance, a Cerceris whom I have found hundreds of times, both - in Spain and round about Saint-Sever. - - ‘My ambition was far from satisfied. It was not enough for me to - identify the kidnapper and her victim: I wanted the larva, the sole - consumer of those rich provisions. After exhausting this first vein - of Buprestes, I hastened to make fresh excavations and, planting my - spade more carefully still, I at last succeeded in discovering two - larvæ which crowned the good fortune of this campaign. In less than - an hour I ransacked the haunts of three Cerceres; and my booty was - some fifteen whole Buprestes, with fragments of a still larger - number. I calculated, keeping, I believe, well within the mark, - that this particular garden contained five-and-twenty nests, making - an enormous total of buried Buprestes. What must it be, I thought, - in places where in a few hours I have caught on the garlic-flowers - as many as sixty Cerceres, whose nests were apparently in the - neighbourhood and no doubt victualled just as abundantly? And so my - imagination, never going beyond the bounds of probability, showed - me underground, within a small radius, Buprestis fasciata by the - thousand, whereas, during the thirty years and upwards that I have - been studying the entomology of this district, I never discovered a - single one in the open. - - ‘Once only, perhaps twenty years ago, I found the abdomen of this - insect, together with its wing-cases, stuck in a hole in an old - oak. This fact was illuminating. By informing me that the larva of - Buprestis fasciata must live in the wood of the oak, it completely - explained why this Beetle is so common in a district which has none - but oak-forests. As Cerceris bupresticida is rare in the clay hills - of such districts, as compared with the sandy plains thickly - planted with the maritime pine, it became an interesting question - to know whether this Wasp, when she inhabits the pine country, - victuals her nest in the same way as in the oak country. I had a - strong presumption that this was not the case; and you will soon - see, not without surprise, what exquisite entomological - discrimination our Cerceris displays in her choice of the numerous - species of the genus Buprestis. - - ‘We will therefore hasten to the pine region to reap new delights. - The field to be explored is the garden of a country-house standing - amid forests of maritime pines. One soon recognized the dwellings - of the Cerceris; they had been made solely in the main paths, where - the firm, compact soil offered the Burrowing Hymenopteron a solid - foundation for the construction of her subterranean abode. I - inspected some twenty, I may say, by the sweat of my brow. It is a - very laborious sort of undertaking, for the nests, and consequently - the provisions, are not found at less than a foot below the - surface. It becomes necessary, therefore, lest they should be - damaged, to begin by inserting a grass-stalk, serving as a landmark - and a guide, into the Cerceris’ gallery and next to invest the - place with a square of trenches, some seven or eight inches from - the orifice or the landmark. The sapping must be done with a - garden-spade, so that the central clod can be completely detached - on every side and raised in one piece, which we turn over on the - ground and then break up carefully. This was the method that - answered with me. - - ‘You would have shared our enthusiasm, my friend, at the sight of - the beautiful specimens of Buprestes which this original method of - treasure-hunting disclosed, one after the other, to our eager gaze. - You should have heard our exclamations each time that the mine was - turned upside down and new glories stood revealed, rendered more - brilliant still by the blazing sun; or when we discovered, here, - larvæ of all ages fastened to their prey, there, the cocoons of - those larvæ all encrusted with copper, bronze, and emerald. I who - had been studying insects at close quarters for three or four - decades—alas!—had never witnessed such a lovely sight nor enjoyed - so great a treat. It only needed your presence to double our - delight. Our ever-increasing admiration was devoted by turns to - those brilliant Beetles and to the marvellous discernment, the - astonishing sagacity of the Cerceris who had buried and stored them - away. Will you believe it, of more than four hundred Beetles [3] - that we dug up, there was not one but belonged to the old genus - Buprestis! Not even the very smallest mistake had been made by the - wise Wasp. What can we not learn from this intelligent industry in - so tiny an insect! What value would not Latreille [4] have set upon - this Cerceris’ support of the natural method! - - ‘We will now pass to the different manœuvres of the Cerceris for - establishing and victualling her nests. I have already said that - she chooses ground with a firm, compact, and smooth surface; I will - add that this ground must be dry and fully exposed to the sun. She - reveals in this choice an intelligence, or, if you prefer, an - instinct, which one might be tempted to consider the result of - experience. Loose earth or a merely sandy soil would doubtless be - much easier to dig; but then how is she to get an aperture that - will remain open for goods to pass in and out, or a gallery whose - walls will not constantly be liable to fall in, to lose their - shape, to be blocked after a few days of rain? Her choice therefore - is both sensible and nicely calculated. - - ‘Our Burrowing Wasp digs her gallery with her mandibles and her - front tarsi, which are furnished for this purpose with stiff spikes - that perform the office of rakes. The orifice must not only have - the diameter of the miner’s body: it must also be able to admit a - capture of large bulk. It is an instance of admirable foresight. As - the Cerceris goes deeper into the earth, she casts out the rubbish: - this forms the heap which I likened above to a tiny mole-hill. The - gallery is not perpendicular, for then it would inevitably become - blocked up, owing either to the wind or to other causes. Not far - from where it starts, it forms an angle; its length is seven or - eight inches. At the end of the passage the industrious mother - establishes the cradles of her offspring. These consist of five - separate cells, independent of one another, arranged in a - semicircle and hollowed into the shape and nearly the size of an - olive. Inside, they are polished and firm. Each of them is large - enough to contain three Buprestes, which form the usual allowance - for each larva. The mother lays an egg in the middle of the three - victims and then stops up the gallery with earth, so that, when the - victualling of the whole brood is finished, the cells no longer - communicate with the outside. - - ‘Cerceris bupresticida must be a dexterous, daring, and skilful - huntress. The cleanliness and freshness of the Buprestes whom she - buries in her lair incline one to believe that she must seize these - Beetles at the moment when they are leaving the wooden galleries in - which their final metamorphosis has taken place. But what - inconceivable instinct urges her, a creature that lives solely on - the nectar of flowers, to procure, in the face of a thousand - difficulties, animal food for carnivorous children which she will - never see, and to take up her post on utterly dissimilar trees, - which conceal deep down in their trunks the insects destined to - become her prey? What yet more inconceivable entomological judgment - lays down the strict law that she shall confine herself in the - choice of her victims to a single generic group and capture - specimens differing greatly among themselves in size, shape, and - colour? For observe, my friend, how slight the resemblance is - between Buprestis biguttata, with a long, slender body and a dark - colour; B. octoguttata, oval-oblong, with great patches of a - beautiful yellow on a blue or green ground; and B. micans, who is - three or four times the size of B. biguttata and glitters with a - metallic lustre of a fine golden green. - - ‘There is another very singular fact about the manœuvres of our - Buprestis-slayer. The buried Buprestes, like those whom I have - seized in the grasp of their kidnappers, are always deprived of any - sign of life; in a word, they are decidedly dead. I was surprised - to remark that, no matter when these corpses were dug up, they not - only preserved all their freshness of colouring, but their legs, - antennæ, palpi, and the membranes uniting the various parts of the - body remained perfectly supple and flexible. There was no - mutilation, no apparent wound to be seen. One might at first - believe the reason, in the case of the buried ones, to be due to - the coolness of the bowels of the earth, in the absence of air and - light; and, in the case of those taken from the kidnappers, to the - very recent date of their death. But please observe that, at the - time of my explorations, after placing the numerous exhumed - Buprestes in separate screws of paper, I often left them in their - little bags for thirty-six hours before pinning them out. Well, - notwithstanding the dryness of the air and the burning July heat, I - always found the same flexibility in their joints. Nay more: I have - dissected several of them, after that lapse of time, and their - viscera were as perfectly preserved as if I had used my scalpel on - the insects’ live entrails. Now long experience has taught me that, - even in a Beetle of this size, when twelve hours have passed after - death in summer, the internal organs become either dried up or - putrefied, so that it is impossible to make sure of their form or - structure. There is some special circumstance about the Buprestes - killed by the Cerceres that saves them from desiccation and - putrefaction for a week and perhaps two. But what is this - circumstance?’ - - -To explain this wonderful preservation of the tissues which makes of an -insect smitten for many weeks past with a corpse-like inertness a piece -of game which does not even go high and which, during the greatest heat -of summer, keeps as fresh as at the moment of its capture, the able -historian of the Buprestis-huntress surmises the presence of an -antiseptic fluid, acting similarly to the preparations used for -preserving anatomical specimens. This fluid, he suggests, can be -nothing but the poison of the Wasp, injected into the victim’s body. A -tiny drop of the venomous liquid accompanying the sting, the needle -destined for the inoculation, would therefore serve as a kind of brine -or pickle to preserve the meat on which the larva is to feed. But how -immensely superior to our own pickling processes is that of the Wasp! -We salt, or smoke, or tin foodstuffs which remain fit to eat, it is -true, but which are very far indeed from retaining the qualities which -they possessed when fresh. Tins of sardines soaked in oil, Dutch smoked -herrings, codfish reduced to hard slabs by salt and sun: which of these -can compare with the same fish supplied to the cook, so to speak, all -alive and kicking? In the case of flesh-meat, things are even worse. -Apart from salting and curing, we have nothing that can keep a piece of -meat fit for consumption for even a fairly short period. - -Nowadays, after a thousand fruitless attempts in the most varied -directions, we equip special ships at great cost; and these ships, -fitted with a powerful refrigerating-plant, bring us the flesh of sheep -and oxen slaughtered in the South American pampas, frozen and preserved -from decomposition by the intense cold. How much more excellent is the -Cerceris’ method, so swift, so inexpensive, and so efficacious! What -lessons can we not learn from her transcendental chemistry! With an -imperceptible drop of her poison-fluid, she straightway renders her -prey incorruptible! Incorruptible, did I say? It is much more than -that! The game is brought to a condition which prevents desiccation, -leaves the joints supple, keeps all the organs, both internal and -external, in their pristine freshness, and, in short, places the -sacrificed insect in a state that differs from life only by its -corpse-like immobility. - -This is the theory that satisfied Léon Dufour, as he contemplated the -incomprehensible marvel of those dead Buprestes proof against -corruption. A preserving-fluid, incomparably superior to aught that -human science can produce, explains the mystery. He, the master, the -ablest of them all, an expert in the niceties of anatomy; he who, with -magnifying-glass and scalpel, examined the whole entomological series, -leaving no nook or corner unexplored; he, in short, for whom insect -organism possessed no secrets can think of nothing better than an -antiseptic fluid to give at least the semblance of an explanation of a -fact that leaves him confounded. I crave permission to emphasize this -comparison between animal instinct and the reasoning power of the sage -in order the better to bring to light, in due season, the overwhelming -superiority of the former. - -I will add but a few words to the history of the Buprestis-hunting -Cerceris. This Wasp, who is common in the Landes, as her historian -tells us, appears to be very rarely found in the department of -Vaucluse. I have met her only at long intervals, in autumn—and then -only isolated specimens—on the spiny heads of the field eryngo -(Eryngium campestre), in the neighbourhood either of Avignon or of -Orange and Carpentras. In this last spot, so favourable to the work of -the Burrowing Wasps owing to its sandy soil of Molasse formation, I -have had the good fortune, not to witness the exhumation of such -entomological treasures as Léon Dufour describes, but to find some old -nests which I attribute without hesitation to the Buprestis-huntress, -basing my opinion upon the shape of the cocoons, the nature of the -provisioning, and the presence of the Wasp in the neighbourhood. These -nests, dug in the heart of a very crumbly sandstone, known in the -district as safre, were crammed with remains of Beetles, remains easily -recognized and consisting of detached wing-cases, gutted corselets and -entire legs. Now these broken victuals of the larva’s banquet all -belonged to a single species; and that species was once more a -Buprestis, the Double-lined Buprestis (Sphenoptera geminata). [5] Thus -from the west to the east of France, from the department of the Landes -to that of Vaucluse, the Cerceris remains faithful to her favourite -prey; longitude makes no difference to her predilections; a huntress of -Buprestes among the maritime pines of the sand-dunes along the coast -remains a huntress of Buprestes among the olive-trees and evergreen -oaks of Provence. She changes the species according to place, climate, -and vegetation, which alter the nature of the insect population so -greatly; but she never departs from her favoured genus, the genus -Buprestis. What can her reason be? That is what I shall try to show. - - - - - - - - -CHAPTER II - -THE GREAT CERCERIS - - -With my memory full of the prowess of the Buprestis-huntress, I watched -for an opportunity to observe in my turn the labours of the Cerceres; -and I watched to such good purpose that I ended by being successful. -True, the Wasp was not the one celebrated by Léon Dufour, with her -sumptuous victuals whose remains, when unearthed, suggest the dust of -some nugget broken by the gold-miner’s pick: it was a kindred species, -a gigantic brigand who contents herself with humbler prey; in short, it -was Cerceris tuberculata or C. major, the largest and most powerful of -the genus. - -The last fortnight in September is the time when our Burrowing Wasp -digs her lairs and buries in their depths the victim destined for her -grubs. The site of the home, always selected with discrimination, is -subject to those mysterious laws which differ in different species but -are invariable throughout any one species. Léon Dufour’s Cerceris -requires a level, well-trodden, compact soil, such as that of a path, -to prevent the possibility of landslips and other damage which would -ruin her gallery at the first shower of rain. Ours, on the contrary, is -not very particular about the nature of her soil, but must have that -soil vertical. With this slight architectural modification, she avoids -most of the dangers that might threaten her gallery; and consequently -she digs her burrows indifferently in a loose and slightly clayey soil -and in the soft sand of the Molasse formation, which makes the work of -excavation much easier. The only indispensable condition appears to be -that the earth should be dry and exposed to the sun’s rays for the best -part of the day. It is therefore in the steep roadside banks, in the -sides of the ravines hollowed by the rains in the sandstone, that our -Wasp elects to establish her home. These conditions are common in the -neighbourhood of Carpentras, in the part known as the Hollow Road; and -it is here that I have observed Cerceris tuberculata in her largest -numbers and that I gathered most of my facts relating to her history. - -The choice of this vertical site is not enough for her: other -precautions are taken to guard against the inevitable rains of the -season, which is already far advanced. If there be some bit of hard -sandstone projecting like a ledge, if there be naturally hollowed in -the ground some hole large enough to put one’s fist in, it will be -under that shelter or in this cavity that she contrives her gallery, -thus adding a natural vestibule to the edifice of her own construction. -Though no sort of communism exists among them, these insects -nevertheless like to associate in small numbers; and I have always -observed their nests in groups of about ten at least, with the -orifices, which are usually pretty far apart, sometimes close enough to -touch one another. - -On a bright, sunny day it is wonderful to watch the different -operations of these industrious miners. Some patiently remove with -their mandibles a few bits of gravel from the bottom of the pit and -push the heavy mass outside; others, scraping the walls of the corridor -with the sharp rakes of their tarsi, collect a heap of rubbish which -they sweep out backwards and send streaming down the sides of the -slopes in a long thread of dust. It was these periodical billows of -sand discharged from the galleries in process of building that betrayed -the presence of my first Cerceres to me and enabled me to discover -their nests. Others, either because they are tired or because they have -finished their hard task, seem to rest and polish their antennæ and -wings under the natural eaves that most frequently protect their -dwelling; or else they remain motionless at the mouth of the hole, -merely showing their wide, square faces, striped black and yellow. -Others, lastly, flit gravely humming on the neighbouring -kermes-oak-bushes, where the males, always on the watch near the -burrows in course of construction, are not slow to join them. Couples -form, often disturbed by the arrival of a second male, who strives to -supplant the happy possessor. The humming becomes threatening, brawls -take place and often the two males roll in the dust until one of them -acknowledges the superiority of his rival. Near by, the female awaits -the outcome of the struggle with indifference; she finally accepts the -male whom the chances of the contest bestow upon her; and the couple -fly out of sight in search of peace and quiet on some distant -brushwood. Here the part played by the males ends. Only half the size -of the females and nearly as numerous, they prowl all around the -burrows, but never enter and never take part in the laborious mining -operations nor in the perhaps even more difficult hunting expeditions -by means of which the cells are to be stocked. - -The galleries are ready in a few days, especially as those of the -previous year are employed with the aid of a few repairs. The other -Cerceres, so far as I know, have no fixed home, no family inheritance -handed down from generation to generation. A regular gipsy tribe, they -settle singly wherever the chances of their vagrant life may lead them, -provided that the soil suits them. But the Great Cerceris is faithful -to her household gods. The overhanging blade of sandstone that -sheltered her predecessors is adopted by her in her turn; she digs in -the same layer of sand wherein her forbears dug; and, adding her own -labours to those which went before, she obtains deep retreats that are -not always easy of inspection. The diameter of the galleries is wide -enough to admit a man’s thumb; and the insect moves about in them -readily, even when laden with the prey which we shall see it capture. -Their direction, at first horizontal to a depth of four to eight -inches, describes a sudden bend and dips more or less obliquely now to -this side, now to that. With the exception of the horizontal part and -the bend, the direction of the rest of the tube seems to be regulated -by the difficulties presented by the ground, as is proved by the twists -and turns observed in the more distant portion. The total length of the -shaft attains as much as eighteen inches. At the far end of the tube -are the cells, few in number and each provisioned with five or six -corpses of the Beetle order. But let us leave these building details -and come to facts more capable of exciting our admiration. - -The victim which the Cerceris chooses whereon to feed her grubs is a -large-sized Weevil, Cleonus ophthalmicus. We see the kidnapper arrive -heavily laden, carrying her victim between her legs, body to body, head -to head, and plump down at some distance from her hole, to complete the -rest of the journey without the aid of her wings. The Wasp is now -dragging her prey in her mandibles up a vertical, or at least a very -steep surface, productive of frequent tumbles which send kidnapper and -kidnapped rolling helter-skelter to the bottom, but incapable of -discouraging the indefatigable mother, who, covered with dirt and dust, -ends by diving into the burrow with her booty, which she has not let go -for a single moment. Whereas the Cerceris finds it far from easy to -walk with such a burden, especially on ground of this character, it is -a different matter when she is flying, which she does with a vigour -that astonishes us when we consider that the sturdy little creature is -carrying a prize almost as large as herself and heavier. I had the -curiosity to compare the weight of the Cerceris and her victim: the -first turned the scale at 150 milligrammes; [6] the second averaged 250 -milligrammes, [7] or nearly double. - -These figures are eloquent of the powers of the huntress, nor did I -ever weary of admiring the nimbleness and ease with which she resumed -her flight, with the game between her legs, and rose to a height at -which I lost sight of her whenever, tracked too close by my -indiscretion, she resolved to flee in order to save her precious booty. -But she did not always fly away; and I would then succeed, not without -difficulty, lest I should hurt her, in making her drop her prey by -worrying her and rolling her over. I would then seize the Weevil; and -the Cerceris, thus despoiled, would hunt about here and there, enter -her lair for a moment and soon come out again to fly off on a fresh -chase. In less than ten minutes the skilled huntress had found a new -victim, performed the murder and accomplished the rape, which I often -allowed myself to turn to my own profit. Eight times in succession I -have committed the same robbery at the expense of the same Wasp; eight -times, with unshaken consistency, she has recommenced her fruitless -expedition. Her patience outwore mine; and I left her in undisturbed -possession of her ninth capture. - -By this means, or by violating cells already provisioned, I procured -close upon a hundred Weevils; and, notwithstanding what I was entitled -to expect from what Léon Dufour has told us of the habits of the -Buprestis-hunting Cerceris, I could not repress my surprise at the -sight of the singular collection which I had made. Whereas the -Buprestis-slayer, while confining herself to one genus, passes -indiscriminately from one species to another, the more exclusive Great -Cerceris preys invariably on the same species, Cleonus ophthalmicus. -When going through my bag I came upon but one exception, and even that -belonged to a kindred species, Cleonus alternans, a species which I -never saw again in my frequent visits to the Cerceris. Later researches -supplied me with a second exception, in the shape of Bothynoderus -albidus; and that is all. Is this predilection for a single species -adequately explained by the greater flavour and succulence of the prey? -Do the grubs find in this monotonous diet juices which suit them and -which they would not find elsewhere? I do not think so; and, if Léon -Dufour’s Cerceris hunts every sort of Buprestis without distinction, -this is doubtless because all the Buprestes possess the same nutritive -properties. But this must be generally the case with the Weevils also: -their nourishing qualities must be identical; and then this surprising -choice becomes only a question of size and consequently of economy of -labour and time. Our Cerceris, the mammoth of her race, tackles the -Ophthalmic Cleonus by preference because this Weevil is the largest in -our district and perhaps also the commonest. But, if her favourite prey -should fail, she must fall back upon other species, even though they be -smaller, as is proved by the two exceptions stated. - -Besides, she is far from being the only one to go hunting at the -expense of the snouted clan, the Weevils. Many other Cerceres, -according to their size, their strength and the accidents of the chase, -capture Weevils varying infinitely in genus, species, shape, and -dimensions. It has long been known that Cerceris arenaria feeds her -grubs on similar provisions. I myself have encountered in her lairs -Sitona lineata, S. tibialis, Cneorinus hispidus, Brachyderes gracilis, -Geonemus flabellipes and Otiorhynchus maleficus. Cerceris aurita is -known to make her booty of Otiorhynchus raucus and Phynotomus -punctatus. The larder of Cerceris Ferreri has shown me the following: -Phynotomus murinus, P. punctatus, Sitona lineata, Cneorinus hispidus, -Rhynchites betuleti. The last, who rolls vine-leaves in the shape of -cigars, is sometimes a superb steel-blue and more ordinarily shines -with a splendid golden copper. I have found as many as seven of these -brilliant insects victualling a single cell; and the gaudiness of the -little subterranean heap might almost stand comparison with the jewels -buried by the Buprestis-huntress. Other species, notably the weaker, go -in for lesser game, whose small size is atoned for by larger numbers. -Thus Cerceris quadricincta stacks quite thirty specimens of Apion -gravidum in each of her cells, without disdaining on occasion such -larger Weevils as Sitona lineata and Phynotomus murinus. A similar -provision of small species falls to the share of Cerceris labiata. -Lastly, the smallest Cerceris in my district, Cerceris Julii, [8] -chases the tiniest Weevils, Apion gravidum and Bruchus granarius, -victims proportioned to the diminutive huntress. To finish with this -list of game, let us add that a few Cerceres observe other gastronomic -laws and raise their families on Hymenoptera. One of these is Cerceris -ornata. We will dismiss these tastes as foreign to the subject in hand. - -Of the eight species then of Cerceres whose provisions consist of -Beetles, seven adopt a diet of Weevils and one a diet of Buprestes. For -what singular reasons are the depredations of these Wasps confined to -such narrow limits? What are the motives for this exclusive choice? -What inward likeness can there be between the Buprestes and the -Weevils, outwardly so entirely dissimilar, that they should both become -the food of kindred carnivorous grubs? Beyond a doubt, there are -differences of flavour between this victim and that, nutritive -differences which the larvæ are well able to appreciate; but some -graver reason must overrule all such gastronomic considerations and -cause these curious predilections. - -After all the admirable things that have been said by Léon Dufour upon -the long and wonderful preservation of the insects destined for the -flesh-eating larvæ, it is almost needless to add that the Weevils, both -those whom I dug up and those whom I took from between the legs of -their kidnappers, were always in a perfect state of preservation, -though deprived for ever of the power of motion. Freshness of colour, -flexibility of the membranes and the lesser joints, normal condition of -the viscera: all these combine to make you doubt that the lifeless body -before your eyes is really a corpse, all the more as even with the -magnifying-glass it is impossible to perceive the smallest wound; and, -in spite of yourself, you are every moment expecting to see the insect -move and walk. Nay more: in a heat which, in a few hours, would have -dried and pulverized insects that had died an ordinary death, or in -damp weather, which would just as quickly have made them decay and go -mouldy, I have kept the same specimens, both in glass tubes and paper -bags, for more than a month, without precautions of any kind; and, -incredible though it may sound, after this enormous lapse of time the -viscera had lost none of their freshness and dissection was as easily -performed as though I were operating on a live insect. No, in the -presence of such facts, we cannot speak of the action of an antiseptic -and believe in a real death: life is still there, latent, passive life, -the life of a vegetable. It alone, resisting yet a little while longer -the all-conquering chemical forces, can thus preserve the structure -from decomposition. Life is still there, except for movement; and we -have before our eyes a marvel such as chloroform or ether might -produce, a marvel which owes its origin to the mysterious laws of the -nervous system. - -The functions of this vegetative life are no doubt enfeebled and -disturbed; but at any rate they are exercised in a lethargic fashion. I -have as a proof the evacuation performed by the Weevils normally and at -intervals during the first week of this deep slumber, which will be -followed by no awakening and which nevertheless is not yet death. It -does not cease until the intestines are emptied of their contents, as -shown by autopsy. Nor do the faint glimmers of life which the insect -still manifests stop at that; and, though irritability of the organs -seems annihilated for good, I have nevertheless succeeded in arousing -slight signs of it. Having placed some recently exhumed and absolutely -motionless Weevils in a bottle containing sawdust moistened with a few -drops of benzine, I was not a little astonished to see their legs and -antennæ moving a quarter of an hour later. For a moment I thought that -I could recall them to life. Vain hope! Those movements, the last -traces of a susceptibility about to be extinguished, soon cease and -cannot be excited a second time. I have tried this experiment in some -cases a few hours after the murderous blow, in others as late as three -or four days after, and always with the same success. Still, the -movement is feeble in proportion to the time that has elapsed since the -fatal stroke. It always spreads from front to back: the antennæ first -wave slowly to and fro; then the front tarsi tremble and take part in -the oscillation; next the tarsi of the second pair of legs and lastly -those of the third pair hasten to do likewise. Once movement sets in, -these different appendages execute their vibrations without any order, -until the whole relapses into immobility, which happens more or less -quickly. Unless the blow has been dealt quite recently, the motion of -the tarsi extends no farther and the legs remain still. - -Ten days after an attack I was unable to obtain the least vestige of -susceptibility by the above process; and I then had recourse to the -Voltaic battery. This method is more powerful and provokes muscular -contractions and movements where the benzine-vapour fails. We have only -therefore to apply the current of one or two Bunsen cells through the -conductors of some slender needles. Thrusting the point of one under -the farthest ring of the abdomen and the point of the other under the -neck, we obtain, each time the current is established, not only a -quivering of the tarsi, but a strong reflexion of the legs, which draw -up under the abdomen and then straighten out when the current is turned -off. These flutterings, which are very energetic during the first few -days, gradually diminish in intensity and appear no more after a -certain time. On the tenth day I have still obtained perceptible -movements; on the fifteenth day the battery was powerless to provoke -them, despite the suppleness of the limbs and the freshness of the -viscera. To effect a comparison, I subjected to the action of the -Voltaic pile Beetles really dead, Cellar-beetles, Saperdæ and Lamiæ, -asphyxiated with benzine or sulphuric acid gas. Two hours at most after -the asphyxiation, it was impossible for me to provoke the movements so -easily obtained in Weevils who have already for several days been in -that curious intermediate state between life and death into which their -formidable enemy plunges them. - -All these facts are opposed to the idea of something completely dead, -to the theory that we have here a veritable corpse which has become -incorruptible by the action of a preservative fluid. They can be -explained only by admitting that the insect is smitten in the very -origin and mainspring of its movements; that its susceptibility, -suddenly benumbed, dies out slowly, while the more tenacious vegetative -functions die still more slowly and keep the intestines in a state of -preservation for the space of time required by the larvæ. - -The particular thing which it was most important to ascertain was the -manner in which the murder is committed. It is quite evident that the -chief part in this must be played by the Cerceris’ venom-laden sting. -But where and how does it enter the Weevil’s body, which is covered -with a hard and well-riveted cuirass? In the various insects pierced by -the assassin’s dart, nothing, even under the magnifying-glass, betrayed -her method. It became a matter, therefore, of discovering the murderous -manœuvres of the Wasp by direct observation, a problem whose -difficulties had made Léon Dufour recoil and whose solution seemed to -me for a time undiscoverable. I tried, however, and had the -satisfaction of succeeding, though not without some preliminary -groping. - -When flying from their caverns, intent upon the chase, the Cerceres -would take any direction indifferently, turning now this way, now that; -and they would come back, laden with their prey, from all quarters. -Every part of the neighbourhood must therefore have been explored -without distinction; but, as the huntresses were hardly more than ten -minutes in coming and going, the radius worked could not be one of -great extent, especially when we allow for the time necessary for the -insect to discover its prey, to attack it and to reduce it to an inert -mass. I therefore set myself to inspect the adjacent ground with every -possible attention, in the hope of finding a few Cerceres engaged in -hunting. An afternoon devoted to this thankless task ended by -persuading me of the futility of my quest and of the small chance which -I had of catching in the act a few scarce huntresses, scattered here -and there and soon lost to view through the swiftness of their flight, -especially on difficult ground, thickly planted with vines and -olive-trees. I abandoned the attempt. - -By myself bringing live Weevils into the vicinity of the nests, might I -not tempt the Cerceres with a victim all ready to hand and thus witness -the desired tragedy? The idea seemed a good one; and the very next -morning I went off in search of live specimens of Cleonus ophthalmicus. -Vineyards, cornfields, lucerne-crops, hedges, stone-heaps, roadsides: I -visited and inspected one and all; and, after two mortal days of minute -investigation, I was the possessor—dare I say it?—I was the possessor -of three Weevils, flayed, covered with dust, minus antennæ or tarsi, -maimed veterans whom the Cerceres would perhaps refuse to look at! Many -years have passed since the days of that fevered quest when, bathed in -sweat, I made those wild expeditions, all for a Weevil; and, despite my -almost daily entomological explorations, I am still ignorant how and -where the celebrated Cleonus lives, though I meet him occasionally, -roaming on the edge of the paths. O wonderful power of instinct! In the -selfsame places and in a mere fraction of time, our Wasps would have -found by the hundred these insects undiscoverable by man; and they -would have found them fresh and glossy, doubtless just issued from -their nymphal cocoons! - -No matter, let us see what we can do with my pitiful bag. A Cerceris -has just entered her gallery with her usual prey; before she comes out -again for a new expedition, I place a Weevil a few inches from the -hole. The insect moves about; when it strays too far, I restore it to -its position. At last the Cerceris shows her wide face and emerges from -the hole; my heart beats with excitement. The Wasp stalks about the -approaches to her home for a few moments, sees the Weevil, brushes -against him, turns round, passes several times over his back and flies -away without honouring my capture with a touch of her mandibles: the -capture which I was at such pains to acquire. I am confounded, I am -floored. Fresh attempts at other holes lead to fresh disappointments. -Clearly these dainty sports-women will have none of the game which I -offer them. Perhaps they find it uninteresting, not fresh enough. -Perhaps, by taking it in my fingers, I have given it some odour which -they dislike. With these epicures a mere alien touch is enough to -produce disgust. - -Should I be more fortunate if I obliged the Cerceris to use her sting -in self-defence? I enclosed a Cerceris and a Cleonus in the same bottle -and stirred them up by shaking it. The Wasp, with her sensitive nature, -was more impressed than the other prisoner, with his dull and clumsy -organization; she thought of flight, not of attack. The very parts were -interchanged: the Weevil, becoming the aggressor, at times seized with -his snout a leg of his mortal enemy, who was so greatly overcome with -fear that she did not even seek to defend herself. I was at the end of -my resources; yet my wish to behold the catastrophe was but increased -by the difficulties already experienced. Well, I would try again. - -A bright idea flashed across my mind, entering so naturally into the -very heart of the question that it brought hope in its train. Yes, that -must be it; the thing was bound to succeed. I must offer my scorned -game to the Cerceris in the heat of the chase. Then, carried away by -her absorbing preoccupation, she would not perceive its imperfections. - -I have already said that, on her return from hunting, the Cerceris -alights at the foot of the slope, at some distance from the hole, -whither she laboriously drags her prey. It became a matter, therefore, -of robbing her of her victim by drawing it away by one foot with my -forceps and at once throwing her the live Weevil in exchange. The trick -succeeded to perfection. As soon as the Cerceris felt her prey slip -from under her belly and escape her, she tapped the ground impatiently -with her feet, turned round and, perceiving the Weevil that had taken -the place of her own, flung herself upon him and clasped him in her -legs to carry him away. But she soon became aware that her prey was -alive; and now the tragedy began, only to end with inconceivable -rapidity. The Wasp faced her victim and, gripping its snout with her -powerful mandibles, soon had it at her mercy. Then, while the Weevil -reared on his six legs, the other pressed her forefeet violently on his -back, as if to force open some ventral joint. I next saw the assassin’s -abdomen slip under the Cleonus’ belly, bend into a curve, and dart its -poisoned lancet briskly, two or three times, into the joint of the -prothorax, between the first and second pair of legs. All was over in a -moment. Without the least convulsive movement, without any of that -stretching of the limbs which accompanies an animal’s death, the victim -fell motionless for all time, as though struck by lightning. It was -terribly and at the same time wonderfully quick. The murderess next -turned the body on its back, placed herself belly to belly with it, -with her legs on either side, clasped it and flew away. Thrice over I -renewed the experiment, with my three Weevils; and the process never -varied. - -Of course I gave the Cerceris back her first prey each time and -withdrew my own Cleonus to examine him at my leisure. The inspection -but confirmed my high opinion of the assassin’s formidable skill. It -was impossible to perceive the least sign of a wound, the slightest -flow of vital fluid at the point attacked. But what was most -striking—and justly so—was the prompt and complete annihilation of all -movement. Immediately after the murder I sought in vain for traces of -irritability of the organs in the three Weevils dispatched before my -eyes: those traces were never revealed, whether I pinched or pricked -the insect; and it required the artificial means described above to -provoke them. Thus these powerful Cleoni, which, if pierced alive with -a pin and fixed on the insect-collector’s fatal sheet of cork, would -have kicked and struggled for days and weeks, nay, for whole months on -end, instantly lose all power of movement from the effect of a tiny -prick which inoculates them with an invisible drop of venom. But -chemistry has no poison so potent in so minute a dose; prussic acid -would hardly produce those effects, if indeed it can produce them at -all. It is not to toxology then, surely, but to physiology and anatomy -that we must turn to grasp the cause of this instantaneous -annihilation; and to understand these marvellous happenings we must -consider not so much the intense strength of the poison injected as the -importance of the organ injured. - -What is there, then, at the point where the sting enters? - - - - - - - - -CHAPTER III - -A SCIENTIFIC SLAUGHTERER - - -The wasp has told us part of her secret by showing us the spot which -her sting touches. Does this solve the question? Not yet, nor by a long -way. Let us go back for a moment, forget what the insect has just -taught us and, in our turn, set ourselves the problem of the Cerceris. -The problem is this: to store underground, in a cell, a big enough pile -of game to feed the larva which will be hatched from the egg laid on -the heap. - -At first sight this victualling seems simple enough; but a little -reflection shows that it is attended by very grave difficulties. Our -own game, for instance, is brought down by a shot from a gun; it is -killed with horrible wounds. The Wasp has refinements of taste unknown -to us: she must have the prey intact, with all its elegance of form and -colouring, no broken limbs, no gaping wounds, no hideous -disembowelling. Her victim has all the freshness of the live insect; it -retains, without the loss of a single speck, that fine tinted bloom -which is destroyed by the mere contact of our fingers. If the insect -were dead, if it were really a corpse, how great would be our -difficulty in obtaining a like result! Each of us can kill an insect by -brutally crushing it under foot; but to kill it neatly, with no sign of -injury, is not an easy operation, is not an operation which any one can -perform. How many would be utterly perplexed if they were called upon -to kill, then and there, without crushing it, a hardy little insect -which, even when you cut off its head, goes on struggling for a long -time after! One has to be a practical entomologist to think of the -various ways of asphyxiation; and even here success would be doubtful -with primitive methods, such as the fumes of benzine or burning -sulphur. In this unwholesome atmosphere the insect flounders about too -long and loses its glory. We must have recourse to more heroic -measures, such as the terrible exhalations of prussic acid emanating -slowly from strips of paper steeped in cyanide of potassium, or else -and better still, as being free from danger to the insect-hunter, the -all-powerful fumes of bisulphide of carbon. It is quite an art, you -see—and an art which has to call to its aid the formidable arsenal of -chemistry—to kill an insect neatly, to do what the Cerceris performs so -quickly and so prettily, that is, if we are stupid enough to assume -that her captured prey actually becomes a corpse. - -A corpse! But that is by no means the fare prescribed for the larvæ, -those little ogres clamouring for fresh meat, whom game ever so -slightly high would inspire with insurmountable disgust. They want meat -killed that day, with no suspicion of taint, the first sign of -corruption. Nevertheless, the prey cannot be packed into the cell -alive, as we pack the cattle destined to furnish fresh meat for the -passengers and crew of a ship. What indeed would become of the delicate -egg laid among live provisions? What would become of the feeble larva, -a tiny grub which the least touch would bruise, among lusty Beetles who -would go on kicking for weeks with their long, spurred legs? We need -here two things which seem utterly irreconcilable: the immobility of -death combined with the sweet wholesomeness of life. Before such a -dietetic problem the most deeply read layman would stand powerless; the -practical entomologist himself would own himself beaten. The Cerceris’ -larder would defy their reasoning power. - -Let us then suppose an academy of anatomists and physiologists; let us -imagine a congress at which the question is raised among such men as -Flourens, [9] Magendie [10] and Claude Bernard. [11] If we want to -obtain both complete immobility of the victim and also its preservation -during a long period without going bad, the simplest and most natural -idea which comes to us is that of tinned foods. Our congress would -suggest the use of some preserving liquid, just as the famous Landes -scientist did when he was confronted with his Buprestes; they would -attribute exquisite antiseptic virtues to the Wasp’s poison-fluid; but -these strange virtues would still remain to be proved. And perhaps the -conclusion of that learned assembly, like the conclusion of the sage of -the Landes, would be a purely gratuitous supposition which would simply -substitute one unknown quantity for another, giving us in the place of -the mystery of those uncorrupted tissues the mystery of that wonderful -preserving fluid. - -If we insist, if we point out that the larvæ need, not preserved food, -which could never possess the properties of still palpitating flesh, -but something that shall be just as if it were live prey, despite its -complete inertia, the learned congress, after due reflection, will fix -on paralysis: - -‘Yes, that’s it, of course! The creature must be paralysed; it must be -deprived of movement, without being deprived of life.’ - -There is only one way of achieving this result: to injure, cut or -destroy the insect’s nervous system in one or more skilfully-selected -places. But, even at that stage, if left in hands unfamiliar with the -anatomical secrets of a delicate organism, the question would not have -advanced much further. What in fact is the disposition of this nervous -system which has to be smitten if we would paralyse the insect without -at the same time killing it? And, first of all, where is it? In the -head, no doubt, and down the back, like the brain and the spinal marrow -of the higher animals. - -‘You make a grave mistake,’ our congress would say. ‘The insect is like -an inverted animal, walking on its back; that is to say, instead of -having the spinal marrow on the top, it has it below, along the breast -and the belly. The operation on the insect to be paralysed must -therefore be performed on the lower surface and on that surface alone.’ - -This difficulty once removed, another arises, equally serious in a -different way. Armed with his scalpel, the anatomist can direct the -point of his instrument wherever he thinks fit, in spite of obstacles, -for these he can eliminate. The Wasp, on the contrary, has no choice. -Her victim is a Beetle in his stout coat of mail; her lancet is her -sting, an extremely delicate weapon which would inevitably be stopped -by the horny armour. Only a few points are accessible to the fragile -implement, namely, the joints, which are protected merely by an -unresisting membrane. Moreover, the joints of the limbs, though -vulnerable, do not in the least fulfil the desired conditions, for the -utmost that could be obtained by means of them would be a partial -paralysis and not a general paralysis affecting the whole of the motor -organism. Without a prolonged struggle, which might be fatal to the -patient, without repeated operations, which, if too numerous, might -jeopardize the Beetle’s life, the Wasp has, if possible, to suppress -all power of movement at one blow. It is essential, therefore, that she -should aim her sting at the nervous centres, the seat of the motor -faculties, whence radiate the nerves scattered over the several organs -of movement. Now these sources of locomotion, these nervous centres, -consist of a certain number of nuclei or ganglia, more numerous in the -larva, less numerous in the perfect insect and arranged along the -median line of the lower surface in a string of beads more or less -distant one from the other and connected by a double ribbon of the -nerve-substance. In all the insects in the perfect state, the so-called -thoracic ganglia, that is to say, those which supply nerves to the -wings and legs and govern their movements, are three in number. These -are the points to be struck. If their action can be destroyed, no -matter how, the power of movement will be destroyed likewise. - -There are two methods of reaching these motor centres with the Wasp’s -feeble instrument, the sting: through the joint between the neck and -the corselet; and through the joint between the corselet and the rest -of the thorax, in short, between the first and second pair of legs. The -way through the joint of the neck is hardly suitable: it is too far -from the ganglia, which are near the base of the legs which they endow -with movement. It is at the other point and there alone that the blow -must be struck. That would be the opinion of the academy in which the -Claude Bernards were treating the question in the light of their -profound knowledge. And it is here, just here, between the first and -second pair of legs, on the median line of the lower surface, that the -Wasp inserts her dirk. By what expert instinct is she inspired? - -To select, as the spot wherein to drive her sting, the one vulnerable -point, the point which none save a physiologist versed in insect -anatomy could determine beforehand: even that is far from being enough. -The Wasp has a much greater difficulty to surmount; and she surmounts -it with an ease that stupefies us. The nerve-centres governing the -locomotory organs of the insect are, we were saying, three in number. -They are more or less distant from one another; sometimes, but rarely, -they are close together. Altogether they possess a certain independence -of action, so that an injury done to any one of them induces, at any -rate for the moment, the paralysis only of the limbs that correspond -with it, without affecting the other ganglia and the limbs which they -control. To strike in succession these three motor centres, each -farther back than the one before it, and to do so between the first and -second pair of legs, seems an impracticable operation for such a weapon -as the Wasp’s sting, which is too short and is besides very difficult -to guide under such conditions. It is true that certain Beetles have -the three ganglia of the thorax very near together, almost touching, -while others have the last two completely united, soldered, welded -together. It is also a recognized fact that, in proportion as the -different nervous nuclei tend towards a closer combination and greater -centralization, the characteristic functions of animal nature become -more perfect and consequently, alas, more vulnerable. Here we have the -prey which the Cerceris really needs. Those Beetles with motor centres -brought close together or even gathered into a common mass, making them -mutually dependent on one another, will be at the same instant -paralysed with a single stroke of the dagger; or, if several strokes be -needed, the ganglia to be stung will at any rate all be there, -collected under the point of the dart. - -Which Beetles are they, then, that constitute a prey so eminently -convenient for paralysing? That is the question. The lofty science of a -Claude Bernard, concerning itself only with the fundamental -generalities of organism and life, would not suffice here; it could -never tell us how to make this entomological selection. I appeal to any -physiologist under whose eyes these lines may come. Without referring -to his library, could he name the Beetles in whom that centralization -of the nervous system occurs; and, even with the aid of his books, -would he at once know where to find the desired information? The fact -is that, with these minute details, we are now entering the domain of -the specialist; we are leaving the public road for the path known to -the few. - -I find the necessary information in M. Émile Blanchard’s fine work on -the nervous system of the Coleoptera. [12] I see there that this -centralization of the nervous system is the prerogative, in the first -place, of the Scarabæidæ, or Chafers; but most of these are too large: -the Cerceris could perhaps neither attack them nor carry them away; -besides, many of them live in the midst of ordure where the Wasp, -herself so cleanly, would refuse to go in search of them. Motor centres -very close together are found also in the Histers, who live on carrion -and dung, in an atmosphere of loathsome smells, and who must therefore -be eliminated; in the Scolyti, who are too small; and lastly in the -Buprestes and the Weevils. - -What an unexpected light amid the original darkness of the problem! -Among the immense number of Beetles whereon the Cerceres might seem -able to prey, only two groups, the Weevils and the Buprestes, fulfil -the indispensable conditions. They live far removed from stench and -filth, two qualities perhaps invincibly repugnant to the dainty -huntress; their numerous representatives vary considerably in size, in -much the same way as their kidnappers, who can thus pick and choose the -victims that suit them; they are far more vulnerable than any of the -others at the one point where the Wasp’s dart can penetrate, for at -this point the motor centres of the feet and wings are crowded -together, all easily accessible to the sting. At this point, in the -Weevils, the three thoracic ganglia are very close together, the last -two even touching; at the same point, in the Buprestes, the second and -third are mingled in one large mass, very near the first. And it is -just Buprestes and Weevils that we see hunted, to the absolute -exclusion of all other game, by the eight species of Cerceres whose -provisions have been found to consist of Beetles! A certain inward -resemblance, that is to say, the centralization of the nervous system, -must therefore be the reason why the lairs of the different Cerceres -are crammed with victims bearing no outward resemblance whatever. - -The most exalted knowledge could make no more judicious choice than -this, by which so great a collection of difficulties is magnificently -solved that we wonder if we be not the dupes of some involuntary -illusion, whether preconceived theoretic notions have not obscured the -actual facts, whether, in short, the pen have not described imaginary -marvels. No scientific conclusion is firmly established until it has -received confirmation by means of practical tests, carried out in every -variety of way. We will therefore subject to experimental proof the -physiological operation of which the Great Cerceris has just apprised -us. If it be possible to obtain artificially what the Wasp obtains with -her sting, namely, the abolition of movement and the continued -preservation of the patient in a perfectly fresh condition; if it be -possible to work this wonder with the Beetles hunted by the Cerceris, -or with those presenting a similar nervous centralization, while we are -unsuccessful with Beetles whose ganglia are far apart, then we shall be -bound to admit, however hard to please we may be in the matter of -tests, that in the unconscious inspiration of her instinct the Wasp has -all the resources of consummate art. Let us see what experiment has to -tell us. - -The operating method is of the simplest. It is a question of taking a -needle, or, better and more convenient, the point of a fine steel nib, -and introducing a tiny drop of some corrosive fluid into the thoracic -motor centres, by pricking the insect slightly at the junction of the -prothorax, behind the first pair of feet. The fluid which I employ is -ammonia; but obviously any other liquid as powerful in its action would -produce the same results. The nib being charged with ammonia as it -might be with a very small drop of ink, I give the prick. The effects -obtained differ enormously, according to whether we experiment upon -species whose thoracic ganglia are close together or upon species in -which those same ganglia are far apart. In the first class, my -experiments were made on Dung-beetles: the Sacred Scarab [13] and the -Wide-necked Scarab; on Buprestes: the Bronze Buprestis; lastly, on -Weevils, in particular on the Cleonus hunted by the heroine of this -essay. In the second class, I experimented on Ground-beetles: Carabi, -Procrustes, Chlænii, Sphodri, Nebriæ; on Longicornes: Saperdæ and -Lamiæ; on Melasoma-beetles: Cellar-beetles, Scauri, Asidæ. - -In the Scarabæi, the Buprestes and the Weevils the effect is -instantaneous: all movement ceases suddenly, without convulsions, so -soon as the fatal drop has touched the nerve-centres. The Cerceris’ own -sting produces no more speedy annihilation. There is nothing more -striking than this immediate immobility provoked in a powerful Sacred -Beetle. - -But this is not the only resemblance between the effects produced by -the Wasp’s sting and those resulting from the nib poisoned with -ammonia. The Scarabs, Buprestes and Beetles artificially stung, -notwithstanding their complete immobility, preserve for three weeks, a -month or even two the perfect flexibility of all their joints and the -normal freshness of their internal organs. Evacuation takes place with -them during the first days as in the normal state; and movements can be -induced by the electric battery. In a word, they behave exactly like -the Beetles immolated by the Cerceris; there is absolute identity -between the state into which the kidnapper puts her victims and that -which we produce at will by injuring the thoracic nerve-centres with -ammonia. Now, as it is impossible to attribute the perfect preservation -of the insect for so long a period to the tiny drop injected, we must -reject altogether any notion of an antiseptic fluid and admit that, -despite its perfect immobility, the insect is not really dead, that it -still retains a glimmer of life, which for some time to come keeps the -organs in their normal condition of freshness, but gradually fades out, -until at last it leaves them the prey of corruption. Besides, in some -cases, the ammonia does not produce complete annihilation of movement -except in the insect’s legs; and then, as the deleterious action of the -liquid has doubtless not extended far enough, the antennæ preserve a -remnant of mobility and we see the insect, even more than a month after -the inoculation, draw them back quickly at the least touch: a -convincing proof that life has not entirely deserted the inanimate -body. This movement of the antennæ is also not uncommon in the Weevils -wounded by the Cerceris. - -In every case the injection of ammonia at once stops all movement in -Scarabs, Weevils and Buprestes; but we do not always succeed in -reducing the insect to the condition just described. If the wound be -too deep, if the drop administered be too strong, the victim really -dies; and, in two or three days’ time, we have nothing but a putrid -body before us. If the prick, on the other hand, be too slight, the -insect, after a longer or shorter period of deep torpor, comes to -itself and at least partially recovers its power of motion. The -assailant herself may sometimes operate clumsily, just like man, for I -have noticed this sort of resurrection in a victim stung by the dart of -a Digger-wasp. The Yellow-winged Sphex, whose story will shortly occupy -our attention, stacks her lairs with young Crickets first pricked with -her poisoned lancet. I have extracted from one of those lairs three -poor Crickets whose extreme limpness would, in any other circumstances, -have denoted death. But here again death was only apparent. Placed in a -flask, these Crickets kept in very good condition, perfectly motionless -all the time, for nearly three weeks. In the end, two went mouldy, and -the third partly revived, that is to say, he recovered the power of -motion in his antennæ, in his mouth-parts and, what is more remarkable, -in his first two pair of legs. If the Wasp’s skill sometimes fails to -benumb the victim permanently, one can hardly expect invariable success -from man’s rough experiments. - -In the Beetles of the second class, that is to say, those whose -thoracic ganglia are some distance apart, the effect of the ammonia is -quite different. The least vulnerable are the Ground-beetles. A -puncture which would have produced instant annihilation of movement in -a large Sacred Beetle produces nothing but violent and disordered -convulsions in the medium-sized Ground-beetles, be they Chlænius, -Nebria or Calathus. Little by little the insect quiets down and, after -a few hours’ rest, its usual movements are resumed as though it had met -with no accident whatever. If we repeat the experiment on the same -specimen, twice, thrice, or four times over, the results remain the -same, until the wound becomes too serious and the insect actually dies, -as is proved by its desiccation and putrefaction, which follows soon -after. - -The Melasoma-beetles and Longicornes are more sensitive to the action -of the ammonia. The injection of the corrosive drop pretty quickly -renders them motionless; and, after a few convulsions, the insect seems -dead. But this paralysis, which would have persisted in the -Dung-beetles, the Weevils and the Buprestes, is only temporary here: -within a day, motion is once more apparent, as energetic as ever. It is -only when the dose of ammonia is of a certain strength that the -movements fail to reappear; but then the insect is dead, quite dead, -for it soon begins to decay. It is impossible, therefore, to produce -complete and persistent paralysis in Beetles that have their ganglia -far apart by the same measures which proved so efficacious in Beetles -with ganglia close together: the utmost that we can obtain is a -temporary paralysis whose effects pass off within a day. - -The demonstration is conclusive; the Cerceres that prey on Beetles -conform in their selection to what could be taught only by the most -learned physiologists and the finest anatomists. One would vainly -strive to see no more in this than casual coincidences: it is not in -chance that we shall find the key to such harmonies as these. - - - - - - - - -CHAPTER IV - -THE YELLOW-WINGED SPHEX - - -Under their powerful armour, which no dart can penetrate, the insects -of the Beetle tribe offer but a single vulnerable spot to the -sting-bearing enemy. This defect in the breastplate is known to the -murderess, who drives in her poisoned dagger there and at one blow -strikes the three motor centres, for she selects her victims from the -Weevil and Buprestis families, whose nervous system is centralized to -the requisite degree. But what will happen when the prey is an insect -clad not in mail but in a soft skin, which the Wasp can stab here or -there indifferently, in any part of the body that chances to be -exposed? In that case are the blows still delivered scientifically? -Like the assassin who strikes at the heart to cut short the dangerous -resistance of his victim, does the assailant follow the tactics of the -Cerceres and wound the motor ganglia by preference? If that be so, then -what happens when these ganglia are some distance apart and so -independent in their action that paralysis of one is not necessarily -followed by paralysis of the others? These questions will be answered -by the story of a Cricket-huntress, the Yellow-winged Sphex (Sphex -flavipennis). - -It is at the end of July that the Yellow-winged Sphex tears the cocoon -that has protected her until then and flies out of her subterranean -cradle. During the whole of August she is frequently seen flitting, in -search of some drop of honey, around the spiked heads of the field -eryngo, the commonest of the hardy plants that brave the heat of the -dog-days in this month. But this careless life does not last long, for -by the beginning of September the Sphex is at her arduous task as a -sapper and huntress. She generally selects some small plateau, on the -high banks by the side of the roads, wherein to establish her home, -provided that she find two indispensable things there: a sandy soil, -easy to dig; and sunshine. No other precaution is taken to protect the -dwelling against the autumn rains or winter frosts. A horizontal site, -unprotected, lashed by the rain and the winds, suits her perfectly, on -condition, however, that it is exposed to the sun. And, when a heavy -shower comes in the middle of her mining, it is pitiful next day to see -the half-built galleries in ruins, choked with sand and finally -abandoned by their engineers. - -The Sphex seldom practises her industry alone; the site selected is -usually exploited by small bands of ten or twenty sappers or more. One -must have spent days in contemplating one of these villages to form any -idea of the restless activity, the spasmodic haste, the abrupt -movements of those hard-working miners. The soil is rapidly attacked -with the rakes of the forefeet: canis instar, as Linnæus says. No -mischievous puppy displays more energy in digging up the ground. At the -same time, each worker sings her glad ditty, which consists of a shrill -and strident noise, constantly broken off and modulated by the -vibrations of the wings and thorax. One would think that they were a -troop of merry companions encouraging one another in their work with a -cadenced rhythm. Meanwhile the sand flies, falling in a fine dust on -their quivering wings; and the too bulky gravel, removed bit by bit, -rolls far away from the workyard. If a piece seems too heavy to be -moved, the insect gets up steam with a shrill note which reminds one of -the woodman’s ‘Hoo!’ Under the redoubled efforts of tarsi and mandibles -the cave soon takes shape; the insect is already able to dive into it -bodily. We then see a lively alternation of forward movements, to -loosen new materials, and backward movements, to sweep the rubbish -outside. In this constant hurrying to and fro the Sphex does not walk, -she darts as though shot from a spring; she bounds with throbbing -abdomen and quivering antennæ, her whole body, in short, animated with -a musical vibration. The miner is now out of sight; but we still hear -underground her untiring song, while at intervals we catch a glimpse of -her hind-legs, pushing a torrent of sand backwards to the mouth of the -burrow. From time to time the Sphex interrupts her subterranean -labours, either to come and dust herself in the sun, to rid herself of -the grains of sand which, slipping into her delicate joints, might -hamper the liberty of her movements, or else to reconnoitre the -neighbourhood. Despite these interruptions, which for that matter do -not last long, the gallery is dug in the space of a few hours; and the -Sphex comes to her threshold to chant her triumph and give the -finishing polish to her work by removing some unevenness and carrying -away a speck or two of earth whose drawbacks are perceptible to her -discerning eye alone. - -Of the numerous tribes of Sphex-wasps which I have visited, one in -particular remains fixed in my memory because of its curious -dwelling-place. On the edge of a high-road were some small heaps of -mud, taken from the ditches by the road-mender’s shovel. One of these -heaps, long ago dried in the sun, formed a cone-shaped mound, -resembling a large sugar-loaf twenty inches high. The site seemed to -have attracted the Wasps, who had established themselves there in a -more populous colony than I have ever since beheld. The cone of dry mud -was riddled from top to bottom with burrows, which gave it the -appearance of an enormous sponge. On every storey there was a feverish -animation, a busy coming and going which reminded one of the scenes in -some great yard when the work is urgent. Crickets were being dragged by -the antennæ up the slopes of the conical city; victuals were being -stored in the larders of the cells; dust was pouring from the galleries -in process of excavation by the miners; grimy faces appeared at -intervals at the mouths of the tunnels; there were constant exits and -constant entrances; and now and again a Sphex, in her brief intervals -of leisure, would climb to the top of the cone, perhaps to cast a look -of satisfaction from this belvedere over the works in general. What a -spectacle to tempt me, to make me long to carry the whole city and its -inhabitants away with me! It was useless even to try: the mass was too -heavy. One cannot root up a village from its foundations to transplant -it elsewhere. - -We will return, therefore, to the Sphex-wasps working on level ground, -in ordinary soil, as happens in by far the greater number of cases. As -soon as the burrow is dug, the chase begins. Let us profit by the -Wasp’s distant excursions in search of her game and examine the -dwelling. The usual site of a Sphex colony is, as I said, level ground. -Nevertheless, the soil is not so smooth but that we find a few little -mounds crowned with a tuft of grass or wormwood, a few cracks -consolidated by the scanty roots of the vegetation that covers them. It -is in the sides of these furrows that the Sphex builds her dwelling. -The gallery consists first of a horizontal portion, two or three inches -long and serving as an approach to the hidden retreat destined for the -provisions and the larvæ. It is in this entrance-passage that the Sphex -takes shelter in bad weather; it is here that she retires for the night -and rests for a few moments in the daytime, putting outside only her -expressive face, with its great, bold eyes. Following on the vestibule -comes a sudden bend, which descends more or less obliquely to a depth -of two or three inches more and ends in an oval cell of somewhat larger -diameter, whose main axis lies horizontally. The walls of the cell are -not coated with any particular cement; but, in spite of their bareness, -we can see that they have been the object of the most conscientious -labour. The sand has been heaped up and carefully levelled on the -floor, the ceiling and the sides, so as to prevent landslips and remove -any roughness that might hurt the delicate skin of the grub. Lastly, -this cell communicates with the passage by a narrow entrance, just wide -enough to admit the Sphex laden with her prey. - -When this first cell is supplied with an egg and the necessary -provisions, the Sphex walls up the entrance, but does not yet abandon -her burrow. A second cell is dug beside the first and victualled in the -same way; then a third and sometimes a fourth. Not till then does the -Sphex shoot back into the burrow all the rubbish accumulated outside -the door and completely remove all the outward traces of her work. -Thus, to each burrow there are usually three cells, rarely two and -still more rarely four. Now, as we ascertain when dissecting the -insect, we can estimate the number of eggs laid at about thirty, which -brings up to ten the number of burrows needed. On the other hand, the -operations are hardly begun before September and are finished by the -end of the month. The Sphex, therefore, can devote only two or three -days at most to each burrow and its provisioning. No one will deny that -the active little creature has not a moment to lose, when, in so short -a time, she has to excavate her den, to procure a dozen Crickets, to -carry them sometimes from a distance in the face of innumerable -difficulties, to store them away and finally to stop up the burrow. -And, besides, there are days when the wind makes hunting impossible, -rainy days or even merely grey days, which cause all work to be -suspended. One can readily imagine from this that the Sphex is unable -to give to her buildings the perhaps permanent solidity which the Great -Cerceres bestow upon their long galleries. The latter hand down from -generation to generation their substantial dwellings, each year -excavated to a greater depth than the last, galleries which threw me -into a sweat when I tried to inspect them and which generally triumphed -over my efforts and my implements. The Sphex does not inherit the work -of her predecessors: she has to do everything for herself and quickly. -Her dwelling is but a tent, hastily pitched for a day and shifted on -the morrow. As compensation, the larvæ, who have only a thin layer of -sand to cover them, are capable themselves of providing the shelter -which their mother could not create: they clothe themselves in a -threefold and fourfold waterproof wrapper, far superior to the thin -cocoon of the Cerceres. - -But here, with a loud buzz, comes a Sphex who, returning from the -chase, stops on a neighbouring bush, holding in her mandibles, by one -antenna, a large Cricket, several times her own weight. Exhausted by -the burden, she takes a moment’s rest. Then she once more grips her -captive between her feet and, with a supreme effort, covers in one -flight the width of the ravine that separates her from her home. She -alights heavily on the level ground where I am watching, in the very -middle of a Sphex village. The rest of the journey is performed on -foot. The Wasp, not at all intimidated by my presence, bestrides her -victim and advances, bearing her head proudly aloft and hauling the -Cricket, who trails between her legs, by an antenna held in her -mandibles. If the ground be bare, it is easy to drag the victim along; -but, should some grass-tuft spread the network of its shoots across the -road, it is curious to observe the amazement of the Sphex when one of -these little ropes suddenly thwarts her efforts; it is curious to -witness her marches and counter-marches, her reiterated attempts, until -the obstacle is overcome, either with the aid of the wings or by means -of a clever deviation. The Cricket is at last conveyed to his -destination and is so placed that his antennæ exactly touch the mouth -of the burrow. The Sphex then abandons her prey and descends hurriedly -to the bottom of the cave. A few seconds later we see her reappear, -showing her head out of doors and giving a little cry of delight. The -Cricket’s antennæ are within her reach; she seizes them and the game is -brought quickly down to the lair. - -I still ask myself, without being able to find a sufficiently -convincing solution, the reason for these complicated proceedings at -the moment when the Cricket is introduced into the burrow. Instead of -going down to her den alone, to reappear afterwards and pick up the -prey left for a time on the threshold, would not the Sphex have done -better to continue to drag the Cricket along the gallery as she does in -the open air, seeing that the width of the tunnel permits it, or else -to go in first, backwards, and pull him after her? The various -Predatory Wasps whom I have hitherto been able to observe carry down to -their cells straight away, without preliminaries, the game which they -hold clasped beneath their bellies with the aid of their mandibles and -their middle-legs. Léon Dufour’s Cerceris begins by complicating her -procedure, because, after laying her Buprestis for a moment at the door -of her underground home, she at once enters her gallery backwards and -then seizes the victim with her mandibles and drags it to the bottom of -the burrow. But it is a far cry from these tactics and those adopted in -a like case by the Cricket-hunters. Why that domiciliary visit which -invariably precedes the entrance of the game? Could it not be that, -before descending with a cumbrous burden, the Sphex thinks it wise to -take a look at the bottom of her dwelling, so as to make sure that all -is well and, if necessary, to drive out some brazen parasite who may -have slipped in during her absence? If so, who is the parasite? Several -Diptera, Predatory Gnats, especially Tachinæ, watch at the doors of the -Hunting Wasps, spying for the propitious moment to lay their eggs on -others’ provisions; but none of them enters the home or ventures into -the dark passages where the owner, if by ill-luck she happened to be -in, would perhaps make them pay dearly for their audacity. The Sphex, -like all the rest, pays her tribute to the plundering Tachinæ; but -these never enter the burrow to perpetrate their misdeeds. Besides, -have they not all the time that they need to lay their eggs on the -Cricket? If they are sharp about it, they can easily profit by the -temporary abandonment of the victim to entrust their progeny to it. -Some greater danger still must therefore threaten the Sphex, since her -preliminary descent of the burrow is of such imperious necessity. - -Here is the only fact observed by myself that may throw a little light -on the problem. Amid a colony of Sphex-wasps in full swing, a colony -from which any other Wasp is usually excluded, I one day surprised a -huntress of a different genus, Tachytes nigra, carrying one by one, -without hurrying, in the midst of the crowd where she was but an -intruder, grains of sand, bits of little dry stalks and other -diminutive materials to stop up a burrow of the same shape and width as -the adjacent burrows of the Sphex. The labour was too carefully -performed to allow of any doubt of the presence of the worker’s egg in -the tunnel. A Sphex moving about uneasily, apparently the lawful owner -of the burrow, did not fail, each time that the strange Wasp entered -the gallery, to rush in pursuit of her; but she emerged swiftly, as -though frightened, followed by the other, who impassively continued her -work. I inspected this burrow, evidently an object in dispute between -the two Wasps, and found in it a cell provisioned with four Crickets. -Suspicion almost makes way for certainty: these provisions are far in -excess of the needs of a Tachytes-grub, who is certainly not more than -half the size of the larva of the Sphex. She whose impassiveness, whose -care to stop up the burrow would at first have made one take her for -the mistress of the house, was in reality a mere usurper. How is it -that the Sphex, who is larger and more powerful than her adversary, -allows herself to be robbed with impunity, confining herself to -fruitless pursuits and fleeing like a coward when the interloper, who -does not even appear to notice her presence, turns round to leave the -burrow? Can it be that, in insects as in man, the first chance of -success lies in de l’audace, encore de l’audace et toujours de -l’audace? The usurper certainly had audacity and to spare. I see her -still, with imperturbable calmness, moving in and out in front of the -complaisant Sphex, who stamps her feet with impatience but does not -fall upon the thief. - -I will add that, in other circumstances, I have repeatedly found the -same Wasp, whom I presume to be a parasite, in short the Black -Tachytes, dragging a Cricket by one of his antennæ. Was he a -lawfully-acquired prey? I should like to think so; but the vacillating -behaviour of the insect, who went straying about the ruts in the roads -as though seeking for a burrow to suit it, always left me uncertain. I -have never witnessed its digging-work, if it really undertakes the -labour of excavation. And, a more serious matter, I have seen it leave -its game on the rubbish-heap, perhaps not knowing what to do with it, -for lack of a burrow wherein to place it. Such wastefulness as this -seems to me to point to ill-gotten goods; and I ask myself if the -Cricket were not stolen from the Sphex at the moment when she abandoned -her prey on the threshold. My suspicions also fall upon Tachytes -obsoleta, banded with white round the abdomen like Sphex albisecta and -feeding her larvæ on Crickets similar to those hunted by the latter. I -have never seen her digging any galleries, but I have caught her with a -Cricket whom the Sphex would not have rejected. This identity of -provisions in species of different genera raises doubts in my mind as -to the lawfulness of the booty. Let me add, lastly, to atone in a -measure for the injury which my suspicions may do to the reputation of -the genus, that I have been the eye-witness of a perfectly -straightforward capture of a small and still wingless Cricket by -Tachytes tarsina and that I have seen her digging cells and victualling -them with game acquired by her own valiant exertions. - -I have therefore only suspicions to offer in explanation of the -obstinacy of the Sphex-wasps in going down their tunnels before -carrying in their prey. Can they have some other object besides that of -dislodging a parasite who may have arrived during their absence? This -is what I despair of ever knowing; for who can interpret the thousand -ruses of instinct? Poor human reason, which cannot even fathom the -wisdom of a Sphex! - -At any rate, it has been proved that these ruses are singularly -invariable. In this connection I will mention an experiment which -interested me greatly. Here are the particulars: at the moment when the -Sphex is making her domiciliary visit, I take the Cricket left at the -entrance to the dwelling and place her a few inches farther away. The -Sphex comes up, utters her usual cry, looks here and there in -astonishment, and, seeing the game too far off, comes out of her hole -to seize it and bring it back to its right place. Having done this, she -goes down again, but alone. I play the same trick upon her; and the -Sphex has the same disappointment on her arrival at the entrance. The -victim is once more dragged back to the edge of the hole, but the Wasp -always goes down alone; and this goes on as long as my patience is not -exhausted. Time after time, forty times over, did I repeat the same -experiment on the same Wasp; her persistency vanquished mine and her -tactics never varied. - -Having demonstrated the same inflexible obstinacy which I have just -described in the case of all the Sphex-wasps on whom I cared to -experiment in the same colony, I continued to worry my head over it for -some time. What I asked myself was this: - -‘Does the insect obey a fatal tendency, which no circumstances can ever -modify? Are its actions all performed by rule; and has it no power of -acquiring the least experience on its own account?’ - -Some additional observations modified this too absolute view. Next year -I visit the same spot at the proper season. The new generation has -inherited the burrowing-site selected by the previous generation; it -has also faithfully inherited its tactics: the experiment of -withdrawing the Cricket yields the same results. Such as last year’s -Sphex-wasps were, such are those of the present year, equally -persistent in a fruitless procedure. The illusion was simply growing -worse, when good fortune brought me into the presence of another colony -of Sphex-wasps, in a district at some distance from the first. I -recommenced my attempts. After two or three experiments with results -similar to those which I had so often obtained, the Sphex got astride -of the Cricket, seized him with her mandibles by the antennæ, and at -once dragged him into the burrow. Who was the fool now? Why, the -experimenter foiled by the clever Wasp! At the other holes, her -neighbours likewise, one sooner, another later, discovered my treachery -and entered the dwelling with the game, instead of persisting in -abandoning it on the threshold to seize it afterwards. What did all -this mean? The colony which I was now inspecting, descended from -another stock—for the children return to the site selected by their -parents—was cleverer than the colony of the year before. Craft is -handed down: there are tribes that are sharper-witted and tribes that -are duller-witted, apparently according to the faculties of their -elders. With the Sphex as with us, the intellect differs with the -province. - -Next day, in a different locality, I repeated my experiment with -another Cricket; and every time the Sphex was hoodwinked. I had come -upon a dense-minded tribe, a regular village of Bœotians, as in my -first observations. - - - - - - - - -CHAPTER V - -THE THREE DAGGER-THRUSTS - - -There is no doubt that the Sphex displays her most cunning resources at -the moment of immolating a Cricket; it is important, therefore, to -ascertain the manner wherein the victim is sacrificed. Profiting by the -repeated attempts which I had made when I was studying the tactics of -the Cerceres, I at once applied to the Sphex the method which had -succeeded with the other Wasps, a method that consisted in taking the -prey from the huntress and forthwith replacing it by another, living -prey. The substitution is all the easier inasmuch as we have seen the -Sphex herself releasing her victim in order to go down the burrow for a -moment alone. Her daring familiarity, which makes her come and take -from your fingers and even out of your hand the Cricket whom you have -stolen from her and now offer her again, also lends itself admirably to -the successful issue of the experiment, by allowing you to observe -every detail of the drama closely. - -Again, to find live Crickets is an easy matter: we have but to lift the -first stone that we see and we find them crouching underneath, -sheltered from the sun. These Crickets are young ones, of the same -year, who as yet boast but rudimentary wings and who, not possessing -the industry of the full-grown insect, have not learnt to dig those -cavernous retreats where they would be safe from the Sphex’ -investigations. In a few moments I have as many live Crickets as I -could wish for. This completes my preparations. I climb to the top of -my observatory, establish myself on the level ground, in the centre of -the Sphex village, and wait. - -A huntress appears upon the scene, carts her Cricket to the entrance of -the home and goes down her burrow by herself. I quickly remove the -Cricket and substitute one of mine, placing him, however, some distance -away from the hole. The kidnapper returns, looks round, and runs and -seizes the victim, which is too far off for her. I am all eyes, all -attention. Nothing would induce me to give up my part in the tragic -spectacle which I am about to witness. The terrified Cricket takes to -flight, hopping as fast as he can; the Sphex pursues him hot-foot, -reaches him, rushes upon him. There follows, amid the dust, a confused -encounter, wherein each champion, now victor, now vanquished, by turns -is at the top or at the bottom. Success, for a moment undecided, at -last crowns the aggressor’s efforts. Despite his vigorous kicks, -despite the snaps of his pincer-like mandibles, the Cricket is laid low -and stretched upon his back. - -The murderess soon makes her arrangements. She places herself belly to -belly with her adversary, but in the opposite direction, grasps one of -the threads at the tip of the Cricket’s abdomen with her mandibles and -masters with her fore-legs the convulsive efforts of his thick hinder -thighs. At the same time, her middle-legs hug the heaving sides of the -beaten insect; and her hind-legs, pressing like two levers on the front -of the head, force the joint of the neck to open wide. The Sphex then -curves her abdomen vertically, so as to offer only an unattackable -convex surface to the Cricket’s mandibles; and we see, not without -emotion, its poisoned lancet drive once into the victim’s neck, next -into the joint of the front two segments of the thorax, and lastly -towards the abdomen. In less time than it takes to relate, the murder -is consummated; and the Sphex, after adjusting the disorder of her -toilet, makes ready to haul home the victim, whose limbs are still -quivering in the throes of death. - -Let us consider for a moment the excellence of the tactics of which I -have given a feeble glimpse. The Cerceris attacks a passive adversary, -incapable of flight, almost devoid of offensive weapons, whose sole -chances of safety lie in a stout cuirass, the weak point of which, -however, is known to the murderess. But what a difference here! The -quarry is armed with dreadful mandibles, capable of disembowelling the -assailant if they succeed in seizing her; it sports a pair of powerful -legs, regular clubs bristling with a double row of sharp spikes, which -can be used either to enable the Cricket to hop out of his enemy’s -reach, or to send her sprawling with brutal kicks. Observe, therefore, -the precautions which the Sphex takes before setting her sting in -motion. The victim, turned upon his back, cannot, for lack of any -purchase, use his hind-levers to escape with, which he certainly would -do if he were attacked in the normal position, as are the big Weevils -of the Great Cerceris. His spurred legs, mastered by the Sphex’ -fore-feet, cannot act as offensive weapons either; and his mandibles, -kept at a distance by the Wasp’s hind-legs, open in wide menace without -being able to seize a thing. But it is not enough for the Sphex to -render her Cricket incapable of hurting her; she must also hold him so -firmly pinioned that he cannot make the slightest movement capable of -diverting the sting from the points at which the poison is to be -injected; and it is probably with the object of stilling the movements -of the abdomen that one of its terminal threads is grasped. No, if a -fertile imagination had allowed itself free scope to invent a plan of -attack at will, it could not have contrived anything better; and it is -open to doubt whether the athletes of the classic palestræ, when -grappling with an adversary, boasted more scientific attitudes. - -I have said that the sting is driven several times into the patient’s -body: first under the neck, then behind the prothorax, next and lastly -towards the top of the abdomen. It is in these three dagger-thrusts -that the infallibility and the intuitive science of instinct appear in -all their splendour. Let us first recall the principal conclusions to -which our earlier study of the Cerceris has led us. The victims of the -Wasps whose larvæ live on prey are not proper corpses, in spite of -their immobility, which is sometimes complete. They suffer simply from -a total or partial locomotory paralysis, from a more or less thorough -annihilation of animal life; but vegetable life, the life of the organs -of nutrition, is maintained for a long while yet and preserves from -decomposition the prey which the larva is not to devour for some time -to come. To produce this paralysis the Hunting Wasps employ precisely -the process which the advanced science of our own day might suggest to -the experimental physiologists, that is to say, they injure, by means -of their poisoned sting, the nerve-centres that control the locomotory -organs. We know besides that the several centres or ganglia of the -nervous system of articulate animals are, within certain limits, -independent of one another in their action, so that an injury to any -one of them does not, or at any rate not immediately, entail more than -the paralysis of the corresponding segment; and this applies all the -more when the different ganglia are farther apart. When, on the other -hand, they are welded together, the lesion of this common centre -induces paralysis of all the segments over which its ramifications are -distributed. This is the case with the Buprestes and the Weevils, whom -the Cerceres paralyse with a single thrust of the sting, aimed at the -common mass of the nerve-centres of the thorax. But open a Cricket. -What do we find to set the three pairs of legs in motion? We find what -the Sphex knew long before the anatomists: three nerve-centres at a -great distance one from the other. Hence the magnificent logic of her -needle-thrusts thrice repeated. Proud science, bend the knee! - -Despite the appearances that might make us think otherwise, the -Crickets immolated by the Yellow-winged Sphex are no more dead than the -Weevils pierced by the Cerceris’ dart. The flexibility of the victims’ -integuments, faithfully revealing the slightest internal movement, -enables us in this case to dispense with the artificial methods which I -employed to demonstrate the presence of a remnant of life in the Cleoni -of the Great Cerceris. In fact, if we assiduously observe a Cricket -stretched on his back, a week, a fortnight even or more after the -murder, we see the abdomen heaving deeply at long intervals. Pretty -often we can still perceive a few quiverings in the palpi and -exceedingly-pronounced movements on the part of both the antennæ and -the abdominal threads, which diverge and separate and then suddenly -come together. I have succeeded, by placing the sacrificed Crickets in -glass tubes, in keeping them perfectly fresh for a month and a half. -Consequently, the Sphex-grubs, which live for less than a fortnight -before shrouding themselves in their cocoons, are certain of fresh meat -until their banquet is finished. - -The chase is over; the three or four Crickets that are the allotted -portion of each cell are stacked methodically, lying on their backs, -with their heads at the far end of the cell and their feet at the -entrance. An egg is laid on one of them. The burrow must now be closed. -The sand resulting from the excavation, which is lying in a heap -outside the front-door, is quickly swept backwards down the passage. -From time to time some fair-sized bits of gravel are picked out singly, -by scratching the heap of rubbish with the fore-feet, and carried with -the mandibles to strengthen the crumbly mass. Should the Wasp find none -within reach to suit her, she goes and searches for them in the -neighbourhood, and seems to choose them as conscientiously as a mason -would choose the chief stones for his building. Vegetable remains, tiny -fragments of dead leaves, are also employed. In a few moments every -outward trace of the underground dwelling has disappeared; and, if we -have not been careful to mark the site of the abode, it becomes -impossible for the most watchful eye to find it again. When this is -finished, a new burrow is dug, provisioned and walled up as often as -the teeming ovaries demand. Having completed the laying of her eggs, -the Sphex resumes her careless, vagrant life, until the first cold snap -puts an end to her well-filled existence. - -The Sphex’ task is accomplished; and I will finish mine with an -examination of her weapon. The organ destined for the elaboration of -her poison consists of two prettily-ramified tubes, ending separately -in a common reservoir or phial, shaped like a pea. From this phial -starts a slender channel which runs down the axis of the sting and -conducts the little drop of poison to its tip. The dimensions of the -lancet are very small and not such as one would expect from the size of -the Sphex, and especially from the effects which its prick produces on -the Crickets. The point is quite smooth and entirely deprived of those -backward indentations which we find in the Hive-bee’s sting. The reason -for this is obvious. The Bee uses her sting only to avenge an injury, -even at the cost of her life; and the teeth of the dart resist its -withdrawal from the wound and thus cause mortal ruptures in the viscera -at the extremity of the abdomen. What would the Sphex have done with a -weapon that would have been fatal to her on her first expedition? -Supposing that the dart could be withdrawn in spite of its teeth, I -doubt whether any Hymenopteron using her weapon chiefly to wound the -game destined for her larvæ would be supplied with a toothed sting. -With her, the dirk is not a show weapon, unsheathed to satisfy revenge: -revenge, the so-called pleasure of the gods, but a very costly -pleasure, for the vindictive Bee sometimes pays for it with her life; -it is an implement for use, a tool, on which the future of the grubs -depends. It must therefore be one easy to wield in the struggle with -the captured prey; it must be capable of being inserted in the flesh -and withdrawn without the least hesitation, a condition much better -fulfilled by a smooth than by a barbed blade. - -I wished to find out at my own expense if the Sphex’ sting is very -painful, this sting which lays low sturdy victims with terrible -rapidity. Well, I confess with profound admiration that it is -insignificant and bears no comparison, for intensity of pain, with the -stings of the irascible Bees and Social Wasps. It hurts so little that, -instead of using the forceps, I would not scruple to take in my fingers -any live Sphex-wasps that I needed in my experiments. I can say the -same of the different Cerceres, of the Philanthi, [14] of the Palari, -of even the huge Scoliæ, [15] whose very view inspires dismay, and, -generally speaking, of all the Hunting Wasps that I have been able to -observe. I make an exception of the Spider-huntresses, the Pompili; -[16] and even then their sting is much less painful than the Bees’. - -One last word: we know how furiously the Hymenoptera armed with a -purely defensive dart—the Social Wasps, for instance—rush upon him who -is bold enough to disturb their dwelling-house and punish him for his -temerity. On the other hand, those whose sting is intended for killing -game are very pacific, as though they were aware of the importance -which the little drop of poison in their phial possesses for their -family. This tiny drop is the safeguard of their race, I might say, its -livelihood; and so they are very economical in its use, reserving it -for the serious business of the chase, without any parade of vindictive -courage. I was not once punished with a sting when I established myself -amid the villages of our various Hunting Wasps, though I overturned -their nests and stole the larvæ and the provisions. You must lay hold -of the insect to make it use its weapon; and even then it does not -always pierce the skin, unless you place within its reach a part more -delicate than the fingers, such as, for instance, the wrist. - - - - - - - - -CHAPTER VI - -THE LARVA AND THE NYMPH - - -The egg of the Yellow-winged Sphex is white, elongated, cylindrical, -slightly bow-shaped and measures three to four millimetres [17] in -length. So far from being laid anywhere on the victim, at random, it is -deposited on a specially favoured spot, which is always the same; in -short, it is placed across the Cricket’s breast, a little to one side, -between the first and second pair of legs. The egg of the White-edged -Sphex and that of the Languedocian Sphex occupy a similar position: the -first on the breast of a Locust, the second on the breast of an -Ephippiger. [18] The point selected must present some peculiarity of -great importance to the young larva’s safety, for I have never known it -to vary. - -The egg hatches after three or four days. A very delicate wrapper tears -asunder; and there lies before our eyes a feeble grub, transparent as -crystal, a little attenuated and as it were compressed in front, -slightly swollen at the back and adorned on either side with a narrow -white thread formed of the principal trachean ducts. The frail creature -occupies the same position as the egg. Its head is, so to speak, -planted at the very spot where the upper end of the egg was fixed; and -all the remainder simply rests upon the victim, without being fastened -to it. The grub’s transparency enables us readily to distinguish rapid -undulations inside it, ripples which follow one upon the other with -mathematical regularity and which, beginning in the middle of the body, -spread some forward and some backward. These fluctuating movements are -due to the digestive canal, which takes long draughts of the juices -drawn from the victim’s body. - -Let us dwell for a moment upon a sight which cannot fail to attract our -attention. The Wasp’s prey lies on its back, motionless. In the cell of -the Yellow-winged Sphex it is a Cricket, or rather three or four -Crickets stacked one atop the other; in the cell of the Languedocian -Sphex it is a single head of game, but large in proportion, a -fat-bellied Ephippiger. The grub is lost should it happen to be torn -from the spot whence it derives life; a fall would be the end of it, -for, weak as it is and deprived of all means of motion, how could it -make its way back to the spot at which it slakes its appetite? The -slightest movement would enable the victim to rid itself of the atom -gnawing at its entrails; and yet the gigantic prey submits meekly, -without the least quiver of protest. I well know that it is paralysed, -that it has lost the use of its legs through the sting of its -murderess; but still, recent victim that it is, it retains more or less -power of movement and sensation in the regions not affected by the -dart. The abdomen throbs, the mandibles open and close, the abdominal -filaments wave to and fro, as do the antennæ. What would happen if the -worm were to bite into one of the still impressionable parts, near the -mandibles, or even on the belly, which, being more tender and more -succulent, seems as though it ought, after all, to supply the first -mouthfuls of the feeble grub? Bitten to the quick, the Cricket, Locust -or Ephippiger would at least shiver; and this faint tremor of the skin -would be enough to shake off the tiny larva and bring it to the ground, -where it would no doubt perish, for it might at any moment find itself -in the grips of those dreadful mandibles. - -But there is one part of the body where no such danger is to be feared, -the part which the Wasp has wounded with her sting—in short, the -thorax. Here and here alone, on a victim of recent date, the -experimenter can rummage with a needle, driving it through and through, -without producing a sign of suffering in the patient. Well, it is here -that the egg is invariably laid; it is here that the young larva always -takes its first bite at its prey. Gnawed at a point no longer -susceptible to pain, the Cricket remains motionless. Later, when the -wound has reached a sensitive point, he will doubtless toss about to -such extent as he can; but then it will be too late: his torpor will be -too deep; and besides the enemy will have gained strength. This -explains why the egg is laid on a spot which never varies, near the -wounds caused by the sting—in short, on the thorax: not in the middle, -where the skin would perhaps be too thick for the new-born grub, but on -one side, towards the juncture of the legs, where it is much thinner. -What a judicious choice, how logical on the part of the mother when, -underground, in complete darkness, she discerns the one suitable spot -on the victim and selects it for her egg! - -I have reared Sphex-grubs by giving them, one after the other, the -Crickets taken from the cells; and I was then able to follow day by day -the rapid progress of my nurselings. The first Cricket, the one on whom -the egg was laid, is attacked, as I have said, near the point where the -huntress administered her second sting, that is to say, between the -first and second pair of legs. In a few days the young larva has dug in -the victim’s breast a hollow large enough to admit half its body. It is -not uncommon to see the Cricket, bitten to the quick, uselessly waving -his antennæ and his abdominal threads, opening and closing his -mandibles on space and even moving a leg. But the enemy is safe and is -ransacking his entrails with impunity. What an awful nightmare for the -paralysed Cricket! - -The first ration is finished in six or seven days’ time; none of it -remains but the framework of skin, with all its parts more or less in -position. The larva, whose length is now twelve millimetres, [19] -leaves the Cricket’s body through the hole in the thorax which it made -to start with. During this operation it moults; and its cast skin often -remains caught in the opening through which it made its exit. It rests -after the moulting and then attacks a second ration. Being stronger -now, the larva has nothing to fear from the feeble movements of the -Cricket, whose daily-increasing torpor has had time to extinguish the -last glimmers of resisting-power during the week and more that has -elapsed since the dagger-thrusts were given. It is therefore assailed -with no precautions, usually at the belly, which is the tenderest part -and the richest in juices. Soon the turn comes of the third Cricket and -lastly of the fourth, who is devoured in ten hours or so. Of these last -three victims all that remains is the tough integuments, whose various -parts are severed one by one and carefully emptied. If a fifth ration -be presented, the larva scorns it, or hardly touches it, not from -abstemiousness, but from imperious necessity. For observe that hitherto -the larva has ejected no excrement and that its intestines, into which -four Crickets have been crammed, are distended to bursting-point. A new -ration cannot therefore tempt its gluttony; and henceforth it thinks -only of making itself a silken tabernacle. - -In all, its repast has lasted from ten to twelve days without -cessation. At this period the larva’s length measures from twenty-five -to thirty millimetres [20] and its greatest breadth from five to six. -[21] Its general outline, spreading a little at the back and gradually -tapering in front, conforms with the usual type of Hymenopteron-grubs. -Its segments are fourteen in number, including the head, which is very -small and armed with weak mandibles that would appear unequal to the -part which they have just played. Of these fourteen segments the middle -ones are supplied with stigmata, or breathing-holes. Its livery -consists of a yellowish-white ground, studded with innumerable dots of -a chalky white. - -We have seen the larva begin its second Cricket with the belly, the -juiciest and softest part. Like a child, which first licks the jam off -its bread and then bites into the crumb with a disdainful tooth, the -larva makes straight for the best part, the abdominal viscera, and -leaves until later the meat that has to be patiently extracted from its -horny sheath: a task for a leisure hour, when it is comfortably -digesting the earlier meal. Nevertheless, the grub, when quite young, -when newly hatched, is not so dainty: it goes for the bread first and -the jam afterwards. It has no choice: it is obliged to bite its first -mouthful right out of the breast, at the spot where the mother fixed -the egg. The food here is a little harder, but the place is safe, -because of the profound inertia into which the thorax has been plunged -by three thrusts of the dagger. Elsewhere there would be, if not -always, at least often, spasmodic shudders which would dislodge the -feeble grub and expose it to terrible hazards among a heap of victims -whose hind-legs, toothed like saws, might give an occasional jerk and -whose mandibles might still be capable of snapping. It is therefore the -question of safety and not of the grub’s likes or dislikes that -determines the mother’s choice in placing the egg. - -And here a suspicion occurs to my mind. The first ration, the Cricket -on whom the egg is laid, exposes the grub to more parlous risks than do -the others. To begin with, the larva is still but a frail worm; and -then the victim is quite a recent one and therefore most likely to give -evidence of a spark of life. This first victim has to be paralysed as -completely as possible: consequently it receives the Wasp’s three -dagger-thrusts. But the others, whose torpor deepens the older they -grow, the others whom the larva attacks after it has gained in -strength: do they need to be operated on as carefully? Might not one -prick be enough, or two pricks, the effects of which would spread -little by little while the grub is consuming its first ration? The -poison-fluid is too precious for the Wasp to lavish it unnecessarily: -it is hunting-ammunition, to be employed with due economy. At any rate, -though I have witnessed three consecutive stabs given to the same -victim, at other times I have seen only two administered. It is true -that the quivering tip of the Sphex’ abdomen seemed to be seeking the -favourable spot for a third wound; but, if it was really given, it -escaped me. I should therefore be inclined to think that the victim -forming the first ration is always stabbed thrice, whereas the others, -from motives of economy, receive only two stings. Our study of the -Ammophilæ, who hunt Caterpillars, will confirm this suspicion later. - -After devouring the last Cricket the larva sets about weaving its -cocoon. The work is finished well within forty-eight hours. Henceforth -the skilful worker, safe within her impenetrable shelter, can yield to -the irresistible lethargy that invades her, to that nameless mode of -existence, neither sleep nor waking, neither death nor life, from which -she will emerge, ten months from now, transfigured. Very few cocoons -are so complicated as hers. It consists, in fact, in addition to a -coarse outer network, of three distinct layers, presenting the -appearance of three cocoons one inside the other. Let us examine in -detail these several courses of the silken edifice. - -There is first an open woof, of a rough cobweb texture, whereon the -larva begins by isolating itself, hanging as in a hammock, to work more -easily at the cocoon proper. This unfinished net, hastily woven to -serve as a builder’s scaffolding, is made of threads flung out at -random, which hold together grains of sand, bits of earth and the -leavings of the larva’s feast: the Cricket’s thighs, still braided with -red, his shanks and pieces of his skull. The next covering, which is -the first covering of the cocoon proper, consists of a much-creased -felted tunic, light-red in colour, very fine and very flexible. A few -threads flung out here and there join it to the previous scaffolding -and to the second wrapper. It forms a cylindrical wallet, closed on -every side and too large for its contents, thus causing the surface to -wrinkle. - -Next comes an elastic sheath, distinctly smaller than the wallet that -contains it, almost cylindrical, rounded at the upper end, towards -which the larva’s head is turned, and finishing in a blunt cone at the -lower end. Its colour is still light-red, save towards the cone at the -bottom, where the shade is darker. Its consistency is pretty firm; -nevertheless, it yields to moderate squeezing, except in its conical -part, which resists the pressure of the fingers and seems to contain a -hard substance. On opening this sheath, we see that it is formed of two -layers closely applied one to the other, but easily separated. The -outer layer is a silk felt, exactly like that of the wallet which comes -before; the inner layer, the third layer of the cocoon, is a sort of -shellac, a shiny wash of a dark violet-brown, brittle, very soft to the -touch, and of a nature apparently quite different from the rest of the -cocoon. We see, in fact, under the microscope that, instead of being a -felt of silky threads like the previous wrapper, it is a homogeneous -coating of a peculiar varnish, whose origin is rather singular, as we -shall see. As for the resistance of the cone-shaped end of the cocoon, -we discover that this is due to a plug of crumbly matter, violet-black -and sparkling with a number of black particles. This plug is the dried -mass of the excrement which the larva ejects, once and for all, inside -the cocoon itself. The same stercoral kernel also causes the darker -shade of the cone-shaped end of the cocoon. The complicated dwelling -averages twenty-seven millimetres in length, while its greatest width -is nine millimetres. [22] - -Let us return to the violet varnish that lines the inside of the -cocoon. I thought at first that I must attribute it to the silk-glands, -which, after giving a glossy coat to the double wrapper of silk and the -scaffolding, have still a secret store of the fluid. To convince -myself, I opened some larvæ which had just finished their work as -weavers and had not yet begun to apply their lacquer. At that period I -saw no trace of violet fluid in the silk-glands. This shade is found -only in the digestive canal, which bulges with a purple-coloured pulp; -we find it also, but later, in the stercoral plug relegated to the -lower end of the cocoon. With this exception, everything is white, or -faintly tinged with yellow. Far be it from me to suggest that the larva -plasters its cocoon with its excreta; and yet I am convinced that this -plaster is a product of the digestive organs and I suspect, though I -cannot say for certain—having been clumsy enough several times to miss -a favourable opportunity of making sure—that the larva disgorges and -applies with its mouth the quintessence of the purple pulp from its -stomach in order to form the shellac glaze. Only after this last -performance would it reject its digestive residuum in a single lump; -and this would explain the unpleasant necessity in which the larva -finds itself of making room for its excreta inside its actual -habitation. - -Be this as it may, there can be no doubt about the usefulness of the -coating of shellac; its complete impermeability must protect the larva -against the damp which would certainly attack it in the precarious -refuge dug for it by the mother. Remember that the larva is buried only -a few inches down in uncovered, sandy ground. To judge to what extent -the cocoons thus varnished are able to resist the damp, I kept some -steeped in water for several days on end, without afterwards finding a -trace of moisture inside them. Compare the Sphex’ cocoon, with its -manifold linings, which are so well adapted for the protection of the -larva in an unprotected burrow, with the cocoon of the Great Cerceris, -lying under the dry shelter of a slab of sandstone and at a distance of -eighteen or twenty inches underground: this cocoon has the shape of a -very long pear, with the narrow end lopped off. It consists of a single -silken wrapper, so thin and fine that the larva shows through it. In my -numerous entomological investigations I have always seen the larva’s -industry and the mother’s thus making good each other’s deficiencies. -In a deep, well-sheltered abode, the cocoon is of a light material; in -a surface dwelling, exposed to the inclemencies of the weather, the -cocoon is stoutly built. - -Nine months elapse, during which a task is performed wherein all is -mystery. I skip this period, filled with the dead secret of the -transformation, and, to come to the nymph, pass at once from the end of -September to the first days of the following June. The larva has cast -its withered slough; the nymph, that transitory organism, or rather -that perfect insect in swaddling-bands, motionlessly awaits the -awakening which will not take place for another month to come. The -legs, the antennæ, the exposed mouth-parts and the wing-stumps have the -appearance of clearest crystal and lie evenly spread under the thorax -and the abdomen. The rest of the body is an opaque white, very faintly -smeared with yellow. The middle four segments of the abdomen carry a -narrow and blunt extension on either side. The last segment, -terminating above in a blade-like expansion shaped like the sector of a -circle, is equipped below with two conical protuberances set side by -side: this makes in all eleven appendages studding the outline of the -abdomen. Such is the delicate creature which, to become a Sphex, must -don a motley livery of black and red and throw off the fine skin in -which it is closely swathed. - -I was curious to follow from day to day the appearance and the progress -of the nymph’s colouring and to test whether the light of the sun, that -rich palette whence nature derives her colours, could influence that -progress. With this object, I took pupæ from their cocoons and put them -in glass tubes, of which some, kept in complete darkness, realized the -natural conditions of the nymphs and served me as a standard of -comparison, while the others, hung against a white wall, received a -strong diffused light throughout the day. Under these diametrically -opposed conditions, the evolution of the colours remained absolutely -uniform in both cases, or, if there were some slight discrepancies, -these were to the disadvantage of the pupæ exposed to the light. It is, -therefore, exactly the reverse of what happens in the case of plants: -light does not affect the colouring of insects, does not even -accelerate the process; and this must be so, because, in the species -which are the most brilliant in colouring, the Buprestes and -Ground-beetles, for instance, the wondrous hues which one would imagine -to be stolen from a sunbeam are really elaborated in the dusky bowels -of the earth or deep down in the decaying trunk of some venerable tree. - -The first outlines of colour show on the eyes, whose faceted cornea -changes successively from white to fawn, next to slate-grey, lastly to -black. The simple eyes at the top of the forehead, the ocelli, share in -this colouring, in their turn, before the rest of the body has yet lost -any of its neutral, white tint. It should be remarked that this early -development of the most delicate organ, the eye, is general in all -animals. Later, a smoky line appears on the upper part of the groove -separating the mesothorax and the metathorax; and, twenty-four hours -later, the whole back of the metathorax is black. At the same time, the -edge of the prothorax becomes shaded, a black dot appears in the -central and upper part of the metathorax, and the mandibles assume a -rusty tinge. Gradually a deeper and deeper shade creeps over the two -end segments of the thorax and finally reaches the head and the -hind-quarters. A day is enough to turn the smoky hue of the head and of -the end segments deep black. Thereupon the abdomen begins to share in -the rapidly-increasing coloration. The edge of its front segments is -tinted saffron; and its hinder segments acquire a dull-black border. -Lastly, the antennæ and legs, after passing through darker and darker -shades, turn black; the lower part of the abdomen is now entirely -orange-red and the tip black. The livery is complete except for the -tarsi and the mouth-parts, which are a transparent red, and the -wing-stumps, which are dull black. In four-and-twenty hours the nymph -will burst its fetters. - -It takes the nymph only six or seven days to don its final tints, -omitting the eyes, whose colouring precedes that of the rest of the -body by fourteen or fifteen days. The law governing the insect’s -chromatic evolution is easily gathered from this brief sketch. We see -that, with the exception of the eyes and the ocelli, whose early -development recalls what takes place in the higher animals, the -starting-point of the coloration is a central spot, the mesothorax, -whence it gradually invades, by centrifugal progression, first the rest -of the thorax, then the head and abdomen, lastly the different -appendages, the legs and antennæ. The tarsi and the mouth-parts colour -later still; and the wings do not assume their hue until after they are -taken from their cases. - -We now have the Sphex arrayed in her livery. She has yet to cast her -nymphal wrapper. This is a very fine tunic, moulded exactly in -accordance with the smallest structural details and scarcely veiling -the shape and colours of the perfect insect. As a prelude to the last -act of the metamorphosis, the Sphex, suddenly shaking off her torpor, -begins to move about violently, as though to call her long-numbed limbs -to life. The abdomen is alternately lengthened and shortened; the legs -are abruptly extended, then bent, then extended again; and their -different joints are stiffened with an effort. The insect, using its -head and the tip of its abdomen as a lever, with the ventral surface -underneath, repeatedly distends with vigorous jerks the joint of the -neck and that of the peduncle connecting the abdomen and the thorax. At -last its efforts are crowned with success; and, after a quarter of an -hour of these rough gymnastics, the scabbard, tugged in every -direction, rips open at the neck, at the point where the legs are -attached and near the peduncle of the abdomen, in short, wherever the -mobility of the parts has permitted any violent dislocation to take -place. - -All these rents in the veil that is being cast result in a number of -irregular shreds, whereof the largest envelops the abdomen and runs up -the back of the thorax. To this shred belong the wing-cases. A second -shred covers the head. Lastly, each leg has its own sheath, more or -less badly treated near the base. The large shred, which in itself -forms the best part of the wrapper, is thrown off by means of alternate -contractions and expansions of the abdomen. By this mechanical process -it is slowly forced backwards, where it ends by forming a little pellet -that for some time remains fastened to the insect by the tracheal -gills. The Sphex then once more becomes motionless; and the operation -is over. However, the head, antennæ and legs are still more or less -veiled. It is evident that the legs in particular cannot be freed all -in one piece, because of the numerous excrescences or spines with which -they are armed. These different shreds of skin dry up on the insect and -are removed afterwards by rubbing the legs. It is not until the Sphex -has acquired her full vigour that she finishes her moulting by -brushing, smoothing and combing her whole body with her tarsi. - -The way in which the wings come out of their sheaths is the most -remarkable part of the sloughing. In their incomplete stump stage they -are folded lengthwise and are very much compressed. It is easy to -extract them from their cases a little while before the normal date of -their appearance; but then they remain permanently contracted and do -not fill out. On the other hand, when once the large strip of skin to -which the sheaths of the wings belong is pushed back by the movements -of the abdomen, we see the wings come slowly out of their cases and -straightway, as they become free, assume dimensions out of all -proportion to the narrow prison whence they emerge. They are therefore -the seat of an abundant rush of vital fluids which swell them and -spread them out, and which, owing to the inflation which they provoke, -must be the chief cause of the wings’ emergence from their cases. When -newly expanded, the wings are heavy, full of juices and of a very pale -straw-colour. If the rush of the fluids takes place irregularly, we -then see the end of the wing weighed down by a little yellow drop -contained between the two scales. - -After stripping herself of the abdominal sheath, which carries the -wing-cases with it, the Sphex relapses into immobility for about three -days. During this time the wings assume their normal hue, the tarsi -become coloured, and the mouth-parts, at first extended, adopt their -proper position. After twenty-four days spent in the nymphal stage, the -insect has achieved the perfect state. It tears the cocoon that holds -it captive, opens itself a passage through the sand and comes out one -fine morning into the light of day, undazzled by that hitherto unknown -radiance. Bathed in sunshine, the Sphex brushes her antennæ and her -wings, passes and repasses her legs over her abdomen, washes her eyes -with her front tarsi wetted with saliva, like a cat; and, her toilet -finished, flies away joyfully: she has two months to live. - -You pretty Sphex-wasps hatched before my eyes, brought up by my hand, -ration by ration, on a bed of sand in an old quill-box; you whose -transformations I have followed step by step, starting up from my sleep -in alarm lest I should have missed the moment when the nymph is -bursting its swaddling-bands or the wing leaving its case; you who have -taught me so much and learned nothing yourselves, knowing without -teachers all that you have to know: O my pretty Sphex-wasps, fly away -without fear of my tubes, my boxes, my bottles, or any of my -receptacles, through this warm sunlight beloved of the Cicadæ; [23] go, -but beware of the Praying Mantis, [24] who is plotting your ruin on the -flowering heads of the thistles, and mind the Lizard, who is lying in -wait for you on the sunny slopes; go in peace, dig your burrows, stab -your Crickets scientifically and continue your kind, to procure one day -for others what you have given me: the few moments of happiness in my -life! - - - - - - - - -CHAPTER VII - -ADVANCED THEORIES - - -The species of the genus Sphex are fairly numerous, but are for the -most part strangers to my country. As far as I know, the French fauna -numbers only three, all lovers of the hot sun of the olive district, -namely, the Yellow-winged Sphex (Sphex flavipennis), the White-edged -Sphex (S. albisecta), and the Languedocian Sphex (S. occitanica). Now -it is not without a lively interest that the observer notices in the -case of these three freebooters a choice of provisions which is in -strict accordance with the rigid laws of entomological classification. -To feed their grubs, all three choose solely Orthoptera. [25] The first -hunts Crickets, the second Locusts, the third Ephippigers. - -The prey selected have such great outward differences one from the -other that to associate them and grasp their similarity calls for the -practised eye of the entomologist or the no less experienced eye of the -Sphex. Pray compare the Cricket with the Locust: the first has a large, -round, stumpy head, is short and thickset and black all over, with red -stripes on his hinder thighs; the second is greyish in colour, long and -slim, with a small, tapering head, leaps forward by suddenly unbending -his long hind-legs and continues this flight with wings furled like a -fan. Next compare both of these with the Ephippiger, who carries his -musical instrument, two shrill cymbals shaped like concave scales, on -his back and who waddles along with his pendulous belly, ringed -pale-green and buttercup-yellow and armed with a long dirk. Place the -three side by side and you will agree with me that, to guide her in -choosing between such dissimilar species, while still keeping to the -same entomological order, the Sphex must have an eye so expert that no -man—not your ordinary layman, but a man of science—need be ashamed to -own it. - -In the face of these singular predilections, which seem to have had -their limits laid down for them by some master of classification, by a -Latreille, for instance, it becomes interesting to investigate whether -the Sphex-wasps that are not natives of our country hunt game of the -same order. Unfortunately, information on this point is scanty and, in -the case of most of the species, is lacking altogether. The chief cause -of this regrettable lacuna is the superficial method generally adopted. -People catch an insect, stick a long pin through it, fix it in the -cork-bottomed box, gum a label with a Latin name underneath its feet, -and let its history end there. It is not thus that I understand the -duties of an entomological biographer. It is no use telling me that -this or that species has so many joints to its antennæ, so many -nervures to its wings, so many hairs on a region of the belly or -thorax; I do not really know the insect until I am acquainted with its -manner of life, its instincts and its habits. - -And see the immense and luminous advantage which a description of this -kind, told in two or three words, would possess over those long -descriptive details, sometimes so hard to grasp. Suppose that you wish -to make the Languedocian Sphex known to me and you begin by describing -the number and distribution of the nervures of the wings; you speak to -me of cubital nervures and recurrent nervures. Next comes the insect’s -pen-portrait. Black here, rusty red there, smoky brown at the tips of -the wings; black velvet in this part, silvery down in that, a smooth -surface in a third. It is all very definite and minute: we must do this -much justice to the precision and patience of the narrator; but it is -very long and also it is by no means always clear, so much so that we -may be excused if we are not quite able to follow it, even when we are -not altogether new to the business. But add to the tedious description -merely this: ‘Hunts Ephippigers’; and these two words at once shed -light: there is no possibility of my now mistaking my Sphex, for she -alone possesses the monopoly of that particular prey. To give this -illuminating note, what would be needed? The habit of really observing -and of not making entomology consist of so many series of impaled -insects. - -But let us pass on and examine the little that is known about the -hunting methods of the foreign Sphex-wasps. I open Lepeletier de -Saint-Fargeau’s [26] Natural History of Hymenoptera and find that, on -the other side of the Mediterranean, in our Algerian provinces, the -Yellow-winged Sphex and the White-edged Sphex retain the same habits -that characterize them here. They capture Orthoptera in the land of -palm-trees even as they do in the land of olive-trees. Though separated -from the others by the vast width of the sea, the hunting compatriots -of the Kabyles and the Berbers pursue the same game as their kindred in -Provence. I also see that a fourth species, the African Sphex (S. -afra), is the scourge of the Locusts in the neighbourhood of Oran. -Lastly, I remember reading, I forget where, of a fifth species which -also wages war on Locusts in the steppes near the Caspian. Thus, on the -borders of the Mediterranean, we have five different species of Sphex, -whose larvæ all live on a diet of Orthoptera. - -Now let us cross the equator and go right down to the southern -hemisphere, to the islands of Mauritius and Réunion: we shall here find -not a Sphex, but a closely-allied Wasp of the same tribe, the -Compressed Chlorion, hunting the horrible Kakerlak, that ravager of the -foodstuffs in the ships and harbours of the colonies. These Kakerlaks -are none other than Cockroaches, whereof one species haunts our -dwellings. Who does not know the evil-smelling insect, which, thanks to -its flat body, like that of a huge Bug, slips at night through the gaps -in furniture and the crannies of partitions and invades any place -containing provisions to be devoured? This is the Black-beetle of our -houses, a disgusting counterpart of the no less disgusting prey beloved -of the Chlorion. What is there about the Kakerlak to cause him to be -selected as a prey by a near cousin of our Sphex-wasps? It is quite -simple: with his Bug shape, the Kakerlak also is an Orthopteron, just -as much as the Cricket, the Ephippiger or the Locust. From these six -examples, the only ones known to me and of such different origins, we -might perhaps deduce that all the Sphex hunt Orthoptera. At any rate, -without adopting so general a conclusion, we see what the food of their -larvæ must be in most cases. - -There is a reason for this surprising choice. What is it? What are the -grounds for a diet which, within the strict limits of one entomological -order, is composed here of stinking Kakerlaks, there of somewhat dry, -but highly-flavoured Locusts, elsewhere again of plump Crickets or fat -Ephippigers? I confess that I cannot tell, that I am absolutely in the -dark; and I leave the problem to others. At the same time, we may -observe that the Orthoptera are among insects what the Ruminants are -among mammals. Endowed with a mighty paunch and a placid temperament, -they graze contentedly and soon put on flesh. They are numerous, widely -distributed and slow in movement, which renders them easy to catch; -moreover, they are of a large size, making fine heads of game. Who can -say if the Sphex-wasps, powerful huntresses, requiring big prey, do not -find in these Ruminants of the insect world what we ourselves find in -our domestic Ruminants, the Sheep and the Ox, peaceable victims -yielding plenty of flesh? It is just a possibility, but no more. - -I have something better than a possibility to offer in reply to another -and no less important question. Do the Orthopteron-eaters ever vary -their diet? Should the favourite type of game fall short, can they not -accept a different one? Does the Languedocian Sphex consider that there -is nothing in the world worth having but fat Ephippigers? Does the -White-edged Sphex allow none but Locusts to figure on her table; and -the Yellow-winged Sphex none but Crickets? Or, according to time, place -and circumstances, does each make up for the lack of her favourite -victuals by others more or less equivalent? To ascertain such facts, if -they exist, would be of the greatest importance, for they would tell us -if the inspirations of instinct are absolute and unchangeable, or if -they vary and within what limits. It is true that the cells of one and -the same Cerceris contain the most varied species of either the -Buprestis or the Weevil group, which shows that the huntress has a -great latitude of choice; but this extension of the hunting-fields -cannot be presumed in the case of the Sphex-wasps, whom I have seen so -faithful to an exclusive victim, always the same for each of them, and -who moreover find, among the Orthoptera, groups that differ very widely -in shape. Nevertheless, I have had the good fortune to come upon one -case, one only, of complete change in the larva’s nourishment; and I -record it the more willingly in the Sphegian archives inasmuch as such -facts, scrupulously observed, will one day form foundation-stones for -any one who cares to build up the psychology of instinct on a solid -basis. - -Here are the facts. The scene is enacted on a towing-path along the -Rhône. On one side is the mighty stream, with its roaring waters; on -the other is a thick hedge of osiers, willows, and reeds; between the -two runs a narrow walk, with a carpet of fine sand. A Yellow-winged -Sphex appears, hopping along, dragging her prey. What do I see! The -prey is not a Cricket, but a common Acridian, a Locust! And yet the -Wasp is really the Sphex with whom I am so familiar, the Yellow-winged -Sphex, the keen Cricket-huntress. I can hardly believe the evidence of -my own eyes. - -The burrow is not far off: the insect enters it and stores away the -booty. I sit down, determined to wait for a new expedition, to wait -hours if necessary, so that I may see if the extraordinary capture is -repeated. My sitting attitude makes me take up the whole width of the -path. Two raw conscripts heave in sight, their hair newly cut, wearing -that inimitable automaton look which the first days of barrack-life -bestow. They are chatting together, talking no doubt of home and the -girl they left behind them; and each is innocently whittling a -willow-switch with his knife. I am seized with a sudden apprehension. -Ah, it is no easy matter to experiment on the public road, where, when -the long-awaited event occurs at last, the arrival of a wayfarer is -likely to disturb or ruin opportunities that may never return! I rise, -anxiously, to make way for the conscripts; I stand back in the -osier-bed and leave the narrow passage free. To do more would have been -unwise. To say, ‘Don’t go this way, my good lads,’ would have made bad -worse. They would have suspected some trap hidden under the sand, -giving rise to questions to which no reply that I could have made would -have sounded satisfactory. Besides, my request would have turned those -idlers into lookers-on, very embarrassing company in such studies. I -therefore got up without speaking and trusted to my lucky star. Alas -and alack, my star betrayed me: the heavy regulation boot came straight -down upon the ceiling of the Sphex! A shudder ran through me as though -I myself had received the impress of the hobnailed sole. - -When the conscripts had passed, I proceeded to save what I could of the -ruined burrow’s contents. The Sphex was there, crushed and mangled; and -with her not only the Locust whom I had seen carried down, but two -others as well, making three Locusts in all instead of the usual -Crickets. What was the reason of this curious change? Were there no -Crickets in the neighbourhood of the burrow and was the distressed Wasp -making up for them with Locusts: a case of Hobson’s choice, in fact? I -hesitate to believe it, for there was nothing about the neighbourhood -to warrant the supposition that the favourite game was absent. Another, -luckier than I, will unriddle this new and unknown mystery. The fact -remains that the Yellow-winged Sphex, either from imperious necessity -or for some reason that escapes me, sometimes replaces her chosen prey, -the Cricket, with another prey, the Locust, presenting no external -resemblance to the first, but itself also an Orthopteron. - -The observer on whose authority Lepeletier de Saint-Fargeau says a word -or two touching the habits of this same Sphex witnessed a similar -storing away of Locusts in Africa, near Oran. He surprised a -Yellow-winged Sphex dragging an Acridian along. Was it an accidental -case, like that which I witnessed on the banks of the Rhône? Was it an -exception or the rule? Can there be a lack of Crickets in the country -around Oran and does the Wasp fill their place with Acridians? The -force of circumstances compels me to put the question without finding a -reply. - -This is the place to interpolate a certain passage from Lacordaire’s -[27] Introduction to Entomology against which I am eager to protest. -Here it is: - - - ‘Darwin, [28] who wrote a book on purpose to prove the identity of - the intellectual principle actuating men and animals, was walking - one day in his garden when he saw on the path a Sphex who had just - possessed herself of a Fly almost as large as herself. He saw her - cut off the victim’s head and abdomen with her mandibles, keeping - only the thorax, to which the wings remained attached, after which - she flew away; but a breath of wind, striking the Fly’s wings, made - the Sphex spin round and prevented her progress; hereupon she - alighted again on the path, cut off one of the Fly’s wings and then - the other, and, after thus destroying the cause of her - difficulties, resumed her flight with what remained of her prey. - This fact carries with it manifest signs of reasoning power. - Instinct might have led this Sphex to cut off her victim’s wings - before carrying it to her nest, as do some species of the same - genus; but here there was a sequence of ideas and results from - those ideas, which are quite inexplicable unless we allow the - intervention of reason.’ - - -This little story, which so lightly grants reason to an insect, lacks I -will not say truth, but even mere likelihood, not in the act itself, -which I accept without reserve, but in the motives for the act. Darwin -saw what he tells us; only, he was mistaken as to the heroine of the -drama, the drama itself and its significance. He was profoundly -mistaken; and I will prove it. - -First of all, the old English scientist was bound to know enough about -the creatures to which he gives these high dignities to call things by -their right names. Let us therefore take the word Sphex in its strict -scientific meaning. Under this assumption, by what strange aberration -was this English Sphex, if any such there be, choosing a Fly for her -prey, when her kinswomen hunt such different game, Orthoptera? Even -admitting what I consider to be inadmissible, a Fly to form the quarry -of a Sphex, other difficulties come crowding up. It is now duly proved -that the Burrowing Wasps do not take dead bodies to their larvæ, but a -victim merely numbed, paralysed. Then what is the meaning of this prey -of which the Sphex cuts off the head, the abdomen, the wings? The stump -carried away is no more than a fragment of a corpse, which would infect -the cell with its rottenness, without being of any use to the larva, -whose hatching is not due for some days yet. It is as clear as -daylight: when making his observation, Darwin did not have before him a -Sphex in the strict sense of the word. Then what did he see? - -The term Fly, by which the captured prey is designated, is a very -elastic word, which can be applied to the immense order of Diptera and -which therefore leaves us undecided among thousands of species. The -expression Sphex is most likely also employed in an equally indefinite -sense. At the end of the eighteenth century, when Darwin’s book -appeared, this expression was used to denote not only the Sphegidæ -proper, but particularly the Crabronidæ. Now, among the latter, some, -when storing provisions for their larvæ, hunt Diptera, Flies, the prey -required by the unknown Hymenopteron of the English naturalist. Then -was Darwin’s Sphex a Crabro? No; for these Dipteron-hunters, like the -hunters of any other prey, want game that keeps fresh, motionless but -half-alive, for the fortnight or three weeks required for the hatching -of the eggs and the complete development of the larvæ. All these little -ogres need meat killed that day and not gone bad or even a little high. -This is a rule to which I know of no exception. The word Sphex cannot -be accepted therefore, even with its old meaning. - -Instead of a precise fact, really worthy of science, we have a riddle -to read. Let us continue to examine the riddle. Different species of -the Crabro family are so like the Social Wasps in size, in shape and in -their black-and-yellow livery as to deceive any eye unversed in the -delicate distinctions of entomology. To any one who has not made a -special study of such subjects a Crabro is a Common Wasp. May it not -have happened that the English observer, looking at things from a -height and thinking unworthy of strict investigation the tiny fact -which nevertheless was to corroborate his transcendental theories and -help to bestow reason upon an animal, made a mistake in his turn, but -one in the other direction and quite pardonable, by taking a Wasp for a -Crabro? I would almost dare swear so; and here are my reasons. - -Wasps, if not always, at least often bring up their family on animal -food; but, instead of accumulating a provision of game in each cell -beforehand, they distribute the food to the larvæ, one by one and -several times a day; they feed them with their mouths, as the father -and mother feed young birds with their beaks. And the mouthful consists -of a fine mash of chewed insects, ground between the mandibles of the -Wasp nurse. The favourite insects for the preparation of this infants’ -food are Diptera, especially Common Flies; when fresh meat can be had, -it is a windfall eagerly turned to account. Who has not seen Wasps -boldly enter our kitchens or pounce upon the meat hanging in the -butchers’ shops, to cut off a scrap that suits them and carry it away -forthwith, as spolia opima for the use of the grubs? When the -half-closed shutters admit a streak of sunlight to the floor of a room, -where the Housefly is taking a luxurious nap or polishing her wings, -who has not seen the Wasp rush in, swoop down upon the Fly, crush her -in her mandibles and make off with the booty? Once again, a morsel -reserved for the carnivorous nurselings. - -The prey is dismembered now on the spot where captured, now on the way, -now at the nest. The wings, which possess no nutritive value, are cut -off and rejected; the legs, which are poor in juices, are also -sometimes disdained. There remains a mutilated corpse, head, thorax, -abdomen, united or separated, which the Wasp chews and rechews to -reduce it to the pap beloved of the larvæ. I have tried to take the -place of the nurses in this method of rearing grubs on Fly-soup. The -subject of my experiment was a nest of Polistes gallica, the Wasp who -fastens her little rosette of brown-paper cells to the roots of a -shrub. My kitchen-table was a flat piece of marble on which I crushed -the Fly-pap after cleaning the heads of game, that is to say, after -removing the parts that were too tough, the wings and legs; lastly, the -feeding-spoon was a fine straw, at the tip of which the dish was -served, from cell to cell, to each nurseling, which opened its -mandibles just as the young birds in the nest might do. I used to go to -work in exactly the same way and succeeded no better when bringing up -broods of Sparrows, that joy of my childhood. All went well as long as -my patience did not fail me, tried as it was by the cares of so finikin -and absorbing an education. - -The obscurity of the enigma gives way to the full light of truth thanks -to the following observation, made with all the deliberateness which -strict precision calls for. In the early days of October, two large -clumps of asters in blossom outside the door of my study became the -meeting-place of a host of insects, among which the Hive-bee and an -Eristalis-fly (Eristalis tenax) predominate. A gentle murmur rose from -them, like that of which Virgil sings: - - - Sæpe levi somnum suadebit inire susurro. [29] - - -But, where the poet finds but an incitement to the delights of sleep, -the naturalist beholds a subject for study: all this small folk making -holiday on the last flowers of the year will perhaps furnish him with -some fresh data. Behold me then on observation duty before the two -clumps with their thousands of lilac petals. - -The air is absolutely still, the sun blazing, the atmosphere heavy: -signs of an approaching storm, but conditions eminently favourable to -the work of the Hymenoptera, who seem to foresee to-morrow’s rain and -redouble their activity to improve the opportunity. And so the Bees -plunder eagerly, while the Eristales fly clumsily from flower to -flower. At times, the peaceable multitude, filling its crop with -nectar, is disturbed by the sudden invasion of the Wasp, a ravening -insect attracted hither by prey, not honey. - -Equally ardent in carnage, but very unequal in strength, two species -divide the hunting between them: the Common Wasp (Vespa vulgaris), who -catches Eristales, and the Hornet (Vespa crabro), who preys on -Hive-bees. The methods are the same in either case. Both bandits -explore the expanse of flowers with an impetuous flight, going -backwards and forwards in a thousand directions, and then make a sudden -rush for the coveted prey, which is on its guard and flies away, while -the kidnapper’s impetus brings her up with a bump against the deserted -flower. Then the pursuit continues in the air, as though a Sparrow-hawk -were chasing a Lark. But the Bee and the Eristalis, by taking brisk -turns, soon baffle the attempts of the Wasp, who resumes her evolutions -above the clustering blossoms. At last, sooner or later, some quarry -less quick at flight is captured. Forthwith, the Common Wasp drops on -to the lawn with her Eristalis; I also instantly lie on the ground, -quietly removing with my hands the dead leaves and bits of grass that -might interfere with my view; and I witness the following tragedy, if I -have taken proper precautions not to scare the huntress. - -First, there is a wild struggle in the tangle of the grass between the -Wasp and the Eristalis, who is bigger than her assailant. The Fly is -unarmed, but powerful; a shrill buzz of her wings tells of her -desperate resistance. The Wasp carries a dagger; but she does not -understand the methodical use of it, is unacquainted with the -vulnerable points so well known to the marauders who need a prey that -keeps fresh for long. What her nurselings want is a mess of Flies that -moment reduced to pulp; and, so long as this is achieved, the Wasp -cares little how the game is killed. The sting therefore is used -blindly, without any method. We see it pointed indifferently at the -victim’s back, sides, head, thorax, or belly, according to the chances -of the scuffle. The Hunting Wasp paralysing her victim acts like a -surgeon who directs his scalpel with a skilled hand; the Social Wasp -killing her prey behaves like a common assassin who stabs at random. -For this reason the Eristalis’ resistance is prolonged; and her death -is the result of scissor-cuts rather than dagger-thrusts. When the -victim is duly garrotted, motionless between its ravisher’s legs, the -head falls under a snap of the mandibles; then the wings are cut off at -their juncture with the shoulder; the legs follow, severed one by one; -lastly, the belly is flung aside, but emptied of the entrails, which -the Wasp appears to add to the one favoured portion. This choice morsel -is solely the thorax, which is richer in lean meat than the rest of the -Eristalis’ body. Without further delay the Wasp flies off with it, -carrying it in her legs. On reaching the nest, she will make it into -potted Fly and serve it in mouthfuls to the larvæ. - -The Hornet who has caught a Bee acts in much the same manner; but, in -the case of an assailant of her dimensions, the struggle cannot last -long, notwithstanding the victim’s sting. The Hornet may prepare her -dish on the very flower where the capture was effected, or more often -on some twig of an adjacent shrub. The Bee’s crop is first ripped open -and the honey that runs out of it lapped up. The prize is thus a -twofold one: a drop of honey for the huntress to feast upon and the Bee -herself for the larvæ. Sometimes the wings are removed and also the -abdomen; but generally the Hornet is satisfied with reducing the Bee to -a shapeless mass, which she carries off without disdaining anything. -Those parts which have no nutritive value, especially the wings, will -be rejected on arriving at the nest. Lastly, she sometimes prepares the -mash in the actual hunting-field, that is to say, she crushes the Bee -between her mandibles after removing the wings, the legs, and at times -the abdomen as well. - -Here then, in all its details, is the incident observed by Darwin. A -Wasp (Vespa vulgaris) catches a big Fly (Eristalis tenax); she cuts off -the victim’s head, wings, abdomen, and legs with her mandibles and -keeps only the thorax, which she carries off flying. But here there is -not the least breath of wind to explain the carving process; besides, -the thing happens in a perfect shelter, in the thick tangle of the -grass. The butcher rejects such parts of her prey as she considers -valueless to her larvæ; and that is all about it. - -In short, the heroine of Darwin’s story is certainly a Wasp. Then what -becomes of that rational calculation on the part of the insect which, -the better to contend with the wind, cuts off its prey’s abdomen, head -and wings and keeps only the thorax? It becomes a most simple incident, -leading to none of the mighty consequences which the writer seeks to -deduce from it: the very trivial incident of a Wasp who begins to carve -up her prey on the spot and keeps only the stump, the one part which -she considers fit for her larvæ. Far from seeing the least sign of -reason in this, I look upon it as a mere act of instinct, one so -elementary that it is really not worth expatiating upon. - -To disparage man and exalt animals in order to establish a point of -contact, followed by a point of union, has been and still is the -general tendency of the ‘advanced theories’ in fashion in our day. Ah, -how often are these ‘sublime theories,’ that morbid craze of the time, -based upon ‘proofs’ which, if subjected to the light of experiment, -would lead to as ridiculous results as the learned Erasmus Darwin’s -Sphex! - - - - - - - - -CHAPTER VIII - -THE LANGUEDOCIAN SPHEX - - -When the chemist has fully prepared his plan of research, he mixes his -reagent at the most convenient moment and lights a flame under his -retort. He is the master of time, place and circumstances. He chooses -his hour, shuts himself up in his laboratory, where nothing can come to -disturb the business in hand; he produces at will this or that -condition which reflection suggests to him: he is in quest of the -secrets of inorganic matter, whose chemical activities science can -awaken whenever it thinks fit. - -The secrets of living matter—not those of anatomical structure, but -really those of life in action, especially of instinct—present much -more difficult and delicate conditions to the observer. Far from being -able to choose his own time, he is the slave of the season, of the day, -of the hour, of the very moment. When the opportunity offers, he must -seize it as it comes, without hesitation, for it may be long before it -presents itself again. And, as it usually arrives at the moment when he -is least expecting it, nothing is in readiness for making the most of -it. He must then and there improvise his little stock of experimenting -material, contrive his plans, evolve his tactics, devise his tricks; -and he can think himself lucky if inspiration comes fast enough to -allow him to profit by the chance offered. This chance, moreover, -hardly ever comes except to those who look for it. You must watch for -it patiently for days and days, now on sandy slopes exposed to the full -glare of the sun, now on some path walled in by high banks, where the -heat is like that of an oven, or again on some sandstone ledge which is -none too steady. If it is in your power to set up your observatory -under a meagre olive-tree that pretends to protect you from the rays of -a pitiless sun, you may bless the fate that treats you as a sybarite: -your lot is an Eden. Above all, keep your eyes open. The spot is a good -one; and—who knows?—the opportunity may come at any moment. - -It came—late, it is true; but still it came. Ah, if you could now -observe at your ease, in the quiet of your study, with nothing to -distract your mind from your subject, far from the profane wayfarer -who, seeing you so busily occupied at a spot where he sees nothing, -will stop, overwhelm you with queries, take you for some water-diviner, -or—a graver suspicion this—regard you as some questionable character -searching for buried treasure and discovering by means of incantations -where the old pots full of coin lie hidden! Should you still wear a -Christian aspect in his eyes, he will approach you, look to see what -you are looking at, and smile in a manner that leaves no doubt as to -his poor opinion of people who spend their time in watching Flies. You -will be lucky indeed if the troublesome visitor, with his tongue in his -cheek, walks off at last without disturbing things and without -repeating in his innocence the disaster brought about by my two -conscripts’ boots. - -Should your inexplicable doings not puzzle the passer-by, they will be -sure to puzzle the village keeper, that uncompromising representative -of the law in the ploughed acres. He has long had his eye on you. He -has so often seen you wandering about, like a lost soul, for no -appreciable reason; he has so often caught you rooting in the ground, -or, with infinite precautions, knocking down some strip of wall in a -sunken road, that in the end he has come to look upon you with dark -suspicion. You are nothing to him but a gipsy, a tramp, a -poultry-thief, a shady person or, at the best, a madman. Should you be -carrying your botanizing-case, it will represent to him the poacher’s -ferret-cage; and you would never get it out of his head that, -regardless of the game-laws and the rights of landlords, you are -clearing all the neighbouring warrens of their rabbits. Take care. -However thirsty you may be, do not lay a finger on the nearest bunch of -grapes: the man with the municipal badge will be there, delighted to -have a case at last and so to receive an explanation of your highly -perplexing behaviour. - -I have never, I can safely say, committed any such misdemeanour; and -yet, one day, lying on the sand, absorbed in the details of a Bembex’ -household, I suddenly heard beside me: - -‘In the name of the law, I arrest you! You come along with me!’ - -It was the keeper of Les Angles, who, after vainly waiting for an -opportunity to catch me at fault and being daily more anxious for an -answer to the riddle that was worrying him, at last resolved upon the -brutal expedient of a summons. I had to explain things. The poor man -seemed anything but convinced: - -‘Pooh!’ he said. ‘Pooh! You will never make me believe that you come -here and roast in the sun just to watch Flies. I shall keep an eye on -you, mark you! And, the first time I...! However, that’ll do for the -present.’ - -And he went off. I have always believed that my red ribbon had a good -deal to do with his departure. And I also put down to that red ribbon -certain other little services by which I benefited during my -entomological and botanical excursions. It seemed to me—or was I -dreaming?—it seemed to me that, on my botanizing expeditions up Mont -Ventoux, the guide was more tractable and the donkey less obstinate. - -The aforesaid bit of scarlet ribbon did not always spare me the -tribulations which the entomologist must expect when experimenting on -the public way. Here is a characteristic example. Ever since daybreak I -have been ambushed, sitting on a stone, at the bottom of a ravine. The -subject of my matutinal visit is the Languedocian Sphex. Three women, -vine-pickers, pass in a group, on the way to their work. They give a -glance at the man seated, apparently absorbed in reflection. At sunset, -the same pickers pass again, carrying their full baskets on their -heads. The man is still there, sitting on the same stone, with his eyes -fixed on the same place. My motionless attitude, my long persistency in -remaining at that deserted spot, must have impressed them deeply. As -they passed by me, I saw one of them tap her forehead and heard her -whisper to the others: - -‘Un paouré inoucènt, pécaïre!’ - -And all three made the sign of the Cross. - -An innocent, she had said, un inoucènt, an idiot, a poor creature, -quite harmless, but half-witted; and they had all made the sign of the -Cross, an idiot being to them one with God’s seal stamped upon him. - -‘How now!’ thought I. ‘What a cruel mockery of fate! You, who are so -laboriously seeking to discover what is instinct in the animal and what -is reason, you yourself do not even possess your reason in these good -women’s eyes! What a humiliating reflection!’ - -No matter: pécaïre, that expression of supreme compassion, in the -Provençal dialect, pécaïre, coming from the bottom of the heart, soon -made me forget inoucènt. - -It is in this ravine with its three grape-gathering women that I would -meet the reader, if he be not discouraged by the petty annoyances of -which I have given him a foretaste. The Languedocian Sphex frequents -these points, not in tribes congregating at the same spot when -nest-building work begins, but as solitary individuals, sparsely -distributed, settling wherever the chances of their vagabondage lead -them. Even as her kinswoman, the Yellow-winged Sphex, seeks the society -of her kind and the animation of a yard full of workers, the -Languedocian Sphex prefers isolation, quiet and solitude. Graver of -gait, more formal in her manners, of a larger size and also more -sombrely clad, she always lives apart, not caring what others do, -disdaining company, a genuine misanthrope among the Sphegidæ. The one -is sociable, the other is not: a profound difference which in itself is -enough to characterize them. - -This amounts to saying that, with the Languedocian Sphex, the -difficulties of observation increase. No long-meditated experiment is -possible in her case; nor, when the first attempts have failed, can one -hope to try them again, on the same occasion, with a second or a third -subject and so on. If you prepare the materials for your observation in -advance, if, for instance, you have in reserve a piece of game which -you propose to substitute for that of the Sphex, it is to be feared, -nay, it is almost certain that the huntress will not appear; and, when -she does come at last, your materials are no longer fit for use and -everything has to be improvised in a hurry, that very moment, under -conditions that are not always satisfactory. - -Let us take heart. The site is a first-rate one. Many a time already I -have surprised the Sphex here, sunning herself on a vine-leaf. The -insect, spread out flat, is basking voluptuously in the heat and light. -From time to time it has a sort of frenzied outburst of pleasure: it -quivers with content; it rapidly taps its feet on its couch, producing -a tattoo not unlike that of rain falling heavily on the leaf. The -joyous thrum can be heard several feet away. Then immobility begins -again, soon followed by a fresh nervous commotion and by the whirling -of the tarsi, a symbol of supreme felicity. I have known some of these -passionate sun-lovers suddenly to leave the work-yard, when the larva’s -cave has been half-dug, and go to the nearest vine to take a bath of -heat and light, after which they would come back to the burrow, as -though reluctantly, just to give a perfunctory sweep and soon end by -knocking off work, unable to resist the exquisite temptation of -luxuriating on the vine-leaves. - -It may be that the voluptuous couch is also an observatory, whence the -Wasp surveys the surrounding country in order to discover and select -her prey. Her exclusive game is the Ephippiger of the Vine, scattered -here and there on the branches or on any brambles hard by. The joint is -a substantial one, especially as the Sphex favours solely the females, -whose bellies are swollen with a mighty cluster of eggs. - -Let us take no notice of the repeated trips, the fruitless searches, -the tedium of frequent long waiting, but rather present the Sphex -suddenly to the reader as she herself appears to the observer. Here she -is, at the bottom of a sunken road with high, sandy banks. She comes on -foot, but gets help from her wings in dragging her heavy prize. The -Ephippiger’s antennæ, long and slender as threads, are the -harnessing-ropes. Holding her head high, she grasps one of them in her -mandibles. The antenna gripped passes between her legs; and the game -follows, turned over on its back. Should the soil be too uneven and so -offer resistance to this method of carting, the Wasp clasps her -unwieldy burden and carries it with very short flights, interspersed, -as often as possible, with journeys on foot. We never see her undertake -a sustained flight, for long distances, holding the game in her legs, -as is the practice of those expert aviators, the Bembeces and Cerceres, -for instance, who bear through the air for more than half a mile their -respective Flies or Weevils, a very light booty compared with the huge -Ephippiger. The overpowering weight of her capture compels the -Languedocian Sphex to make the whole, or nearly the whole, journey on -foot, her method of transport being consequently slow and laborious. - -The same reason, the bulk and weight of the prey, have entirely -reversed the usual order which the Burrowing Wasps follow in their -operations. This order we know: it consists in first digging a burrow -and then stocking it with provisions. As the victim is not out of -proportion to the strength of the spoiler, it is quite simple to carry -it flying, which means that the Wasp can choose any site that she likes -for her dwelling. She does not mind how far afield she goes for her -prey: once she has captured her quarry, she comes flying home at a -speed which makes questions of distance quite immaterial. Hence she -prefers as the site for her burrow the place where she herself was -born, the place where her forbears lived; she here inherits deep -galleries, the accumulated work of earlier generations; and, by -repairing them a little, she makes them serve as approaches to new -chambers, which are in this way better protected than they would be if -they depended upon the labours of a single Wasp, who had to start -boring from the surface each year. This happens, for instance, in the -case of the Great Cerceris and the Bee-eating Philanthus. And, should -the ancestral abode not be strong enough to withstand the rough weather -from one year to the next and to be handed down to the offspring, -should the burrower have each time to start her tunnelling afresh, at -least the Wasp finds greater safety in places consecrated by the -experience of her forerunners. Consequently she goes there to dig her -galleries, each of which serves as a corridor to a group of cells, thus -effecting an economy in the aggregate labour expended upon the whole -business of the laying. - -In this way are formed not real societies, for there are no concerted -efforts towards a common object, but at least assemblies where the -sight of her kinswomen and her neighbours doubtless puts heart into the -labour of the individual. We can observe, in fact, between these little -tribes, springing from the same stock, and the burrowers who do their -work alone, a difference in activity which reminds us of the emulation -prevailing in a crowded yard and the indifference of labourers who have -to work in solitude. Action is contagious in animals as in men; it is -fired by its own example. - -To sum up: when of a moderate weight for its captor, the prey can be -conveyed flying, to a great distance. The Wasp can then choose any site -that she pleases for her burrow. She adopts by preference the spot -where she was born and uses each passage as a common corridor giving -access to several cells. The result of this meeting at a common -birthplace is the formation of groups, like turning to like, which is a -source of friendly rivalry. This first step towards social life comes -from facilities for travelling. Do not things happen in the same way -with man, if I may be permitted the comparison? When he has nothing but -trackless paths, man builds a solitary hut; when supplied with good -roads, he and his fellows collect in populous cities; when served by -railways which, so to speak, annihilate distance, they assemble in -those immense human hives called London or Paris. - -The situation of the Languedocian Sphex is just the reverse. Her prey -is a heavy Ephippiger, a single dish representing by itself the sum -total of provisions which the other freebooters amass on numerous -journeys, insect by insect. What the Cerceres and the other plunderers -strong on the wing accomplish by dividing the labour she does in a -single journey. The weight of the prey makes any distant flight -impossible; it has to be brought home slowly and laboriously, for it is -a troublesome business to cart things along the ground. This alone -makes the site of the burrow dependent on the accidents of the chase: -the prey comes first and the dwelling next. So there is no assembling -at a common meeting-place, no association of kindred spirits, no tribes -stimulating one another in their work by mutual example, but isolation -in the particular spot where the chances of the day have taken the -Sphex, solitary labour, carried on without animation though with -unfailing diligence. First of all, the prey is sought for, attacked, -reduced to helplessness. Not until after that does the digger trouble -about the burrow. A favourable place is chosen, as near as possible to -the spot where the victim lies, so as to cut short the tedious work of -transport; and the chamber of the future larva is rapidly hollowed out -and at once receives the egg and the victuals. There you have an -example of the inverted method of the Languedocian Sphex, a method, as -all my observations go to prove, diametrically opposite to that of the -other Hymenoptera. I will give some of the more striking of these -observations. - -When caught digging, the Languedocian Sphex is always alone, sometimes -at the bottom of a dusty recess left by a stone that has dropped out of -an old wall, sometimes ensconced in the shelter formed by a flat, -projecting bit of sandstone, a shelter much sought after by the fierce -Eyed Lizard to serve as an entrance-hall to his lair. The sun beats -full upon it; it is an oven. The soil, consisting of old dust that has -fallen little by little from the roof, is very easy to dig. The cell is -soon scooped out with the mandibles, those pincers which are also used -for digging, and the tarsi, which serve as rubbish-rakes. Then the -miner flies off, but with a slow flight and no sudden display of -wing-power, a manifest sign that the insect is not contemplating a -distant expedition. We can easily follow it with our eyes and perceive -the spot where it alights, usually ten or twelve yards away. At other -times it decides to walk. It goes off and makes hurriedly for a spot -where we will have the indiscretion to follow it, for our presence does -not trouble it at all. On reaching its destination, either on foot or -on the wing, it looks round for some time, as we gather from its -undecided attitude and its journeys hither and thither. It looks round; -at last it finds or rather retrieves something. The object recovered is -an Ephippiger, half-paralysed, but still moving her tarsi, antennæ and -ovipositor. She is a victim which the Sphex certainly stabbed not long -ago with a few stings. After the operation the Wasp left her prey, an -embarrassing burden amid the suspense of house-hunting; she abandoned -it perhaps on the very spot where she captured it, contenting herself -with making it more or less conspicuous by placing it on some -grass-tuft, in order to find it more easily later; and, trusting to her -good memory to return presently to the spot where the booty lies, she -set out to explore the neighbourhood with the object of finding a -suitable site and there digging a burrow. Once the home was ready, she -came back to her prize, which she found again without much hesitation, -and she now prepares to lug it home. She bestrides the victim, seizes -one or both of the antennæ, and off she goes, tugging and dragging with -all the strength of her loins and jaws. - -Sometimes she has only to make one journey; at other times and more -often, the carter suddenly plumps down her load and quickly runs home. -Perhaps it occurs to her that the entrance-door is not wide enough to -admit so substantial a morsel; perhaps she remembers some lack of -finish that might hamper the storing. And, in point of fact, the worker -does touch up her work: she enlarges the doorway, smooths the -threshold, strengthens the ceiling. It is all done with a few strokes -of the tarsi. Then she returns to the Ephippiger, lying yonder, on her -back, a few steps away. The hauling begins again. On the road, the -Sphex seems struck with a new idea, which flashes through her quick -brain. She has inspected the door, but has not looked inside. Who knows -if all is well in there? She hastens to see, dropping the Ephippiger -before she goes. The interior is inspected; and apparently a few pats -of the trowel are administered with the tarsi, giving a last polish to -the walls. Without lingering too long over these delicate -after-touches, the Wasp goes back to her booty and harnesses herself to -its antennæ. Forward! Will the journey be completed this time? I would -not answer for it. I have known a Sphex, more suspicious than the -others, perhaps, or more neglectful of the minor architectural details, -to repair her omissions, to dispel her doubts, by abandoning her prize -on the way five or six times running, in order to hurry to the burrow, -which each time was touched up a little or merely inspected within. It -is true that others make straight for their destination, without even -stopping to rest. I must also add that, when the Wasp goes home to -improve the dwelling, she does not fail to give a glance from a -distance every now and then at the Ephippiger over there, to make sure -that nothing has happened to her. This solicitude recalls that of the -Sacred Beetle when he leaves the hall which he is excavating in order -to come and feel his beloved pellet and bring it a little nearer to -him. - -The inference to be drawn from the details which I have related is -manifest. The fact that every Languedocian Sphex surprised in her -mining operations, even though it be at the very beginning of the -digging, at the first stroke of the tarsus in the dust, afterwards, -when the home is prepared, makes a short excursion, now on foot, anon -flying, and invariably finds herself in possession of a victim already -stabbed, already paralysed, compels us to conclude, in all certainty, -that this Wasp does her work as a huntress first and as a burrower -after, so that the place of the capture decides the place of the home. - -This reversal of procedure, which causes the food to be prepared before -the larder, whereas hitherto we have seen the larder come before the -food, I attribute to the weight of the Sphex’ prey, a prey which it is -not possible to carry far through the air. It is not that the -Languedocian Sphex is ill-built for flight: on the contrary, she can -soar magnificently; but the prey which she hunts would weigh her down -if she had no other support than her wings. She needs the support of -the ground for her hauling-work, in which she displays wonderful -strength. When laden with her prey, she always goes afoot, or takes but -very short flights, even under conditions when flight would save her -time and trouble. I will quote an instance taken from my latest -observations on this curious Wasp. - -A Sphex appears unexpectedly, coming I know not whence. She is on foot, -dragging her Ephippiger, a capture which apparently she has made that -moment in the neighbourhood. In the circumstances it behoves her to dig -herself a burrow. The site is as bad as bad can be. It is a well-beaten -path, hard as stone. The Sphex, who has no time to make laborious -excavations, because the already captured prize must be stored as -quickly as possible, the Sphex wants soft ground, wherein the larva’s -chamber can be contrived in one short spell of work. I have described -her favourite soil, namely, the dust of years which has accumulated at -the bottom of some hole in a wall or of some little shelter under the -rocks. Well, the Sphex whom I am now observing stops at the foot of a -house with a newly-whitewashed front some twenty to twenty-five feet -high. Her instinct tells her that up there, under the red tiles of the -roof, she will find nooks rich in old dust. She leaves her prey at the -foot of the house and flies up to the roof. For some time I see her -looking here, there, and everywhere. After finding a proper site, she -begins to work under the curve of a pantile. In ten minutes, or fifteen -at most, the home is ready. The insect now flies down again. The -Ephippiger is promptly found. She has to be taken up. Will this be done -on the wing, as circumstances seem to demand? Not at all. The Sphex -adopts the toilsome method of scaling a perpendicular wall, with a -surface smoothed by the mason’s trowel and measuring twenty to -twenty-five feet in height. Seeing her take this road, dragging the -game between her legs, I at first think the feat impossible; but I am -soon reassured as to the outcome of the bold attempt. Getting a -foothold on the little roughnesses in the mortar, the plucky insect, -despite the hindrance of her heavy load, walks up this vertical plane -with the same assured gait and the same speed as on level ground. The -top is reached without the least accident; and the prey is laid -temporarily on the edge of the roof, upon the rounded back of a tile. -While the digger gives a finishing touch to the burrow, the -badly-balanced prey slips and drops to the foot of the wall. The thing -must be done all over again and once more by laboriously climbing the -height. The same mistake is repeated. Again the prey is incautiously -left on the curved tile, again it slips and again it falls to the -ground. With a composure which accidents such as these cannot disturb, -the Sphex for the third time hoists up the Ephippiger by scaling the -wall and, better advised, drags her forthwith right into the home. - -As even under these conditions no attempt has been made to carry the -prey on the wing, it is clear that the Wasp is incapable of long flight -with so heavy a load. To this incapacity we owe the few characteristics -that form the subject of this chapter. A quarry that is not too big to -permit the effort of flying makes of the Yellow-winged Sphex a -semisocial species, that is to say, one seeking the company of her -fellows; a quarry too heavy to carry through the air makes of the -Languedocian Sphex a species vowed to solitary labour, a sort of savage -disdainful of the pleasures that come from the proximity of one’s kind. -The lighter or heavier weight of the game selected here determines the -fundamental character of the huntress. - - - - - - - - -CHAPTER IX - -THE WISDOM OF INSTINCT - - -To paralyse her prey, the Languedocian Sphex, I have no doubt, pursues -the method of the Cricket-huntress and drives her lancet repeatedly -into the Ephippiger’s breast in order to strike the ganglia of the -thorax. The process of wounding the nerve-centres must be familiar to -her; and I am convinced beforehand of her consummate skill in that -scientific operation. This is an art thoroughly known to all the -Hunting Wasps, who carry a poisoned dart that has not been given them -in vain. At the same time, I must confess that I have never yet -succeeded in witnessing the deadly performance. This omission is due to -the solitary life led by the Languedocian Sphex. - -When a number of burrows are dug on a common site and then provisioned, -one has but to wait on the spot to see now one huntress and now another -arrive with the game which they have caught. It is easy in these -circumstances to try upon the new arrivals the substitution of a live -prey for the doomed victim and to repeat the experiment as often as we -wish. Besides, the certainty that we shall not lack subjects of -observation, as and when wanted, enables us to arrange everything in -advance. With the Languedocian Sphex these conditions of success do not -exist. To set out expressly to look for her, with one’s material -prepared, is almost useless, as the solitary insect is scattered one by -one over vast expanses of ground. Moreover, if you do come upon her, it -will most often be in an idle hour and you will get nothing out of her. -As I said before, it is nearly always unexpectedly, when your thoughts -are elsewhere engaged, that the Sphex appears, dragging her Ephippiger -after her. - -This is the moment, the only propitious moment, to attempt a -substitution of prey and invite the huntress to let you witness her -lancet-thrusts. Quick, let us procure an alternative morsel, a live -Ephippiger! Hurry, time presses: in a few minutes the burrow will have -received the victuals and the glorious occasion will be lost! Must I -speak of my mortification at these moments of good fortune, the mocking -bait held out by chance? Here, before my eyes, is matter for -interesting observations; and I cannot profit by it! I cannot surprise -the Sphex’ secret for the lack of something to offer her in the place -of her prize! Try it for yourself, try setting out in quest of an -alternative piece with only a few minutes at your disposal, when it -took me three days of wild running about before I found Weevils for my -Cerceres! And yet I made the desperate experiment twice over. Ah, if -the keeper had caught me this time, tearing like mad through the -vineyards, what a good opportunity it would have been for crediting me -with robbery and having me up before the magistrate! Vine-branches and -clusters of grapes: not a thing did I respect in my mad rush, hampered -by the trailing shoots. I must have an Ephippiger at all costs, I must -have him that moment. And once I did get my Ephippiger during one of -these frenzied expeditions. I was radiant with joy, never suspecting -the bitter disappointment in store for me. - -If only I arrive in time, if only the Sphex be still engaged in -transport work! Thank heaven, everything is in my favour! The Wasp is -still some distance away from her burrow and still dragging her prize -along. With my forceps I pull gently at it from behind. The huntress -resists, stubbornly clutches the antennæ of her victim and refuses to -let go. I pull harder, even drawing the carter back as well; it makes -no difference: the Sphex does not loose her hold. I have with me a pair -of sharp scissors, belonging to my little entomological case. I use -them and promptly cut the harness-ropes, the Ephippiger’s long antennæ. -The Sphex continues to move ahead, but soon stops, astonished at the -sudden decrease in the weight of the burden which she is trailing, for -this burden is now reduced merely to the two antennæ, snipped off by my -mischievous wiles. The real load, the heavy, pot-bellied insect, -remains behind and is instantly replaced by my live specimen. The Wasp -turns round, lets go the ropes that now draw nothing after them, and -retraces her steps. She comes face to face with the prey substituted -for her own. She examines it, walks round it gingerly, then stops, -moistens her foot with saliva, and begins to wash her eyes. In this -attitude of meditation, can some such thought as the following pass -through her mind: - -‘Come now! Am I awake or am I asleep? Do I know what I am about or do I -not? That thing’s not mine. Who or what is trying to humbug me?’ - -At any rate, the Sphex shows no great hurry to attack my prey with her -mandibles. She keeps away from it and shows not the smallest wish to -seize it. To excite her, I offer the insect to her in my fingers, I -almost thrust the antennæ under her teeth. I know that she does not -suffer from shyness; I know that she will come and take from your -fingers, without hesitation, the prey which you have snatched from her -and afterwards present to her. But what is this? Scorning my offers, -the Sphex retreats instead of snapping up what I place within her -reach. I put down the Ephippiger, who, obeying a thoughtless impulse, -unconscious of danger, goes straight to his assassin. Now we shall see! -Alas, no: the Sphex continues to recoil, like a regular coward, and -ends by flying away. I never saw her again. Thus ended, to my -confusion, an experiment that had filled me with such enthusiasm. - -Later and by degrees, as I inspected an increasing number of burrows, I -came to understand my failure and the obstinate refusal of the Sphex. I -always found the provisions to consist, without a single exception, of -a female Ephippiger, harbouring in her belly a copious and succulent -cluster of eggs. This appears to be the favourite food of the grubs. -Well, in my hurried rush through the vines, I had laid my hands on an -Ephippiger of the other sex. I was offering the Sphex a male. More -far-seeing than I in this important question of provender, the Wasp -would have nothing to say to my game: - -‘A male, indeed! Is that a dinner for my larvæ? What do you take them -for?’ - -What nice discrimination they have, these dainty epicures, who are able -to differentiate between the tender flesh of the female and the -comparatively dry flesh of the males! What an unerring glance, which -can distinguish at once between the two sexes, so much alike in shape -and colour! The female carries a sword at the tip of her abdomen, the -ovipositor wherewith the eggs are buried in the ground; and that is -about the only external difference between her and the male. This -distinguishing feature never escapes the perspicacious Sphex; and that -is why, in my experiment, the Wasp rubbed her eyes, hugely puzzled at -beholding swordless a prey which she well knew carried a sword when she -caught it. What must not have passed through her little Sphex brain at -the sight of this transformation? - -Let us now watch the Wasp when, having prepared the burrow, she goes -back for her victim, which, after its capture and the operation that -paralysed it, she has left at no great distance. The Ephippiger is in a -condition similar to that of the Cricket sacrificed by the -Yellow-winged Sphex, a condition proving for certain that stings have -been driven into her thoracic ganglia. Nevertheless, a good many -movements still continue; but they are disconnected, though endowed -with a certain vigour. Incapable of standing on its legs, the insect -lies on its side or on its back. It flutters its long antennæ and also -its palpi; it opens and closes its mandibles and bites as hard as in -the normal state. The abdomen heaves rapidly and deeply. The ovipositor -is brought back sharply under the belly, against which it almost lies -flat. The legs stir, but languidly and irregularly; the middle legs -seem more torpid than the others. If pricked with a needle, the whole -body shudders convulsively; efforts are made to get up and walk, but -without success. In short, the insect would be full of life, but for -its inability to move about or even to stand upon its legs. We have -here therefore a wholly local paralysis, a paralysis of the legs, or -rather a partial abolition and ataxy of their movements. Can this very -incomplete inertia be caused by some special arrangement of the -victim’s nervous system, or does it come from this, that the Wasp -perhaps administers only a single prick, instead of stinging each -ganglion of the thorax, as the Cricket-huntress does? I cannot tell. - -Still, for all its shivering, its convulsions, its disconnected -movements, the victim is none the less incapable of hurting the larva -that is meant to devour it. I have taken from the burrow of the Sphex -Ephippigers struggling just as lustily as when they were first -half-paralysed; and nevertheless the feeble grub, hatched but a few -hours since, was digging its teeth into the gigantic victim in all -security; the dwarf was biting into the colossus without danger to -itself. This striking result is due to the spot selected by the mother -for laying her egg. I have already said how the Yellow-winged Sphex -glues her egg to the Cricket’s breast, a little to one side, between -the first and second pair of legs. Exactly the same place is chosen by -the White-edged Sphex; and a similar place, a little farther back, -towards the root of one of the large hind-thighs, is adopted by the -Languedocian Sphex, all three thus giving proof, by this uniformity, of -wonderful discernment in picking out the spot where the egg is bound to -be safe. - -Consider the Ephippiger pent in the burrow. She lies stretched upon her -back, absolutely incapable of turning. In vain she struggles, in vain -she writhes: the disordered movements of her legs are lost in space, -the room being too wide to afford them the support of its walls. The -grub cares nothing for the victim’s convulsions: it is at a spot where -naught can reach it, not tarsi, nor mandibles, nor ovipositor, nor -antennæ; a spot absolutely stationary, devoid of so much as a surface -tremor. It is in perfect safety, on the sole condition that the -Ephippiger cannot shift her position, turn over, get upon her feet; and -this one condition is admirably fulfilled. - -But, with several heads of game, all in the same stage of paralysis, -the larva’s danger would be great. Though it would have nothing to fear -from the insect first attacked, because of its position out of the -reach of its victim, it would have every occasion to dread the -proximity of the others, which, stretching their legs at random, might -strike it and rip it open with their spurs. This is perhaps the reason -why the Yellow-winged Sphex, who heaps up three or four Crickets in the -same cell, practically annihilates all movement in its victims, whereas -the Languedocian Sphex, victualling each burrow with a single piece of -game, leaves her Ephippigers the best part of their power of motion and -contents herself with making it impossible for them to change their -position or stand upon their legs. She may thus, though I cannot say so -positively, economize her dagger-thrusts. - -While the only half-paralysed Ephippiger cannot imperil the larva, -fixed on a part of the body where resistance is impossible, the case is -different with the Sphex, who has to cart her prize home. First, having -still, to a great extent, preserved the use of its tarsi, the victim -clutches with these at any blade of grass encountered on the road along -which it is being dragged; and this produces an obstacle to the hauling -process which is difficult to overcome. The Sphex, already heavily -burdened by the weight of her load, is liable to exhaust herself with -her efforts to make the other insect relax its desperate grip in grassy -places. But this is the least serious drawback. The Ephippiger -preserves the complete use of her mandibles, which snap and bite with -their customary vigour. Now what these terrible nippers have in front -of them is just the slender body of the enemy, at a time when she is in -her hauling attitude. The antennæ, in fact, are grasped not far from -their roots, so that the mouth of the victim dragged along on its back -faces either the thorax or the abdomen of the Sphex, who, standing high -on her long legs, takes good care, I am convinced, not to be caught in -the mandibles yawning underneath her. At all events, a moment of -forgetfulness, a slip, the merest trifle can bring her within the reach -of two powerful nippers, which would not neglect the opportunity of -taking a pitiless vengeance. In the more difficult cases at any rate, -if not always, the action of those formidable pincers must be done away -with; and the fish-hooks of the legs must be rendered incapable of -increasing their resistance to the process of transport. - -How will the Sphex go to work to obtain this result? Here man, even the -man of science, would hesitate, would waste his time in barren efforts -and would perhaps abandon all hope of success. He can come and take one -lesson from the Sphex. She, without ever being taught it, without ever -seeing it practised by others, understands her surgery through and -through. She knows the most delicate mysteries of the physiology of the -nerves, or rather she behaves as if she did. She knows that under her -victim’s skull there is a circlet of nervous nuclei, something similar -to the brain of the higher animals. She knows that this main centre of -innervation controls the action of the mouth-parts and moreover is the -seat of the will, without whose orders not a single muscle acts; -lastly, she knows that, by injuring this sort of brain, she will cause -all resistance to cease, the insect no longer possessing any will to -resist. As for the mode of operating, this is the easiest matter in the -world to her; and, when we have been taught in her school, we are free -to try her process in our turn. The instrument employed is no longer -the sting: the insect, in its wisdom, has deemed compression preferable -to a poisoned thrust. Let us accept its decision, for we shall see -presently how prudent it is to be convinced of our own ignorance in the -presence of the animal’s knowledge. Lest by editing my account I should -fail to give a true impression of the sublime talent of this masterly -operator, I here copy out my note as I pencilled it on the spot, -immediately after the stirring spectacle. - -The Sphex finds that her victim is offering too much resistance, -hooking itself here and there to blades of grass. She then stops to -perform upon it the following curious operation, a sort of coup de -grâce. The Wasp, still astride her prey, forces open the articulation -of the neck, high up, at the nape. Then she seizes the neck with her -mandibles and, without making any external wound, probes as far forward -as possible under the skull, so as to seize and chew up the ganglia of -the head. When this operation is done, the victim is utterly -motionless, incapable of the least resistance, whereas previously the -legs, though deprived of the power of connected movement needed for -walking, vigorously opposed the process of traction. - -There is the fact in all its eloquence. With the points of its -mandibles, the insect, while leaving uninjured the thin and supple -membrane of the neck, goes rummaging into the skull and munching the -brain. There is no effusion of blood, no wound, but simply an external -pressure. Of course, I kept for my own purposes the Ephippiger -paralysed before my eyes, in order to ascertain the effects of the -operation at my leisure; also, of course, I hastened to repeat in my -turn, upon live Ephippigers, what the Sphex had just taught me. I will -here compare my results with the Wasp’s. - -Two Ephippigers whose cervical ganglia I squeeze and compress with a -forceps fall rapidly into a state resembling that of the victims of the -Sphex. Only, they grate their cymbals if I tease them with a needle; -and the legs still retain a few disordered and languid movements. The -difference no doubt is due to the fact that my patients were not -previously injured in their thoracic ganglia, as were those of the -Sphex, who were first stung on the breast. Allowing for this important -condition, we see that I was none too bad a pupil and that I imitated -pretty closely my teacher of physiology, the Sphex. I confess it was -not without a certain satisfaction that I succeeded in doing almost as -well as the insect. - -As well? What am I talking about? Wait a bit and you shall see that I -still have much to learn from the Sphex. For what happens is that my -two patients very soon die: I mean, they really die; and, in four or -five days, I have nothing but putrid corpses before my eyes. And the -Wasp’s Ephippiger? I need hardly say that the Wasp’s Ephippiger, even -ten days after the operation, is perfectly fresh, just as she will be -required by the larva for which she has been destined. Nay, more: only -a few hours after the operation under the skull, there reappeared, as -though nothing had occurred, the disorderly movements of the legs, -antennæ, palpi, ovipositor and mandibles; in a word, the insect -returned to the condition wherein it was before the Sphex bit its -brain. And these movements were kept up after, though they became -feebler every day. The Sphex had merely reduced her victim to a passing -state of torpor, lasting amply long enough to enable her to bring it -home without resistance; and I, who thought myself her rival, was but a -clumsy and barbarous butcher: I killed my prize. She, with her -inimitable dexterity, shrewdly compressed the brain to produce a -lethargy of a few hours; I, brutal through ignorance, perhaps crushed -under my forceps that delicate organ, the main seat of life. If -anything could prevent me from blushing at my defeat, it would be the -conviction that very few, if any, could vie with these clever ones in -cleverness. - -Ah, I now understand why the Sphex does not use her sting to injure the -cervical ganglia! A drop of poison injected here, at the centre of -vital force, would destroy the whole nervous system; and death would -follow soon after. But it is not death that the huntress wishes to -obtain; the larvæ have not the least use for dead game, for a corpse, -in short, smelling of corruption; and all that she wants to bring about -is a lethargy, a passing torpor, which will put a stop to the victim’s -resistance during the carting process, this resistance being difficult -to overcome and moreover dangerous for the Sphex. The torpor is -obtained by a method known in laboratories of experimental physiology: -compression of the brain. The Sphex acts like a Flourens, [30] who, -laying bare an animal’s brain and bearing upon the cerebral mass, -forthwith suppresses intelligence, will, sensibility and movement. The -pressure is removed; and everything reappears. Even so do the remains -of the Ephippiger’s life reappear, as the lethargic effects of a -skilfully-directed pressure pass off. The ganglia of the skull, -squeezed between the mandibles but without fatal contusions, gradually -recover their activity and put an end to the general torpor. Admit that -it is all alarmingly scientific. - - - -Fortune has her entomological whims: you run after her and catch no -glimpse of her; you forget about her and behold, she comes tapping at -your door! How vainly I watched and waited, how many useless journeys I -made to see the Languedocian Sphex sacrifice her Ephippigers! Twenty -years pass; these pages are in the printer’s hands; and, one day early -this month, on the 8th of August 1878, my son Emile comes rushing into -my study: - -‘Quick!’ he shouts. ‘Come quick: there’s a Sphex dragging her prey -under the plane-trees, outside the door of the yard!’ - -Emile knew all about the business, from what I had told him, to amuse -him when we used to sit up late, and better still from similar -incidents which he had witnessed in our life out of doors. He is right. -I run out and see a magnificent Languedocian Sphex dragging a paralysed -Ephippiger by the antennæ. She is making for the hen-house close by and -seems anxious to scale the wall, with the object of fixing her burrow -under some tile on the roof; for, a few years ago, in the same place, I -saw a Sphex of the same species accomplish the ascent with her game and -make her home under the arch of a badly-joined tile. Perhaps the -present Wasp is descended from the one who performed that arduous -climb. - -A like feat seems about to be repeated; and this time before numerous -witnesses, for all the family, working under the shade of the -plane-trees, come and form a circle around the Sphex. They wonder at -the unceremonious boldness of the insect, which is not diverted from -its work by a gallery of onlookers; all are struck by its proud and -lusty bearing, as, with raised head and the victim’s antennæ firmly -gripped in its mandibles, it drags the enormous burden after it. I, -alone among the spectators, feel a twinge of regret at the sight: - -‘Ah, if only I had some live Ephippigers!’ I cannot help saying, with -not the least hope of seeing my wish realized. - -‘Live Ephippigers?’ replies Émile. ‘Why, I have some perfectly fresh -ones, caught this morning!’ - -He dashes upstairs, four steps at a time, and runs to his little den, -where a fence of dictionaries encloses a park for the rearing of some -fine caterpillars of the Spurge Hawk-moth. He brings me three -Ephippigers, the best that I could wish for, two females and a male. - -How did these insects come to be at hand, at the moment when they were -wanted, for an experiment tried in vain twenty years ago? That is -another story. A Lesser Grey Shrike had nested in one of the tall -plane-trees of the avenue. Now a few days earlier, the mistral, the -brutal north-west wind of our parts, blew with such violence as to bend -the branches as well as the reeds; and the nest, turned upside down by -the swaying of its support, had dropped its contents, four small birds. -Next morning I found the brood upon the ground; three were killed by -the fall, the fourth was still alive. The survivor was entrusted to the -cares of Émile, who went Cricket-hunting twice a day on the -neighbouring grass-plots for the benefit of his young charge. But -Crickets are small and the nurseling’s appetite called for many of -them. Another dish was preferred, the Ephippiger, of whom a stock was -collected from time to time among the stalks and prickly leaves of the -eryngo. The three insects which Émile brought me came from the Shrike’s -larder. My pity for the fallen nestling had procured me this -unhoped-for success. - -After making the circle of spectators stand back so as to leave the -field clear for the Sphex, I take away her prey with a pair of pincers -and at once give her in exchange one of my Ephippigers, carrying a -sword at the end of her belly, like the game which I have abstracted. -The dispossessed Wasp stamps her feet two or three times; and that is -the only sign of impatience which she gives. She goes for her new prey, -which is too stout, too obese even to try to avoid pursuit, grips it -with her mandibles by the saddle-shaped corselet, gets astride and, -curving her abdomen, slips the end of it under the Ephippiger’s thorax. -Here, no doubt, some stings are administered, though I am unable to -state the number exactly, because of the difficulty of observation. The -Ephippiger, a peaceable victim, suffers herself to be operated on -without resistance; she is like the silly Sheep of our -slaughter-houses. The Sphex takes her time and wields her lancet with a -deliberation which favours accuracy of aim. So far, the observer has -nothing to complain of; but the prey touches the ground with its breast -and belly, and exactly what happens underneath escapes his eye. As for -interfering and lifting the Ephippiger a little, so as to see better, -that must not be thought of: the murderess would resheathe her weapon -and retire. The act that follows is easy to observe. After stabbing the -thorax, the tip of the abdomen appears under the victim’s neck, which -the operator forces open by pressing the nape. At this point the sting -probes with marked persistency, as if the prick administered here were -more effective than elsewhere. One would be inclined to think that the -nerve-centre attacked is the lower part of the œsophageal chain; but -the continuance of movement in the mouth-parts—the mandibles, jaws and -palpi—controlled by this seat of innervation shows that such is not the -case. Through the neck the Sphex reaches simply the ganglia of the -thorax, or at any rate the first of them, which is more easily -accessible through the thin skin of the neck than through the -integuments of the chest. - -And in a moment it is all over. Without the least shiver denoting pain, -the Ephippiger becomes henceforth an inert mass. I remove the Sphex’ -patient for the second time and replace it by the other female at my -disposal. The same proceedings are repeated, followed by the same -result. The Sphex has performed her skilful surgery thrice over, almost -in immediate succession, first with her own prey and then with my -substitutes. Will she do so a fourth time with the male Ephippiger whom -I still have left? I have my doubts, not because the Wasp is tired, but -because the game does not suit her. I have never seen her with any prey -but females, who, crammed with eggs, are the food which the larvæ -appreciate above all others. My suspicion is well founded; deprived of -her capture, the Sphex stubbornly refuses the male whom I offer to her. -She runs hither and thither, with hurried steps, in search of the -vanished game; three or four times she goes up to the Ephippiger, walks -round him, casts a scornful glance at him; and at last she flies away. -He is not what her larvæ want; experiment demonstrates this once again -after an interval of twenty years. - -The three females stabbed, two of them before my eyes, remain in my -possession. In each case all the legs are completely paralysed. Whether -lying naturally, on its belly or on its back or side, the insect -retains indefinitely whatever position we give it. A continued -fluttering of the antennæ, a few intermittent pulsations of the belly, -and the play of the mouth-parts are the only signs of life. Movement is -destroyed but not susceptibility; for, at the least prick administered -to a thin-skinned spot, the whole body gives a slight shudder. Perhaps, -some day, physiology will find in such victims the material for -valuable work on the functions of the nervous system. The Wasp’s sting, -so incomparably skilful at striking a particular point and -administering a wound which affects that point alone, will supplement, -with immense advantage, the experimenter’s brutal scalpel, which rips -open where it ought to give merely a light touch. Meanwhile, here are -the results which I have obtained from the three victims, but in -another direction. - -As only the movement of the legs has been destroyed, without any wound -save that of the nerve-centres, which are the seat of that movement, -the insect must die of inanition and not of its injuries. The -experiment was conducted as follows: two sound and healthy Ephippigers, -just as I picked them up in the fields, were imprisoned without food, -one in the dark, the other in the light. The second died in four days, -the first in five. This difference of a day is easily explained. In the -light, the insect made greater exertions to recover its liberty; and, -as every movement of the animal machine is accompanied by a -corresponding expenditure of energy, a greater sum total of activity -has involved a more rapid consumption of the reserve force of the -organism. In the light, there is more restlessness and a shorter life; -in the dark, less restlessness and a longer life, while no food at all -was taken in either case. - -One of my three stabbed Ephippigers was kept in the dark, fasting. In -her case there were not only the conditions of complete abstinence and -darkness, but also the serious wounds inflicted by the Sphex; and -nevertheless for seventeen days I saw her continually waving her -antennæ. As long as this sort of pendulum keeps on swinging, the clock -of life does not stop. On the eighteenth day the creature ceased its -antennary movements and died. The badly-wounded insect therefore lived, -under the same conditions, four times as long as the insect that was -untouched. What seemed as though it should be a cause of death was -really a cause of life. - -However paradoxical it may seem at first sight, this result is -exceedingly simple. When untouched, the insect exerts itself and -consequently uses up its reserves. When paralysed, it has merely the -feeble, internal movements which are inseparable from any organism; and -its substance is economized in proportion to the weakness of the action -displayed. In the first case, the animal machine is at work and wears -itself out; in the second, it is at rest and saves itself. There being -no nourishment now to repair the waste, the moving insect spends its -nutritive reserves in four days and dies; the motionless insect does -not spend them and lives for eighteen days. Life is a continual -dissolution, the physiologists tell us; and the Sphex’ victims give us -the neatest possible demonstration of the fact. - -One remark more. Fresh food is absolutely necessary for the Wasp’s -larvæ. If the prey were warehoused in the burrow intact, in four or -five days it would be a corpse abandoned to corruption; and the -scarce-hatched grub would find nothing to live upon but a putrid mass. -Pricked with the sting, however, it can keep alive for two or three -weeks, a period more than long enough to allow the egg to hatch and the -larva to grow. The paralysing of the victim therefore has a twofold -result: first, the living dish remains motionless and the safety of the -delicate grub is not endangered; secondly, the meat keeps good a long -time and thus ensures wholesome food for the larva. Man’s logic, -enlightened by science, could discover nothing better. - -My two other Ephippigers stung by the Sphex were kept in the dark with -food. To feed inert insects, hardly differing from corpses except by -the perpetual waving of their long antennæ, seems at first an -impossibility; still, the play of the mouth-parts gave me some hope and -I tried. My success exceeded my anticipations. There was no question -here, of course, of giving them a lettuce-leaf or any other piece of -green stuff on which they might have browsed in their normal state; -they were feeble valetudinarians, who needed spoon-feeding, so to -speak, and supporting with liquid nourishment. I used sugar-and-water. - -Laying the insect on its back, I place a drop of the sugary fluid on -its mouth with a straw. The palpi at once begin to stir; the mandibles -and jaws move. The drop is swallowed with evident satisfaction, -especially after a somewhat prolonged fast. I repeat the dose until it -is refused. The meal takes place once a day, sometimes twice, at -irregular intervals, lest I should become too much of a slave to my -patients. Well, one of the Ephippigers lived for twenty-one days on -this meagre fare. It was not much, compared with the eighteen days of -the one whom I had left to die of starvation. True, the insect had -twice had a bad fall, having dropped from the experimenting-table to -the floor owing to some piece of awkwardness on my part. The bruises -which it received must have hastened its end. The other, which suffered -no accidents, lived for forty days. As the nourishment employed, -sugar-and-water, could not indefinitely take the place of the natural -green food, it is very likely that the insect would have lived longer -still if the usual diet had been possible. And so the point which I had -in view is proved: the victims stung by the Digger-wasps die of -starvation and not of their wounds. - - - - - - - - -CHAPTER X - -THE IGNORANCE OF INSTINCT - - -The Sphex has shown us how infallibly and with what transcendental art -she acts when guided by the unconscious inspiration of her instinct; -she is now going to show us how poor she is in resource, how limited in -intelligence, how illogical even, in circumstances outside of her -regular routine. By a strange inconsistency, characteristic of the -instinctive faculties, profound wisdom is accompanied by an ignorance -no less profound. To instinct nothing is impossible, however great the -difficulty may be. In building her hexagonal cells, with their floors -consisting of three lozenges, the Bee solves with absolute precision -the arduous problem of how to achieve the maximum result at a minimum -cost, a problem whose solution by man would demand a powerful -mathematical mind. The Wasps whose larvæ live on prey display in their -murderous art methods hardly rivalled by those of a man versed in the -intricacies of anatomy and physiology. Nothing is difficult to -instinct, so long as the act is not outside the unvarying cycle of -animal existence; on the other hand, nothing is easy to instinct, if -the act is at all removed from the course usually pursued. The insect -which astounds us, which terrifies us with its extraordinary -intelligence, surprises us, the next moment, with its stupidity, when -confronted with some simple fact that happens to lie outside its -ordinary practice. The Sphex will supply us with a few instances. - -Let us follow her dragging her Ephippiger home. If fortune smile upon -us, we may witness some such little scene as that which I will now -describe. When entering her shelter under the rock, where she has made -her burrow, the Sphex finds, perched on a blade of grass, a Praying -Mantis, a carnivorous insect which hides cannibal habits under a pious -appearance. The danger threatened by this robber ambushed on her path -must be known to the Sphex, for she lets go her game and pluckily -rushes upon the Mantis, to inflict some heavy blows and dislodge her, -or at all events to frighten her and inspire her with respect. The -robber does not move, but closes her lethal machinery, the two terrible -saws of the arm and fore-arm. The Sphex goes back to her capture, -harnesses herself to the antennæ and boldly passes under the blade of -grass whereon the other sits perched. By the direction of her head we -can see that she is on her guard and that she holds the enemy rooted, -motionless, under the menace of her eyes. Her courage meets with the -reward which it deserves: the prey is stored away without further -mishap. - -A word more on the Praying Mantis, or, as they say in Provence, lou -Prégo Diéou, the Pray-to-God. Her long, pale-green wings, like -spreading veils, her head raised heavenwards, her folded arms, crossed -upon her breast, are in fact a sort of travesty of a nun in ecstasy. -And yet she is a ferocious creature, loving carnage. Though not her -favourite spots, the work-yards of the various Digger-wasps receive her -visits pretty frequently. Posted near the burrows, on some bramble or -other, she waits for chance to bring within her reach some of the -arrivals, forming a double capture for her, as she seizes both the -huntress and her prey. Her patience is long put to the test: the Wasp -suspects something and is on her guard; still, from time to time, a -rash one gets caught. With a sudden rustle of wings half-unfurled as by -the violent release of a clutch, the Mantis terrifies the newcomer, who -hesitates for a moment, in her fright. Then, with the sharpness of a -spring, the toothed fore-arm folds back on the toothed upper arm; and -the insect is caught between the blades of the double saw. It is as -though the jaws of a Wolf-trap were closing on the animal that had -nibbled at its bait. Thereupon, without unloosing the cruel machine, -the Mantis gnaws her victim by small mouthfuls. Such are the ecstasies, -the prayers, the mystic meditations of the Prégo Diéou. - -Of the scenes of carnage which the Praying Mantis has left in my -memory, let me relate one. The thing happens in front of a work-yard of -Bee-eating Philanthi. These diggers feed their larvæ on Hive-bees, whom -they catch on the flowers while gathering pollen and honey. If the -Philanthus who has made a capture feels that her Bee is swollen with -honey, she never fails, before storing her, to squeeze her crop, either -on the way or at the entrance of the dwelling, so as to make her -disgorge the delicious syrup, which she drinks by licking the tongue -which her unfortunate victim, in her death-agony, sticks out of her -mouth at full length. This profanation of a dying creature, whose enemy -squeezes its belly to empty it and feast on the contents, has something -so hideous about it that I should denounce the Philanthus as a brutal -murderess, if animals were capable of wrongdoing. At the moment of some -such horrible banquet, I have seen the Wasp, with her prey, seized by -the Mantis: the bandit was rifled by another bandit. And here is an -awful detail: while the Mantis held her transfixed under the points of -the double saw and was already munching her belly, the Wasp continued -to lick the honey of her Bee, unable to relinquish the delicious food -even amid the terrors of death. Let us hasten to cast a veil over these -horrors. - -We will return to the Sphex, with whose burrow we must make ourselves -acquainted before we go further. This burrow is a hole made in fine -sand, or rather in a sort of dust at the bottom of a natural shelter. -Its entrance-passage is very short, merely an inch or two, without a -bend, and leads to a single, roomy, oval chamber. The whole thing is a -rough den, hastily dug out, rather than a leisurely and artistically -excavated dwelling. I have explained that the reason for this -simplicity is that the game is captured first and set down for a moment -on the hunting-field while the Wasp hurriedly makes a burrow in the -vicinity, a method of procedure which allows of but one chamber or cell -to each retreat. For who can tell whither the chances of the day will -lead the huntress for her second capture? The prisoner is heavy and the -burrow must therefore be near; so to-day’s home, which is too far away -for the next Ephippiger to be conveyed to it, cannot be utilized -to-morrow. Thus, as each prey is caught, there is a fresh excavation, a -fresh burrow, with its single chamber, now here, now there. Having said -this, we will try a few experiments to see how the insect behaves when -we create circumstances new to it. - - - -EXPERIMENT I - -A Sphex, dragging her prey along, is a few inches from the burrow. -Without disturbing her, I cut with a pair of scissors the Ephippiger’s -antennæ, which the Wasp, as we know, uses for harness-ropes. On -recovering from the surprise caused by the sudden lightening of her -load, the Sphex goes back to her victim and, without hesitation, now -seizes the root of the antenna, the short stump left by the scissors. -It is very short indeed, hardly a millimetre; [31] no matter: it is -enough for the Sphex, who grips this fag-end of a rope and resumes her -hauling. With the greatest precaution, so as not to injure the Wasp, I -now cut the two antennary stumps level with the skull. Finding nothing -left to catch hold of at the familiar points, the insect seizes, close -by, one of the victim’s long palpi and continues its hauling-work, -without appearing at all perturbed by this change in the harness. I -leave it alone. The prey is brought home and placed so that its head -faces the entrance to the burrow; and the Wasp goes in by herself, to -make a brief inspection of the inside of the cell before proceeding to -warehouse the provisions. Her behaviour reminds us of that of the -Yellow-winged Sphex in similar circumstances. I take advantage of this -short moment to seize the abandoned prey, remove all its palpi and -place it a little farther off, about half a yard from the burrow. The -Sphex reappears and goes straight to her captive, whom she has seen -from her threshold. She looks at the top of the head, she looks -underneath, on either side, and finds nothing to take hold of. A -desperate attempt is made: the Wasp, opening wide her mandibles, tries -to grab the Ephippiger by the head; but the pincers have not a -sufficient compass to take in so large a bulk and they slip off the -round, polished skull. She makes several fresh endeavours, each time -without result. She is at length convinced of the uselessness of her -efforts. She draws back a little to one side and appears to be -renouncing further attempts. One would say that she was discouraged; at -least, she smooths her wings with her hind-legs, while with her front -tarsi, which she first puts into her mouth, she washes her eyes. This, -so it has always seemed to me, is a sign in Hymenoptera of giving up a -job. - -Nevertheless there is no lack of parts by which the Ephippiger might be -seized and dragged along as easily as by the antennæ and the palpi. -There are the six legs, there is the ovipositor: all organs slender -enough to be gripped boldly and to serve as hauling-ropes. I agree that -the easiest way to effect the storing is to introduce the prey head -first, drawn down by the antennæ; but it would enter almost as readily -if drawn by a leg, especially one of the front legs, for the orifice is -wide and the passage short or sometimes even non-existent. Then how is -it that the Sphex did not once try to seize one of the six tarsi or the -tip of the ovipositor, whereas she attempted the impossible, the -absurd, in striving to grip, with her much too short mandibles, the -huge skull of her prey? Can it be that the idea did not occur to her? -Then we will try to suggest it. - -I offer her, right under her mandibles, first a leg, next the end of -the abdominal rapier. The insect obstinately refuses to bite; my -repeated blandishments lead to nothing. A singular huntress, to be -embarrassed by her game, not knowing how to seize it by a leg when she -is not able to take it by the horns! Perhaps my prolonged presence and -the unusual events that have just occurred have disturbed her -faculties. Then let us leave the Sphex to herself, between her -Ephippiger and her burrow; let us give her time to collect herself and, -in the calm of solitude, to think out some way of managing her -business. I leave her therefore and continue my walk; and, two hours -later, I return to the same place. The Sphex is gone, the burrow is -still open, and the Ephippiger is lying just where I placed her. -Conclusion: the Wasp has tried nothing; she went away, abandoning -everything, her home and her game, when, to utilize them both, all that -she had to do was to take her prey by one leg. And so this rival of -Flourens, who but now was startling us with her cleverness as she -dexterously squeezed her victim’s brain to produce lethargy, becomes -incredibly helpless in the simplest case outside her usual habits. She, -who so well knows how to attack a victim’s thoracic ganglia with her -sting and its cervical ganglia with her mandibles; she, who makes such -a judicious difference between a poisoned prick annihilating the vital -influence of the nerves for ever and a pressure causing only momentary -torpor, cannot grip her prey by this part when it is made impossible -for her to grip it by any other. To understand that she can take a leg -instead of an antenna is utterly beyond her powers. She must have the -antenna, or some other string attached to the head, such as one of the -palpi. If these cords did not exist, her race would perish, for lack of -the capacity to solve this trivial problem. - - - -EXPERIMENT II - -The Wasp is engaged in closing her burrow, where the prey has been -stored and the egg laid upon it. With her front tarsi she brushes her -doorstep, working backwards and sweeping into the entrance a stream of -dust which passes under her belly and spurts behind in a parabolic -spray as continuous as a liquid spray, so nimble is the sweeper in her -actions. From time to time the Sphex picks out with her mandibles a few -grains of sand, so many solid blocks which she inserts one by one into -the mass of dust, causing it all to cake together by beating and -compressing it with her forehead and mandibles. Walled up by this -masonry, the entrance-door soon disappears from sight. - -I intervene in the middle of the work. Pushing the Sphex aside, I -carefully clear the short gallery with the blade of a knife, take away -the materials that close it and restore full communication between the -cell and the outside. Then, with my forceps, without damaging the -edifice, I take the Ephippiger from the cell, where she lies with her -head at the back and her ovipositor towards the entrance. The Wasp’s -egg is on the victim’s breast, at the usual place, the root of one of -the hinder thighs: a proof that the Sphex was giving the finishing -touch to the burrow, with the intention of never returning. - -Having done this and put the stolen prey safely away in a box, I yield -my place to the Sphex, who has been on the watch beside me while I was -rifling her home. Finding the door open, she goes in and stays for a -few moments. Then she comes out and resumes her work where I -interrupted it, that is to say, she starts conscientiously stopping the -entrance to the cell by sweeping dust backwards and carrying grains of -sand, which she continues to heap up with scrupulous care, as though -she were doing useful work. When the door is once again thoroughly -walled up, the insect brushes itself, seems to give a glance of -satisfaction at the task accomplished, and finally flies away. - -The Sphex must have known that the burrow contained nothing, because -she went inside and even stayed there for some time; and yet, after -this inspection of the pillaged abode, she once more proceeds to close -up the cell with the same care as though nothing out of the way had -happened. Can she be proposing to use this burrow later, to return to -it with a fresh victim and lay a new egg there? If so, her work of -closing would be intended to prevent the access of intruders to the -dwelling during her absence; it would be a measure of prudence against -the attempts of other diggers who might covet the ready-made chamber; -it might also be a wise precaution against internal dilapidations. And, -as a matter of fact, some Hunting Wasps do take care to protect the -entrance to the burrow by closing it temporarily, when the work has to -be suspended for a time. Thus I have seen certain Ammophilæ, whose -burrow is a perpendicular shaft, block the entrance to the home with a -small flat stone when the insect goes off hunting or ceases its mining -operations at sunset, the hour for striking work. But this is a slight -affair, a mere slab laid over the mouth of the shaft. When the insect -comes, it only takes a moment to remove the little flat stone; and the -entrance is free. - -On the other hand, the obstruction which we have just seen built by the -Sphex is a solid barrier, a stout piece of masonry, where dust and -gravel form alternate layers all the way down the passage. It is a -definite performance and not a provisional defence, as is proved by the -care with which it is constructed. Besides, as I think I have shown -pretty clearly, it is very doubtful, considering the way in which she -acts, whether the Sphex will ever return to make use of the home which -she has prepared. The next Ephippiger will be caught elsewhere; and the -warehouse destined to receive her will be dug elsewhere too. But these, -after all, are only arguments: let us rather have recourse to -experiment, which is more conclusive here than logic. - -I allowed nearly a week to elapse, in order to give the Sphex time to -return to the burrow which she had so methodically closed and to make -use of it for her next laying if such were her intention. Events -corresponded with the logical inferences: the burrow was in the -condition wherein I left it, still firmly closed, but without -provisions, egg or larva. The proof was decisive: the Wasp had not been -back. - -So the plundered Sphex enters her house, makes a leisurely inspection -of the empty chamber, and, a moment afterwards, behaves as though she -had not perceived the disappearance of the bulky prey which but now -filled the cell. Did she, in fact, fail to notice the absence of the -provisions and the egg? Is she, who is so clear-sighted in her -murderous proceedings, dense enough not to realize that the cell is -empty? I dare not accuse her of such stupidity. She is aware of it. But -then why that other piece of stupidity which makes her close—and very -conscientiously close—an empty burrow, one which she does not purpose -to victual later? Here the work of closing is useless, is supremely -absurd; no matter: the insect performs it with the same ardour as -though the larva’s future depended on it. The insect’s various -instinctive actions are then fatally linked together. Because one thing -has been done, a second thing must inevitably be done to complete the -first or to prepare the way for its completion; and the two acts depend -so closely upon each other that the performing of the first entails -that of the second, even when, owing to casual circumstances, the -second has become not only inopportune but sometimes actually opposed -to the insect’s interests. What object can the Sphex have in blocking -up a burrow which has become useless, now that it no longer contains -the victim and the egg, and which will always remain useless, since the -insect will not return to it? The only way to explain this inconsequent -action is to look upon it as the inevitable complement of the actions -that went before. In the normal order of things, the Sphex hunts down -her prey, lays an egg and closes her burrow. The hunting has been done; -the game, it is true, has been withdrawn by me from the cell; never -mind: the hunting has been done, the egg has been laid; and now comes -the business of closing up the home. This is what the insect does, -without another thought, without in the least suspecting the futility -of her present labours. - - - -EXPERIMENT III - -To know everything and to know nothing, according as it acts under -normal or exceptional conditions: that is the strange antithesis -presented by the insect race. Other examples, also drawn from the Sphex -tribe, will confirm this conclusion. The White-edged Sphex (S. -albisecta) attacks medium-sized Locusts, whereof the different species -to be found in the neighbourhood of the burrow all furnish her with -their tribute of victims. Because of the abundance of these Acridians, -there is no need to go hunting far afield. When the burrow, which takes -the form of a perpendicular shaft, is ready, the Sphex merely explores -the purlieus of her lair, within a small radius, and is not long in -finding some Locust browsing in the sunshine. To pounce upon her and -sting her, despite her kicking, is to the Sphex the matter of a moment. -After some fluttering of its wings, which unfurl their carmine or azure -fan, after some drowsy stretching of its legs, the victim ceases to -move. It has now to be brought home, on foot. For this laborious -operation the Sphex employs the same method as her kinswomen, that is -to say, she drags her prize along between her legs, holding one of its -antennæ in her mandibles. If she encounters some grassy jungle, she -goes hopping and flitting from blade to blade, without ever letting -slip her prey. When at last she comes within a few feet of her -dwelling, she performs a manœuvre which is also practised by the -Languedocian Sphex; but she does not attach as much importance to it, -for she frequently neglects it. Leaving her captive on the road, the -Wasp hurries home, though no apparent danger threatens her abode, and -puts her head through the entrance several times, even going part of -the way down the burrow. She next returns to the Locust and, after -bringing her nearer the goal, leaves her a second time to revisit the -burrow. This performance is repeated over and over again, always with -the same anxious haste. - -These visits are sometimes followed by grievous accidents. The victim, -rashly abandoned on hilly ground, rolls to the bottom of the slope; and -the Sphex on her return, no longer finding it where she left it, is -obliged to seek for it, sometimes fruitlessly. If she find it, she must -renew a toilsome climb, which does not prevent her from once more -abandoning her booty on the same unlucky declivity. Of these repeated -visits to the mouth of the shaft, the first can be very logically -explained. The Wasp, before arriving with her heavy burden, inquires -whether the entrance to the home be really clear, whether nothing will -hinder her from bringing in her game. But, once this first -reconnaissance is made, what can be the use of the rest, following one -after the other, at close intervals? Is the Sphex so volatile in her -ideas that she forgets the visit which she has just paid and runs -afresh to the burrow a moment later, only to forget this new inspection -also and to start doing the same thing over and over again? That would -be a memory with very fleeting recollections, whence the impression -vanished almost as soon as it was produced. Let us not linger too long -on this obscure point. - -At last the game is brought to the brink of the shaft, with its antennæ -hanging down the hole. We now again see, faithfully imitated, the -method employed in the like case by the Yellow-winged Sphex and also, -but under less striking conditions, by the Languedocian Sphex. The Wasp -enters alone, inspects the interior, reappears at the entrance, lays -hold of the antennæ and drags the Locust down. While the -Locust-huntress was making her examination of the home, I have pushed -her prize a little farther back; and I obtained results similar in all -respects to those which the Cricket-huntress gave me. Each Sphex -displays the same obstinacy in diving down her burrow before dragging -in the prey. Let us recall here that the Yellow-winged Sphex does not -always allow herself to be caught by this trick of pulling away her -Cricket. There are picked tribes, strong-minded families which, after a -few disappointments, see through the experimenter’s wiles and know how -to baffle them. But these revolutionaries, fit subjects for progress, -are the minority; the remainder, mulish conservatives clinging to the -old manners and customs, are the majority, the crowd. I am unable to -say whether the Locust-huntress also varies in ingenuity according to -the district which she hails from. - -But here is something more remarkable; and it is this with which I -wanted to conclude the present experiment. After repeatedly withdrawing -the White-edged Sphex’ prize from the mouth of the pit and compelling -her to come and fetch it again, I take advantage of her descent to the -bottom of the shaft to seize the prey and put it in a place of safety -where she cannot find it. The Sphex comes up, looks about for a long -time and, when she is convinced that the prey is really lost, goes down -into her home again. A few moments after, she reappears. Is it with the -intention of resuming the chase? Not the least in the world: the Sphex -begins to stop up the burrow. And what we see is not a temporary -closing, effected with a small flat stone, a slab covering the mouth of -the well; it is a final closing, carefully done with dust and gravel -swept into the passage until it is filled up. The White-edged Sphex -makes only one cell at the bottom of her shaft and puts one head of -game into this cell. That single Locust has been caught and dragged to -the edge of the hole. If she was not stored away, it was not the -huntress’s fault, but mine. The Wasp performed her task according to -the inflexible rule; and, also according to the inflexible rule, she -completes her work by stopping up the dwelling, empty though it be. We -have here an exact repetition of the useless exertions made by the -Languedocian Sphex whose home has just been plundered. - - - -EXPERIMENT IV - -It is almost impossible to make certain whether the Yellow-winged -Sphex, who constructs several cells at the end of the same passage and -stacks several Crickets in each, is equally illogical when accidentally -disturbed in her proceedings. A cell can be closed though empty or -imperfectly victualled, and the Wasp will none the less continue to -come to the same burrow in order to work at the others. Nevertheless, I -have reason to believe that this Sphex is subject to the same -aberrations as her two kinswomen. My conviction is based on the -following facts: the number of Crickets found in the cells, when all -the work is done, is usually four to each cell, although it is not -uncommon to find only three, or even two. Four appears to me to be the -normal number, first, because it is the most frequent and, secondly, -because, when rearing young larvæ dug up while they were still engaged -on their first joint, I found that all of them, those actually provided -with only two or three pieces of game as well as those which had four, -easily managed the various Crickets wherewith I served them one by one, -up to and including the fourth, but that after this they refused all -nourishment, or barely touched the fifth ration. If four Crickets are -necessary to the larva to acquire the full development called for by -its organization, why are sometimes only three, sometimes only two -provided for it? Why this enormous difference in the quantity of the -victuals, some larvæ having twice as much as the others? It cannot be -because of any difference in the size of the dishes provided to satisfy -the grub’s appetite, for all have very much the same dimensions; and it -can therefore be due only to the wastage of game on the way. We find, -in fact, at the foot of the banks whose upper stages are occupied by -the Sphex-wasps, Crickets that have been paralysed but lost, owing to -the slope of the ground, down which they have slipped when the -huntresses have momentarily left them, for some reason or other. These -Crickets fall a prey to the Ants and Flies; and the Sphex-wasps who -come across them take good care not to pick them up, for, if they did, -they would themselves be admitting enemies into the house. - -These facts seem to me to prove that, while the Yellow-winged Sphex’ -arithmetical powers enable her to calculate exactly how many victims to -capture, she cannot achieve a census of those which have safely reached -their destination. It is as though the insect had no mathematical guide -beyond an irresistible impulse that prompts her to hunt for game a -definite number of times. When the Sphex has made the requisite number -of journeys, when she has done her utmost to store the captures that -result from these, her work is ended; and she closes the cell whether -completely or incompletely provisioned. Nature has endowed her with -only those faculties called for in ordinary circumstances by the -interests of her larvæ; and, as these blind faculties, which cannot be -modified by experience, are sufficient for the preservation of the -race, the insect is unable to go beyond them. - -I conclude therefore as I began: instinct knows everything, in the -undeviating paths marked out for it; it knows nothing, outside those -paths. The sublime inspirations of science and the astounding -inconsistencies of stupidity are both its portion, according as the -insect acts under normal or accidental conditions. - - - - - - - - -CHAPTER XI - -AN ASCENT OF MONT VENTOUX - - -Thanks to its isolated position, which leaves it freely exposed on -every side to atmospheric influence; thanks also to its height, which -makes it the topmost point of France within the frontiers of either the -Alps or Pyrenees, our bare Provençal mountain, Mont Ventoux, lends -itself remarkably well to the study of the climatic distribution of -plants. At its base the tender olive thrives, with all that multitude -of semiligneous plants, such as the thyme, whose aromatic fragrance -calls for the sun of the Mediterranean regions; on the summit, mantled -with snow for at least half the year, the ground is covered with a -northern flora, borrowed to some extent from arctic shores. Half a -day’s journey in an upward direction brings before our eyes a -succession of the chief vegetable types which we should find in the -course of a long voyage from south to north along the same meridian. At -the start, your feet tread the scented tufts of the thyme that forms a -continuous carpet on the lower slopes; in a few hours they will be -treading the dark hassocks of the opposite-leaved saxifrage, the first -plant to greet the botanist who lands on the coast of Spitzbergen in -July. Below, in the hedges, you have picked the scarlet flowers of the -pomegranate, a lover of African skies; above you will pick a shaggy -little poppy, which shelters its stalks under a coverlet of tiny -fragments of stone and unfolds its spreading yellow corolla as readily -in the icy solitudes of Greenland and the North Cape as on the upper -slopes of the Ventoux. - -These contrasts have always something fresh and stimulating about them; -and, after twenty-five ascents, they still retain their interest for -me. I made my twenty-third in August 1865. There were eight of us: -three whose chief object was to botanize and five attracted by a -mountain expedition and the panorama of the heights. Not one of our -five companions who were not interested in the study of plants has -since expressed a desire to accompany me a second time. The fact is -that the climb is a hard and tiring one; and the sight of a sunrise -does not make up for the fatigue endured. - -One might best compare the Ventoux with a heap of stones broken up for -road-mending purposes. Raise this heap suddenly to a height of a mile -and a quarter, increase its base in proportion, cover the white of the -limestone with the black patch of the forests, and you have a clear -idea of the general aspect of the mountain. This accumulation of -rubbish—sometimes small chips, sometimes huge blocks—rises from the -plain without preliminary slopes or successive terraces that would -render the ascent less arduous by dividing it into stages. The climb -begins at once by rocky paths, the best of which is worse than the -surface of a road newly strewn with stones, and continues, becoming -ever rougher and rougher, right to the summit, the height of which is -6270 feet. Greenswards, babbling brooks, the spacious shade of -venerable trees, all the things, in short, that lend such charm to -other mountains, are here unknown and are replaced by an interminable -bed of limestone broken into scales, which slip under our feet with a -sharp, almost metallic ‘click.’ By way of cascades the Ventoux has -rills of stones; the rattle of falling rocks takes the place of the -whispering waters. - -We are at Bédoin, at the foot of the mountain. The arrangements with -the guide have been made, the hour of the start fixed; the provisions -are being talked over and got ready. Let us try to rest, for we shall -have to spend a sleepless night on the mountain to-morrow. But sleeping -is just the difficulty; I have never managed it and that is where the -chief cause of fatigue lies. I would therefore advise those of my -readers who think of making a botanizing ascent of the Ventoux not to -arrive at Bédoin on a Sunday evening. They will thus avoid the noisy -bustle of an inn with a café attached to it, those endless loud-voiced -conversations, those echoing cannons of the billiard-balls, the ringing -of glasses, the drinking-songs, the ditties of nocturnal wayfarers, the -bellowing of the brass band at the ball hard by, and the other -tribulations inseparable from this blessed day of idleness and -jollification. Will they obtain a better rest on a week-day? I hope so, -but I do not guarantee it. For my part, I did not close an eye. All -night long, the rusty spit, working to provide us with food, creaked -and groaned under my bedroom. A thin board was all that separated me -from that machine of the devil. - -But already the sky is growing light. A donkey brays beneath the -windows. It is time to get up. We might as well not have gone to bed. -Foodstuffs and baggage are strapped on; and, with a ‘Ja! Hi!’ from the -guide, we are off. It is four o’clock in the morning. At the head of -the caravan walks Triboulet, with his Mule and his Ass: Triboulet, the -Nestor of the Ventoux guides. My botanical colleagues inspect the -vegetation on either side of the road by the cold light of the dawn; -the others talk. I follow the party with a barometer slung from my -shoulder and a note-book and pencil in my hand. - -My barometer, intended for taking the altitude of the principal -botanical halts, soon becomes a pretext for attacks on the gourd with -the rum. No sooner is a noteworthy plant observed than somebody cries: - -‘Quick, let’s look at the barometer!’ - -And we all crowd around the gourd, the scientific instrument coming -later. The coolness of the morning and our walk make us appreciate -these references to the barometer so thoroughly that the level of the -stimulant falls even more swiftly than that of the mercury. In the -interests of the immediate future, I must consult Torricelli’s tube a -little less often. - -As the temperature grows too cold for them, first the oak and the ilex -disappear by degrees; then the vine and the almond-tree; and next the -mulberry, the walnut-tree and the white oak. Box becomes plentiful. We -enter upon a monotonous region extending from the end of the cultivated -fields to the lower boundary of the beech-woods, where the predominant -plant is Satureia montana, the winter savory, known here by its popular -name of pébré d’asé, Ass’s pepper, because of the acrid flavour of its -tiny leaves, impregnated with essential oil. Certain small cheeses -forming part of our stores are powdered with this strong spice. Already -more than one of us is biting into them in imagination and casting -hungry glances at the provision-bags carried by the Mule. Our hard -morning exercise has brought appetite and more than appetite, a -devouring hunger, what Horace calls latrans stomachus. I teach my -colleagues how to stay this rumbling stomach until they reach the next -halt; I show them a little sorrel-plant, with arrow-head leaves, the -Rumex scutatus, or French sorrel; and, practising what I preach, I pick -a mouthful. At first they laugh at my suggestion. I let them laugh and -soon see them all occupied, each more eagerly than his fellow, in -plucking the precious sorrel. - -While chewing the bitter leaves, we come to the beeches. These are -first big, solitary bushes, trailing on the ground; soon after, dwarf -trees, clustering close together; and, finally, mighty trunks, forming -a dense and gloomy forest, whose soil is a mass of rough limestone -blocks. Bowed down in winter by the weight of the snow, battered all -the year round by the fierce gusts of the mistral, many of the trees -have lost their branches and are twisted into grotesque positions, or -even lie flat on the ground. An hour or more is spent in crossing this -wooded zone, which from a distance shows against the sides of the -Ventoux like a black belt. Then once more the beeches become bushy and -scattered. We have reached their upper boundary and, to the great -relief of all of us, despite the sorrel-leaves, we have also reached -the stopping-place selected for our lunch. - -We are at the source of the Grave, a slender stream of water caught, as -it bubbles from the ground, in a series of long beech-trunk troughs, -where the mountain shepherds come to water their flocks. The -temperature of the spring is 45° F.; and its coolness is a priceless -boon for us who have come from the sultry oven of the plain. The cloth -is spread on a charming carpet of Alpine plants, with glittering among -them the thyme-leaved paronychia, whose wide, thin bracts look like -silver scales. The food is taken out of the bags, the bottles extracted -from their bed of hay. On this side are the joints, the legs of mutton -stuffed with garlic, the stacks of loaves; on that, the tasteless -chickens, for our grinders to toy with presently, when the edge has -been taken off our appetite. At no great distance, set in a place of -honour, are the Ventoux cheeses spiced with winter savory, the little -pébré d’asé cheeses, flanked by Aries sausages, whose pink flesh is -mottled with cubes of bacon and whole pepper-corns. Over here, in this -corner, are green olives still dripping with brine and black olives -soaking in oil; in that other, Cavaillon melons, some white, some -orange, to suit every taste; and, down there, a jar of anchovies which -make you drink hard and so keep your strength up. Lastly, the bottles -are cooling in the ice-cold water of the trough over there. Have we -forgotten anything? Yes, we have not mentioned the crowning side-dish, -the onions, to be eaten raw with salt. Our two Parisians—for we have -two among us, my fellow-botanists—are at first a little startled by -this very invigorating bill of fare; soon they will be the first to -burst into praises. Are we all ready? Then let us sit down. - -And now begins one of those Homeric repasts which mark red-letter days -in one’s life. The first mouthfuls are almost frenzied. Slices of -mutton and chunks of bread follow one another with alarming rapidity. -Each of us, without communicating his apprehensions to the others, -casts an anxious glance at the victuals and asks himself: - -‘If this is the way we are going on, shall we have enough for to-night -and to-morrow?’ - -However, the craving is allayed; we began by devouring in silence, we -now eat and talk. Our apprehensions for the morrow are likewise -relieved; and we give due credit to the man who ordered the menu, who -foresaw this hunger-fit and who arranged to cope with it worthily. The -time has come for us to appreciate the victuals as connoisseurs. One -praises the olives, stabbing them one by one with the point of his -knife; another lauds the anchovies as he cuts up the little -ochre-coloured fishes on his bread; a third waxes enthusiastic about -the sausage; and all with one accord extol the pébré d’asé cheeses, no -larger than the palm of a man’s hand. Pipes and cigars are lit; and we -stretch ourselves on our backs in the grass, with the sun shining down -upon us. - -An hour’s rest and we are off again, for time presses. The guide with -the baggage will go alone, towards the west, skirting the edge of the -woods, which has a Mule-path. He will wait for us at the Jas, or -Bâtiment, on the upper boundary of the beeches, some 5000 feet above -the level of the sea. The Jas is a large stone hut, which is to shelter -us, man and beast, to-night. As for us, we continue the ascent to the -ridge, by following which we shall reach the highest peak more easily. -From the top, after sunset, we shall go down to the Jas, where the -guide will have arrived long before us. This is the plan proposed and -adopted. - -We reach the crested ridge. On the south, the comparatively easy slopes -which we have just climbed stretch as far as the eye can see; on the -north, the scene is full of wild grandeur: the mountain, sometimes hewn -perpendicularly, sometimes carved into rough steps, alarmingly steep, -is little else than a sheer precipice a mile high. If you throw a -stone, it never stops, but falls from rock to rock until it reaches the -bottom of the valley, where you can distinguish the bed of the -Toulourenc looking like a ribbon. While my companions loosen masses of -rock and send them rolling into the abyss so that they may watch the -frightful fall, I discover under a broad flat stone one of my old -insect acquaintances, the Hairy Ammophila, whom I had always met by -herself on the roadside banks in the plain, whereas here, almost at the -top of the Ventoux, I find her to the number of several hundreds heaped -up under one and the same shelter. - -I was beginning to investigate the reasons for this agglomeration, when -the southerly breeze, which already during the morning had inspired us -with a few vague fears, suddenly brought up a cohort of clouds which -melted into rain. Before we knew it, we were shrouded in a thick, -drizzling mist, which prevented us from seeing two yards in front of -us. By an unfortunate coincidence, one of us, my good friend Delacour, -had strayed aside in search of Euphorbia saxitalis, one of the -botanical curiosities of these heights. Making a speaking-trumpet of -our hands, we shouted as one man. No answer came. Our voices were lost -in the flaky thickness and the dull sound of the whirling mist. As the -wanderer could not hear us, we had to look for him. In the darkness it -was impossible to see one another at a distance of two or three yards; -and I was the only one of the seven to know the locality. So that -nobody might be left in the lurch, we took hands and I placed myself at -the head of the chain. For some minutes we played a regular game of -blind-man’s-buff, leading to nothing. No doubt, on seeing the clouds -drift up, Delacour, who knew the Ventoux, had taken advantage of the -last gleams of light to hasten to the shelter of the Jas. We resolved -to make for it ourselves as quickly as possible, for already our -clothes were streaming with rain inside as well as out. Our white-duck -trousers were sticking to us like a second skin. - -A serious difficulty arose: the hurrying backwards and forwards, the -twisting and turning, while we looked about us, had reduced me to the -plight of a person whose eyes are bandaged and who is then made to spin -round on his heels. I had lost all sense of direction; I had not the -least idea which was the southern slope. I questioned this man and -that; opinions were divided and most uncertain. The upshot was that not -one of us could say where the north lay and where the south. Never in -all my life had I realized the value of the points of the compass as I -did at that moment. All around us was the mystery of the grey haze; -beneath our feet we could just make out the beginning of a slope here -and a slope there. But which was the right one? We had to make a choice -and to launch out boldly. If, by bad luck, we went down the northern -slope, we risked breaking our bones over the precipices the sight of -which had but now filled us with dread. Perhaps not one of us would -survive it. I passed a few minutes of acute perplexity. - -‘Let’s stay here,’ said the majority, ‘and wait till the rain stops.’ - -‘That’s bad advice,’ replied the others, of whom I was one, ‘that’s bad -advice: the rain may last a long while; and, wet through as we are, we -shall freeze on the spot at the first chill of night.’ - -My worthy friend Bernard Verlot, who had come from the Paris Jardin des -Plantes on purpose to climb the Ventoux in my company, displayed an -imperturbable calmness, trusting to my good sense to get us out of our -scrape. I drew him a little to one side, in order not to increase the -panic of the others, and revealed my terrible fears to him. We held a -council of two and tried to make up by the compass of reasoning for the -absence of the magnetic needle. - -‘When the clouds came,’ I asked him, ‘wasn’t it from the south?’ - -‘From the south, certainly.’ - -‘And, though one could hardly perceive the wind, the rain slanted -slightly from south to north?’ - -‘Yes, I noticed that as long as I could see anything. Isn’t that enough -to tell us the way? Let us go down on the side from which the rain -comes.’ - -‘I thought of that, but I have my doubts. The wind is not strong enough -to have a definite direction. It may be an eddying breeze, as happens -on a mountain-top surrounded by clouds. There is nothing to tell me -that the direction is still the same and that the wind is not now -blowing from the north.’ - -‘I have my doubts also. Then what shall we do?’ - -‘What shall we do? That’s the difficulty! But look here: if the wind -has not changed, we ought to be wetter on the left, because we got the -rain on that side until we lost our bearings. If it has changed, we -must be more or less equally wet all over. Let us feel ourselves and -decide. Will that do?’ - -‘Yes.’ - -‘And suppose I’m wrong?’ - -‘You’re not wrong.’ - -The matter was explained to our companions in a few words. All felt -themselves, not outside, which would not have been enough, but right -inside their underclothing, and it was with unspeakable relief that I -heard them unanimously declare their left side to be much wetter than -the right. The wind had not changed. All was well; and we determined to -go towards the rain. The chain was formed once more, with myself at the -head and Verlot in the rear, so as to leave no stragglers behind. -Before starting, I asked my friend, for the last time: - -‘Well, shall we risk it?’ - -‘Yes, let’s risk it; I’ll follow you.’ - -And we plunged blindly into the formidable unknown. - -We had not taken twenty strides, twenty of those strides which one is -not able to control on a steep slope, before all fear of danger was -over. Under our feet was not the empty space of the abyss but the -longed-for ground, the ground covered with small stones, which rolled -down in long torrents. To all of us, this rattling sound, denoting a -firm footing, was heavenly music. In a few minutes we reached the upper -edge of the beeches. Here the darkness was even greater than at the top -of the mountain: we had to stoop to the ground to see where we were -walking. How, in the gloom, were we to find the Jas, buried away in the -dense wood? Two plants, the assiduous haunters of places frequented by -man—the Chenopodium bonus-Henricus, or good-king-Henry, and the common -nettle—served me as a clue. I swept my free hand through the air as I -went along. Each sting that I felt told me of a nettle, in other words, -a landmark. Verlot, in the rear, also lunged about as best he could and -let smarting stings make up for the lack of vision. Our companions had -but little faith in this style of reconnoitring. They spoke of -continuing the furious descent, of going back, if necessary, all the -way to Bédoin. Verlot, more trustful of the botanical insight with -which he himself was so richly endowed, joined me in pursuing our -search, in reassuring the more demoralized and in showing them that it -was possible, by questioning the plants with our hands, to reach our -night’s lodging in spite of the darkness. They gave way to our -arguments; and, not long after, pressing on from one clump of nettles -to another, our party arrived at the Jas. - -There we found Delacour, as well as the guide with our luggage, -sheltered betimes from the rain. A blazing fire and a change of clothes -soon restored our wonted cheerfulness. A block of snow, brought from -the valley near by, was hung in a bag in front of the hearth. A bottle -caught the water as the snow melted: this was the cistern for our -evening meal. And the night was spent on a bed of beech-leaves, rubbed -into powder by our predecessors; and they were numerous. Who knows how -many years had passed since that mattress, now a vegetable mould, was -last renewed! - -Those who could not sleep were told off to keep up the fire. There was -no lack of hands to stir it, for the smoke, which had no other outlet -than a large hole made by the partial collapse of the roof, filled the -hut with an atmosphere fit to smoke herrings. To obtain a few mouthfuls -of breathable air, we had to seek them in the lower strata, with our -noses almost on the ground. And so we coughed and cursed and poked the -fire, but vainly tried to sleep. We were all afoot by two o’clock in -the morning, ready to climb the highest cone and watch the sunrise. The -rain had stopped, the sky was glorious, promising a perfect day. - -During the ascent some of us felt a sort of seasickness, caused first -by fatigue and secondly by the rarefaction of the air. The barometer -had fallen 5·4 inches; the air which we were breathing had lost a fifth -of its density and was therefore one-fifth less rich in oxygen. Had we -been in good condition, this slight alteration in the air would have -passed unnoticed; but, coming immediately after the exertions of the -day before and a sleepless night, it increased our discomfort. And so -we climbed slowly, with aching legs and panting chests. More than one -of us had to stop and rest after every twentieth step. - -At last we were there. We took refuge in the rustic chapel of -Sainte-Croix to take breath and counteract the nipping morning air by a -pull at the gourd, which this time was drained to the last drop. Soon -the sun rose. Ventoux projected to the extreme limits of the horizon -its triangular shadow, whose sides became brightly tinged with violet -by the effect of the diffracted rays. To the south and west stretched -misty plains, where, when the sun was higher in the heavens, we should -be able to make out the Rhône, looking like a silver thread. On the -north and east, under our feet, lay an enormous bank of clouds, a sort -of ocean of cotton-wool, whence peeped, like islands of slag, the dark -summits of the lower mountains. A few tops, with their trailing -glaciers, gleamed in the direction of the Alps. - -But botany called our attention and we had to tear ourselves from this -magic spectacle. The time of our ascent, in August, was a little late -in the year; many plants were no longer in flower. Would you do some -really fruitful herborizing? Be there in the first fortnight of July; -above all, be ahead of the grazing herds: where the Sheep has browsed -you will gather none but wretched leavings. While still spared by the -hungry flocks, the top of the Ventoux in July is a literal bed of -flowers; its loose stony surface is studded with them. My memory -recalls, all streaming with the morning dew, those elegant tufts of -Androsace villosa, with its pink-centred white blooms; the Mont-Cenis -violet, spreading its great blue blossoms over the chips of limestone; -the spikenard valerian, which blends the sweet perfume of its flowers -with the offensive odour of its roots; the wedge-leaved globularia, -forming close carpets of bright green dotted with blue capitula; the -Alpine forget-me-not, whose blue rivals that of the skies; the Candolla -candytuft, whose tiny stalk bears a dense head of little white flowers -and goes winding among the loose stones; the opposite-leaved saxifrage -and the musky saxifrage, both of them packed into little dark cushions, -studded in the first case with purple flowers and in the second with -white flowers washed with yellow. When the sun’s rays are hotter, we -shall see fluttering idly from one tuft of blossom to another a -magnificent Butterfly with white wings adorned with four bright-crimson -spots, surrounded with black. ’Tis Parnassius Apollo, the beautiful -occupant of the Alpine solitudes, near the eternal snows. Her -caterpillar lives on the saxifrages. - -Here let us end this sketch of the sweet joys that await the naturalist -on the summit of Mont Ventoux and return to the Hairy Ammophila, who -was lurking yesterday in her legions under the shelter of a stone when -the misty rain came and enshrouded us. - - - - - - - - -CHAPTER XII - -THE TRAVELLERS - - -I have told in the last chapter how, on the ridges of Mont Ventoux, at -a height of nearly 6000 feet, I had one of those entomological -windfalls which would be rich in results if they occurred often enough -to serve the purpose of continuous study. Unfortunately, mine was a -solitary instance and I despair of ever repeating it. I can therefore -only base conjectures on it, in the hope that future observers will -replace my surmises with certainties. - -Under the shelter of a broad, flat stone I discovered some hundreds of -Ammophilæ (A. hirsuta), heaped one on top of the other almost as -closely as the Bees in a swarm. As soon as I lifted the stone, all this -little hairy world began to run about, without making any attempt to -fly away. I shifted the mass by handfuls: not one of the Wasps looked -as though she wished to desert the rest. They seemed indissolubly -united by common interests; none of them would go unless all went. I -examined with every possible care the flat stone that sheltered them, -as well as the ground underneath and just around it, and discovered not -a thing to tell me the cause of this strange assemblage. Having nothing -better left to do, I tried to count them; and it was then that the -clouds came and put an end to my observations and plunged us into that -darkness of which I have described the anxious consequences. At the -first drops of rain, before leaving the spot, I hastened to put back -the stone and replace the Ammophilæ in their shelter. I give myself a -good mark, which I hope that the reader will confirm, for having taken -the precaution not to leave the poor insects whom my curiosity had -disturbed at the mercy of the downpour. - -The Hairy Ammophila is not rare in the plains, but she is always found -singly by the side of the paths or on the sandy slopes, now engaged in -digging her well, anon busily carting her heavy caterpillar. She lives -alone, like the Languedocian Sphex; and it was a great surprise to me -to come upon such a number of this species collected under one and the -same stone almost at the top of Mont Ventoux. Instead of the isolated -specimen which I had known hitherto, a crowded company presented itself -to my eyes. Let us try to trace the probable causes of this -agglomeration. - -The Hairy Ammophila is one of the very rare exceptions among the -Digger-wasps in the matter of nest-building; she gets hers ready in the -early days of spring. Towards the end of March, if the season be mild, -or at latest in the first fortnight of April, when the Crickets assume -the adult form and laboriously cast the skin of infancy on the -threshold of their homes, when the poet’s-narcissus puts forth its -first flowers and the Bunting utters his long-drawn call from the top -of the poplars in the fields, Ammophila hirsuta is at work digging a -home for her grubs and victualling it, whereas the other Ammophilæ and -the various Hunting Wasps in general postpone this labour until autumn, -during September and October. This early nidification, preceding by six -months the date adopted by the vast majority, at once suggests a few -reflections. - -We wonder if the Ammophilæ whom we find occupied with their burrows in -the first days of April are really insects of that year, that is to -say, if these spring workers completed their metamorphosis and left -their cocoons during the previous three months. The general rule is for -the Digger to become a perfect insect, to quit her subterranean -dwelling and to busy herself with her larvæ all in one season. Most of -the Predatory Wasps leave the galleries where they lived as larvæ in -the months of June and July and display their talents as miners and -hunters in the following months of August, September and October. - -Does a similar law apply to the Hairy Ammophila? Does the same season -witness the insect’s final transformation and its labours? It is very -doubtful, for the Wasp occupied on the work of the burrow at the end of -March would in that case have to complete her metamorphosis and to -break out of her cocoon during the winter, or at latest in February. -The severity of the climate at this period does not allow us to accept -such a conclusion. It is not at a time when the bleak mistral howls for -a fortnight without intermission and freezes the ground hard, it is not -at a time when snowstorms follow close upon that icy blast, that the -delicate transformations of the nymphosis are able to take place or the -insect to dream of abandoning the shelter of its cocoon. It needs the -warm moisture of the earth under the summer sun before it can leave its -cell. - -If I knew the exact period at which the Hairy Ammophila emerges from -her native burrow, this would help me greatly; but, to my intense -regret, I do not know it. My notes, collected day by day, with the lack -of order inevitable in a type of research that is constantly subject to -the hazards of the unforeseen, are silent on this point, of which I -clearly perceive the importance now that I am trying to arrange my -materials in order to write these lines. I find the Sandy Ammophila -mentioned as hatching on the 5th of June and the Silvery Ammophila on -the 20th of that month; but my records contain not a word that relates -to the hatching of the Hairy Ammophila. It is a detail which, by an -oversight, has never been cleared up. The dates given for the other two -species come under the general law, which lays down that the perfect -insect shall appear during the hot season. I fix the same period, by -analogy, as that for the Hairy Ammophila’s emergence from the cocoon. - -Then whence come the Ammophilæ whom we see working at their burrows at -the end of March and in April? We are driven to the conclusion that -these Wasps belong not to the present but to the previous year; that -they left their cells at the usual time, in June and July, got through -the winter and began to make their nests as soon as the spring came. In -a word, they are hibernating insects. And this conclusion is fully -borne out by experiment. - -If we will but search patiently in the perpendicular banks of earth or -sand facing due south, especially those in which generations of -different honey-gathering Bees have succeeded one another year after -year and riddled the wall with a labyrinth of tunnels until it looks -like an enormous sponge, we are almost sure, in midwinter, to find the -Hairy Ammophila snugly ensconced in the shelters provided by the sunny -bank, alone or in groups of three or four, idly awaiting the arrival of -the fine weather. I have been able to give myself as often as I wished -this little treat of renewing my acquaintance, amid the gloom and cold -of winter, with the pretty Wasp who enlivens the greensward beside the -paths at the first notes of the Bunting and the Cricket. When there is -no wind and the sun is shining brightly, the warmth-loving insect comes -to its threshold to bask luxuriously in the hottest rays, or it will -even timidly venture outside and, step by step, stroll over the surface -of the spongy bank, polishing its wings as it goes. Even so does the -little Grey Lizard behave, when the sun once more begins to warm the -old wall that represents his native land. - -But vain would be our search in winter, even in the most sheltered -refuges, for a Cerceris, Sphex, Philanthus, Bembex or other Wasp with -carnivorous grubs. All died after their autumnal labours and their race -is not represented, in the cold season, save by the larvæ slumbering in -their cells. It is, then, by a most rare exception that the Hairy -Ammophila, hatched in the hot season, spends the following winter in -some warm shelter; and this is the reason why she appears so very early -in the spring. - -With these data to go upon, let us try to explain the cluster of -Ammophilæ which I observed on the ridges of Mont Ventoux. What could -these numerous Wasps have been doing, heaped up under their stone? Were -they preparing to take up their winter quarters there and, slumbering -under cover, to await the season favourable to their work? Everything -tends to show that this is improbable. It is not in August, at the -hottest time of year, that an animal is overcome with its winter -drowsiness. Nor is it any use to suggest the want of food, of honeyed -juices sucked from the flowers. The September showers are at hand; and -vegetation, suspended for a moment by the heat of the dog-days, will -gather fresh vigour and cover the fields with blossoms almost as -diverse as those of spring. This season of revelry for the majority of -Wasps and Bees could never be a period of torpor for the Hairy -Ammophila. - -And then have we any right to imagine that the heights of Ventoux, -swept by the gusts of the mistral, which sometimes uproots both beech -and pine; that crests where the north wind sends the snow-flakes -whirling for six months in succession; that peaks wrapped for the best -part of the year in cold cloud-fogs, can be adopted as a winter refuge -by an insect enamoured of the sun? One might as well suggest that it -should hibernate among the ice-floes of the North Cape. No, it is not -here that the Hairy Ammophila can spend the cold season. The group -which I observed was only passing through. At the first hint of rain, a -hint that escaped us but could not escape the insect, which is so -highly sensitive to the atmospheric variations, the band of travellers -had taken shelter under a stone, waiting for the rain to stop before -resuming their flight. Whence did they come? Whither were they bent? - -In this same month of August, and still more in September, we are -visited, in our warm, olive-clad regions, by caravans of little birds -of passage descending by easy stages from the countries where they have -wooed and loved, countries cooler, more thickly wooded, less wild than -ours, where they have reared their broods. They arrive almost on a -fixed day, in an unvarying order, as though guided by the dates of a -calendar known only to themselves. They sojourn for some time in our -plains, a halting-place rich in insects, which form the exclusive fare -of most of them; they ransack every clod in our fields, where the -ploughshare by now has laid bare in the furrows a multitude of grubs, -their special delight; thanks to this diet, they soon put on a fine -cushion of fat, a storehouse of reserve provisions for the coming -exertions; and at last, supplied with this viaticum, they continue -their southward flight, making for the winterless lands where insects -are never lacking: Spain, Southern Italy, the Mediterranean islands and -Africa. This is the season for brave sport with the gun and for dainty -roasts of small birds. - -The first to arrive is the Shore-lark, or, as he is called in these -parts, the Crèou. August is hardly here before we see him exploring the -pebbly fields, in search of the little seeds of setaria, an ill weed -that overruns our tilled soil. At the least alarm he flies away with a -harsh clattering in his throat which is not badly represented by his -Provençal name. He is soon followed by the Whin-chat, who preys -placidly on small Weevils, Locusts, and Ants in the old lucern-fields. -With him begins the long line of small winged things, the glory of the -spit. It is continued, when September comes, by the most famous of -them, the Common Wheat-ear, or White-tail, extolled by all who are able -to appreciate his exalted qualities. No Beccafico of the Roman -epicures, immortalized in Martial’s epigrams, ever equalled the -exquisite, scented ball of fat that is the Wheat-ear, grown shamefully -stout on gluttonous living. He is an unbridled devourer of every kind -of insect. The notes which I have taken as a sportsman and naturalist -bear witness to the contents of his gizzard. It includes the whole -little world of the fallow fields: grubs and Weevils of every species, -Locusts, Tortoise-beetles, Golden Apple-beetles, Crickets, Earwigs, -Ants, Spiders, Wood-lice, Snails, Millipedes, and ever so many others. -And, as a change from this full-flavoured diet, there are grapes, -blackberries and dogberries. Such is the bill of fare for which the -Wheat-ear is ever in search, as he flies from clod to clod, with the -white feathers of his outspread tail giving him that fictitious look of -a Butterfly on the wing. And Heaven knows what prodigies of plumpness -he is able to achieve. - -He has only one master in the art of self-fattening. This is one whose -migration synchronizes with his, one who is likewise an enthusiastic -insect-eater: the Bush-pipit, as the nomenclators so absurdly call him, -whereas the dullest of our shepherds never hesitates to speak of him as -the Grasset, the champion fat bird. The name in itself fully describes -his leading characteristic. No other achieves such a degree of obesity. -A moment comes when, laden with pads of fat up to its wings, its neck -and the back of its head, the bird looks like a little pat of butter. -The poor thing can hardly flutter from one mulberry-tree to the next, -where it stops to pant in the thick leafage, half choked with melting -fat, a martyr to its passion for Weevils. - -October brings us the slender White Wagtail, half pearly grey, half -white, with a large black-velvet chest-protector. The graceful little -bird, trotting along and cocking up its tail, follows the ploughman -almost under the horses’ feet and picks the grubs in the new-turned -furrow. About the same time the Skylark arrives, first in little -companies sent out as scouting-parties, next in countless battalions, -which take possession of the cornfields and fallow land, with their -plentiful setaria-seeds, the bird’s usual fare. Then, in the plain, -amid the universal glitter of dewdrops and rime-crystals hanging from -every blade of grass, the treacherous mirror shoots forth its -intermittent flashes in the rays of the morning sun; then the little -Owl, released by the hunter’s hand, makes his short flight, alights, -starts up again convulsively, rolling frightened eyes; and the Lark -arrives, dipping on the wing, curious to obtain a closer view of the -bright apparatus or the grotesque bird. He is there, in front of you, a -dozen yards away, with feet pendant and wings outspread like the Dove -in a sacred picture. Now then: take aim and fire! I wish my readers the -excitement of this fascinating sport. - -With the Skylark, often in the same companies, comes the Titlark, -commonly called the Sisi. Here again an onomatopœia gives us the bird’s -little call-note. None goes with greater fury for the Owl, round whom -he manœuvres and hovers constantly. But we will not continue the list -of the birds of passage that visit us. Most of them make but a short -halt here; they stay for a few weeks, attracted by the abundance of -food, especially of insects; then, plump and strong, they pursue their -southward journey. Others, fewer these, take up their winter quarters -in our plains, where snow is very rare and where thousands of little -seeds lie exposed on the ground, even in the depth of winter. One of -these is the Skylark, who gives his attention to the corn-fields and -fallows; another is the Titlark, who prefers the lucern-fields and -meadows. - -The Skylark, so common in almost every part of France, does not nest in -the Vaucluse plains, where his place is taken by the Crested Lark, that -frequenter of the broad highway, the roadmender’s friend. But one need -not go far north to find the favourite spots for the Skylark’s broods: -the next department, the Drôme, is rich in his nests. It is very -probable therefore that, out of the numbers of Skylarks that come to -take possession of our plains for the whole of autumn and winter, there -are many that travel no farther than the Drôme. They have only to -migrate to the next department to find plains free from snow and a -steady supply of tiny seeds. A like migration to a short distance seems -to me to have caused the crowd of Ammophilæ which I surprised near the -top of Mont Ventoux. I have shown that this Wasp spends the winter in -the perfect insect state, hidden in some shelter and waiting until -April to make her nest. She also, like the Skylark, must take her -precautions against the frosty season. Though she need not fear the -lack of food, being capable of fasting until the return of the flowers, -she must at least, delicate creature that she is, guard against the -fatal attacks of the cold. She will therefore flee snowy country, the -districts where the ground freezes to a great depth; she will assemble -in a migratory caravan, after the manner of the birds, and, crossing -hill and dale, will select a home in old walls and sandy banks warmed -by the southern sun. Then, when the cold is past, all or part of the -troop will return to the place whence they came. This would explain the -Ventoux band of Ammophilæ. It was a travelling tribe which, coming from -the cold uplands of the Drôme and descending into the warm plains -beloved of the olive-tree, had crossed the wide, deep valley of the -Toulourenc and, when surprised by the rain, had called a halt on the -mountain-ridge. Apparently, therefore, the Hairy Ammophila has to -migrate in order to escape the cold of winter. At the time when the -little birds of passage start their procession of caravans, she too -journeys from a colder to a warmer neighbourhood. She has but to cross -a few valleys and a few mountains to find the climate which she wants. - -I have two other instances of extraordinary gatherings of insects at -great heights. In October I have found the chapel at the summit of Mont -Ventoux covered with Coccinella septempunctata, the Seven-spot -Ladybird. The insects clinging to the stone of both the roof and walls -were packed so close together that the rude edifice looked, from a -little way off, like a piece of coral-work. I should not care to guess -the myriad numbers of the Ladybirds collected there. Those Aphis-eaters -had certainly not been attracted by the hope of food to the top of the -Ventoux, some 6000 feet above the level of the sea. Vegetation is too -scanty up there; and no Plant-louse ever ventured so high. - -On another occasion, in June, on the tableland of Saint-Amans, a -neighbour of the Ventoux, at a height of 2400 feet, I witnessed a -similar gathering, only much less numerous. At the most prominent part -of the plateau, on the edge of a bluff of perpendicular rocks, stands a -cross with a pedestal of hewn stone. On each face of this pedestal and -on the rocks supporting it, the same Beetles, the Seven-spot Ladybirds -of the Ventoux, had gathered in their legions. The insects were mostly -stationary; but, wherever the sun beat at all fiercely, there was a -continual exchange between the newcomers, anxious to find room, and the -old occupants of the wayside cross, who took to their wings only to -return after a short flight. - -Nothing here, any more than on the summit of the Ventoux, was able to -tell me the cause of these strange meetings on arid spots, containing -no Plant-lice and possessing no attraction for Ladybirds; nothing -suggested the secret of these crowded gatherings on masonry situated at -a great height. Were these again instances of entomological migration? -Were they general musterings, similar to that of the Swallows on the -day before their common departure? Were they meeting-places whence the -swarm of Ladybirds was to make for some district richer in edibles? It -is possible, but it is also very extraordinary. The Ladybird has rarely -been noted as a devotee of travel. She seems to us a very stay-at-home -creature when we see her butchering the Green-fly on our rose-trees and -the Black-fly on our beans; and yet, with her short wings, she holds -plenary assemblies, in immense numbers, on the summit of Mont Ventoux, -where the Martin himself ascends only at moments of violent energy. Why -these meetings at such altitudes? What can be the reason of this -predilection for blocks of masonry? - - - - - - - - -CHAPTER XIII - -THE AMMOPHILÆ - - -A slender waist, a slim shape; an abdomen tapering very much at the -upper part and fastened to the body as though by a thread; black -raiment with a red sash across the belly: there you have a summary -description of these burrowers, who are akin to the Sphex in form and -colouring, but differ greatly from them in habits. The Sphex hunt -Orthoptera—Locusts, Grasshoppers, Crickets—while caterpillars are the -quarry of the Ammophilæ. This change of prey in itself suggests new -methods in the lethal tactics of instinct. - -If the name did not sound so pleasant to the ear, I would willingly -quarrel with the term Ammophila, which means ‘sand-lover,’ as being too -exclusive and often erroneous. The real lovers of sand, of dry, dusty, -streaming sand, are the Bembex, who prey on Flies; but the -caterpillar-hunters, whose story I now propose to relate, have no -predilection for ordinary shifting sand, and even avoid it as being -liable to landslips on the slightest provocation. Their perpendicular -shaft, which has to remain open until the cell receives the provisions -and an egg, requires a firmer setting if it is not to be prematurely -blocked. What they want is a light soil, easily tunnelled, in which the -sandy element is cemented with a little clay and lime. Edges of paths, -sunny banks where the grass is rather bare: those are the favourite -spots. In spring, quite early in April, we see the Hairy Ammophila (A. -hirsuta) there; when September and October come, we find the Sandy -Ammophila (A. sabulosa), the Silvery Ammophila (A. argentata), and the -Silky Ammophila (A. holosericea). I will here condense the information -which I have gathered from the four species. - -In the case of all four the burrow is a vertical shaft, a sort of well, -possessing at most the diameter of a thick goose-quill and a depth of -about two inches. At the bottom is the cell, which is always solitary -and consists of a mere widening of the entrance-shaft. It is, when all -is said, a poor lodging, obtained economically, in one day’s work; the -larva will find no protection there against the winter except from the -four wrappers of its cocoon, copied from that of the Sphex. The -Ammophila digs by herself, quietly, without hurrying, without any -joyous enthusiasm. As usual, the fore-tarsi serve as rakes and the -mandibles do duty as mining-tools. When some grain of sand offers too -much resistance to its removal, you hear rising from the bottom of the -well, as though to give voice to the insect’s efforts, a sort of shrill -grating sound produced by the quivering of the wings and of the whole -body. At frequent intervals the Wasp appears in the open with a load of -refuse in her teeth, some bit of gravel which she flies away with and -drops at a distance of a few inches, so as not to litter the place. Of -the grains extracted some appear to deserve special attention, owing to -their shape and size; at least, the Ammophila does not treat them as -she does the rest: instead of flying off and dropping them far from the -work-yard, she removes them on foot and lays them near the well. These -are picked materials, ready-made blocks of stone which will serve -presently for closing the dwelling. - -This outside work is performed with measured movements and solemn -diligence. The insect stands high on its legs, with its abdomen -stretched at the end of its long pedicle, and turns round slowly, -pivoting its whole body stiffly, with the geometrical rigidity of a -line revolving on itself. If it wishes to fling to a distance the -rubbish which it thinks will be in the way, it does so in short silent -flights, often backwards, as though the Wasp, emerging from her well -head last, avoided turning, so as to save time. It is the species -carrying their abdomens on the longest stalks, such as the Sandy -Ammophila and the Silky Ammophila, which mainly display this -automaton-like rigidity in action. That belly swelling into a pear at -the end of a thread is in fact a very delicate thing to steer: a sudden -movement might warp the fine stalk. So we must walk with a sort of -geometrical rigour; if we have to fly, we will do so backwards, to -avoid tacking too often. On the other hand, the Hairy Ammophila, who -has a short abdominal pedicle, works at her burrow with the heedless, -nimble movements which we admire in most of the Digger-wasps. She has -more freedom of action, because her belly does not get in her way. - -The home is dug. At a later hour in the day, or even merely when the -sun has left the place where the burrow has just been bored, the -Ammophila invariably visits the little heap of stones placed in reserve -during the excavating, with the object of choosing a bit to suit her. -If there is nothing that satisfies her needs, she explores the -neighbourhood and soon discovers what she wants, a small flat stone -slightly larger in diameter than the mouth of her hole. She carries off -this slab in her mandibles and lays it, as a temporary door, over the -opening of the burrow. To-morrow, when the weather is once more hot and -the sun bathes the slopes and encourages hunting, the Wasp will know -quite well how to find her home, rendered inviolable by the massive -door; she will come back with a paralysed caterpillar, grasped by the -skin of its neck and dragged between its captor’s legs; she will lift -the slab, which nothing distinguishes from other little stones around -and which she alone is able to identify; she will let down the game to -the bottom of the well, lay her egg, and close the house for good by -sweeping into the perpendicular shaft all the rubbish which she has -kept in the vicinity. - -Time after time the Sandy Ammophila and the Silvery Ammophila have -shown me this temporary closing of the hole when the sun begins to go -down and when the lateness of the hour compels the victualling to be -put off till the morrow. When the dwelling had been sealed up by the -Wasp, I too would postpone my observations till the next day, but only -after first making a map of the ground, choosing my lines and landmarks -and planting a few stalks as signposts to show me the way to the well -when it was filled. If I did not come back very early in the morning, -if I left the Wasp time to take advantage of the hours of bright -sunshine, I invariably found the burrow finally stocked with provisions -and closed. - -This faithfulness of memory is striking. The Wasp, delayed in her task, -puts off the rest of her work to the next day. She does not spend the -evening, she does not spend the night in the home which she has just -dug: on the contrary, she leaves the premises altogether and goes away, -after concealing the entrance with a little stone. The locality is not -familiar to her; she knows it no better than any other spot, for the -Ammophilæ behave like the Languedocian Sphex and lodge their families -here or there, wherever they happen to roam. The Wasp was there by -chance; the soil suited her; she dug her burrow; and she now goes off. -Where to? Who can tell? Perhaps to the flowers not far away, where, by -the last gleams of daylight, she will sip a drop of sugary liquid at -the bottom of the cups, even as our miners, after toiling in their dark -galleries, fly for comfort to the bottle in the evening. She goes off, -to a less or greater distance, stopping at this bin and that in the -flowers’ cellar. The evening, the night, the morning slip by. Still, -she must return to the burrow and complete her task, she must return -after the marches and countermarches of the morning hunt and the -bewildering flight from flower to flower during the libations of the -evening before. That the Social Wasp should return to her nest and the -Social Bee to her hive does not surprise me at all: the hive and the -nest are permanent residences, the way to which becomes known by long -practice; but the Ammophila has no acquaintance with the locality which -could help her to return to her burrow after such a long absence. Her -tunnel is at a spot which she perhaps visited yesterday for the first -time and which she must find again to-morrow, when she is quite out of -her bearings and moreover hampered with a heavy load of game. -Nevertheless, this little feat of topographical memory is performed, -sometimes with a precision that left me astounded. The Wasp would walk -straight to her burrow as if she had long been using all the little -paths in the neighbourhood. At other times she would wander backwards -and forwards and renew her search over and over again. - -If the quest is greatly prolonged, the prey, which is a troublesome -burden when you are in a hurry to find your home, is laid down in some -high place, on a cluster of thyme or a tuft of grass, where it will be -well in sight presently, when wanted. Thus eased, the Ammophila resumes -her active search. I made a pencil-sketch, as she moved about, of the -tracks followed. The result was a medley of tangled lines, with sudden -bends and turns, branches in and branches out, windings and repeated -intersections—in short, a regular labyrinth whose complicated maze was -an ocular demonstration of the perplexity of the lost one. - -When the well has been found and the slab removed, the Wasp has to come -back to the caterpillar, which is not always done without some groping -about, in cases where her wanderings to and fro have been very -numerous. Though she left her prey easily visible, the Wasp appears to -foresee the difficulty of finding it again when the moment comes to -drag it home. At least, if the search is unduly prolonged, you see her -suddenly interrupt her exploration of the ground and return to her -caterpillar, which she feels and nibbles at for a moment, as though to -make sure that it is really her own game, her property. Then she -hurries back again to the field of search, which she leaves a second -time, if need be, and a third, in order to inspect the prey. I am not -at all sure that these repeated visits of the Wasp to the caterpillar -are not a means of refreshing her memory of the place where she left -it. - -This is what happens in exceedingly complicated cases; but as a rule -the Wasp goes back quite easily to the well dug the day before on the -spot to which chance has taken her. The vagabond’s guide is her -topographical memory, whose marvellous feats I shall have to tell -later. As for me, in order to return next day to the well hidden under -the lid of the little flat stone, I dared not trust to my unaided -memory: I needed notes, sketches, lines of latitude and longitude, -landmarks—in short, all the minutiæ of geometry. - -The temporary closing of the burrow with a flat stone, as practised by -the Sandy Ammophila and the Silvery Ammophila, is apparently unknown to -the other two species. At any rate, I never saw their homes protected -by a lid. Besides, this absence of a provisional door seems to be -obligatory upon the Hairy Ammophila. In fact, as far as I could see, -this species hunts its prey first and then digs its burrow near the -place of capture. In this way the storing of the provisions can be done -straight away; and there is no need to trouble about a lid. As for the -Silky Ammophila, I suspect that she has another reason for not -employing a temporary cover. Whereas the three others put only one -caterpillar in each burrow, she puts in as many as five, though much -smaller ones. Just as we ourselves neglect to shut a door through which -we are constantly passing, so perhaps the Silky Ammophila neglects the -precaution of placing a stone over a well down which she has to go at -least five times in a short space of time. - -In the case of all four, the provisions of the larvæ consist of -caterpillars of Moths. The Silky Ammophila selects, though not -exclusively, those long, thin caterpillars which walk by looping and -unlooping their bodies. Their gait suggests a pair of compasses that -makes its way by opening and closing in turns. Hence they are known by -two expressive names: Loopers and Measuring-worms. [32] The same burrow -contains provisions varying greatly in colour, a proof that the -Ammophila hunts without distinction every species of Loopers, provided -that they be small, for the huntress herself is anything but large and -her grub cannot get through very much, in spite of the five pieces of -game set before her. If Loopers fail, the Wasp falls back on other -equally slender caterpillars. Curved into a hoop as the result of the -sting that paralysed them, the five pieces are stacked up in the cell: -the uppermost carries the egg for which the provisions are made. - -The three other Ammophilæ give only one caterpillar to each larva. It -is true that here bulk makes up for number: the game selected is big, -plump, capable of amply satisfying the grub’s appetite. For instance, I -have taken from the mandibles of the Sandy Ammophila a caterpillar -weighing fifteen times as much as its captor: fifteen times, an -enormous figure when we consider the strength which the huntress must -expend in dragging game of this kind by the skin of the neck over the -countless obstacles on the road. No other Wasp, tried in the balance -with her prey, has shown me a like disproportion between spoiler and -booty. - -The almost indefinite variety of colouring in the provisions which I -unearth from the burrows or see between the legs of the Ammophilæ also -proves that the three brigands have no preference and pounce upon the -first caterpillar which comes along, provided that it be of a suitable -size, neither too large nor too small, and that it belongs to the Moth -division. The commonest game consists of those grey-clad caterpillars -which penetrate a little way into the ground and devour the plant at -the junction of root and stem. - -What governs the whole history of the Ammophilæ and more particularly -attracted my attention is the manner in which the insect overpowers its -prey and reduces it to the condition of helplessness which the safety -of the larva requires. The game hunted, the caterpillar, possesses a -very different structure from that of the victims which we have seen -immolated hitherto: Buprestes, Weevils, Locusts and Ephippigers. The -creature is composed of a series of similar rings or segments set end -to end. Three of these segments, the first three, carry the real legs, -which will become the legs of the future Moth; others have membranous -legs, or pro-legs, which are peculiar to the caterpillar and not -represented in the Moth; others, lastly, have no limbs at all. Each -segment has its nerve-nucleus, or ganglion, the seat of sensibility and -movement, so that the nervous system includes twelve distinct centres, -separated one from the other, without counting the ganglionic -neck-piece placed under the skull and comparable, in a manner of -speaking, with the brain. - -We are here very far removed from the nerve-centralization of the -Weevils and the Buprestes, which lends itself so well to general -paralysis by a single prick of the sting; we are also a long way from -the thoracic ganglia which the Sphex smites, one after the other, to -suppress all movement in her Crickets. Instead of a solitary -centralized point or of three nerve-nuclei, the caterpillar has twelve, -separated from one another by the distance between one segment and the -next and arranged like a string of beads on the ventral surface, along -the median line of the body. Moreover, as is the general rule in the -lower animals, where the same organ is repeated a great number of times -and loses power by its diffusion, these different nerve-centres are -largely independent of one another: each of them exercises its -influence over its particular segment; and its functions are only very -gradually affected by the derangement of the adjoining segments. One of -the caterpillar’s rings can lose its power of moving and feeling and -the remainder will nevertheless remain capable of both for a -considerable time. These facts are enough to show the great interest -attaching to the methods of slaughter which the Wasp adopts with her -prey. - -But, while the interest is great, the difficulty of observation is not -small. The solitary habits of the Ammophilæ, their distribution one by -one over wide areas, the fact that one almost always comes across them -merely by chance: all this makes it hardly possible to carry out -premeditated experiments with them, anymore than with the Languedocian -Sphex. You have to be on the look-out a long time for an opportunity, -to wait for it with untiring patience, and to know how to profit by it -at the very moment when at last it presents itself, a moment when you -were not thinking of it. I watched for that opportunity for years and -years; then one day it suddenly appeared before my eyes, offering a -facility of examination and a clearness of detail that compensated me -for my long waiting. - -At the beginning of my investigations I was twice enabled to witness -the murder of the caterpillar, and I saw, as far as the swiftness of -the operation permitted, the Wasp’s sting applied once and for all to -either the fifth or the sixth segment of the victim. To confirm this -result, I thought of ascertaining which ring had been stabbed on -caterpillars which I had not seen sacrificed, but which I had taken -from their captors while they were being dragged to the burrow. It was -no use employing a magnifying-glass, for no magnifying-glass enables -one to discover the least trace of a wound upon the victim. The method -adopted is the following: when the caterpillar is quite still, I try -each segment with the point of a fine needle and thus measure the -amount of sensibility by the more or less manifest signs of pain in the -insect. When the needle pricks the fifth segment or the sixth, even -piercing it right through, the caterpillar does not stir. But if you -prick even slightly a second segment, behind or in front of that -insensible segment, the caterpillar wriggles and struggles with a -violence which increases in proportion to the distance of the point -attacked from the original segment. At the hinder end in particular, -the least touch provokes wild contortions. There was only one sting, -therefore, and it was administered to the fifth or sixth ring. - -What peculiarity then do these two segments possess that one or other -of them should be the target of the assassin’s weapon? None whatever in -their organization; but their position is another matter. Leaving the -Silky Ammophila’s Measuring-worms on one side, I find that the prey of -the others is organized as follows, the head being counted as the first -segment: three pairs of real legs on the second, third and fourth -rings; four pairs of membranous legs on the seventh, eighth, ninth and -tenth rings; lastly, a final pair of membranous legs on the thirteenth -and last ring, making in all eight pairs of legs, of which the first -seven form two vigorous groups, one of three, the other of four pairs. -These two groups are separated by two legless segments, which are -precisely the fifth and sixth. - -Now, in order to deprive the caterpillar of its means of escape, to -render it motionless, will the Wasp drive her sting into each of the -eight rings provided with locomotory organs? Above all, will she take -this superfluity of precaution when the prey is quite weak and small? -Certainly not: a single stab will be enough; but it will be given at a -central point, whence the torpor produced by the tiny drop of poison -can spread gradually, with the least possible delay, to the segments -furnished with legs. There is no doubt about the segment to be picked -out for this single inoculation: it must be the fifth or the sixth, -which separate the two groups of locomotory rings. The point indicated -by rational inferences is therefore also the point adopted by instinct. - -Lastly, let us add that the Ammophila’s egg is invariably laid on the -ring that has been rendered insensible. Here and here alone the young -larva can bite without provoking dangerous contortions; where a -needle-prick has no effect, the grub’s bite will have no effect either. -The grub will thus remain motionless until the nurseling has gained -strength and can forge ahead without running a risk. - -In my later researches, as the number of my observations increased, I -began to entertain doubts, not as to the conclusions which I had -formed, but as to their general application. That feeble Loopers and -other small caterpillars are rendered harmless by a single thrust, -especially when the sting strikes the favourable spot described, is a -thing quite probable in itself and one which can also be proved either -by direct observation or by testing the insect’s sensibility with a -needle. But the Sandy Ammophila and especially the Hairy Ammophila -capture enormous victims, whose weight, as I have said, is fifteen -times that of the kidnapper. Will this giant prey be treated in the -same manner as the frail Measuring-worm? Will one dagger-thrust be -sufficient to subdue the monster and render it incapable of doing harm? -Will the horrid Grey Worm, lashing the walls of the cell with its -powerful tail, not endanger either the egg or the little grub? We dare -not picture the encounter, in the narrow cell of the burrow, between -those two—the feeble, new-hatched creature and that dragony thing still -possessing freedom in its movements to twist and untwist its tortuous -coils. - -My suspicions were confirmed by an examination of the caterpillar from -the point of view of sensibility. Whereas the small game of the Silky -Ammophila and the Silvery Ammophila struggle violently if the needle -touches them elsewhere than in the ring stung by the Wasp, the big -caterpillars of the Sandy Ammophila and especially of the Hairy -Ammophila remain motionless, no matter which segment we prick. With -them there are no contortions, no sudden twists of the hinder parts; -the steel point produces no sign of a remnant of sensibility beyond a -faint quivering of the skin. The power of moving and feeling is -therefore almost wholly abolished, as it needs must be if the grub is -to feed in safety on this monstrous prey. Before placing it in the -burrow, the Wasp has turned it into an inert though still living mass. - -I have been permitted to watch the Ammophila operating with her scalpel -on the sturdy caterpillar, and never did the intuitive science of -instinct show me anything more exciting. With a friend—soon, alas, to -be snatched from me by death!—I was coming back from the plateau of Les -Angles to lay snares for the Sacred Beetle and put his skill to the -test, when we caught sight of a Hairy Ammophila very busily employed at -the foot of a tuft of thyme. We at once lay down on the ground, close -to where she was working. Our presence did not frighten the Wasp; in -fact, she came and settled on my sleeve for a moment, decided that her -two visitors were harmless, since they did not move, and returned to -her tuft of thyme. As an old stager, I knew what that daring -familiarity meant: the Wasp’s attention was occupied with a serious -business. We would wait and see. - -The Ammophila scratched the ground at the foot of the plant, at the -junction of root and stem, pulled up slender grass rootlets and poked -her head under the little clods which she had lifted. She ran hurriedly -this way and that around the thyme, inspecting every crevice that could -give access to what lay below. She was not digging herself a home but -hunting some game hidden underground; this was evident from her -behaviour, which resembled that of a Dog trying to dig a Rabbit out of -his hole. Presently, excited by what was happening overhead and -close-pressed by the Ammophila, a big Grey Worm made up his mind to -leave his lair and come up to the light of day. That settled him; the -huntress was on the spot at once, gripping him by the skin of his neck -and holding tight in spite of his contortions. Perched on the monster’s -back, the Wasp bent her abdomen and deliberately, without hurrying, -like a surgeon thoroughly acquainted with his patient’s anatomy, drove -her lancet into the ventral surface of each of the victim’s segments, -from the first to the last. Not a ring was left without receiving a -stab; all, whether with legs or without, were dealt with in order, from -front to back. - -That is what I saw with all the leisure and ease that an observation -needs in order to be above reproach. The Wasp acts with a precision -that would make science turn green with envy; she knows what man hardly -ever knows; she knows her victim’s complex nervous system and reserves -her successive dagger-thrusts for the successive ganglia of her -caterpillar. I said, she knows; what I should say is, she behaves as -though she knew. Her act is simple inspiration. Animals obey their -compelling instinct, without realizing what they do. But whence comes -that sublime inspiration? Can theories of atavism, of natural -selection, of the struggle for life interpret it reasonably? To me and -my friend, this was and remained one of the most eloquent revelations -of the unutterable logic that rules the world and guides the ignorant -by the laws of its inspiration. Stirred to our innermost being by this -flash of truth, both of us felt tears of undefinable emotion spring to -our eyes. - - - - - - - - -CHAPTER XIV - -THE BEMBEX - - -One of my favourite spots for the observations which I will now -describe is not far from Avignon, on the right bank of the Rhône, -opposite the mouth of the Durance. It is the Bois des Issarts. Let not -the reader mistake the value of this word bois, which usually suggests -a carpet of cool moss and the shade of tall trees, with a dim light -filtering through the leaves. The scorched plains where the Cicada -grates out his ditty on the pale olive-tree know none of these -delicious retreats filled with cool shadow. - -The Bois des Issarts is a coppice of holm-oaks no higher than one’s -head and sparingly distributed in scanty clumps which, even at their -feet, hardly temper the force of the sun’s rays. When I used to settle -myself in some part of the coppice suitable for my observations, on -certain afternoons in the dog-days of July and August, I had the -shelter of a large umbrella, which later, in the most unexpected -fashion, lent me a very precious aid of a different kind, as my story -will show in good time. If I neglected to furnish myself with this -embarrassing adjunct to a long walk, my only resource against sunstroke -was to lie down at full length behind some sandy knoll; and, when the -veins in my temples were throbbing to bursting point, my last hope lay -in putting my head down a Rabbit-burrow. Such are one’s means of -keeping cool in the Bois des Issarts. - -The soil not occupied by those clumps of woody vegetation is almost -bare and consists of fine, dry, very loose sand, which the wind heaps -into little dunes wherever the stems and roots of the holm-oak -interfere with its dissemination. The sides of these sand-dunes are -generally very smooth, because of the extreme lightness of the -materials, which slide down into the smallest depression and of their -own accord restore the evenness of the surface. You need but push your -finger into the sand and take it out again to bring about an immediate -landslip which fills up the hole and restores things to their original -condition without leaving a visible trace. But, at a certain depth, -which varies according to the more or less recent date of the last -rains, the sand retains a lingering dampness which keeps it in its -place and gives it a consistency that enables it to have small -excavations made in it without a subsequent collapse of walls and roof. -A blazing sun, a gloriously blue sky, sandy slopes that yield without -the least difficulty to the strokes of the Wasp’s rake, game galore for -the grub’s food, a peaceful site hardly ever disturbed by the foot of -man: all the good things are combined in this Bembex paradise. Let us -watch the industrious insect at work. - -If the reader will sit with me under the umbrella, or consent to share -my Rabbit-burrow, this is the sight which he is invited to behold, at -the end of July: a Bembex (B. rostrata) arrives suddenly, I know not -whence, and alights, without preliminary investigations or the least -hesitation, at a spot which to my eyes differs in no respect from the -rest of the sandy surface. With her fore-tarsi, which are armed with -rows of stiff hairs and suggest at the same time a broom, a brush and a -rake, she works at clearing her subterranean dwelling. The insect -stands on its four hind-legs, holding the two at the back a little wide -apart, while the front ones alternately scratch and sweep the shifting -sand. The precision and quickness of the performance could not be -greater if the circular movement of the tarsi were worked by a spring. -The sand, shot backwards under the abdomen, passes through the arch of -the hind-legs, gushes like a fluid in a continuous stream, describes -its parabola and falls to the ground some seven or eight inches away. -This spray of dust, kept up evenly for five or ten minutes at a time, -is enough to show the dazzling rapidity of the tools employed. I know -no other example of this swiftness, which nevertheless in no way -detracts from the easy grace and the free movement of the insect, as it -advances and retires first on this side, then on that, without -discontinuing its parabolic streams of sand. - -The soil excavated is of the lightest kind. As the Wasp digs, the sand -near by slips back and fills the cavity. Amongst the rubbish that falls -are tiny bits of wood, decayed leaf-stalks and particles of grit larger -than the rest. The Bembex takes them up in her mandibles and carries -them away, moving backwards as she goes; then she returns to her -sweeping, but never going to any length and making no attempt to bury -herself underground. What is her object in thus labouring entirely on -the surface? It would be impossible to tell from this first glance; -but, after spending many days with my beloved Wasps and grouping -together the scattered facts resulting from my observations, I seem to -catch a glimpse of the reason for the present proceedings. - -The Wasp’s nest is certainly there, a few inches below the ground; in a -little cell dug in the cool, firm sand lies an egg, perhaps a grub for -which the mother caters from day to day, bringing it Flies, the -unvarying food of the Bembex in their first state. The mother has to be -able at any moment to enter the nest, as she flies up carrying in her -legs the nurseling’s daily portion of game, even as the bird of prey -enters its eyrie with the food for its young in its talons. But, while -the bird returns to a home on some inaccessible ledge of rock, with no -difficulty to overcome but that of the weight and encumbrance of the -captured prey, the Bembex has each time to undertake rough miner’s work -and open up anew a gallery blocked and closed by the mere fact that the -sand gives way as the insect proceeds. In that underground dwelling, -the only room with steady walls is the spacious cell where the larva -lives amid the remnants of its fortnight’s feast; the narrow corridor -which the mother enters to reach the flat at the back or to come out -and go hunting collapses each time, at least in the front part dug out -of very dry sand, which repeated exits and entrances make looser still. -Each time therefore that the Wasp goes in or out, she has to clear -herself a passage through the débris. - -Going out presents no difficulty, even should the sand retain the -consistency which it might have at the start, when first disturbed: the -insect’s movements are free, it is safe under cover, it can take its -time and use its tarsi and mandibles without undue hurry. Going in is a -very different matter. The Bembex is hampered by her prey, which her -legs hold clasped to her body; and the miner is thus deprived of the -free use of her tools. And a still graver circumstance is this: brazen -parasites, veritable bandits in ambush, crouch here and there in the -neighbourhood of the burrow, spying on the mother Wasp as she makes her -laborious entrance, so that they may rush in and lay their egg on the -piece of game at the very moment when it is about to disappear down the -corridor. If they succeed, the Wasp’s nurseling, the son of the house, -will perish, starved by its gluttonous fellow-boarders. - -The Bembex seems aware of these dangers and makes arrangements for her -entrance to be effected swiftly, without serious obstacles—in short, -for the sand blocking the door to yield to a mere push of her head, -aided by a brisk sweep of her front tarsi. With this object, the -material at the approaches to the home are subjected to a sort of -sifting. At leisure moments, under a kindly sun, when the larva has its -food and does not need her attentions, the mother rakes the ground in -front of her door; she removes little bits of wood, any extra-large -particles of gravel, any leaves that might get in the way and bar her -passage at the dangerous moment of her return. The Bembex whom we have -just seen so zealously employed was busy at this work of sifting: to -facilitate the access to her home, the materials of the corridor have -to be dug up, carefully sorted and rid of anything likely to obstruct -the road. Who indeed can tell whether, by that nimble eagerness, that -joyous activity, the insect is not expressing in its own way its -maternal satisfaction, its happiness in watching over the roof of the -cell to which the precious egg has been entrusted? - -As the Wasp is confining herself to her duties outside the house, -without trying to penetrate into the sand, everything must be in order -inside and there is no hurry about anything. We should only wait in -vain: the insect would tell us nothing more for the time being. Let us -therefore examine the underground dwelling. If we scrape the dune -lightly with the blade of a knife at the point where the Bembex was -busiest, we soon discover the entrance-corridor, which, though blocked -for part of the way down, is nevertheless recognizable by the -distinctive appearance of the materials moved. This passage, which is -as wide as one’s finger and straight or winding, longer or shorter -according to the nature and the accidents of the ground, measures eight -to twelve inches. It leads to a single chamber, hollowed in the damp -sand, whose walls are not coated with any kind of mortar likely to -prevent a subsidence or to lend a polish to the rough surface. The -ceiling will do, if it can hold out while the larva is growing up; it -does not matter what falls in afterwards, when the larva is enclosed in -its stout cocoon, a sort of safe which we shall see it building. The -workmanship of the cell, therefore, is very rustic: the whole thing is -reduced to a rough excavation, of no definite shape, with a low roof -and space enough to contain two or three walnuts. - -In this retreat lies a piece of game, one only, quite small and quite -insufficient for the greedy nurseling which it is meant to feed. It is -a golden-green Fly, a Green-bottle (Lucilia Cæsar), [33] who lives on -putrid flesh. The Fly served up as food is absolutely motionless. Is -she quite dead, or only paralysed? This question will be cleared up -later. For the moment we will note the presence, on the side of the -game, of a cylindrical egg, white, very slightly curved and a couple of -millimetres [34] long. It is the egg of the Bembex. As we expected from -the mother’s behaviour, there is nothing urgent indoors: the egg is -laid and provided with a first ration apportioned to the requirements -of the feeble grub which will hatch twenty-four hours hence. The Bembex -had no need to re-enter the underground passage for some time and was -confining herself to keeping a good look-out all round, or perhaps to -digging fresh burrows and continuing to lay her eggs, one by one, each -in a cell to itself. - -This peculiarity of beginning the provisioning with a single head of -small game is not confined to the Rostrate Bembex. All the other -species do the same thing. If we open the cell of any Bembex shortly -after the egg is laid, we shall always find the tiny cylinder glued to -the side of a Fly, who constitutes the entire provision; moreover, this -initial ration is invariably small, as though the mother went in search -of the tenderest mouthfuls for the feeble nurseling. Besides, another -reason, the abiding freshness of the food, might easily prompt her to -make this choice. We will look into that later. This first portion, -always a scanty one, varies greatly in nature, according to the -frequency of this or that kind of game in the neighbourhood of the -nest. It is sometimes a Green-bottle, sometimes a Stomoxys, or some -small Eristalis, sometimes a dainty Bee-fly clad in black velvet; but -the most usual dish is a slim-bellied Sphærophoria. - -This general fact, to which there is no exception, of the victualling -of the egg with a single Fly, a ration infinitely too small for a larva -blessed with a voracious appetite, at once puts us on the track of the -most remarkable habit of the Bembex. Wasps whose larvæ live on prey -heap up in each cell the number of victims necessary for the rearing of -the grub; they lay the egg on one of the bodies and close the dwelling, -which they do not enter again. From that moment the larva hatches and -develops alone, having before it from the very beginning the whole -stock of provisions which it is to consume. The Bembex form an -exception to this rule. The cell is first stocked with a single head of -game, always small in size, and the egg is laid on it. When that is -done, the mother leaves the burrow, which closes of itself; besides, -before going away, the insect is careful to rake over the outside, so -as to smooth the surface and hide the entrance from any eye but her -own. - -Two or three days elapse; the egg hatches and the little larva eats up -the choice ration served to it. Meanwhile the mother remains in the -neighbourhood and you see her sometimes feeding herself by sipping the -sugary exudations of the field eringo, sometimes settling happily on -the burning sand, no doubt watching the outside of the house. Every now -and again she sifts the sand at the entrance; then she flies away and -disappears, perhaps to dig other cells elsewhere and to stock them in -the same way. But, however long she may stay away, she never forgets -the young larva so scantily provided for; the instinct of a mother -tells her the hour when the grub has finished its food and is calling -for fresh nourishment. She therefore returns to the nest, of which she -is wonderfully capable of discovering the invisible entrance; she goes -down into the earth, this time carrying a bulkier piece of game. After -depositing her prey, she again leaves the house and waits outside till -the moment arrives to serve a third course. This moment is not slow in -coming, for the larva devours its food with a lusty appetite. Again the -mother appears with fresh provisions. - -During nearly a fortnight, while the larva is growing up, the meals -thus follow in succession, one by one, as needed, and coming closer -together as the nurseling waxes bigger. Towards the end of the -fortnight it takes all the mother’s activity to satisfy the appetite of -the glutton, who crawls heavily along with his great lumbering belly, -amid the scorned leavings: rejected wings and legs and horny abdominal -segments. You see her at every moment returning with a recent capture, -at every moment setting out again upon the chase. In short, the Bembex -brings up her family from day to day, without storing up provisions in -advance, just as the bird does, which feeds its nestlings from hand to -mouth. Of the many proofs that are evidence of this method of -upbringing, a very singular method for a Wasp who feeds her offspring -on prey, I have already mentioned the presence of the egg in a cell -containing no provisions but one small Fly, never more. And here is -another one, which can be verified at any time. - -Let us look into the burrow of a Wasp who stocks her grubs’ provisions -in advance: if we select the moment when the insect is going in with -its prey, we shall find in the cell a certain number of victims, the -commencement of a larder, but never at that time a grub, nor even an -egg, for this is not laid until the provisions are quite complete. When -the egg is laid, the cell is closed and the mother does not return to -it. It is therefore only in burrows where the mother’s visits are no -longer necessary that we can find larvæ side by side with larger or -smaller stocks of food. On the other hand, let us inspect the home of a -Bembex at the moment when she is entering with the fruits of her -hunting. We are certain of finding in the cell a larva, big or little -as the case may be, among remnants of provisions already consumed. The -portion which the mother is now bringing is therefore intended to -prolong a meal which has already lasted several days and which is to -continue for some time further with the produce of future hunting -expeditions. Should we be fortunate enough to make this search towards -the end of the larva’s infancy—an advantage which I have enjoyed as -often as I wished to—we shall find, on a copious heap of remnants, a -large and portly grub, to which the mother is still bringing fresh -victuals. The Bembex does not cease her catering and does not leave the -cell for good until the larva, distended by a purply paste, refuses its -food and lies down, stuffed to repletion, on the jumble of legs and -wings of the game which it has devoured. - -Each time that the mother enters the burrow on returning from the -chase, she brings but a single Fly. If it were possible, by counting -the remnants contained in a cell whose occupant is full-grown, to tell -the number of victims supplied to the larva, we should know how often -at the least the Wasp visited her burrow after laying the egg. -Unfortunately, these broken victuals, chewed and chewed again at -moments of scarcity, are for the most part unrecognizable. But, if we -open a cell with a less forward nurseling, the provisions lend -themselves to examination, some of them being still whole or nearly -whole, while others, more numerous, are represented by fragments in a -state of preservation that enables them to be identified. Incomplete -though it be, the list obtained under these conditions is surprising -and shows what activity the Wasp must display to satisfy the needs of -such a table. I will set forth one of the bills of fare which I have -observed. - -At the end of September, around the larva of a Jules’ Bembex (Bembex -Julii), [35] which has reached almost a third of the size which it will -finally attain, I find the following heads of game: six Echinomyia -rubescens (two whole and four in pieces); four Syrphus corollæ (two -complete, the other two broken up); three Gonia atra (all three -untouched: one of them had that moment been brought along by the -mother, which led to my discovering the burrow); two Pollenia rufescens -(one untouched, the other partly eaten); one Bombylius (reduced to -pulp); two Echinomyia intermedia (in bits); and two Pollenia floralis -(likewise in bits): twenty pieces in all. This certainly makes a both -plentiful and varied bill of fare; but, as the larva was only a third -of its ultimate size, the complete menu might easily number as many as -sixty items. - -It is not at all difficult to verify this sumptuous figure: I will -myself take the place of the Bembex in her maternal functions and -supply the larva with food till it is ready to burst. I move the cell -into a little cardboard box which I furnish with a layer of sand. I -place the larva on this bed, with all due consideration for its -delicate skin. Around it, without omitting a single fragment, I arrange -the provisions with which it was supplied. Then I go home, still -holding the box in my hand, to avoid any shaking which might turn the -house upside down and endanger my charge during a walk of several -miles. Any one who had met me on the dusty Nîmes Road, dropping with -fatigue and religiously carrying in my hand, as the sole fruit of my -laborious trip, an ugly grub battening on a heap of Flies, would -certainly have smiled at my simplicity. - -The journey was effected without damage: when I reached home, the larva -was placidly eating its Flies as though nothing had happened. On the -third day of captivity the provisions taken from the burrow were -finished; the grub was rummaging with its pointed mouth among the heap -of remains without finding anything to suit it; the dry particles taken -hold of, all horny, juiceless bits, were rejected with disgust. The -moment has come for me to continue the food supply. The first Flies -within reach shall form my prisoner’s diet. I kill them by pressing -them in my fingers, but without crushing them. The first ration -consists of three Eristalis tenax and one Sarcophaga. [36] This is all -gobbled up in twenty-four hours. Next day I provide two Eristales, or -Drone-flies, and four House-flies. It was enough for the day, but left -nothing over. I went on like this for eight days, giving the grub a -larger portion every morning. On the ninth day the larva refused all -food and began to spin its cocoon. The full record of this eight days’ -feast amounts to sixty-two pieces, composed mainly of Drone-flies and -House-flies, which, added to the twenty items found whole or in pieces -in the cell, brings up the total to eighty-two. - -It is possible that I did not rear my larva with the wholesome -frugality and the wise economy which the mother would have shown; there -was perhaps some waste in the daily provisions served all at one time -and left entirely to the grub’s discretion. In some respects I feel -inclined to believe that things do not happen just like that in the -maternal cell, for my notes contain such details as the following. In -the alluvial sands of the Durance I discover a burrow which the Wasp -(Bembex oculata) has just entered with a Sarcophaga agricola. Inside I -find a larva, numerous fragments and a few whole Flies, namely, four -Sphærophoria scripta, one Onesia viarum and two Sarcophaga agricola, -including the one which the Bembex has just brought along before my -eyes. Now it is worthy of remark that half of this game, namely, the -Sphærophoriæ, is right at the end of the cell, under the larva’s very -teeth, whereas the other half is still in the passage, on the threshold -of the cell, and therefore beyond the reach of the grub, which is -unable to change its position. It seems to me then that, when game is -plentiful, the mother lays her captures on the threshold of the cell -for the time and forms a reserve on which she draws as and when -necessary, especially on rainy days when all labour is at a standstill. - -Thus practised with economy, the distribution of food would save a -waste which I was not able to prevent with my larva, treated I dare say -too sumptuously. I therefore lower the figure obtained and reduce it to -some sixty pieces, of middling size, between that of the House-fly and -of the Eristalis tenax. This would about represent the number of Flies -supplied by the mother to the larva when the prey is of a moderate -size, as is the case with all the Bembex of my district except the -Rostrate Bembex (B. rostrata) and the Two-pronged Bembex (B. -bidentata), who have a preference for Gad-flies. With them, the number -of victims would be from one to two dozen, according to the size of the -Fly, which varies greatly in the different species of Gad-flies. - -To avoid reopening this question of the nature of the provisions, I -will here give a list of the Flies observed in the burrows of the six -species of Bembex that form the subject of this essay. - -1. Bembex olivacea, Rossi. I only once saw this species, at Cavaillon, -feeding on Green-bottles. The five other species are common in the -Avignon neighbourhood. - -2. Bembex oculata, Jur. The Fly carrying the egg is most often a -Sphærophoria, especially S. scripta; sometimes it is a Geron gibbosus. -The later provisions include Stomoxys calcitrans, Pollenia ruficollis, -P. rudis, Pipiza nigripes, Syrphus corollæ, Onesia viarum, Calliphora -vomitoria, [37] Echinomyia intermedia, Sarcophaga agricola and Musca -domestica. [38] The usual fare consists of Stomoxys calcitrans, of -which I have many a time found fifty or sixty in a single burrow. - -3. Bembex tarsata, Lat. This one also lays her egg on Sphærophoria -scripta. She next hunts: Anthrax flava, Bombylius nitidulus, Eristalis -æneus, E. sepulchralis, Merodon spinipes, Syrphus corollæ, Helophilus -trivittatus and Zodion notatum. Her favourite game consists of -Bombylii, or Bee-flies, and Anthrax-flies. [39] - -4. Bembex Julii (sp. nov.). The egg is laid on a Sphærophoria or on a -Pollenia floralis. The provisions are a hotchpotch of Syrphus corollæ, -Echinomyia rubescens, E. intermedia, Gonia atra, Pollenia floralis, P. -ruficollis, Clytia pellucens, Lucilia Cæsar, Dexia rustica and -Bombylius. - -5. Bembex rostrata, Fab. This is preeminently a consumer of Gad-flies. -She lays her egg on a Syrphus corollæ or a Lucilia Cæsar, after which -she feeds her larva exclusively on big game belonging to the various -species of the genus Tabanus. - -6. Bembex bidentata, V. L. Another ardent huntress of Gad-flies. I have -never seen her pursue other game and I do not know on what Fly the egg -is laid. - -This great variety of provisions shows that the Bembex have no -exclusive tastes and fall upon any species of Flies, indifferently, -which the hazards of the chase place within their reach. They seem -nevertheless to entertain a few preferences. Thus one species feeds -more particularly on Bee-flies, a second on Stomoxys-flies, a third and -a fourth on Gad-flies. - - - - - - - - -CHAPTER XV - -THE FLY-HUNT - - -After our list, in the last chapter, of the fare on which the Bembex -feed in the larval form, it behoves us to seek the motive that induces -these Wasps to adopt a method of victualling so exceptional among the -digger-insects. Why, instead of previously storing a sufficient -quantity of provisions on which the egg could be laid—which would -enable the mother to close the cell immediately afterwards and never to -return to it—why, I ask, does she tie herself down for a fortnight to -this incessant, toilsome coming and going from the burrow to the fields -and from the fields to the burrow, forcing her way each time through -the unstable sand, either to go hunting or to bring the larva her -latest capture? It is, first and foremost, a question of having fresh -victuals for her larva: an all-important question, for the grub -absolutely refuses any high or tainted game. Like the grubs of the -other Diggers, it wants fresh meat and nothing but fresh meat. - -We have seen in the case of the Cerceres, the Sphex and the Ammophilæ -how the mother solves the problem of preserved food-stuffs, the problem -of stocking a cell with the requisite quantity of game for its future -occupant and keeping the meat fresh for whole weeks at a time; indeed, -it is something more than fresh, for the victims are kept in an almost -living state, except that they are incapable of movement, an essential -condition if the grub is to feed on them in safety. The miracle is -performed by the most cunning methods known to physiology. The poisoned -lancet is driven into the nerve-centres once or oftener, according to -the structure of the nervous system. Thus operated upon, the victim -retains all the attributes of life, short of the power of moving. - -Let us see if the Bembex make use of this profound science of -slaughter. The Flies taken from between the legs of the kidnapper as -she enters her burrow present, in most cases, every appearance of -death. They are motionless; occasionally we can detect in a few of them -some faint convulsions of the tarsi, the last vestiges of a life that -is passing away. The same appearance of complete death is usually found -in the insects which are not actually killed but paralysed by the -adroit dagger-thrust of a Cerceris or a Sphex. The question whether -they are alive or dead can therefore be decided only according to the -manner in which the victims keep fresh. - -Placed in little screws of paper or in glass tubes, the Crickets and -Grasshoppers of the Sphex, the caterpillars of the Ammophilæ, and the -Beetles and Weevils of the Cerceres preserve their flexibility of limb, -their freshness of colouring and the normal condition of their -intestines for weeks and months. They are not corpses but bodies sunk -in a lethargy from which there is no awaking. The Flies of the Bembex -behave quite differently. The Eristales, the Syrphi—in short, all those -whose livery is at all brightly coloured—soon lose the brilliancy of -their attire. The eyes of certain Gad-flies, magnificently gilded, with -three purple bands, very quickly grow pale and dim, like the eyes of a -dying man. All these Flies, large and small, when placed in little -paper bags through which the air circulates freely, dry up in two or -three days and become brittle; all, when preserved against evaporation -in glass tubes in which the air is stationary, go mouldy and decay. -They are dead, therefore, really and truly dead, when the Wasp brings -them to her larva. Should some of them still retain a remnant of life, -a few days or even hours put an end to their agony. Consequently, for -lack of talent in the use of her dagger or for some other reason, the -murderess kills her victims outright. - -In view of this fact, that the prey is quite dead at the moment when it -is carried off, who would not admire the logic of the Bembex’ -procedure? How methodical and consistent everything is in the actions -of the cunning Wasp! As the provisions cannot keep beyond two or three -days without going bad, they must not be stored entire in the first -stages of an infancy which will last at least a fortnight; and the -hunting and distribution must necessarily be done day by day, bit by -bit, as the larva grows up. The first ration, the one that receives the -egg, will last longer than the others; the budding grub will take -several days to eat its flesh. It must therefore be small, otherwise -the joint would begin to putrefy before it was all finished. This joint -therefore will not be a bulky Gad-fly or a corpulent Bombylius, but -rather a tiny Sphærophoria, or something similar, making a dainty meal -for the larva which is still so delicate. Later, getting bigger and -bigger in time, will come the larger joints of venison. - -The burrow must be kept shut during the mother’s absence, to save the -larva from regrettable intrusions; nevertheless the entrance must be -one that can be opened very frequently and hurriedly, without much -difficulty, when the Wasp returns laden with her prey and watched by -the sharp eyes of daring parasites. These conditions could not be -obtained with a compact soil such as that in which the Digger-wasps -usually make their abodes: the door, left to itself, would stay open; -and so, each time, there would be the long and toilsome job of either -blocking up the entrance with earth and gravel or unblocking it, as the -case might be. The house therefore must be dug in ground with a very -loose surface, in fine dry sand, which will at once yield to the -slightest effort on the mother’s part and, as it slides down, will -close the door of its own accord, like a curtain which, when you thrust -it aside with your hand, lets you pass through and then falls back -again. There you have the series of actions as deduced by man’s reason -and as practised by the Wasp’s sagacity. - -Why does the spoiler kill the captured prey instead of simply -paralysing it? Is it for want of skill in the use of her sting? Is it -because of some difficulty due to the structure of the Flies or to the -methods employed in the chase? I must begin by confessing that I have -failed in my attempts to place Flies, without killing them, in that -state of complete immobility to which it is so easy to reduce a -Buprestis, a Weevil or a Scarab by injecting a tiny drop of ammonia -with a needle into the thoracic ganglia. In making the experiment, it -is difficult to render the insect motionless; and, by the time that it -has ceased to move, death has actually occurred, as is proved by its -speedy corruption or desiccation. But I have too much confidence in the -resources of instinct and have witnessed the ingenious solution of too -many problems to believe that a difficulty which baffles the -experimenter can bring the insect to a standstill. Therefore, without -throwing doubt upon the Bembex’ talents as a slaughterer, I should be -inclined to look for other reasons. - -Perhaps the Fly, so thinly covered, so devoid of any plumpness, in a -word, so lean, could not, if paralysed by the sting, resist evaporation -long enough and would shrivel up during the two or three weeks of -waiting. Consider the puny Sphærophoria, the larva’s first mouthful. -How much liquid has that body to satisfy the needs of evaporation? An -infinitesimal drop, a mere nothing. The abdomen is a thin strip; its -two sides touch. Can such game as this form the basis of preserved -food, seeing that evaporation would dry up its juices in a few hours -when these are not renewed by nutrition? It is doubtful, to say the -least. - -Let us examine the method of hunting, so as to throw some final light -on the subject. In the quarry removed from between the legs of the -Bembex, it is not rare to observe signs of a hurried capture, made -anyhow, according to the chances of a rough-and-tumble fight. The Fly -sometimes has her head turned the wrong way round, as though the -spoiler had wrung her neck; her wings are crushed; her fur, when she -possesses any, is ruffled. I have seen some that had their bellies -ripped open by their assailant’s mandibles and had lost their legs in -the battle. As a rule, however, the victim is intact. - -No matter: considering the nature of the game, endowed with good wings -for flying, the capture must take place with a suddenness that makes it -hardly possible, I should say, to obtain paralysis unaccompanied by -death. A Cerceris face to face with her clumsy Weevil, a Sphex -grappling with the fat Cricket or the portly Ephippiger, an Ammophila -holding her caterpillar by the skin of its neck, all three have an -advantage over a prey which is too slow in its movements to avoid -attack. They can take their time, select at their ease the mathematical -spot where the sting is to penetrate, and lastly go to work with the -precision of an anatomist probing with his scalpel the patient who lies -before him on the operating-table. But with the Bembex it is a very -different matter: at the least alarm, the game nimbly makes off; and, -once on the wing, it can defy its pursuer. The Wasp has to pounce upon -her prey unawares, without considering how she shall attack or -calculating her blows, just as the Goshawk does when hunting in the -fallows. Mandibles, claws, sting, every weapon must be employed -simultaneously in the fierce fray so as to put an end as early as -possible to a contest in which the least hesitation would give the -victim time to escape. If these conjectures are borne out by the facts, -the Bembex’ prize can be nothing but a corpse or at most a mortally -wounded prey. - -Well, my conjectures are correct: the Bembex delivers her attack with a -dash which would do credit to a bird of prey. To surprise the Wasp -hunting is not an easy thing; were we never so well armed with -patience, we should watch in vain in the neighbourhood of the burrow: -the favourable opportunity would not present itself, for the insect -flies far away and there is no possibility of following it in its rapid -evolutions. Its tactics would doubtless be unknown to me but for the -assistance of a utensil from which I would certainly never have -expected such a service. I am speaking of my umbrella, which I used as -a protection against the sun in the sand of the Bois des Issarts. - -I was not the only one to profit by its shade; I was generally -surrounded by numerous companions. Gad-flies of various species would -take refuge under the silken dome and sit peacefully on every part of -the tightly-stretched cover. I was rarely without their society when -the heat became overpowering. To while away the hours when I had -nothing to do, it amused me to watch their great gold eyes, which shone -like carbuncles under my canopy; I loved to follow their solemn -progress when some part of the ceiling became too hot and obliged them -to move a little way on. - -One day, bang! The tight cover resounded like the skin of a drum. -Perhaps an oak had dropped an acorn on the umbrella. Presently, one -after the other, bang, bang, bang! Can some practical joker have come -to disturb my solitude and fling acorns or little pebbles at my -umbrella? I leave my tent and inspect the neighbourhood: nothing! The -same sharp sound is repeated. I look up at the ceiling, and the mystery -is explained. The Bembex of the vicinity, who all consume Gad-flies, -had discovered the rich provender that was keeping me company and were -impudently penetrating my shelter to seize the Flies on the ceiling. -Things were going to perfection: I had only to sit still and look. - -Every moment a Bembex would enter, swift as lightning, and dart up to -the silken ceiling, which resounded with a sharp thud. Some rumpus was -going on aloft, where the eye could no longer distinguish between -attacker and attacked, so lively was the fray. The struggle did not -last for an appreciable time: the Wasp would retire forthwith with a -victim between her legs. The dull herd of Gad-flies, at this sudden -irruption which slaughtered them one after the other, drew back a -little all round, without quitting the treacherous shelter. It was so -hot outside! Why get excited? - -Obviously, this suddenness of attack, followed by the swift removal of -the prey, does not allow the Bembex to regulate her dagger-play. The -sting no doubt performs its office, but it is directed without -precision at those spots which the hazards of the fight place within -its reach. I have seen Bembex, to finish off their half-killed -Gad-flies still struggling in the assassin’s grasp, munch the head and -thorax of the victims. This habit in itself proves that the Wasp wants -a genuine corpse and not a paralysed prey, since she ends the Fly’s -agony with so little ceremony. All things considered, therefore, I -think that, on the one hand, the nature of the prey, which dries up so -quickly, and, on the other hand, the difficulty of making such rapid -attacks, explain why the Bembex serve up dead prey to their larvæ and -consequently cater for them from day to day. - -Let us watch the Wasp as she returns to the burrow with her capture -held under her abdomen between her legs. Here comes one, the Tarsal -Bembex (B. tarsata), who arrives laden with a Bee-fly. The nest is -situated at the sandy foot of a steep bank. The huntress announces her -approach by a shrill humming, which has something plaintive about it -and which continues until the insect sets foot to earth. We see the -Bembex hover above the bank and then dip straight down, very slowly and -cautiously, all the time emitting her shrill hum. Should her keen eye -descry anything unusual, she slackens her descent, hovers for a second -or two, goes up again, comes down again and flies away, swift as an -arrow. After a few moments, here she is once more. Hovering at a -certain height, she appears to be inspecting the locality, as if from -the top of an observatory. The vertical descent is resumed with the -most cautious slowness; finally, the Wasp alights with no hesitation -whatever at a spot which to my eye has naught to distinguish it from -the rest of the sandy surface. At that instant the plaintive whimper -ceases. - -The insect, no doubt, has landed more or less on chance, since the most -practised eye cannot distinguish one spot from the other on that -expanse of sand; it has alighted somewhere near its home, of which it -will now seek the entrance, concealed after its last exit not only by -the natural falling-in of the materials but also by the Wasp’s own -careful sweeping. But no: the Bembex does not hesitate at all, does not -grope about, does not seek. By common consent the antennæ are looked -upon as organs for guiding insects in their searches. At this moment of -the return to the nest, I see nothing particular in the play of the -antennæ. Without once letting go her prey, the Bembex scratches a -little in front of her, at the very spot where she has alighted, gives -a push with her head and straightway enters, with the Fly under her -abdomen. The sand falls in, the door closes and the Wasp is at home. - -It makes no difference that I have seen the Bembex return to her nest -hundreds of times; it is always with fresh astonishment that I behold -the keen-sighted insect find without hesitation a door whose presence -there is nothing to indicate. This door, in fact, is hidden with -jealous care, not now, after the Bembex has gone in—for the -obliterating sand does not become quite level of its own weight, but -leaves perhaps a slight depression, or an incompletely blocked -porch—but certainly after she comes out, for, when starting on an -expedition, she never fails to put a finishing touch to the result of -the natural landslip. Wait for her departure and you shall see her, -before flying off, sweep the front of the door and level it with -scrupulous care. When she is gone, I defy the most penetrating eye to -find the entrance. To discover it again, when the sandy expanse was of -any size, I had to resort to a kind of triangulation; and how often, -after a few hours’ absence, did not my combinations of triangles and my -efforts of memory prove to be at fault! All that remained was the -stake, a grass-stalk planted on the threshold; and even this method was -not always effective, for the insect, with its passion for continually -improving the outside of the nest, often made the bit of straw -disappear from sight. - - - - - - - - -CHAPTER XVI - -A PARASITE OF THE BEMBEX. THE COCOON - - -I have shown the Bembex hovering with her cumbrous prize above the nest -and then dropping vertically and very slowly: a hesitating descent -accompanied by a sort of plaintive hum. This cautious arrival might -suggest that the insect is examining the ground from above in order to -find its door and trying to recall the locality before alighting. But -another motive is at work, as I propose to demonstrate. Under ordinary -conditions, when no sign of danger is apparent, the Wasp comes -suddenly, at full tilt, without any hovering, hesitating or whimpering, -and settles at once on her threshold or very near it. Her memory is so -faithful that she has no need to search about. Let us then look into -the cause of that hesitating approach which I described in the last -chapter. - -The Wasp hovers, descends slowly, ascends again, flies away and -returns, because the nest is threatened by a very grave danger. Her -plaintive hum denotes anxiety: she never emits it when there is no -peril. But who is the enemy? Can it be I, sitting here and watching? -Why, no: I am nothing to her, nothing but a shapeless mass unworthy of -her attention. The formidable enemy, the fearsome foe that must be -avoided at all costs, is there, sitting motionless on the sand, near -the house. It is a miserable little Fly, feeble and inoffensive in -appearance. This insignificant Gnat is the terror of the Bembex. The -scourge of the Fly-tribe, the fierce slayer who so swiftly wrings the -necks of colossal Gad-flies sated with blood from an Ox’s back, does -not enter her own residence because she sees herself watched by another -Fly, a regular pigmy, who would make scarcely a mouthful for her larvæ. - -Why does she not pounce upon her and get rid of the little wretch? The -Wasp is quick enough on the wing to catch her; and, small though the -capture be, the larvæ will not scorn it, since any sort of Fly suits -them. But no: the Bembex flees from a foe whom she could cut to bits -with a single stroke of her mandibles; it is to me as though I saw my -Cat fleeing in terror from a Mouse. The ardent huntress of Flies is -hunted by a Fly, and a small one at that. I bow before the facts -without hoping ever to understand this inversion of the parts played by -each insect. To be able to rid yourself easily of a mortal enemy who is -contemplating the ruin of your family and would furnish a nice little -meal for it, to be able to do that and not do it when the enemy is -there, within reach of you, watching you, defying you: this is the -height of animal aberration. But aberration is not the right word; let -us rather speak of the harmony of created things, for, since this -wretched little Fly has her tiny part to play in the general order, the -Bembex must needs respect her and like a craven flee before her, else -there would long since have been none of her left in the world. - -Let us now tell the history of this parasite. Among the nests of the -Bembex, we find very frequently some that are occupied at the same time -by the larva of the Wasp and by other larvæ, strangers to the family -and gluttonous companions of the first. These strangers are smaller -than the Bembex’ nurseling, tear-shaped and of a purplish colour, due -to the tint of the baby-food that shows through the transparent body. -They vary in number: there are sometimes half-a-dozen of them, -sometimes ten or more. They belong to a species of Fly, as is evident -from their shape and also confirmed by the pupæ which we find in their -place. Home-breeding completes the proof. When reared in boxes, on a -layer of sand, with Flies renewed from day to day, they turn into pupæ -from which, a year later, there issues a small Fly, a Tachina of the -genus known as Miltogramma. - -It is the same Fly that caused the Bembex such lively fears by lying in -ambush near the burrow. The Wasp’s terror is but too well founded. This -is what happens inside the dwelling: around the heap of food which the -mother exhausts herself in keeping up to the requisite quantity, seated -in company with the lawful offspring, are from six to ten hungry -guests, who dip their sharp-pointed mouths into the common dish with no -more restraint than if they were at home. Harmony seems to prevail at -the table. I have never seen the lawful larva grow indignant at the -indiscretion of the alien grubs, nor have I seen these appear to wish -to interfere with the other’s repast. All help themselves -indiscriminately and eat away peaceably without seeking a quarrel with -their neighbours. - -So far all would be well, if a serious difficulty did not now arise. -However active the mother-nurse may be, she is obviously not equal to -such an output. She had to be constantly hunting to feed one larva, her -own; how could she possibly manage to provide for a dozen greedy -mouths? The result of this enormous increase of family can only be -want, or even starvation, not for the Fly’s maggots, which, developing -more quickly than the Bembex’ larva, get ahead of it and profit by the -days when there is still plenty for everybody, as their host is too -young to need much, but certainly for that unfortunate host, who -arrives at the transformation period without being able to make up for -lost time. Besides, even if the first visitors, in becoming pupæ, leave -him the free run of the table, others appear upon the scene, so long as -the mother continues to come to the nest, and complete his starvation. - -In burrows invaded by numerous parasites, the Bembex’ larva is in point -of fact much smaller than one would suppose from the heap of food -consumed, the remains of which encumber the cell. Limp, emaciated, -reduced to a half or a third of its normal size, it vainly tries to -weave a cocoon for which it does not possess the silk; and it perishes -in a corner of the house among the pupæ of its more fortunate -companions. Its end may be more cruel still. Should the provisions -fail, should the mother-nurse delay too long in returning with food, -the Flies devour the larva of the Bembex. I verified this black deed by -rearing the brood myself. All went well so long as there was plenty to -eat; but, if the daily portion was omitted by accident or design, next -day or the day after I was sure to find the Fly’s grubs greedily -slicing up the larva of the Bembex. So, when the nest is invaded by the -parasites, the lawful larva is doomed to perish, either by hunger or by -a violent death; and this is what makes the Bembex hate the sight of -the Miltogrammæ prowling around her home. - -The Bembex are not the only victims of these parasites: all the -Digger-wasps without distinction have their burrows plundered by -Tachinæ and especially Miltogrammæ. Different observers, notably -Lepeletier de Saint-Fargeau, have spoken of the wiles of these -bold-faced Flies; but none of them, so far as I know, has remarked this -very curious instance of parasitism at the expense of the Bembex. I say -very curious, because the conditions are quite different. The nests of -the other Digger-wasps are stocked beforehand and the Miltogramma drops -her eggs on the pieces of game as they are taken in. When the Wasp has -finished her catering and laid her egg, she closes the cell, where -henceforth the lawful larva and the alien larvæ hatch and live together -without ever being visited in their solitude. The mother therefore is -not aware of the parasites’ brigandage, which remains unpunished -because it is unknown. - -With the Bembex it is quite another matter. The mother is constantly -returning indoors during the fortnight which it takes to rear her -grubs; she knows that her offspring is living in the company of a -number of intruders, who appropriate the best part of the food; each -time that she brings provisions to her larva, she touches and feels at -the bottom of the cavity those hungry guests who, far from contenting -themselves with the remnants, seize upon the pick of the victuals; she -must perceive, however limited her arithmetical faculties, that twelve -are more than one; besides, the consumption of food, which is out of -all proportion to her hunting powers, would tell her; and yet, instead -of taking those presumptuous aliens by the skin of the belly and -chucking them out of doors, she placidly tolerates them. - -Tolerates them, did I say? Why, she feeds them, she brings them -provisions, having perhaps for those intruders the same affection as -for her own larva! It is a new version of the story of the Cuckoo, but -with even more singular circumstances. The theory that the Cuckoo, -almost the size of the Sparrow-hawk and wearing the same dress, -inspires enough respect to enable her to introduce her egg with -impunity into the feeble Warbler’s nest, and that the latter, in her -turn, perhaps over-awed by the fearsome appearance of her Toad-faced -nurseling, accepts and looks after the stranger: this theory has some -plausibility. But what should we say if the Warbler turned parasite -and, with superb audacity, went and confided her eggs to the eyrie of -the bird of prey, to the nest of the Sparrow-hawk himself, the -bloodthirsty devourer of Warblers? What should we say if the rapacious -Hawk accepted the trust and fondly reared the brood of little birds? -And this is exactly what the Bembex does, that ravisher of Flies who -tenderly nurses other Flies, that huntress who provides food for a -quarry whose last meal will be made on her own disembowelled larva! I -leave it to others, cleverer than myself, to interpret these -astonishing relations. - -Let us observe the tactics employed by the Tachina for the purpose of -confiding her eggs to the Digger’s nest. It is an absolute rule that -the Gnat never enters the burrow, even though she should find it open -and the owner absent. The sly parasite would think twice about -venturing down a passage where, being no longer free to escape, she -might pay dear for her brazen effrontery. For her the one and only -favourable moment for her designs, a moment awaited with exquisite -patience, is that at which the Wasp dives into the gallery, with her -prey clasped to her belly. At that instant, however short it may be, -when the Bembex or any other Digger has half her body well within the -entrance and is about to disappear underground, the Miltogramma dashes -up and settles on the piece of game that projects a little way beyond -the hinder extremity of the ravisher; and, while the Bembex is delayed -by the difficulty of entering, the other, with unparalleled swiftness, -lays an egg on the prey, or even two or three in quick succession. - -The hesitation of the Wasp hampered by her load lasts but the twinkling -of an eye. No matter: this is long enough for the Gnat to accomplish -her misdeed without allowing herself to be carried beyond the -threshold. How smoothly her organs must work to adapt themselves to -this instantaneous laying! The Bembex disappears, herself introducing -the enemy to the home; and the Tachina goes and squats in the sun, -close to the burrow, to meditate fresh deeds of darkness. If we wish to -make sure that the Fly’s eggs have really been laid during this rapid -manœuvre, we need only open the burrow and follow the Bembex to the -bottom of her dwelling. The prey which we take from her bears at the -tip of its abdomen at least one egg, sometimes more, according to the -length of the delay at the entrance. These eggs are too small to belong -to any but a parasite; besides, if any doubt remained, separate rearing -in a box results in Fly-grubs, followed by the pupæ and lastly the -Miltogrammæ themselves. - -The moment adopted by the Gnat is chosen with great discrimination: it -is the only moment when she is able to accomplish her designs without -danger, and without useless dodging about. The Wasp, half-trapped in -the entrance-hall, cannot see the foe so daringly perched on the -hind-quarters of the prey; if she suspects the parasite’s presence, she -cannot drive her away, having no liberty of movement in the narrow -corridor; lastly, in spite of all the precautions which she takes to -facilitate her entrance, she cannot always vanish underground with the -necessary speed, the fact being that the bandit is much too quick for -her. This indeed is the auspicious moment and the only one, since -prudence forbids the Fly to penetrate into the cave where other Flies, -far stronger than herself, serve as food for the grub. Outside, in the -open air, the difficulty is insurmountable, thanks to the intense -vigilance of the Bembex. Let us turn for a minute to the arrival of the -mother while her home is being watched by Miltogrammæ. - -A number of these Midges, greater or less from time to time but usually -three or four, station themselves on the sand and remain perfectly -still, all gazing at the burrow, of which they well know the entrance, -carefully hidden though it be. Their dull-brown colour, their great -blood-red eyes, their indefatigable patience have often suggested to me -a picture of brigands, clad in dark frieze, with a red handkerchief -round their heads, waiting in ambush for the moment to strike a felon -blow. The Wasp arrives carrying her prey. If nothing of an alarming -nature troubled her, she would then and there alight at her door. But -she hovers at a certain height, comes down slowly and circumspectly, -hesitates; and a plaintive whimpering, resulting from a special -vibration of her wings, expresses her fears. She has seen the -malefactors therefore. They too have seen the Bembex: they follow her -with their eyes, as the movement of their red heads shows; every gaze -is turned towards the coveted booty. Now come the marches and -countermarches of craft striving to outwit prudence. - -The Bembex comes straight down, with an imperceptible flight, as though -letting herself drop inertly, buoyed up by the parachute of her wings. -She is now hovering a hand’s breadth above the ground. This is the -moment. The Midges take flight and all make for the rear of the Wasp; -they hover in her wake, some nearer, some farther, in a geometrical -line. If the Bembex turns to thwart their designs, they also turn, with -a precision that keeps them in the rear on the same straight line; if -she advances, they advance; if she retreats, they retreat, letting the -Wasp set their pace all the time, now flying slowly, now coming to a -standstill, according to the behaviour of their leader, the Bembex. -They make no attempt to fling themselves on the object of their -cupidity; their tactics are confined to keeping ready, in this -rearguard position, which will save them any hesitation at the critical -moment. - -Sometimes, wearying of this obstinate pursuit, the Bembex alights; the -others instantly settle on the sand, still in the rear, and do not -budge. The Wasp darts off again, with a shriller whimpering, a sign no -doubt of increasing indignation; the Midges dart after her. One last -method remains of throwing off the persistent Flies: dashing off at -full speed, the Bembex flies far away, hoping perhaps to mislead the -parasites by rapid evolutions across country. But the wary Gnats are -not caught in the trap: they let her go and once more take up their -positions on the sand around the burrow. When the Bembex returns, the -same pursuit will begin all over again, until at last the parasites’ -obstinacy has worn down the mother’s prudence. In that second when her -vigilance is relaxed, the Flies are straightway there. One of them, -occupying the most favourable spot, swoops upon the disappearing prey -and the deed is done: the egg is laid. - -There is ample evidence that the Bembex is aware of the danger. The -Wasp knows how disastrous the presence of the hateful Gnat may be to -the future of the nest; on this point her prolonged attempts to put off -the Tachinæ, her hesitations, her flights leave not the shadow of a -doubt. Then how is it, I ask myself once more, that the Fly-huntress -allows herself to be worried by another of the tribe, by an -infinitesimal bandit, incapable of the least resistance, whom she could -reach with a sudden rush if she tried? Why not relieve herself of the -prey that clogs her movements and swoop down upon those evil-doers? -What would be needed to exterminate the ill-omened brood that hangs -around the burrow? A battue that would take her a few seconds. But the -harmony of the universe, the laws that regulate the preservation of -species, will not have it so; and the Bembex will always allow -themselves to be harassed without ever learning from the famous -‘struggle for life’ the radical method of extermination. I have seen -them sometimes, when too close-pressed by the Midges, drop their prey -and fly away in mad haste, but without any hostile demonstration, -though the putting down of the burden left them quite free in their -movements. The abandoned prey, but now so ardently coveted by the -Tachinæ, lay on the ground, for all to do as they pleased with; and not -one of them took any notice of it. This game lying in the open air had -no value for the Midges, whose larvæ require the shelter of a burrow. -It was valueless also to the suspicious Bembex, who, on returning, felt -it for a moment and left it with scorn. A momentary break in her -vigilance had made her doubtful of it. - - - -We will end this chapter with the story of the larva. Its monotonous -life offers nothing remarkable in the fortnight during which it eats -and grows. Next comes the construction of the cocoon. The meagre -development of the silk-producing organs does not allow the grub a -dwelling of pure silk, composed, like those of the Ammophilæ and the -Sphex, of several wrappers, one outside the other, which protect the -larva and afterwards the nymph against the inroads of damp in a shallow -and exposed burrow when the rains of autumn come and the snows of -winter. Nevertheless, the Bembex’ burrow is in a worse plight than that -of the Sphex, being situated at a depth of a few inches in easily -saturated soil. Therefore, in order to construct itself an adequate -shelter, the larva makes up by its industry for its small quantity of -silk. With grains of sand artistically put together and cemented with -the silky material it builds itself an exceedingly solid cocoon, -impenetrable to damp. - -Three general methods are employed by the Digger-wasps in constructing -the sanctum in which the metamorphosis is to take place. Some dig their -burrows at great depths, under shelter: their cocoon then consists of a -single envelope, so thin as to be transparent. This is the case with -the Philanthi and the Cerceres. Others are content with a shallow -burrow in open ground; but in that case they sometimes have enough silk -to increase the number of wrappers for the cocoon, as we see with the -Sphex, the Ammophilæ and the Scoliæ, or sometimes the quantity of silk -is insufficient, when they have recourse to gummed sand, this being the -method practised by the Bembex, the Stizi and the Palari. A -Bembex-cocoon is so compact and strong that it might be taken for the -kernel of some seed. The form is cylindrical, with one end rounded and -the other pointed. The length is about three-quarters of an inch. On -the outside it is slightly wrinkled and rather coarse to look at; but -the inner walls are glazed with a fine varnish. - -My experiments in indoor breeding have enabled me to observe every -detail of the construction of this architectural curiosity, a regular -strong-box inside which the inclemencies of the weather can be braved -in safety. The larva first pushes away the remains of its food and -forces them into a corner of the cell or compartment which I have -arranged for it in a box with paper partitions. Having swept the floor, -it fixes at the different walls of its dwelling threads of a beautiful -white silk, forming a spidery web which keeps off the cumbrous heap of -broken victuals and serves as a scaffolding for the next work. - -This work consists of a hammock slung far from any dirt, in the centre -of the threads stretched from wall to wall. Nothing but silk, -magnificently fine, white silk, enters into its composition. Its shape -is that of a sack open at one end with a wide circular mouth, closed at -the other and ending in a point. An eel-trap would give a very fair -picture of it. The edges of the mouth are kept apart and permanently -stretched by numerous threads starting from there and fastened to the -adjoining walls. Lastly, the texture of this sack is extremely fine and -allows us to see all the grub’s proceedings. - -Things had been in this condition since the day before, when I heard -the larva scratching in the box. I opened it and found my prisoner -engaged in scraping the cardboard wall with its mandibles, while its -body was half outside the sack. The cardboard had already suffered -considerably and a heap of tiny fragments were piled in front of the -opening of the hammock, to be used later. For lack of other materials, -the grub would doubtless have employed these scrapings for its -building. I thought it better to provide something in accordance with -its tastes and to give it sand. Never had Bembex-larva built with such -sumptuous materials. I poured before the captive sand from my -ink-stand: blotting-sand, blue sand sprinkled with little gilt mica -spangles. - -This supply is placed in front of the mouth of the bag. The bag itself -is in a horizontal position, which is convenient for the coming task. -The larva, leaning half out of the hammock, picks up its sand almost -grain by grain, rummaging in the heap with its mandibles. If any grain -is found to be too bulky, the grub takes it and throws it away. When -the sand is thus sorted, the larva introduces a certain quantity into -the silken edifice by sweeping it with its mouth. This done, it retires -into the eel-trap and begins to spread the materials in a uniform layer -on the lower surface of the sack; then it gums the different grains and -inlays them in the fabric, using silk as cement. The upper surface is -built more slowly: the grains are carried up one by one and fixed on -with the silken putty. - -This first layer of sand as yet embraces only the front half of the -cocoon, the half that ends at the mouth of the bag. Before turning -round to work at the back half, the grub renews its supply of materials -and takes certain precautions so as not to be hindered in its mason’s -work. The sand outside, heaped up in front of the entrance, might slip -inside and embarrass the builder in so narrow a space. The grub -foresees this possibility: it glues a few grains together and makes a -rough curtain of sand, which stops up the orifice very imperfectly, but -sufficiently to prevent an accident. Having taken these precautions, -the larva works at the back half of the cocoon. From time to time it -turns round to fetch fresh supplies from outside, tearing a corner of -the curtain that protects it against the outer sand and grabbing -through this window the materials which it requires. - -The cocoon is still incomplete, wide open at the big end; it wants the -spherical cap that is to close it. For this final labour the grub takes -a plentiful supply of sand, the last supply of all, and then pushes -away the heap outside the entrance. At the opening it now weaves a -silken cap, which fits the mouth of the primitive eel-trap precisely. -Lastly, grains of sand, kept in reserve inside, are laid one by one -upon this silken foundation and glued together with silky slime. Having -finished this lid, the larva has nothing else to do but give the last -finish to the inside of the abode and glaze the walls with varnish to -protect its delicate skin against the rough sand. - -The hammock of pure silk and the hemisphere that closes it later are, -as we see, but a scaffolding intended to support the masonry of sand -and give it a regular curve; they might be compared with the wooden -moulds which builders set up when constructing an arch, a vault. Once -the work is done, the timber frame is taken away and the vault is -sustained by virtue of its perfect balance. Even so, when the cocoon is -finished, the silken support disappears, partly lost in the masonry, -partly destroyed by contact with the coarse earth; and not a trace -remains of the ingenious method followed in welding together materials -with so little consistency as sand into a building of such perfect -regularity. - -The round cap closing the mouth of the original eel-trap is a work -apart, adjusted to the main body of the cocoon. However well the two -parts are fitted and soldered, the solidity is not the same as the -larva would obtain if it built its whole dwelling continuously. The -circumference of the lid therefore has a circular line of least -resistance. But this is not a fault of construction; on the contrary, -it is a fresh improvement. The insect would find grave difficulty in -issuing later from its strong-box, so stout are the walls. The line of -junction, weaker than the others, would seem to save it a good deal of -effort, for it is mostly along this line that the cover is removed when -the Bembex emerges from the ground in the perfect state. - -I have called this cocoon a strong-box. It is indeed a very solid piece -of work, both from its shape and from the nature of its materials. -Landslips or subsidences cannot alter its outline, for the strongest -pressure of one’s fingers does not always succeed in crushing it. -Therefore it matters little to the larva if the ceiling of its burrow, -dug in loose soil, should fall in sooner or later; it does not care -much if a passing foot should press upon it under its thin covering of -sand; it has nothing to fear once it is enclosed in its stout bulwark. -Nor does damp endanger it. I have kept Bembex-cocoons immersed in water -for a fortnight at a time without afterwards discovering the least -trace of dampness inside them. Why have we no such waterproofing for -our dwellings! - -Lastly, thanks to its graceful oval, this cocoon seems rather the -product of some elaborate manufacture than that of a grub. To any one -unacquainted with the secret, the cocoons which I had built with -blotting-sand might have been jewels of some unknown workmanship, great -beads studded with golden spots on a lapis-lazuli ground, destined to -form the necklace of a Polynesian belle. - - - - - - - - -CHAPTER XVII - -THE RETURN TO THE NEST - - -The Ammophila sinking her well at a late hour of the day leaves her -work, after closing the orifice with a stone lid, flits away from -flower to flower, goes to another part of the country, and yet next day -is able to come back with her caterpillar to the home excavated on the -day before, notwithstanding the unfamiliar locality, which is often -quite new to her. The Bembex, laden with game, alights with almost -mathematical precision on the threshold of her door, which is blocked -with sand and indistinguishable from the rest of the sandy expanse. -Where my sight and recollection are at fault, their eyes and their -memory possess a sureness that is very nearly infallible. One would -think that insects had something more subtle than mere remembrance, a -kind of intuition for places to which we have nothing similar, in -short, an indefinable faculty which I call memory, failing any other -expression to denote it. There can be no name for the unknown. In order -to throw if possible a little light on this detail of animal -psychology, I made a series of experiments which I will now describe. -[40] - -The first has for its subject the Great Cerceris, who hunts -Cleonus-weevils. About ten o’clock in the morning I catch twelve -females, all belonging to the same colony and at work on the same bank, -busy digging burrows or victualling them. Each prisoner is placed -separately in a little paper bag and the whole lot put in a box. I walk -about a mile and a half from the site of the nests and then release my -Cerceres, first taking care, so that I may know them later, to mark -them with a white dot in the middle of the thorax, using a straw dipped -in indelible paint. - -The Wasps fly only a few yards away, in every direction, one here, -another there; they settle on blades of grass, pass their fore-tarsi -over their eyes for a moment, as though dazzled by the bright sunshine -to which they have suddenly been restored; then they take flight, some -sooner, some later, and all, without hesitation, make straight for the -south, that is to say, for home. Five hours later I return to the -common site of the nests. I am hardly there when I see two of my -Cerceres with white dots working at the burrows; soon a third arrives -from the fields, with a Weevil between her legs; a fourth is not slow -in following. The recognition of four out of twelve in less than -fifteen minutes was enough to convince me. I thought it unnecessary to -wait any longer. What four could do the others would do, if they had -not already done it; and I was quite at liberty to presume that the -absent eight were out hunting or else hidden in their underground -galleries. Therefore, carried for a mile and a half in a direction and -by a road of which they could not have taken cognizance in their paper -prisons, the Cerceres, or at least some of them, had returned home. - -I do not know how far the Cerceres’ hunting-grounds extend; and it is -possible that they know the country more or less over a radius of a -mile and a half. In that case, they would not have felt sufficiently -lost at the spot to which I moved them and they would have got home by -their acquired local knowledge. The experiment had to be repeated, at a -greater distance and from a starting-point which the Wasp could not be -suspected of knowing. - -I therefore take nine female Cerceres from the same group of burrows -that supplied me in the morning. Three of them had just been subjected -to the previous test. They were again carried in a dark box, each -insect enclosed in its paper bag. The starting-point selected is the -nearest town, Carpentras, which lies at about two miles from the -burrow. I am to release my insects not among the fields, as on the -first occasion, but absolutely in the street, in the centre of a -crowded neighbourhood, where the Cerceres, with their rustic habits, -had certainly never penetrated. As the day is already far advanced, I -postpone the experiments; and my captives spend the night in their -prison-cells. - -Next morning, at about eight, I mark them on the thorax with two white -spots, to distinguish them from yesterday’s lot, who were marked with -only one; and I set them free, one after the other, in the middle of -the street. Each Cerceris released first shoots straight up between the -two rows of houses, as though to escape as soon as possible from the -narrow street and gain the spacious horizons; then, rising above the -roofs, she at once darts away vigorously towards the south. And it was -from the south that I brought them; it is in the south that their -burrows are. Nine times, with nine prisoners, freed one after the -other, I had this striking instance of the way in which the insect -stranded far from home takes without hesitation the right direction for -returning to the nest. - -I myself was at the burrows a few hours later. I saw several of -yesterday’s Cerceres, recognizing them by the one white spot on the -thorax; but I saw none of those whom I had just let loose. Had they not -been able to find their home again? Were they hunting? Or were they -hiding in their galleries to recover from the excitement of such a -trial? I do not know. Next day I paid a fresh visit; and this time I -had the satisfaction of finding at work, as active as though nothing -out of the way had happened, five of the Cerceres with two white spots -on the thorax. A journey of quite two miles, the town with its houses, -its roofs, its smoky chimneys, all things so new to these utter -rustics, had not prevented them from going back to the nest. - -When taken from his brood and carried to enormous distances, the Pigeon -returns promptly to the dovecote. If we wanted to work out a proportion -between the length of the journey and the size of the creature, how -greatly superior to the Pigeon would be the Cerceris, who finds her -burrow after being carried a distance of two miles! The bulk of the -insect is not a cubic centimetre, [41] whereas that of the Pigeon must -be quite a cubic decimetre, [42] if not more. The bird, being a -thousand times larger than the Wasp, ought therefore, in order to rival -her, to find the dovecote at a distance of two thousand miles, which is -thrice the greatest length of France from north to south. I do not know -that a Carrier-pigeon has ever performed such a feat. But power of -flight and, still less, lucidity of instinct are qualities that cannot -be measured by the yard. Comparative size cannot here be taken into -consideration; and we must just look upon the insect as a worthy rival -of the bird, without deciding which of the two has the advantage. - -In returning to the dovecote and the burrow, when man has artificially -made them lose their bearings and carried them to great distances, in -unfamiliar directions and into regions which they have not yet visited, -are the Pigeon and the Cerceris guided by recollection? Is memory their -compass when, on reaching a certain height, whence they can, so to -speak, pick up the scent after a fashion, they dart with all their -power of wing towards the horizon where their nests are? Is it memory -that traces their road through the air, across regions which they are -seeing for the first time? Obviously not: there can be no recollection -of the unknown. The Wasp and the bird are unacquainted with the country -around; nothing can have told them the general direction in which they -were moved, for the journey was made in the darkness of a closed basket -or a box. Locality, relative position: everything is unknown to them; -and yet they find their way. They therefore have something better than -mere memory as a guide: they have a special faculty, a sort of -topographical sense of which we cannot possibly form an idea, having -nothing similar ourselves. - -I will show by experiment how subtle and precise this faculty is within -its narrow province, and also how obtuse and dull it becomes when -driven to depart from the usual conditions in which it acts. This is -the invariable antithesis of instinct. - -A Bembex, actively engaged in feeding her larva, leaves the burrow. She -will return presently with the produce of the chase. The entrance is -carefully stopped up with sand, which the insect has swept there -backwards before going away; there is nothing to distinguish it from -other points of the sandy surface; but this does not trouble the Wasp, -who finds her door with a skill which I have already emphasized. Let us -devise some insidious plot and change the conditions of the locality in -order to perplex the insect. I cover the entrance with a flat stone, -the size of my hand. The Wasp soon arrives. The great change effected -on her threshold during her absence appears to cause her not the -slightest hesitation; at least, the Bembex at once alights upon the -stone and tries, for an instant, to dig into it, not at random but at a -spot corresponding with the opening of the burrow. The hardness of the -obstacle soon dissuades her from her enterprise. She then runs about -the stone in every direction, goes all round it, slips underneath and -begins to dig in the exact direction of her dwelling. - -The flat stone is not enough to mislead our wide-awake friend; we must -find something better. To cut things short, I do not allow the Bembex -to continue her excavations, which, I can see, will soon prove -successful; I drive her off with my handkerchief. The fairly long -absence of the frightened insect will give me time to prepare my snares -at leisure. What materials shall I employ now? In these improvised -experiments we must know how to turn everything to use. Not far off, on -the high-road, are the fresh droppings of some beast of burden. The -very thing! The droppings are collected, broken up, crumbled and then -spread in a layer at least an inch thick on the threshold of the burrow -and all around, covering about a quarter of a square yard. This -certainly is a house-front the like of which no Bembex ever knew. The -colouring, the nature of the materials, the stercoral effluvia all -combine to mystify the Wasp. Will she take all this—that expanse of -manure, that dung—for the front of her door? Why, yes: here she comes! -She inspects the unwonted condition of the place from above and settles -in the middle of the layer, just opposite the entrance. She digs, makes -a hole through the stringy mass and reaches the sand, where she at once -finds the orifice of the passage. I stop her and drive her away a -second time. - -Is not the precision with which the Wasp alights just in front of her -door, though this be masked in a way so new to her, a proof that sight -and memory are not her only guide? What else can there be? Could it be -scent? It is very doubtful, for the emanations from the droppings have -not been able to baffle the insect’s perspicacity. Still, let us try a -different smell. I happen to have on me, as part of my entomological -luggage, a small phial of ether. I sweep away the sheet of manure and -replace it by a blanket of moss, not very thick, but spreading to a -considerable distance; and I pour the contents of my phial on it as -soon as I see the Bembex arrive. The ethereal fumes, at first too -strong, keep the Wasp away, but only for a moment. Then she alights on -the moss, which still exhales a very perceptible smell of ether, passes -through the obstacle and makes her way indoors. The ethereal effluvia -put her out no more than did the stercoral effluvia. Something surer -than scent tells her where her nest lies. - -The antennæ have often been suggested as the seat of a special sense -able to guide insects. I have already shown how the amputation of those -organs seems in no way to impede the Wasp’s investigations. Let us try -once more, under more complicated conditions. I seize the Bembex, cut -off her antennæ at the roots, and at once release her. Goaded by pain, -maddened at having been imprisoned in my fingers, the insect darts off -faster than an arrow. I have to wait for a good hour, very uncertain as -to whether it will come back. The Wasp arrives however and, with her -unvarying precision, alights quite close to her door, whose appearance -I have changed for the fourth time. The site of the nest is now covered -with a spreading mosaic of pebbles the size of a walnut. My work, -which, as regards the Bembex, surpasses what the megalithic monuments -of Brittany or the rows of menhirs at Carnac are to us, is powerless to -deceive the mutilated insect. Though deprived of her antennæ, the Wasp -finds her entrance in the middle of my mosaic as easily as the same -insect, supplied with those organs, would have done under other -conditions. This time I let the faithful mother go indoors in peace. - -Four successive alterations in the site; changes in the colour, the -smell, the materials of the outside of the home; lastly, the pain of a -double wound: all had failed to baffle the Wasp or even to make her -waver as to the precise locality of her door. I had come to the end of -my stratagems and understood less than ever how the insect, if it -possess no special guide in some faculty unknown to us, can find its -way when sight and scent are baffled by the artifices which I have -mentioned. - -A few days later, a lucky experiment reopened the question and allowed -me to study it under another aspect. In this case we uncover the -Bembex’ burrow all the way along, without changing its appearance too -much, an operation made easier by the shallowness of the burrow, its -almost horizontal direction, and the lack of consistency of the soil in -which it is dug. With this object we scrape the sand away gradually -with a knife. Thus deprived of its roof from end to end, the -underground dwelling becomes an open trench, a conduit, straight or -curved, some eight inches long, open at the spot where the -entrance-door used to be and finishing in a blind alley at the other -end, where the larva lies amid its victuals. - -Here is the home uncovered, in the bright light, under the sun’s rays. -How will the mother behave on her return? Let us consider the question -in detail, according to scientific precepts: it is a perplexing -position for the observer, as my recent experiences make me suspect. -Here is the problem: the mother on arriving has the feeding of her -larva as her object in view; but to reach this larva she must first -find the door. The grub and the entrance-door: those are the two -aspects of the question that appear to me to merit separate -consideration. I therefore take away the grub, together with the -provisions, and the end of the passage becomes a clear space. After -making these preparations there is nothing to do but exercise patience. - -The Wasp arrives at last and goes straight to where its door ought to -be, that door of which naught but the threshold remains. Here, for more -than an hour, I see her digging on the surface, sweeping, making the -sand fly, and persisting, not in scooping out a new gallery, but in -looking for that loose door which ought easily to give way before a -mere push of the head and let the insect through. Instead of yielding -materials, she finds firm soil, not yet disturbed. Warned by this -resistance, she confines herself to exploring the surface, always in -close proximity to the spot where the entrance should be. A few inches -on either side is all that she allows herself. The places which she has -already tested and swept twenty times over she returns to test and -sweep again, unable to bring herself to leave her narrow radius, so -obstinate is her conviction that the door must be here and not -elsewhere. Several times in succession I push her gently with a straw -to some other point. She will not be put off: she returns straightway -to the place where her door once stood. At rare intervals the gallery, -now an open trench, seems to attract her attention, though very -faintly. The Bembex takes a few steps towards it, still raking, and -then goes back to the entrance. Twice or thrice I see her run the whole -length of the conduit and reach the blind alley, the abode of her grub; -here she gives a few careless strokes of the rake and hurries back to -the spot where the entrance used to be, continuing her quest there with -a persistency that ends by wearying mine. More than an hour has passed -and the stubborn Wasp is still pursuing her search on the site of the -vanished doorway. - -What will happen when the larva is present? This is the next aspect of -the question. To continue the experiment with the same Bembex would not -have given me the positive evidence which I wanted, for the insect, -rendered more obstinate by its vain quest, seemed to me now obsessed by -a fixed idea, which would certainly have obscured the facts which I -wished to ascertain. I needed a fresh subject, one not over-excited and -solely concerned with the impulses of the first moment. An opportunity -soon presented itself. - -I uncover the burrow from end to end as I have just explained, but -without touching the contents: I leave the larva in its place, I -respect the provisions; everything in the house is in order; there is -nothing lacking but the roof. Well, in front of this open dwelling, of -which the eye freely takes in every detail: entrance-hall, gallery, -cell at the back with the grub and its heap of Flies; in front of this -dwelling now a trench, at the end of which the larva wriggles under the -blistering rays of the sun, the mother behaves exactly as her -predecessor did. She alights at the point where the entrance used to -be. It is here that she does her digging and sweeping; and it is here -that she always returns after hurried visits elsewhere, within a radius -of a few inches. There is no exploration of the tunnel, no anxiety -about the tortured larva. The grub, whose delicate epidermis has just -passed from the cool moisture of an underground cave to the fierce -blaze of an untempered sun, is writhing on its heap of chewed Flies; -the mother does not give it a thought. To her it is no more than any -other object lying on the sand: a little pebble, a pellet of earth, a -scrap of dry mud, nothing more. It is unworthy of attention. This -tender and faithful mother, who wears herself out in trying to reach -her nurseling’s cradle, is wanting at the moment her entrance-door, the -usual door and nothing but that door. What stirs her maternal heart is -her yearning for the well-known passage. And yet the way is open: there -is nothing to stop the mother; and the grub, the ultimate object of her -anxiety, is tossing restlessly before her eyes. One bound would bring -her to the side of the poor thing clamouring for assistance. Why does -she not rush to her beloved nurseling? She could dig it a new dwelling -and swiftly place it in safety underground. But no; the mother persists -in seeking a passage that no longer exists, while her child is grilling -in the sun before her eyes. My surprise is intense in the presence of -this short-sighted mother, though the sense of motherhood is the most -powerful and resourceful of all the feelings that stir the animal -creation. I should hardly believe the evidence of my eyes but for -experiments endlessly repeated with Cerceres and Philanthi as well as -with Bembex of different species. - -Here is something more remarkable still: the mother, after prolonged -hesitation, at last enters the roofless trench, all that remains of the -original corridor. She goes forward, draws back, goes forward again, -giving a few careless sweeps, here and there, without stopping. Guided -by vague recollections and perhaps also by the smell of game emitted by -the heap of Flies, she occasionally reaches the end of the gallery, the -very spot at which the larva lies. Mother and son are now together. At -this moment of meeting after long suffering, have we a display of eager -solicitude, exuberant affection, any signs whatever of maternal joy? If -you think so, you need only repeat my experiments to persuade yourself -to the contrary. The Bembex does not recognize her larva at all; it is -to her a worthless thing, something in her way, a nuisance. She walks -over the grub, treads on it ruthlessly, as she hurries to and fro. When -she wants to try and dig at the bottom of the cell, she thrusts it back -with a brutal kick; she shoves it on one side, topples it over, flings -it out as unceremoniously as if it were a big bit of gravel that -hindered her in her work. Thus knocked about, the grub thinks of -defending itself. I have seen it seize its mother by the tarsus with no -more ceremony than it shows when it bites off the leg of its prey, the -Fly. The struggle was hotly contested; but at last the fierce mandibles -let go and the mother vanished in terror, making a shrill whimpering -noise with her wings. This unnatural sight of the son biting his mother -and perhaps even trying to eat her is uncommon and is brought about by -circumstances which the observer has not at his command; but what can -always be witnessed is the Wasp’s profound indifference towards her -offspring and the brutal contempt with which she treats that irksome -lump of rubbish, the grub. Once she has raked out the end of the -passage, which is the work of a moment, the Bembex returns to her -favourite spot, the threshold, where she resumes her useless search. As -for the grub, it continues to writhe and wriggle wherever its mother -has kicked it. It will die without the mother’s coming to its -assistance, for she fails to recognize it because she was unable to -find the customary passage. Go back to-morrow and you shall see it -lying in its trench, half baked by the sun and already a prey to the -very Flies that were once its prey. - -Such is the concatenation of instinctive actions, linked one to the -other in an order which the gravest circumstances are powerless to -disturb. What, after all, is the Bembex looking for? Her larva, -obviously. But, to get at that larva, she must enter the burrow; and, -to enter that burrow, she must first of all find the door. And it is in -the search for this door that the mother persists, despite the -wide-open gallery, despite the provisions, despite the grub, all -exposed to view. At the moment she cares not that her house is in ruins -and her family in danger; what she wants above all things is the -familiar passage, the passage through the loose sand. Perish -everything, dwelling and inmate, if this passage be not found! Her -actions are like a series of echoes each awakening the next in a -settled order, which allows none to sound until the previous one has -sounded. The first action could not be performed, not because of an -obstacle, for the house is wide open, but for want of the usual -entrance. That is enough: the subsequent actions shall not be -performed; the first echo was dumb and all the rest are silent. What a -gulf separates intelligence and instinct! Through the ruins of the -demolished dwelling, a mother guided by intelligence hurries straight -to her son; guided by instinct, she comes to a stubborn halt on the -site of her old door. - - - - - - - - -CHAPTER XVIII - -THE HAIRY AMMOPHILA - - -One day in May I was walking up and down, on the look-out for anything -fresh that might be taking place in the harmas [43] laboratory. Favier -was not far off, at work in the kitchen-garden. Who is Favier? I may as -well say a few words about him at once, for we shall be hearing of him -again. - -Favier is an old soldier. He has pitched his hut of clay and branches -under the African carob-trees; he has eaten Sea-urchins at -Constantinople; he has shot Starlings in the Crimea, during a lull in -the firing. He has seen much and remembered much. In winter, when work -in the fields ends at four o’clock and the evenings are long, he puts -away rake, fork, and barrow and comes and sits on the hearth-stone of -the kitchen fireplace, where the billets of ilex-wood blaze merrily. He -fetches out his pipe, fills it methodically with a moistened thumb and -smokes it solemnly. He has been thinking of it for many a long hour; -but he has abstained, for tobacco is expensive. The privation has -doubled the charm; and not a puff, recurring at regular intervals, is -wasted. - -Meanwhile, we start talking. Favier is, in his fashion, one of those -bards of old who were given the best seat at the hearth, for the sake -of their tales; only, my story-teller was formed in the barrack-room. -No matter: the whole household, large and small, listen to him with -interest; though his speech is full of vivid images, it is always -decent. It would be a great disappointment to us if he did not come, -when his work was done, to take his ease in the chimney-corner. - -What does he talk about to make him so popular? He tells us what he saw -of the coup d’État to which we owe the hated Empire; he talks of the -brandy served out and of the firing into the mob. He—so he assures -me—always aimed at the wall; and I accept his word for it, so -distressed does he appear to me and so ashamed of having taken a hand, -however innocent, in that felon’s game. - -He tells us of his watches in the trenches before Sebastopol; he speaks -of his sudden terror when, at night, all alone on outpost duty, -squatting in the snow, he saw fall beside him what he calls a -flower-pot. It blazed and flared and shone and lit up everything -around. The infernal machine threatened to burst at every second; and -our man gave himself up for lost. But nothing happened: the flower-pot -went out quietly. It was a star-shell, an illuminating contrivance -fired to reconnoitre the assailant’s outworks in the dark. - -The tragedy of the battle-field is followed by the comedy of the -barracks. He lets us into the mysteries of the stew-pan, the secrets of -the mess, the humorous hardships of the cells. And, as his stock of -anecdotes, seasoned with racy expressions, is inexhaustible, the -supper-hour arrives before any of us has had time to remark how long -the evening is. - -Favier first attracted my notice by a master-stroke. One of my friends -had sent me from Marseilles a pair of enormous Crabs, the Maia, the -Sea-spider or Spider-crab of the fishermen. I was unpacking the -captives when the workmen returned from their dinner: painters, -stone-masons, plasterers engaged in repairing the house which had been -empty so long. At the sight of those strange animals, studded with -spikes all over the carapace and perched on long legs that give them a -certain resemblance to a monstrous Spider, the onlookers gave a cry of -surprise, almost of alarm. Favier, for his part, remained unmoved; and, -as he skilfully seized the terrible Spider struggling to get away, he -said - -‘I know that thing; I’ve eaten it at Vasna. It’s first-rate.’ - -And he looked round at the bystanders with an air of humorous mockery -which was meant to convey: - -‘You’ve never been out of your hole, you people.’ - -One more story of him, to have done. A woman living in his -neighbourhood had been, by the doctor’s advice, to take the sea-baths -at Cette. She returned from her trip bringing with her a curious thing, -a strange fruit on which she based high hopes. When held to the ear and -shaken, it rattled, proving that it contained seeds. It was round and -prickly. At one end was a sort of bud, closed with a little white -flower; at the other, a slight cavity was pierced with a few holes. - -The neighbour ran round to Favier to show him her find and asked him to -mention it to me. She would make me a present of the precious seeds, -the idea being that some wonderful shrub would grow from them and -beautify my garden. - -‘Vaqui la flou, vaqui lou pécou: here is the flower, here is the tail.’ -she said, showing Favier the two ends of her fruit. - -Favier roared with laughter: - -‘It’s a Sea-urchin.’ he said, ‘a Sea-chestnut; I’ve eaten them at -Constantinople!’ - -And he explained as best he could what a Sea-urchin is. The woman did -not understand a word of what he said and persisted in her contention. -She was convinced that Favier was deceiving her, jealous at the thought -that such precious seeds should reach me through any other intermediary -than him. The issue was submitted to me. - -‘Vaqui la flou, vaqui lou pécou,’ repeated the good woman. - -I told her that the flou was the cluster formed by the Urchin’s five -white teeth and that the pécou was the antipodes of the mouth. She went -away only half convinced. It may be that, at this moment, the seeds of -the fruit, grains of sand rattling in the empty shell, are germinating -in some old broken-mouthed pipkin. - -Favier, therefore, knows many things; and he knows them more -particularly through having eaten them. He knows the virtues of a -Badger’s back, the toothsome qualities of the leg of a Fox; he is an -expert as to the best part of that Eel of the bushes, the Snake; he has -browned in oil the Eyed Lizard, the ill-famed Rassade of the South; he -has thought-out the recipe of a fry of Locusts. I am astounded at the -impossible stews which he has concocted during his cosmopolitan career. - -I am no less surprised at his penetrating eye and his memory for -things. I have only to describe some plant, which to him is but a -nameless weed, devoid of the least interest; and, if it grows in our -woods, I feel pretty sure that he will bring it to me and tell me the -spot where I can pick it for myself. The botany of the infinitesimal -even does not foil his perspicacity. To complete my already-published -work on the Sphæriaceæ of Vaucluse, I resume my patient herborizing -with the lens during the bad weather, the insect’s slack time. When the -frost hardens the ground, when the rains reduce it to slush, I take -Favier away from his work in the garden to scour the woods with me; and -there, in the tangle of some bramble-bush, we hunt together for those -microscopic growths which speckle with black dots the tiny branches -strewn all over the soil. He calls the largest species ‘gunpowder,’ an -accurate expression which has already been used by the botanists to -describe one of those Sphæriaceæ. He feels quite proud of his bunch of -discoveries, which is richer than mine. When he lights upon a -magnificent rosellinia, a mass of black pustules wrapped in a purplish -down, we smoke a pipe to celebrate the joyous occasion. - -He excels, above all things, in ridding me of the troublesome folk whom -I meet upon my rambles. The peasant is naturally curious, as fond of -asking questions as a child; but his curiosity is flavoured with a -spice of malice and in all his questions there is an undercurrent of -chaff. What he fails to understand he turns into ridicule. And what can -be more ludicrous than a gentleman looking through a glass at a Fly -captured with a gauze net, or a bit of rotten wood picked up from the -ground? Favier cuts short the bantering catechism with a word. - -We were hunting along the ground, step by step, with bent backs, for -some of the evidences of prehistoric times that abound on the south -side of the mountain: serpentine-stone axes, black potsherds, flint -arrow-heads and spear-heads, flakes, side-scrapers, cores. - -‘What does your master do with those ‘payrards?’ [44] asked a new -arrival. - -‘He makes them into putty for the glaziers,’ replied Favier, with an -air of solemn assurance. - -Another time, I had just gathered a handful of Rabbit-droppings in -which the magnifying-glass had shown me a cryptogamous growth worthy of -further inspection. Up comes an inquisitive person who has seen me -carefully packing the precious windfall in a paper bag. He suspects a -money-making business, some crazy trade or other. Everything, to the -countryman, is translatable into terms of francs and sous. In his eyes, -I am making a steady income out of these Rabbit-droppings. - -‘What does your master do with those pétourles?’ [45] he asks Favier, -in ingratiating tones. - -‘He distils them to extract the essential oils,’ replies my man, with -magnificent self-possession. - -Stunned by this revelation, the questioner turns his back and goes -away. - -But let us waste no more time with the waggish old soldier and his -smart repartees and let us rather come to what was attracting my -attention in the harmas laboratory. Some Ammophilæ were exploring on -foot, with brief intervals of flight, both the grass and the bare -patches of ground. I had seen them as early as the middle of March, -when a fine day made its appearance, warming themselves luxuriously in -the dusty paths. All belonged to the same species, the Hairy Ammophila -(A. hirsuta, Kirb.). I have already written of the hibernation of this -Ammophila and her venery in mid-spring, at a period when the other -Hunting Wasps are still imprisoned in their cocoons; I have described -her manner of operating on the caterpillar destined for her grub; I -have told of the repeated stings of her dart, distributed over the -different nerve-centres. This scientific vivisection I had as yet -observed but once; and I longed to see it again. Something might have -escaped me on the first occasion, when a long walk had tired me; and, -even if I had really seen everything correctly, it was advisable to -witness the performance a second time, so as to establish its -authenticity beyond all doubt. I may add that one would never weary of -the spectacle, even if it were repeated a hundred times over. - -I therefore watched my Ammophilæ from the moment of their first -appearance; and, as I had them here, within my precincts, only a few -steps from my door, I could not fail to catch them hunting, provided -that my assiduity were not relaxed. The end of March and the whole of -April were spent in vain waiting, either because the moment of -nidification had not yet come, or, more probably, because my vigilance -was at fault. At last, on the 17th of May, a lucky chance presented -itself. - -A few Ammophilæ strike me as very busy: suppose we follow one of them, -more active than the rest. I detect her giving a last sweep of the rake -to her burrow, on the smooth, hard path, before introducing her -caterpillar, which, already paralysed, must have been abandoned by the -huntress, for the time being, a few yards away from the home. The cave -is pronounced spick and span, the doorway deemed sufficiently wide to -admit a bulky prey; and the Ammophila sets off in search of her -captive. She finds it easily. It is a Grey Worm, lying on the ground; -and the Ants have already invaded it. This prize, for which the Ants -contend with her, is scorned by the huntress. Many predatory Wasps, who -temporarily leave their prisoner to go and complete the burrow, or even -to begin it, lodge their game high up, on a tuft of verdure, to place -it beyond the reach of plunderers. The Ammophila is familiar with this -prudent practice; but perhaps she has omitted to take the precaution, -or else the heavy prize has fallen to the ground, and now the Ants are -tugging in eager rivalry at the sumptuous fare. To drive away those -pilferers is impossible: for one sent to the right-about, ten would -return to the attack. So the Wasp seems to think; for, realizing the -invasion, she resumes her hunting, without indulging in useless strife. - -The quest takes place within a radius of ten yards from the nest. The -Ammophila explores the soil on foot, little by little, without -hurrying; she lashes the ground continually with her antennæ curved -like a bow. The bare soil, the pebbly bits, the grassy parts are -visited without distinction. For nearly three hours, in the heat of the -sun, in sultry weather which means rain to-morrow and a few drops -to-night, I watch the Ammophila’s search, without taking my eyes from -her for a second. What a difficult thing a Grey Worm is to find, for a -Wasp who needs it just at that moment! - -It is no less difficult for man. The reader knows my method of -witnessing the surgical operation to which a Hunting Wasp subjects her -prey, with a view to giving her grubs flesh that is lifeless but not -dead. I rob the marauder of her spoil and, in exchange, give her a live -prey, similar to her own. I was arranging the same manœuvre with regard -to the Ammophila, so that, after she had smitten her caterpillar, which -she was bound to find at any moment now, I might make her perform the -operation a second time. I was therefore in urgent need of a few Grey -Worms. - -Favier was there, gardening. I called out to him: - -‘Come here, quick; I want some Grey Worms!’ - -I explain the thing to him; for that matter, he has known all about it -for some time. I have talked to him of my little creatures and the -caterpillars which they hunt; he has a general knowledge of the habits -of the insect which I am studying. He understands at once and goes in -search. He digs at the foot of the lettuces, he scrapes among the -strawberry-beds, he inspects the iris-borders. I know his sharp eyes -and his intelligence; I have every confidence in him. Meanwhile, time -passes. - -‘Well, Favier? Where’s that Grey Worm?’ - -‘I can’t find one, sir.’ - -‘Bother! Then come to the rescue, you others! Claire, Aglaé, all of -you! Hurry up, hunt and find!’ - -The whole family is brought into requisition. All its members display -an activity worthy of the serious events at hand. I myself, chained to -my post lest I should lose sight of the Ammophila, keep one eye upon -the huntress and with the other watch for Grey Worms. Nothing turns up: -three hours pass and not one of us has found the caterpillar. - -The Ammophila does not find it either. I see her hunting with some -persistency in spots where the earth is slightly cracked. The insect -wears itself out in clearing operations; with a mighty effort it -removes lumps of dry earth the size of an apricot-stone. Those spots -are soon abandoned, however. Then a suspicion comes to me: the fact -that there are four or five of us vainly hunting for a Grey Worm does -not prove that the Ammophila is troubled with the same want of skill. -Where man is helpless, the insect often triumphs. The exquisite -delicacy of perception that guides it cannot leave it at a loss for -hours together. Perhaps the Grey Worm, foreseeing the gathering storm, -has dug its way lower down. The huntress very well knows where it lies, -but cannot extract it from its deep hiding-place. When she abandons a -spot after a few attempts, it is not for want of sagacity, but for want -of the requisite power of digging. Wherever the Ammophila scratches, -there must a Grey Worm be: the place is abandoned because the work of -extraction is admittedly beyond her strength. It was very stupid of me -not to have thought of it earlier. Would such an experienced poacher -pay any attention to a place where there is really nothing? What -nonsense! - -I thereupon resolve to come to her assistance. The insect, at this -moment, is digging a tilled and absolutely bare spot. It leaves the -place, as it has already done with so many others. I myself continue -the work, with the blade of a knife. I do not find anything either; and -I retire. The insect comes back and again begins to scratch at a -certain part of my excavations. I understand: - -‘Get out of that, you clumsy fellow!’ the Hymenopteron seems to say. -‘I’ll show you where the thing lives!’ - -Upon her indications I dig at the required spot and unearth a Grey -Worm. Well done, my canny Ammophila! Did I not say that you would never -have raked at an empty burrow? - -Henceforth, it is like a hunt for truffles, which the Dog points out -and the man extracts. I continue on the same system, the Ammophila -showing me the place and I digging with the knife. I thus obtain a -second Grey Worm, followed by a third and a fourth. The exhumation is -always effected at bare spots that have been turned by the pitchfork a -few months earlier. There is absolutely nothing to denote the presence -of the caterpillar from without. Well, Favier, Claire, Aglaé and the -rest of you, what have you to say? In three hours you have not been -able to dig me up a single Grey Worm, whereas this clever huntress -supplies me with as many as I want, once that I have thought of coming -to her assistance! - -I have now plenty of spare pieces; let us leave the huntress her fifth -prize, which she unearths with my help. I will set forth in numbered -paragraphs the various acts of the gorgeous drama that passes before my -eyes. The observation is made under the most favourable conditions: I -am lying on the ground, close to the slaughterer, and not one detail -escapes me. - -1. The Ammophila seizes the caterpillar by the back of the neck with -the curved pincers of her mandibles. The Grey Worm struggles violently, -rolling and unrolling its contorted body. The Wasp remains quite -unconcerned: she stands aside and thus avoids the shocks. Her sting -strikes the joint between the first segment and the head, on the median -ventral line, at a spot where the skin is more delicate. The dart stays -in the wound with some persistency. This, it appears, is the essential -blow, which will master the Grey Worm and make it more easy to handle. - -2. The Ammophila now quits her prey. She flattens herself on the -ground, with wild, disordered movements, rolling on her side, twitching -and dangling her limbs, fluttering her wings, as though in danger of -death. I fear lest the huntress may have received a nasty wound in the -contest. I am overcome with emotion at seeing the plucky Wasp finish so -piteously, at seeing the experiment that has cost me so many hours of -waiting end in failure. But suddenly the Ammophila recovers, smooths -her wings, curls her antennæ and returns briskly to the attack. What I -had taken for the convulsions of approaching death was the frenzied -enthusiasm of victory. The Wasp was congratulating herself on the -manner in which she had floored the enemy. - -3. The operator grips the caterpillar by the skin of the back, a little -lower than before, and pricks the second segment, still on the ventral -surface. I then see her gradually recoiling along the Grey Worm, each -time seizing the back a little lower down, clasping it with the -mandibles, those wide pincers with the curved jaws, and each time -driving the sting into the next segment. This recoil of the insect and -this gradual clasping of the back, a little farther down on each -occasion, are effected with methodical precision, as though the -huntress were measuring her prey. At each step backward the dart stings -the following segment. In this way are wounded the three thoracic -segments, with the true legs; the next two segments, which are legless; -and the four segments with the pro-legs. In all, nine stings. The last -four segments are disregarded: they consist of three without legs and -the last, or thirteenth, with pro-legs. The operation is accomplished -without serious difficulty: after the first prick of the needle, the -Grey Worm offers but a feeble resistance. - -4. Lastly, the Ammophila, opening the forceps of her mandibles to their -full width, seizes the caterpillar’s head and crunches it, squeezes it -with a series of leisurely movements, without creating a wound. These -squeezings follow upon one another with deliberate slowness: the insect -seems to try each time to learn the effect produced; it stops, waits, -and then resumes the attack. This manipulation of the brain, to attain -the desired end, must have certain limits which, if exceeded, would -bring about death and speedy putrefaction. And so the Wasp regulates -the force of her compressions, which, moreover, are numerous: about a -score, in all. - -The surgeon has finished. The patient lies on the ground on its side, -half doubled up. It is motionless, lifeless, incapable of resistance -during the traction-process that is to bring it home, unable to harm -the grub that is to feed upon it. The Ammophila leaves it at the place -where the operation was performed and goes back to her nest. I follow -her. She makes certain improvements in view of the coming storage. A -pebble projecting from the roof might impede the warehousing of the -bulky quarry. The lump is forthwith removed. A rustle of grazed wings -accompanies the arduous task. The back-room is not large enough: it is -widened. The work is long-drawn-out; and the caterpillar, which I have -neglected to watch, lest I should miss any of the Wasp’s doings, is -invaded by the Ants. When the Ammophila and I return to it, it is black -all over with busy carvers. This is a regrettable incident for me and a -grievous event for the Ammophila; for it is the second time that she -has met with the same mishap. - -The insect appears discouraged. In vain I replace the caterpillar by -one of my reserve of Grey Worms: the Ammophila scorns the substituted -prey. Besides, evening is drawing in, the sky has clouded, there are -even a few drops of rain falling. In these circumstances it is needless -to look for a renewal of the chase. Everything, therefore, ends, -without my being able to use my Grey Worms as I had proposed. - -This observation kept me engaged, without a moment’s respite, from one -o’clock in the afternoon until six o’clock in the evening. - - - - - - - - -CHAPTER XIX - -AN UNKNOWN SENSE - - -I have described the Ammophila’s hunting tactics in detail. The facts -which I ascertained seem to me so rich in results that, even if the -harmas laboratory supplied me with nothing more, I should think myself -indemnified by this one observation. The surgical methods adopted by -the Wasp with the object of paralysing the Grey Worm are the highest -manifestation in the realm of instinct that I have hitherto met. This -inborn science is eminently calculated to give us food for thought. -What a subtle logician, what an unerring operator is that unconscious -physiologist, the Ammophila! - -He who would witness these marvels for himself can hardly count on what -a country walk may happen to show him; besides, if the lucky -opportunity did present itself, he would not have time to profit by it. -An observation, which I kept up for five hours on end, without even -then managing to complete the experiment and obtain the proofs which I -anticipated, is one that, to be properly conducted, should be made at -leisure in one’s own garden. I owe my success, therefore, to my rustic -laboratory. I make a present of the secret to whosoever would continue -those magnificent studies: the harvest is inexhaustible; there will be -sheaves for all. - -When we follow the Ammophila’s hunting in the due sequence of her -actions, the first question that suggests itself is this: how does the -Wasp go to work to recognize the spot beneath which the Grey Worm lies? - -There is nothing outside, nothing, at least, perceptible to the eye, to -indicate the caterpillar’s hiding-place. The soil that conceals the -quarry may be grassy or bare, flinty or earthy, smooth or seamed with -little cracks. These varieties of appearance are matters of -indifference to the huntress, who prospects every spot without showing -preference for one more than another. At no place where the Wasp stops -and digs with some persistency do I see anything particular, in spite -of all my attention; and yet there must be a Grey Worm there, as I have -but now convinced myself, five times in succession, by lending a -helping hand to the insect, which was at first discouraged by a task -out of proportion to its strength. Sight, therefore, is certainly out -of the question here. - -What sense, then? That of touch? Let us inquire. Everything tells us -that the organs of search are the antennæ. With their tips, bent like a -bow and quivering with a continual vibration, the insect tests the -ground, giving a number of little taps. When some crack shows, the -restless threads enter and sound it; when some grass-tuft spreads its -tangled root-stock along the ground, the quivering of the antennæ -redoubles as they grope among its knots and angles. Their tips are -applied for an instant to the spot explored, moulding themselves, so to -speak, upon it. They suggest two tactile filaments, two long fingers of -incomparable mobility, which gather information by feeling. But the -sense of touch can play no part in revealing what is underground: the -thing to be felt is the Grey Worm; and the worm is lying snug in its -burrow, at a depth of some inches below the surface. - -We thereupon turn our thoughts to the faculty of scent. Insects, there -is no denying, possess the sense of smell, often very highly developed. -The Necrophori, [46] the Silphæ, [47] the Histers, [48] the Dermestes -[49] hasten from every side to the spot where lies a little corpse of -which the ground is to be purged. Guided by scent, these grave-diggers -hurry towards the dead Mole. - -But, while the presence of the olfactory sense in insects is -indisputable, we still ask ourselves where it is seated. Many declare -that the seat is in the antennæ. Let us admit this, though it is -difficult to understand how a rod consisting of horny segments, jointed -end to end, can fulfil the office of a nostril which is so very -differently constructed. The organization of one apparatus having -naught in common with the other, can the impressions received by both -be of the same nature? When tools are dissimilar, do their functions -remain alike? - -Besides, there are grave objections in the case of our Wasp. Smell is a -passive rather than an active sense; it does not, like touch, -anticipate the impression: it receives it; it does not inquire after -the scented effluvium: it accepts it when it comes. Now the Ammophila’s -antennæ are always moving: they investigate, they anticipate the -impression. The impression of what? If it were really an impression of -smell, repose would serve them better than a perpetual quivering. - -But there is more to be said: the olfactory sense goes for nothing when -there is no smell. Now I have tested the Grey Worm for myself; I have -given it to young nostrils to sniff, nostrils much more sensitive than -mine: not one of us has perceived the faintest trace of smell in the -caterpillar. When the Dog, famed for his scent, becomes aware of the -truffle underground, he is guided by the tuber’s savour, which is -highly appreciable by ourselves, even through the thickness of the -soil. I admit that the Dog has a more subtle sense of smell than we -have: it is exercised at greater distances, it receives more vivid and -lasting impressions; nevertheless, it is impressed by odorous effluvia -which becomes perceptible to our own nostrils under the proper -conditions of proximity. - -I will allow the Ammophila, if you like, a scent as delicate as that of -the Dog, more delicate even; but still a smell is needed; and I ask -myself how that which is inodorous at the very entrance to our nostrils -can be odoriferous to an insect through the intervening obstacle of the -ground. The senses, if they have the same functions, have the same -excitants, from man to the Infusoria. No animal, so far as I know, can -see clearly in what to us is absolute darkness. True, it may be said -that, in the zoological progression, perception, always fundamentally -the same, has varying degrees of power: this species is capable of more -and that species of less; what is perceptible to one is imperceptible -to another. This is perfectly right; and yet the insect, generally -considered, does not appear to possess exceptional keenness of scent: -the effluvia that attract it are perceived without a sense of smell of -unusual delicacy. When Dermestes, Silphæ and Histers pour into the -chalice of a carrion-scented arum lily, never to come out again; when -swarms of Flies buzz around a dead Dog’s blue and swollen belly, the -whole neighbourhood reeks with the stench. It hardly requires a scent -of exquisite accuracy on the insect’s part to discover putrid meat and -rotten cheese. Wherever we see its hordes gather, with scent for their -undoubted guide, we ourselves are cognizant of a smell. - -There remains hearing. This is another sense about which entomologists -are not adequately informed. Where is its seat? In the antennæ, we are -told. Those fine, quivering stalks would seem fairly well suited to be -put in motion under the impulse of sound. In that case the Ammophila, -exploring the region with her antennæ, would be warned of the presence -of the Grey Worm by a slight noise coming up from the ground, the noise -of the mandibles nibbling a root, the noise of the caterpillar -wriggling its hind-quarters. What a faint sound and how difficult to -transmit through the spongy cushion of the earth! - -It is less than faint, it is non-existent. The Grey Worm is nocturnal -in its habits. By day it skulks in its lair and does not stir. It does -not nibble either; at least, the Grey Worms which I unearthed upon the -Wasp’s indications were nibbling nothing, for the very simple reason -that they had nothing to nibble. They were completely motionless and -therefore silent in a layer of earth devoid of roots. The sense of -hearing must be rejected with that of smell. - -The question recurs, more abstruse than ever. How does the Ammophila go -to work to recognize the spot beneath which the Grey Worm lies? The -antennæ are, beyond a doubt, the organs that guide her. They do not, in -this case, act as olfactory instruments, unless we admit that their dry -and tough surface, which has none of the delicate structure required -for the ordinary sense of smell, is nevertheless capable of perceiving -scents that are non-existent to us. This would be equivalent to -admitting that coarse tools tend to perfection of work. Nor do they act -as instruments of hearing, for there is no sound to be discerned. What -then is their function? I do not know and I despair of ever knowing. - -Inclined as we are—and it could not well be otherwise—to judge all -things by our standard, the only one in any way known to us, we -attribute to animals our own means of perception and do not dream that -they might easily possess others of which it is impossible for us to -have an exact idea because there is nothing like them in ourselves. Are -we quite certain that they are not equipped, in very varying degrees, -for the purpose of sensations as foreign to ourselves as the sensation -of colours would be if we were blind? Has matter no secrets left for -us? Are we so very sure that it is revealed to the living being only by -light, sound, taste, smell and touch? Physics and chemistry, young -though they be, already declare to us that the dark unknown contains an -enormous harvest, in comparison with which our scientific sheaf is the -merest penury. A new sense, perhaps that which dwells in the -grotesquely exaggerated nose of the Rhinolophus, [50] perhaps that -which dwells in the antennæ of the Ammophila, would open to our search -a world which our physical structure no doubt condemns us to leave for -ever unexplored. Cannot certain properties of matter, which have no -perceptible action upon us, find a receptive echo in animals, which are -differently equipped? - -When Spallanzani, [51] after blinding some Bats, released them in a -room converted into a maze by means of cords stretched in every -direction and of heaped-up brambles, how were those animals able to -find their way about, to fly quickly, to move to and fro, from end to -end of the room, without hitting the interposed articles? What sense -analogous to any of ours guided them? Would some one tell me and, above -all, make me understand? I should also like to understand how the -Ammophila infallibly finds her caterpillar’s burrow with the aid of her -antennæ. It is not a case of the sense of smell: we should have to -presume it to possess an unparalleled delicacy, while recognizing that -it is exercised by an organ in which no provision seems made for the -perception of smells. - -What a number of other incomprehensible things do we not ascribe to the -insect’s sense of smell! We are satisfied with a word: the explanation -is ready-found, without laborious search. But, if we care to consider -the matter thoroughly, if we compare the requisite array of facts, then -the cliff of the unknown rises abruptly, not to be climbed by the path -which we insist on following. Let us then change our path and admit -that animals may have other means of information than our own. Our -senses do not represent the sum total of the methods whereby an animal -communicates with that which is not itself: there are others not -capable of comparison, however remote, with those which we possess. - -If the act of the Ammophila were an isolated fact, I should not have -lingered over it as I have done; but I propose to speak of others -stranger still, which will carry conviction to the most exacting mind. -After relating them, therefore, I shall return to the subject of -special senses, irreducible senses, unknown to us. - -For the moment, let us go back to the Grey Worm, which it would be as -well for us to know in a less casual fashion. I have four of them, dug -up with the knife at the spots indicated by the Ammophila. My intention -was to substitute them, by turns, for the doomed victim, so as to see -the Wasp’s operation repeated. When my plan failed, I placed the worms -in a glass jar, with a layer of earth and a lettuce-stalk above them. -By day, my captives remained buried in the earth; at night, they came -up to the surface, where I caught them gnawing at the salad from below. -In August, they dug deep down, not to come up again, and fashioned -themselves a cocoon apiece of earth, very rough on the outer surface, -oval in shape and the size of a small pigeon’s egg. The moth appeared -at the end of the same month. I recognized the Dart or Turnip Moth -(Noctua segetum, Hübn.). - -The Hairy Ammophila, therefore, feeds her grubs on the caterpillars of -Noctuæ; and her choice falls exclusively on the species that live -underground. These caterpillars, commonly known as Grey Worms, because -of their drab garb, are a most formidable scourge to agricultural -crops, as well as to garden produce. Curled in their burrows by day, -they climb to the surface at night and gnaw the base or collar of the -herbaceous plants. Everything suits them: ornamental plants and edible -plants alike. Flower-beds, market-gardens, fields are laid waste -without distinction. When a seedling withers without apparent cause, -draw it to you gently; and the dying plant will come up, but maimed, -severed from its root. The Grey Worm has passed that way in the night; -its greedy mandibles have performed the deadly amputation. Its havoc -rivals that wrought by the White Worm, the grub of the Cockchafer. When -it swarms in a beet-country, the damage amounts to millions. This is -the terrible enemy against which the Ammophila comes to our aid. - -I point out and urgently recommend to agriculturalists this valuable -auxiliary, so zealous in her search of the Grey Worm in spring, so -skilful in discovering its hiding-place. An Ammophila in a garden may -mean the saving of a lettuce-bed, the snatching of a balsam-border from -danger. But there is need here for recommendations. None would dream of -destroying the pretty Wasp that goes fluttering nimbly from one path to -the other, that visits this corner of the garden, then that, then the -next, then the one over there; none dreams either—and none, -unfortunately, can dream—of assisting her to multiply. - -In the immense majority of cases the insect evades our influence: to -exterminate it, if it be harmful, to propagate it, if it be useful, are -impracticable undertakings for us. By a singular contrast of strength -and weakness, man cuts through the neck of continents to join two seas, -he pierces the Alps, he weighs the sun; and yet he cannot prevent a -wretched maggot from enjoying his cherries before he himself does, nor -an odious Louse from destroying his vines! The Titan is vanquished by -the pigmy. - -Now we have here, in this insect-world, an auxiliary of high merit, the -supreme foe of our grievous foe the Grey Worm. Can we do anything to -stock our fields and gardens with it at will? We cannot; for the first -condition of multiplying the Ammophila would be to multiply the Grey -Worm, the only food of her family of grubs. I do not speak of the -insurmountable difficulties which this breeding would present. We have -not to do with the Bee, who is faithful to her hive, because of her -social habits; still less with the stupid Silkworm, perched on its -mulberry-leaf, or its clumsy Moth, who for a moment flutters her wings, -pairs, lays her eggs and dies: we have to do with an insect that is -capricious in its wanderings, swift of flight and independent in its -ways. - -Besides, the first condition shatters all our hopes. Would we have the -helpful Ammophila? Then we must resign ourselves to accepting the Grey -Worm. We move in a vicious circle: to produce good we must invoke the -aid of evil. The hostile band brings the friendly troop to our fields; -but the second cannot live without the first; and the two show an even -balance in numbers. If the Grey Worm abound, the Ammophila finds -copious provender for her grubs and her race prospers; if the Grey Worm -be rare, the Ammophila’s offspring decrease and disappear. This balance -between prosperity and decadence is the immutable law that governs the -proportions between devourers and devoured. - - - - - - - - -CHAPTER XX - -THE MODERN THEORY OF INSTINCT - - -The larvæ of the various Hunting Wasps require their prey to be -incapable of movement, so that there may be no resistance on the -victim’s part, which would be a source of danger to the fragile egg -and, later, to the grub. Moreover, for all its lethargy, it must still -be alive; for the grub would refuse to feed on a corpse. The fare -provided must be fresh meat and not preserved stuff. I have already -laid stress on these two antagonistic conditions, immobility and life, -and enlarged on them so fully that I need hardly dwell upon them for a -second time. I have shown how the Wasp realizes them by the medium of a -paralysis which destroys movement and leaves the organic principle of -life intact. With a skill which our most famous vivisectors would envy, -the insect drives its poisoned sting into the nerve-centres, the seat -of muscular incitation. The operator confines herself to one stroke of -the lancet, or else gives two, three or more, according to the -structure of the particular nervous system and to the number and -grouping of the ganglia. The course of the sting is determined by the -exact anatomy of the victim. - -The particular prey of the Hairy Ammophila is a caterpillar, each of -whose nerve-centres, which are distant one from the other and to a -certain extent independent in their action, occupies a different -segment of the insect. This caterpillar, who is a very lively customer, -cannot be stored in the cell, with the Wasp’s egg upon his flank, until -he has lost all his power of motion. One movement of his body would -crush that egg against the wall of the cell. - -Now the paralysis of one segment would not mean that the next was also -rendered incapable of movement, because of the comparative independence -of the seats of innervation. It is necessary, therefore, that all the -segments, or at least the most important, be operated on, one after the -other, from the first to the last. The course which the Ammophila -adopts is that which the most experienced of physiologists would -recommend: her sting is transferred from one segment to the next, nine -separate times over. - -She does better than that. The victim’s head is still unscathed, the -mandibles are at work: they might easily, as the insect is borne along, -grip some bit of straw in the ground and successfully resist this -forcible removal; the brain, the primary nervous centre, might provoke -a stubborn contest, which would be very awkward with so heavy a burden. -It is well that these hitches should be avoided. The caterpillar, -therefore, must be reduced to a state of torpor which will deprive him -of the least inclination for self-defence. The Ammophila succeeds in -effecting this by munching his head. She takes good care not to use her -needle: she is no clumsy bungler and knows quite well that to inflict a -mortal wound on the cervical ganglia would mean killing the caterpillar -then and there, the very thing to be avoided. She merely squeezes the -brain between her mandibles, calculating every pinch; and, each time, -she stops to ascertain the effect produced, for there is a nice point -to be achieved, a certain degree of torpor that must not be exceeded, -lest death should supervene. In this way the requisite lethargy is -obtained, a somnolence in which all volition is lost. And now the -caterpillar, incapable of resistance, incapable of wishing to resist, -is seized by the nape of the neck and dragged to the nest. Comment -would mar the eloquence of such facts as these. - -The Hairy Ammophila has twice allowed me to attend her surgical -operations. I have described in an earlier chapter of this volume my -first observation, which dates many years back. On that occasion I -witnessed the performance quite unexpectedly; to-day, I have made all -my preparations and have plenty of time at my disposal, so that I am -able to make a much more thorough observation. In each case there was a -multiplicity of needle-pricks, which were distributed methodically, -from front to back, along the ventral surface. Is the number of stings -indeed identical in both cases? This time, it is exactly nine. In the -case of the victim which I saw paralysed on the Plateau des Angles, it -seemed to me that the weapon inflicted more wounds, though I am not -able to state the precise number. It is quite possible that this number -varies slightly and that the last segments of the caterpillar, being -much less important than the others, are attacked or left alone -according to the size and strength of the quarry to be incapacitated. - -On the second occasion, moreover, I had my first view of the squeezing -process to which the caterpillar’s brain is subjected, a process that -produces the torpor which makes the transport and storage of the victim -possible. So remarkable a fact would not have escaped me in the first -instance; it did not, therefore, take place. It follows that this -cerebral compression is a resource which the Wasp has at her disposal, -for use when circumstances demand it, as for instance when the victim -seems likely to offer resistance on the road. - -The malaxation of the cervical ganglia is optional: it has no bearing -on the future of the larva; the Wasp practises it, when needful, to -facilitate transport. I have seen the Languedocian Sphex, who gave me -so much trouble in the old days, at work fairly often, but only once -has she performed this operation on the neck of her Ephippiger in my -presence. The invariable and absolutely necessary part of the Hairy -Ammophila’s procedure seems therefore to be the multiplicity of stings -and their distribution one by one over all or nearly all the -nerve-centres along the median line of the lower surface. - -Let us place side by side with the murderous art of the Wasp the -murderous art of man, practical man, whose business it is to slay -rapidly. I will here recall one of my childhood’s memories. We were -schoolboys of twelve years old, or thereabouts. We were being -instructed in the woes of Melibœus, pouring out his sorrows on the -bosom of Tityrus, who offers him his chestnuts, his sour milk and his -bed of fresh bracken; [52] we were made to recite a poem by Racine the -Younger, [53] La Religion. A curious poem, forsooth, for children who -cared more for marbles than theology! I remember just two lines and a -half: - - - ... et, jusque dans la fange, - L’insecte nous appelle et, certain de son prix, - Ose nous demander raison de nos mépris. [54] - - -Why do these two lines and a half linger in my memory and none of all -the rest? Because already Scarabæus and I were friends. Those two lines -and a half bothered me: I thought it a very absurd idea to relegate you -to the mire, ye insects so seemly clad, so elegantly groomed. I knew -the bronze harness of the Carabus, the Russia-leather jerkin of the -Stag-beetle; I knew that the least of you possesses an ebon sheen and -gleams of precious metals; and therefore the mire wherein the poet -flung you shocked me somewhat. If M. Racine Junior had nothing better -to say about you, he might as well have held his tongue; but he did not -know you, and in his day there were only just a few who were beginning -to have a dim conception of your nature. - -While going over some passage of the tiresome poem for the next day’s -lesson, I would indulge my fancy for another kind of education. I -visited the Linnet in her nest, on a juniper-bush standing as high as -myself; I watched the Jay picking an acorn on the ground; I came upon -the Crayfish, still quite soft after shedding his shell; I made -inquiries as to the exact date when the Cockchafers were due; I went in -quest of the first full-blown Cuckoo-flower. Plants and animals, that -wondrous poem of which a faint echo was beginning to wake in my young -brain, made a very pleasant change from the uninspiring alexandrine. -The problem of life and that other one, with its dark terrors, the -problem of death, at times passed through my mind. It was a fleeting -obsession, soon forgotten by the mercurial spirits of youth. -Nevertheless, the tremendous question would recur, brought to mind by -this incident or that. - -Passing one day by a slaughter-house, I saw an Ox driven in by the -butcher. I have always had an insurmountable horror of blood; when I -was a boy, the sight of an open wound affected me so much that I would -fall into a swoon, which on more than one occasion nearly cost me my -life. How did I screw up courage to set foot in those shambles? No -doubt, the dread problem of death urged me on. At any rate, I entered, -close on the heels of the Ox. - -With a stout rope round its horns, wet-muzzled, meek-eyed, the animal -moves along as though making for the crib in its stable. The man walks -ahead, holding the rope. We enter the hall of death, amid the sickening -stench thrown up by the entrails scattered over the ground and the -pools of blood. The Ox becomes aware that this is not his stable; his -eyes turn red with terror; he struggles; he tries to escape. But an -iron ring is there, in the floor, firmly fixed to a stone flag. The man -passes the rope through it and hauls. The Ox lowers his head; his -muzzle touches the ground. While an assistant keeps him in this -position with the rope, the butcher takes a knife with a pointed blade, -not at all a formidable knife, hardly larger than the one which I -myself carry in my breeches-pocket. For a moment he feels with his -fingers at the back of the animal’s neck and then drives in the blade -at the chosen spot. The great beast gives a shiver and drops, as though -struck by lightning: procumbit humi bos, as we used to say in those -days. - -I fled from the place like one possessed. Afterwards I wondered how it -was possible, with a knife almost identical with that which I used for -prizing open my walnuts and taking the skin off my chestnuts, with that -insignificant blade, to kill an Ox and kill him so suddenly. No gaping -wound, no blood spilt, not a bellow from the animal. The man feels with -his finger, gives a jab and the thing is done: the Bullock’s legs -double up under him. - -This instantaneous death, this lightning-stroke, remained an awesome -mystery to me. It was only later, very much later, that I learnt the -secret of the slaughter-house, at a time when, in the course of my -promiscuous reading, I was picking up a smattering of anatomy. The man -had cut through the spinal marrow where it leaves the skull; he had -severed what our physiologists have called the vital cord. To-day I -might say that he had operated in the manner of the Wasps, whose lancet -plunges into the nerve-centres. - -Let us watch this spectacle a second time, under more exciting -conditions: I mean, in the saladeiros of South America, those immense -establishments for killing and treating meat, where they slaughter as -many as twelve hundred Oxen a day. I will quote the account of an -eye-witness: [55] - - - ‘The cattle arrive in large herds and the matance begins on the day - after the arrival. A whole herd is confined in an enclosed space, - or margueira. From time to time men on horseback drive fifty or - sixty beasts into a narrower and stronger enclosure, with a sloping - floor of brick, boards or concrete, which is always very slippery. - A special operator, standing on an outer platform which runs along - the wall of the smaller margueira, lassoes one of the crowd of - animals by the head or, more often, by the horns. The middle - portion of the long, stout lasso is coiled round a windlass; and a - draught-horse, or sometimes a pair of oxen, drags the lassoed beast - along and makes it slide, in spite of its struggles, right against - the windlass, where it is brought up with a thud and remains - without power of movement. - - ‘Another assistant, the desnucador, also standing on the platform, - has then but to stick a knife, at the back of the head, between the - occipital bone and the axis; and the paralysed animal topples on to - a trolley in which it is carted off. It is at once thrown on an - inclined plane where other special labourers bleed it and skin it. - But, as the injury to the cervical marrow varies a good deal in - position and extent, it often happens that the unfortunate beasts - still retain the motions of the heart and of the respiratory - organs; and, in such cases, they suffer a reaction under the knife; - they utter faint sounds of pain and move their limbs, while already - half-flayed and disembowelled. Nothing could be more painful than - the sight of all those animals skinned alive, cut up and - transformed by those men, covered with blood, who run about in all - directions.’ - - -The murderous methods of the saladeiro are an exact repetition of what -I had seen in the slaughter-house. In both these lethal work-shops they -pierce the vertebral marrow at the base of the skull. The Ammophila -operates in a similar fashion, with this difference, that her surgery -is much more complex, much more difficult, because of the peculiar -organization of her victim. The honours are on her side again when we -consider the delicacy of the result obtained. Her caterpillar is not a -corpse, like the Ox whose spinal cord is cut; it is alive, but -incapable of movement. The insect here is man’s superior in all -respects. - -Now how did the butcher of our parts and the desnucador of the pampas -light upon the idea of plunging a knife into the seat of the marrow, in -order to produce the sudden death of a colossus which would never -suffer its throat to be cut without first offering a dangerous -resistance? Outside those in the trade and men of science, nobody knows -or suspects the lightning result of that particular wound; we are -almost all in the same state of ignorance on this subject in which I -myself was when my childish curiosity drew me into the killing-shed. -The desnucador and the butcher have learnt their craft from the -teachings of tradition and example: they have had masters; and these -were brought up in the school of other masters, harking back by a chain -of linked traditions to him who, served, no doubt, by some hazard of -the chase, first realized the tremendous effects of a wound in the nape -of the neck. Who shall tell us that a pointed flint-stone, driven by -accident into the spinal marrow of the Reindeer or the Mammoth, did not -rouse the attention of the desnucador’s forerunner? A casual incident -furnished the original idea; observation confirmed it; reflection -matured it; tradition preserved it; example disseminated it. After -that, the same transmission-current. For generation might follow -generation in vain: deprived of masters, the desnucador’s descendants -would return to the primitive state of ignorance. Heredity does not -hand down the art of killing by severing the spinal marrow: no man is -born a cattle-slayer by the desnucador’s method. - -Now here is the Ammophila, a slayer of caterpillars by a far more -cunning method. Where are the professors of the art of stinging? There -are not any. When the Wasp rends her cocoon and issues from -underground, her predecessors have long ceased to live; she herself -will perish without seeing her successors. Once the larder is stocked -and the egg laid, all connection with the offspring ends; this year’s -perfect insect dies while next year’s insect, still in the larval -stage, slumbers below ground in its silken cot. Absolutely nothing, -therefore, is transmitted by practical illustration. The Ammophila is -born a finished desnucador even as we are born feeders at our mother’s -breast. The nurseling uses its suction-pump, the Ammophila her dart, -without ever being taught; and both are past masters of the difficult -art from the first attempt. There we have instinct, the unconscious -impulse that forms an essential part of the conditions of life and is -handed down by heredity in the same way as the rhythmic action of the -heart and lungs. - -Let us try, if possible, to trace the Ammophila’s instinct to its -source. We suffer to-day, more than we ever did, from a mania for -explaining what might well be incapable of explanation. There are -some—and their number seems to increase daily—who settle the stupendous -question with magnificent audacity. Give them half-a-dozen cells, a bit -of protoplasm and a diagram for demonstration; and they will account to -you for everything. The organic world, the intellectual and moral -world, everything derives from the original cell, evolving by means of -its own energies. It’s as simple as A B C. Instinct, roused by a chance -action that has proved favourable to the animal, is an acquired habit. -And men argue on this basis, invoking natural selection, heredity, the -struggle for life. I see plenty of big words, but I should prefer a few -small facts. These little facts I have been collecting and catechizing -for nearly forty years; and their replies are not exactly in favour of -current theories. - -You tell me that instinct is an acquired habit, that a casual -circumstance, propitious to the animal’s offspring, was the first to -prompt it. Let us look into the thing more closely. If I understand -aright, we must suppose some Ammophila, in a very remote past, to have -accidentally injured her caterpillar’s nervous centres; to have found -herself the gainer by this operation, both as regards herself, in being -released from a struggle not unattended with danger, and as regards her -larva, thus supplied with fresh, living and yet harmless victuals; and -consequently to have endowed her offspring, by heredity, with a natural -tendency to repeat the advantageous device. The maternal legacy did not -benefit all the descendants equally: some were poor hands at the -newborn art of the stiletto; others were adepts. Then came the struggle -for existence, the hateful væ victis! The weak went under, the strong -flourished; and, as age succeeded age, selection by vital competition -changed the fleeting impression of the start into a deep-rooted, -ineffaceable impression, exemplified in the masterly instinct which we -admire in the Wasp to-day. - -Well, I avow, in all sincerity, this is asking a little too much of -chance. When the Ammophila first found herself in the presence of her -caterpillar, there was nothing, you would have it, to guide the sting. -The choice was made at random. The pricks were directed at the upper -surface of the captured prey, at the lower surface, at the sides, the -front and the back indiscriminately, according to the fortunes of a -close struggle. The Hive-bee and the Social Wasp sting those points -which they are able to reach, without showing a preference for one part -over the other. That is how the Ammophila must have acted, when still -ignorant of her art. - -Now how many points are there in a Grey Worm, above and below? -Mathematical accuracy would answer, an infinity; a few hundreds will -serve our purpose. Of this number, nine or perhaps more have to be -selected; the needle must be inserted there and not elsewhere: a little -higher, a little lower, a little to one side, it would not produce the -desired effect. If the favourable event is a purely accidental result, -how many combinations would be needed to bring it about, how much time -to exhaust all the possible cases? When the difficulty becomes too -pressing, you take refuge behind the mist of the ages; you retreat into -the shadows of the past as far as fancy can carry you; you call upon -time, that factor of which we have so little at our disposal and which, -for this very reason, is so well suited to hide our illusions. Here you -can let yourselves go and lavish the centuries. Suppose we shake up -hundreds of figures, all of different values, in an urn and draw nine -at random. When shall we, in this way, obtain a sequence fixed -beforehand, a sequence that stands alone? The chance is so slight, -answers mathematics, that we may as well put it down as nil and say -that the desired arrangement will never come about. For the Ammophila -of the prehistoric age, the attempt was renewed only at long intervals, -from one year to the next. Then how did this sequence of nine stings at -nine selected points emerge from the urn of chance? When I am driven to -appeal to infinity in time, I am very much afraid of running up against -absurdity. - -‘But,’ say you, ‘the insect did not attain its present surgical -dexterity at the outset: it went through experiments, apprenticeships, -varying degrees of skill. There was a weeding-out by natural selection, -eliminating the less expert, retaining the more gifted; and instinct, -as we know it, developed gradually, thanks to the accumulation of -individual capacities, added to those handed down by heredity.’ - -The argument is erroneous: instinct developed by degrees is flagrantly -impossible in this case. The art of preparing the larva’s provisions -allows of none but masters and suffers no apprentices; the Wasp must -excel in it from the outset or leave the thing alone. Two conditions, -in fact, are absolutely essential: that the insect should be able to -drag home and store a quarry which greatly surpasses it in size and -strength; and that the newly-hatched grub should be able to gnaw -peacefully, in its narrow cell, a live and comparatively enormous prey. -The suppression of all movements in the victim is the only means of -realizing these conditions; and this suppression, to be complete, -requires sundry dagger-thrusts, one in each motor centre. If the -paralysis and the torpor be not sufficient, the Grey Worm will defy the -efforts of the huntress, will struggle desperately on the road and will -not reach the journey’s end; if the immobility be not complete, the -egg, fixed at a given spot on the worm, will perish under the -contortions of the giant. There is no via media, no half-success. -Either the caterpillar is treated according to rule and the Wasp’s -family is perpetuated; or else the victim is only partially paralysed -and the Wasp’s offspring dies in the egg. - -Yielding to the inexorable logic of things, we will therefore admit -that the first Hairy Ammophila, after capturing a Grey Worm to feed her -larva, operated on the patient by the exact method in use to-day. She -seized the creature by the skin of the neck, stabbed it underneath, -opposite each of the nerve-centres and, if the monster threatened -further resistance, munched its brain. It must have happened like this; -for, once more, an unskilled murderess, doing her work in a perfunctory -and haphazard fashion, would leave no successor, since the rearing of -the egg would become impossible. Save for the perfection of her -surgical powers, the slayer of fat caterpillars would die out in the -first generation. - -Again I hear you say: - -‘The Hairy Ammophila, before hunting the Grey Worm, may have picked out -feebler caterpillars and heaped up several in one cell, until they -represented the same bulk of provender as the big prey of to-day. With -puny game, a few thrusts of the needle, perhaps one, would be enough. -Gradually, large-sized prey came to be preferred, as reducing the -number of hunting expeditions. Then, as successive generations went -after bigger game, the dagger-strokes were multiplied, in proportion to -the victim’s power of resistance; and, by degrees, the elementary -instinct of the outset became the highly-developed instinct of our -time.’ - -To these arguments we may begin by replying that the larva’s change of -diet and the substitution of one morsel for a number are diametrically -opposed to what happens before our eyes. The Hunting Wasp, as we know -her, is extremely loyal to old customs; she has sumptuary laws which -she never transgresses. She who fed on Weevils in her youth puts -Weevils and naught else in her larva’s cell; she who was supplied with -Buprestis-beetles persists in the fare which she has adopted and serves -her larva with Buprestis-beetles. One Sphex must have Crickets; a -second, Grasshoppers; a third, Locusts. Nothing is accepted but these -particular dishes. The Bembex who hunts Gad-flies revels in them and -refuses to do without them, whereas Stizus ruficornis, who fills the -larder with Praying Mantes, scorns any other game. And so with the -rest. They have each their own taste. - -It is true that many allow themselves a more varied bill of fare, but -only within the limits of one entomological group: thus the Weevil and -Buprestis hunters prey upon any species proportioned to their strength. -Were the Hairy Ammophila to make a change in her diet, that would be -her case too. Whether small and sundry to each cell or large and -single, the prey would always consist of caterpillars. So far, so good. -But there remains the question of the many replaced by the unit; and I -do not yet know one instance of such an alteration in the Wasp’s -habits. She who stocks the burrow with a single joint never thinks of -heaping up several of smaller size; she who goes on repeated -expeditions to stack a quantity of game in the same cell does not know -how to limit herself to one head by choosing larger meat. The result of -my observations never varies in this regard. The prehistoric Ammophila, -who abandoned her multiplicity of small game for one colossal head, has -nothing to warrant her existence. - -If the point were conceded, would the question be advanced? Not in the -least. Let us accept as the initial prey a feeble caterpillar, -paralysed with a single sting. Even then that sting must not be given -at random, else the act would be more harmful than profitable. -Irritated, but not subdued by the wound, the animal would but become -more dangerous. The dart must strike a nerve-centre, probably in the -middle region of the string of ganglia. This, at any rate, is how the -present-day Ammophilæ seem to go to work when they are addicted to the -rape of frail and slender grubs. What chance would the operator have of -striking that one particular point, if her lancet were wielded without -method? The probability is ludicrously remote: it is as one to the -countless number of points whereof the caterpillar’s body is made up. -And yet, according to the theorists, it is on this probability that the -Wasp’s future depends. What an edifice to balance on the point of a -needle! - -Let us go on admitting and continue. The desired point is struck; the -prey is duly paralysed; the egg laid on its flank will develop in -safety. Is that enough? It is at most but a half of what is absolutely -necessary. Another egg is indispensable to complete the future couple -and ensure offspring. Therefore, within a few days’, within a few -hours’ interval, a second sting must be given, as successful as the -first. In other words, the impossible has to be repeated, the -impossible raised to the second degree. - -Let us not be discouraged yet; let us sound the uttermost depths of the -problem. Here is a Wasp, some precursor, no matter which, of our -Ammophila, who, favoured by chance, has twice and perhaps oftener -succeeded in reducing the prey to that state of inertia which the -rearing of the egg imperatively demands. She does not know, does not -suspect that she inserted her sting opposite a nerve-centre rather than -elsewhere. As there was nothing to prompt her choice, she acted at -random. Nevertheless, if we are to take the theory of instinct -seriously, we shall have to admit that this fortuitous action, though a -matter of indifference to the insect, left a lasting trace and made so -great an impression that, henceforth, the cunning stratagem which -produces paralysis by attacking the nervous centres is transmissible by -heredity. The Ammophila’s successors, by some prodigious privilege, -will inherit what the mother did not possess. They will know by -instinct the point or points towards which the sting must be directed; -for, if they were still in the prentice stage, if they and their -successors had to risk the chance that accident would tend gradually to -strengthen the nascent impulse, they would be going back to the -likelihood so near allied to nil; they would go back to it year by -year, for centuries to come; and yet the one and only favourable chance -would have to be always recurring. I find it very difficult to believe -in a habit acquired by this prolonged repetition of incidents whereof -not one can take place without excluding so many contrary chances. It -is a simple matter of arithmetic to show the number of absurdities -against which the theorists rush headlong. - -Nor is this all. We should have to ask ourselves how casual actions, to -which the insect was not predisposed by nature, can become the source -of a hereditary transmissible habit. We should look upon a man as a -sorry wag who came to us and said that the descendant of the desnucador -knows the art of slaughtering cattle from A to Z merely through being -the son of his father, without the aid of precept or example. The -father does not use his blade just once or twice, by accident; he -operates every day and scores of times a day; he goes to work with -reflection. It is his business. Does this lifelong practice create a -transmissible habit? Are the sons, the grandsons, the great-grandsons -any the wiser, without instruction? No, the thing has to start afresh -each time. Man is not predisposed by nature to this butchery. - -If, on her side, the Wasp excels in her art, it is because she is born -to follow it, because she is endowed not only with tools, but also with -the knack of using them. And this gift is original, perfect from the -outset: the past has added nothing to it, the future will add nothing -to it. As it was, so it is and will be. If you see in it naught but an -acquired habit, which heredity hands down and improves, at least -explain to us why man, who represents the highest stage in the -evolution of your primitive plasma, is deprived of the like privilege. -A paltry insect bequeaths its skill to its offspring; and man cannot. -What an immense advantage it would be to humanity if we were less -liable to see the worker succeeded by the idler, the man of talent by -the idiot! Ah, why has not protoplasm, evolving by its own energy from -one being into another, reserved until it came to us a little of that -wonderful power which it has bestowed so lavishly upon the insects! The -answer is that apparently, in this world, cellular evolution is not -everything. - -For these among many other reasons, I reject the modern theory of -instinct. I see in it no more than an ingenious game in which the -armchair naturalist, the man who shapes the world according to his -whim, is able to take delight, but in which the observer, the man -grappling with reality, fails to find a serious explanation of anything -whatsoever that he sees. In my own surroundings, I notice that those -who are most positive in the matter of these difficult questions are -those who have seen the least. If they have seen nothing at all, they -go to the length of rashness. The others, the timid ones, know more or -less what they are talking about. And is it not the same outside my -modest environment? - - - - - - - - -APPENDIX - - -The following Wasps appear to me to be new to our fauna. I give a -description of each of them. - - - -A - -CERCERIS ANTONIÆ—H. FAB. - -Length, 16 to 18 millimetres. [56] Black, thickly and deeply spotted. -Shield, raised like a nose, that is to say, forming a convex -projection, broad at the base, pointed at the tip and resembling one -half of a cone divided lengthwise. Prominent crest between the antennæ. -A yellow streak above the crest, yellow cheeks and a large yellow spot -behind each eye. Yellow shield, with black dot. Mandibles, iron-yellow, -with black tips. First four or five joints of the antennæ, iron-yellow; -the rest brown. - -Two dots on the prothorax, the wing-scales and the postscutellum -yellow. First segment of the abdomen has two round spots. The next four -segments have on their hinder edge a yellow band cut deeply into the -form of a triangle, or even broken right off; and this is more -noticeable in the less distant segments. - -Under-part of the body, black. Legs, iron-yellow all through. Wings, -slightly bronzed at the tip. - -The above is a description of the female. The male is unknown to me. - -In colouring, this species approaches Cerceris labiata, from which it -differs more particularly by the shape of the shield and by its size, -which is much larger. Observed near Avignon in July. - -I dedicate this species to my daughter Antonia, whose assistance has -often been of great value to me in my entomological researches. - - - -B - -CERCERIS JULII.—H. FAB. - -Length, 7 to 9 millimetres. [57] Black, thickly and deeply spotted. -Shield, flat. Face covered with a fine silvery down. A narrow yellow -band on either side on the inner edge of the eyes. Mandibles, yellow, -with brown tips. Antennæ, black above, pale russet below; lower surface -of their basilar joints, yellow. - -On the prothorax two small yellow dots, some distance apart; yellow -wing-scales and postscutellum. A yellow band on the third segment of -the abdomen and another on the fifth segment; these two bands are -deeply hollowed on the fore-edge, the first into a semicircle, the -second into a triangle. - -Under-part of the body, entirely black. Black hips; thighs of the -hind-legs, all black; those of the two front pairs, black at the root -and yellow at the end. Legs and tarsi, yellow. Wings slightly -smoke-coloured. - -Female. - -Varieties: 1. Prothorax without yellow dots. 2. Two small yellow dots -on the second segment of the abdomen. 3. Wider yellow band on the inner -side of the eyes. 4. Front of shield edged yellow. - -The male is unknown to me. - -This Cerceris, the smallest in my district, feeds her larvæ on very -small-sized Weevils, Bruchus granarius and Apion gravidum. Observed -near Carpentras, where she builds her nest in September, in the soft -sandstone locally known as safre. - - - -C - -BEMBEX JULII.—H. FAB. - -Length, 18 to 20 millimetres. [58] Black, with bristling whitish hairs -on the head, the thorax and the base of the first segment of the -abdomen. Long upper lip, yellow. Ridge-shaped shield, forming a sort of -trihedral angle, of which one side, that of the fore-edge, is all -yellow, while each of the two others is marked with a large rectangular -black patch, touching the adjacent one, so that the two together form a -chevron; these two patches and also the cheeks are covered with a fine -silvery down. Cheeks and a median line between the antennæ, yellow. The -back rim of the eyes has a long yellow border. Yellow mandibles, brown -at the tips. First two joints of the antennæ, yellow underneath, black -above; the others, yellow. - -Prothorax, black, with its sides and dorsal division yellow. -Mesothorax, black; the callous dot and a small dot on either side, -above the base of the intermediate legs, yellow. Metathorax, black, -with two yellow spots behind and a larger one, on either side, above -the base of the hind-legs. The first two spots are sometimes missing. - -Abdomen, brilliant black above and bare, except at the base of the -first segment, which bristles with whitish hairs. All the segments have -a wavy transversal band, wider at the sides than in the middle and -nearer to the hinder edge as the segment is farther back. On the fifth -segment the yellow band touches the hinder edge. Anal segment, yellow, -black at the root, covered all over the dorsal surface with rusty-red -papillæ, forming a base for bristles. A row of similar bristle-bearing -protuberances occupies also the hinder edge of the fifth segment. -Underneath, the abdomen is brilliant black, with a triangular yellow -patch on either side of the four intermediary segments. - -Black hips; thighs, yellow in front, black behind; yellow legs and -tarsi. Transparent wings. - -In the male the chevron mark on the shield is narrower, or even -entirely absent, in which case the face is all yellow. The bands on the -abdomen are a very pale yellow, almost white. The sixth segment has a -band like those which come before, but shorter and often reduced to two -dots. The second segment has underneath it a longitudinal carina, -raised and spine-shaped at the back. Lastly, the anal segment carries -below it a rather thick angular projection. The rest is the same as in -the female. - -This Wasp is very much like Bembex rostrata in size and in the -arrangement of the black and yellow. The chief differences lie in the -following characteristics: the shield of Bembex Julii forms a trihedral -angle, whereas it is rounded and convex in the other Bembex. It also -has at its base a broad, chevron-shaped black band, formed of two -rectangular patches joined together and powdered with a silvery down, -which is very brilliant in a suitable light. The upper surface of the -anal segment bristles with papillæ and reddish hairs, as does the -hinder edge of the fifth segment. Lastly, the mandibles are stained -black at the tips only, whereas the base also is black in Bembex -rostrata. Their habits are equally dissimilar. Bembex rostrata hunts -Gad-flies mainly; Bembex Julii never preys on big Flies but attacks -smaller ones of greatly varying species. - -Jules’ Bembex is frequent in the sandy soil of Les Angles, round about -Avignon and on the hill at Orange. - - - -D - -AMMOPHILA JULII.—H. FAB. - -Length, 16 to 22 millimetres. [59] Abdominal petiole consisting of the -first segment and half the second. Third cubital narrowed towards the -radial. Head, black, with silvery down on the face. Antennæ, black. -Thorax, black, with transverse stripes on its three segments, darker on -the prothorax and the mesothorax. Two patches on the sides and one -behind either side of the metathorax, covered with silvery down. -Abdomen, bare and shiny. First segment, black. Second segment, red in -the part narrowed into a petiole and in the widened part. Third -segment, all red. The others, a beautiful, metallic indigo-blue. Legs, -black, with silvery down on the hips. Wings, slightly reddish. Builds -her nest in October and stocks each cell with two medium-sized -caterpillars. - -Is nearly related to Ammophila holosericea, being of the same size, but -differs markedly in the colour of her legs, which are all black, in her -head and thorax, which are much less hairy, and in the transverse -stripes on the three segments of the thorax. - - - -I wish these three Wasps to bear the name of my son Jules, to whom I -dedicate them. - -Dear Jules, snatched at such an early age from your passionate love of -flowers and insects, you were my fellow-worker; nothing escaped your -clear-sighted glance; I was to write this book for you, to whom its -stories gave such delight; and you yourself were to continue it one -day. Alas, you went to a happier home, knowing nothing of the book but -its first lines! May your name at least figure in it, borne by some of -those industrious and beautiful Wasps whom you loved so well! - - -J. H. F. - -Orange, 3 April 1879. - - - - - - - - -NOTES - - -[1] Léon Dufour (1780–1865) was an army surgeon who served with -distinction in several campaigns and subsequently practised as a doctor -in the Landes. He attained great eminence as a naturalist. Cf. The Life -of the Spider, by J. Henri Fabre, translated by Alexander Teixeira de -Mattos, chap, i.—Translator’s Note. - -[2] For the complete monograph, cf. Annales des sciences naturelles: -Series II., vol. xv.—Author’s Note. - -[3] The 450 Buprestes unearthed belong to the following species: -Buprestis octoguttata; B. fasciata; B. pruni; B. tarda; B. biguttata; -B. micans; B. flavomaculata; B. chrysostigma; and B. -novemmaculata.—Author’s Note. - -[4] Pierre André Latreille (1762–1833), a French naturalist who was one -of the founders of entomological science.—Translator’s Note. - -[5] The Beetle known to Fabre as Sphenoptera geminata, Uliger, is now -considered identical with S. lineola, Herbst, which was known many -years earlier.—Translator’s Note. - -[6] ·528 oz. av.—Translator’s Note. - -[7] ·88 oz. av.—Translator’s Note. - -[8] For a description of this species, which is new to entomology, see -the Appendix.—Author’s Note. - -[9] Marie Jean Pierre Flourens (1794–1867), the celebrated French -physiologist, appointed perpetual secretary of the Academy of Science -in 1833 and a member of the French Academy.—Translator’s Note. - -[10] François Magendie (1783–1855), professor of anatomy in the Collège -de France, noted for his experiments on the physiology of the -nerves.—Translator’s Note. - -[11] Claude Bernard (1813–1878), another distinguished French -physiologist and perhaps the most famous representative of experimental -science in the nineteenth century.—Translator’s Note. - -[12] Annales des sciences naturelles, Series III., vol. v.—Author’s -Note. - -[13] For the Sacred Scarab, or Sacred Beetle, cf. Insect Life, by J. H. -Fabre, translated by the author of Mademoiselle Mori: chaps. i. and -ii.; and The Life and Love of the Insect, by J. Henri Fabre, translated -by Alexander Teixeira de Mattos: chaps, i. to iv.—Translator’s Note. - -[14] For Philanthus Apivorus, the Bee-eating Wasp, cf. Social Life in -the Insect World, by J. H. Fabre, translated by Bernard Miall: chap. -xiii.—Translator’s Note. - -[15] Cf. The Life and Love of the Insect: chap. xi.—Translator’s Note. - -[16] Cf. The Life and Love of the Insect: chap. xii.—Translators Note. - -[17] ·117 to ·156 inch.—Translator’s Note. - -[18] A species of Green Grasshopper.—Translator’s Note. - -[19] Nearly half an inch.—Translator’s Note. - -[20] ·975 to 1·17 inch.—Translator’s Note. - -[21] ·195 to ·234 inch.—Translator’s Note. - -[22] 1·05 × ·35 inch.—Translator’s Note. - -[23] Cf. Social Life in the Insect World: chaps. i. to iv.—Translator’s -Note. - -[24] Cf. Social Life in the Insect World: chaps. v. to -vii.—Translator’s Note. - -[25] The order of insects including Earwigs, Cockroaches, Mantes, -Crickets, Locusts and Grasshoppers.—Translator’s Note. - -[26] Amédée Comte Lepeletier de Saint-Fargeau (1769–circa 1850), author -of an Histoire naturelle des insectes (1836–1846) and of the volume on -insects in the Encyclopédie méthodique. He was a younger brother of -Louis Michel and Félix Lepeletier de Saint-Fargeau, the members of the -Convention.—Translator’s Note. - -[27] Jean Théodore Lacordaire (1801–1870), professor at the university -of Liège from 1835, author of Les Genera des coléoptères, in twelve -volumes, and of the Introduction à l’entomologie quoted above -(1837–1839).—Translator’s Note. - -[28] Erasmus Darwin (1731–1802), the poet and naturalist, grandfather -of Charles Robert Darwin. The book from which the above passage is -quoted is Zoonomia, or, The Laws of Organic Life (1794–1796); but the -reader will note that the author withdraws these comments in a later -essay (cf. The Mason-bees, by J. Henri Fabre, translated by Alexander -Teixeira de Mattos: chap. vii.), where he explains that they are due to -a misquotation or mistranslation made by Lacordaire, who wrote ‘a -Sphex’ where Darwin, as his grandson pointed out to Fabre, had written -‘a Wasp,’ meaning the Common or Social Wasp. It was open to me to -suppress this part of the chapter; but, in that case, there would have -been so little left of the original and so small an excuse for the -title that I might as readily have suppressed the whole chapter, a -liberty which I did not feel justified in taking. Besides, the footnote -to the aforementioned chapter of The Mason-bees, which precedes the -present volume in the English edition, makes sufficient amends for any -injury done to the elder Darwin’s reputation here.—Translator’s Note. - -[29] ‘The busy bees, with a soft murmuring strain, - Invite to gentle sleep the labouring swain.’— - - Pastorals, i., Dryden’s translation. - -[30] Cf. p. 43 n. Flourens’ Expériences sur le système nerveux were -first published in 1825.—Translator’s Note. - -[31] ·039 inch.—Translator’s Note. - -[32] The caterpillars of the Geometræ, or Geometrid Moths, are called -also Inchworms, Spanworms and Surveyors.—Translator’s Note. - -[33] Cf. The Life of the Fly, by J. Henri Fabre, translated by -Alexander Teixeira de Mattos: chap. ix.—Translator’s Note. - -[34] About ·08 inch.—Translator’s Note. - -[35] For a description of this new species, see the Appendix to the -present volume.—Author’s Note. - -[36] Or Flesh-fly. Cf. The Life of the Fly: chap. x.—Translator’s Note. - -[37] The Bluebottle.—Translator’s Note. - -[38] The Common House-fly.—Translator’s Note. - -[39] Cf. The Life of the Fly: chaps. ii. and iv.—Translator’s Note. - -[40] For other essays on the homing of insects, cf. The Mason-bees: -chaps. ii. to vi.—Translator’s Note. - -[41] ·061 cubic inch.—Translator’s Note. - -[42] 61 cubic inches.—Translator’s Note. - -[43] The piece of waste ground on which the author used to study his -insects in their natural state. Cf. The Life of the Fly: chap. -i.—Translator’s Note. - -[44] Gun-flints.—Author’s Note. - -[45] The local expression.—Author’s Note. - -[46] Burying-beetles.—Translator’s Note. - -[47] Carrion-beetles.—Translator’s Note. - -[48] Mimic-beetles.—Translator’s Note. - -[49] Bacon-beetles.—Translator’s Note. - -[50] The Horseshoe Bat.—Translator’s Note. - -[51] Lazaro Spallanzani (1729–1799), the great Italian -naturalist.—Translator’s Note. - -[52] ‘This night, at least, with me forget your care; - Chestnuts and curds and cream shall be your fare - The carpet-ground shall be with leaves o’erspread - And boughs shall weave a covering for your head.’— - - Pastorals, book i., Dryden’s translation. - -[53] Louis Racine (1692–1763), son of Jean Racine.—Translator’s Note. - -[54] ... and even in the mire, - The insect, of its worth assured, once and again - Ventures to challenge us to make good our disdain. - -[55] L. Couty, in the Revue scientifique, 6 August 1881.—Author’s Note. - -[56] ⅝ to ¾ inch.—Translator’s Note. - -[57] ¼ to ⅓ inch.—Translator’s Note. - -[58] ¾ to ⅞ inch.—Translator’s Note. - -[59] ·62 to ·86 inch.—Translator’s Note. - - - - - - - -*** END OF THE PROJECT GUTENBERG EBOOK THE HUNTING WASPS *** - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the -United States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. 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