CIHM Microfiche Series ({Monographs) ICIMH Collection de microfiches (monographles) Canadian Instituta for Historical Microraproductiona / inatitut Canadian da microraproductions hiatoriquaa 994 Technical and Bibliographic Notts / Notts ttchniquts tt bibliographiquas The Institutt has attempted to obtain the best original copy available for filming. Features of th.' THE MASON-WASPS f BY J. HENRI FABRE translated by Alexander Teixeira de Mattos FBLLOW OP THE ZOOLOGICAL SOCIITV OP LONDON McClelland & stewart PUBLISHERS TORONTO 161G97 : OOPTUOBT, 1019 bt dodd, mead and company, Ino. FKINTED IN U. S. A. CONTENTS translator's NOTE .... ""^y CHAPTER I THE EUMENES I II THE ODYNERI 28 HI THE PELOP^US 60 IV THE AGENI^; THE PELOP^US' VICTUALS 84 V ABERRATIONS OF INSTINCT . . 106 VI THE SWALLOW AND THE SPARROW 1 33 VII INSTINCT AND DISCERNMENT . 155 Vin THE NEST-BUILDING ODYNERUS . 1 76 IX INSECT GEOMETRY 219 X THE COMMON WASP .... 240 XI THE COMMON WASP (continued) 270 XII THE VOLUCELLA 288 INDEX -j,^ TRANSLATOR'S NOTE This is the second volume on Wasps in the Collected Edition of Fabre's Souvenirs en- tomologiques. The first of these was The Hunting fVasps; and the present volume is somewhat wilfully entitled, for all Wasps hunt in varying degrees, if not on their own behalf, at least on that of their young. My object, however, was to bring together all the essays treating of those Wasps who actually build homes or nests, as distinct from bur- rows. The last book on Wasps will be called More Hunting fVasps and will be is- sued towards the end of the series. For reasons which will be easily apparent to the reader, I have reprinted the chapter called Instinct and Discernment, which was mcluded in Bramble-bees and Others, and that on the Volucella, which, under the title of The Bumble-bee Fly, formed part of The Life of the Fly. Apart from the two chap- ters named and the essay on the Eumenes, which figures in The JVonders of Instinct, published in America by the Century Co.! Translator's Note none of the contents of this volume has until now appeared in the English language. The Volucella is included by arrangement with Mr. Fisher Unwin, the publisher of The Wonders of Instinct in England. My thanks are due to the late Miss Frances Rodwell and to my friend Bernard Miall, both of whom have been of great as- sistance to me in preparing my translation. Alexander Teixeira de Mattos. CHELSEA, 1 8 April, 19 19. VI CHAPTER I THE EUMENES A WASP-LIKE garb of black and yel- -**• low; a slender, graceful figure; wings that are not spread flat when resting, but are folded lengthwise in two ; the abdomen a sort of chemist's retort, swelling into a gourd and fastened to the thorax by a long neck which first distends into a pear and then shrinks to a thread; a leisurely and silent flight; lonely habits. There we have a summary sketch of the Eumenes. My part of the country pos- sesses two species: the larger E. Amadei, Lep., measures nearly an inch in length; the other, E. pomiformis, Fabr.,^ is a reduction of the first to half the scale. Similar in form and colouring, both pos- sess a like talent for architecture; and this U include three species promiscuously under this one name, that is to say, E. pomiformis, Fabr., E. bipunctis. &AUS3., and E. dubius. Sauss. As I did not distinguish be- tween them in my first investigations, which date a very long time back, it is not possible for me to-day to attribute to each of them its respective nest. But their habits are the same, for which reason this confusion does not injure the order of ideas ia the present chapter.— Author's Note. I f| The Mason-Wasps talent is expressed in a work of the highest perfection, which charms the most untutored lit' ^h p ' d^c»'ng is a masterpiece. And yet the Eumenes follow the profession of arms, which is unfavourable to artistic effort- Plunder 'th'''"^ ' ^'''T '^'^ P'"^^^ ^"^ S^n- .u • '^. "' predatory Wasps, vie tualhng their larvae with caterpillars. It wiJh^ ?hnl"^'T^'!;^ ^° '°"^P"« ^he'r habits with those of the operator on the Grey Worm.> Though the quarry — caterpillars which ''l-Ti' ""'""*"'". '^' «^"^^' '"^t'nct, which IS liable to vary with the species, majl have fresh glimpses in store for us. Besides, the edifice built by the Eumenes in itself de^ serves mspection. . il^u- ?""^'"g Wasps whose story we have told hitherto 2 are wonderfully well-versed "s witrt?' "'"''^« ^ ^^"^^^^^^^y -"-n^ us with then surgical methods, which they the Dart ?r% W?""™ » ^he caterpillar of Nocfua segetum P.K?/' P' """j^^S ^'"P^- passim; Insect life by T H Teixeira de M««i. t ^^'''"' translated by Alexander The Eumenes seem to have learnt from some physiologist who allows nothing to escape him; but these skilful slayers have no merit as builders of dwelling-houses. What is their home, in point of fact? An underground passage, with a cell at the end of it; a gallery, an ex- cavation, a shapeless cave. It is miner's work, navvy's work: vigorous sometimes, ar- tistic never. They use the pick for loosen- ing, the crowbar for shifting, the rake for extracting the materials, but never the trowel for laying. Now in the Eumenes we sec real masons, who build their houses bit by bit with stone and mortar and nm them up in the open, either on firm rock or on the shaky sup- port of a bough. Hunting alternates with architecture; the insect is a Nimrod or a Vi- truvius ^ by turns. And, first of all, what sites do these build- ers select for their homes? Should you pass some little garden-wall, facing south, in a sun-scorched corner, look at the stones which are not covered with plaster, look at them one by one, especially the largest; examine the masses of boulders, at no great height from the ground, where the fierce rays have heated them to the temperature of a Turkish ^ Marcus Vitruvius Pollio, the Roman architect and en- gineer.— Translator's Note. 3 The Mason-Wasps bath ; and perhaps, if you search long enough, yoj will light upon the structure of Eumenes Amadet. The insect is scarce and lives apart; a meeting is an event upon which we must not count with too great confidence. It IS an African species and loves the heat that ripens the carob and the date. It haunts the sunniest spots and selects rocks or hrm stones as a foundation for its nest. Sometimes also, but seldom, it copies the Chahcodoma of the Walls ^ and builds upon an ordinary pebble. E, pomiformis is much more common and IS comparatively indifferent to the nature of the foundation on which she constructs her cell. She builds on walls, on isolated stones, on the inner wooden surface of half-dosed shutters; or else she adopts an aerial base, the slender twig of a shrub, the withered sprig of a plant of some sort. Any form of support serves her purpose. Nor does she trouble about shelter. Less chilly than her Atrican cousin, she docs not shun the un- protected spaces exposed to every wind that When erected on a horizontal surface, where nothing interferes with it, the struc- Al^LLi''r^'"''"^1"l}'^ J- "'^"" f'^^'^e. translated by 4 The Eumenes turc o( E. Amadi'i is a symmetrical cupola, a spherical skull-cap, having at the top a nar- row passage just wide enough for the insect and surmounted by a neatly-funnclled neck. It suggests the round hut of the Eskimo or of the ancient Gael, with its central chimney. An inch, more or less, represents the dia- meter; three-quarters of an inch the height. When the support is a perpendicular plane, the buildmg still retains the domed shape, but the entrance- and exit-funnel opens at the side, upwards. The floor of this apartment calls for no labour: it is supplied direct by the bare stone. Having chosen the site, the builder erects a circular fence about an eighth of an inch thick. The materials consist of mortar anj small stones. The insect selects its stone- quarry in some well-trodden path or on some neighbouring highroad, at the driest, hard- est spots. With its mandibles, it scrapes to- gether a small quantity of dust and soaks it with saliva until the whole becomes a regu- lar hydraulic mortar which soon sets and is no longer susceptible to damp. The Ma- son-bees have shown us a similar exploita- tion of the beaten paths and of the road- mender's macadam. All these open-air builders, all these erectors of monuments ex- 5 The Mason-Wasps posed to wind and weather require an ex- ceedingly dry stone-dust; otherwise the ma- terial, already moistened with water, would not properly absorb the liquid that is to give It cohesion; and the edifice would soon be wrecked by the rains. They possess the sense of discrimination shown by the plas- terer, who rejects plaster injured by the wet. We shall see presently how the insects that build under cover avoid this laborious macadam-scraping and give the preference to fresh earth already reduced to a paste by Its own dampness. When common lime answers our purpose, we do not trouble about Roman cement. Now Eumenes Ama- del requires a first-class cement, even su- Pf"or to that of the Chalicodoma of the Walls, for the work, when finished, does not receive the thick outer casing wherewith the Ma^on-bee protects her cluster of cells. And therefore the cupola-builder, as often as she can, uses the highway as her stone-pit. With the mortar, bricks are needed. These are bits of gravel of an almost un- varying size -— that of a pepper-corn — but of a shape and kind that differ greatly, ac- cording to the places worked. Some are sharp-cornered, with facets determined by chance fractures; some arc round, polished The Eumenes by friction under water. Some are of lime- stone, others of flinty material. The favourite stones, when the neighbourhood of the nest permits, are smooth, semitrans- parent little lumps of quartz. These are selected with minute care. The insect weighs them, so to say, measures them with the compass of its mandibles and docs not accept them until after making sure that they possess the requisite qualities of size and hardness. A circular fence, we were saying, is b**. gun on the bare rock. Before the mortar sets, which does not take long, the mason, as the work advances, sticks a few stones mto the soft mass. She dabs them hal way into the cement, so as to leave the. jutting out to a large extent, without pene- trating to the inside, where the wall must remam smooth for the sake of the larva's comfort. If necessary, she adds a little plaster, to tone down any inner excrescences. The sohdly-embedded stonework alternates with the pure mortarwork, of which each fresh course receives its facing of tiny en- crusted pebbles. As the edifice is raised, the builder slopes the construction a little towards the centre and fashions the curve which will give the spherical shape. We 7 The Mason- Wasps employ arched centerings to support the masonry of a dome while building; the Eumenes, more daring than we, erects her cupola without any scaffolding. A round opening is contrived at the top; and above this opening rises a funnelled mouth built of pure cement. It might be the graceful neck of some Etruscan vase. When the cell is victualled and the egg laid, the mouth is closed with a cement plug; and m this plug is set a little pebble, one alone, no more: the ritual never varies. This work of rustic architecture has naught to fear from the inclemencies of the weather; It does not yield to the pressure of the fingers; it resists the knife that attempts to remove it without breaking it. Its nipple- shape and -he bits of gravel wherewith it bristles all over the outside remind one of certain cromlechs of olden time, of certain tumuli whose domes are strewn with Cy- clopean blocks of stone. Such is the appearance of the edifice when the cell stands alone; but the Wasp nearly always fixes other domes against her first, to the number of five or six or more. This shortens the labour by allowing her to use «ie same partition for two adjoining rooms. The original elegant symmetry is lost and 8 The Eumenes the whole now forms a cluster which, at first sight, might be merely a clod of dry mud, sprinkled with little pebbles. But examine the shapeless mass more closely; and we perceive the number of chambers compo- sing the habitation with the funnelled mouths, each quite distinct and each furnished with its gravel stopper set in the cement. The Chalicodoma of the Walls employs the same building-methods as Eumenes Ama- dei:'m the courses of cement, she fixes, on the outside, small stones of minor bulk. Her work begins by being a turret of rustic art, not without a certain prettiness; then, when the cells are placed side by side, the whole construction degenerates into a lump gov- erned apparently by no architectural rule. Moreover, the Mason-bee covers her mass of cells with a thick layer of cement, which conceals the original rockwork edifice. The Eumenes does not resort to this general coat- ing: her building is too strong to need it; she leaves the pebbly facings uncovered, as well as the entrances to the cells. The two sorts of nests, though constructed of similar materials, are therefore easily distinguished. The Eumenes' cupola is a piece of artist's work; and the artist would be sorry to hide 9 The Mason-Wasps her masterpiece under whitewash. I crave forgiveness for a suggestion which I ad- vance with all the reserve befitting so deli- cate a subject. Would it not be possible for the cromlech-builder to take a pride in her handiwork, to look upon it with some affection and to feel gratified by this evidence of her cleverness? Might there not be an insect science of aesthetics? I seem at least to catch a glimpse, in the Eumenes, of a propensity to beautify her product. The nest must be first and fore- most a solid habitation, an inviolable strong- hold; but, should ornament intervene with- out jeopardizing the power of resistance, will the worker remain indifferent to it? Who could say? Let us set forth the facts. The orifice at the top, if left as a mere hole, would suit the purpose quite as well as an elaborate door: the insect would lose nothing in re- gard to facilities for coming and going and would gain by shortening the labour. Yet we find, on the contrary, the mouth of an amphora, gracefully curved, worthy of a potter's wheel. Choice cement and careful work are needed for the confection of its slender, funnelled shaft. Why this nice fin- 10 The Eumenes ish, if the builder be wholly absorbed in the solidity of her work? Here is another detail: among the bits of gravel employed for the outer covering of the cupola, grains of quartz predominate. They are polished and translucent; they glitter slightly and please the eye. Why are these little pebblcc preferred to chips of limestone, when both materials exist in equal abundance around the nest? A yet more remarkable feature: we find pretty often, encrusted on the dome, a few tiny empty Snail-shells, bleached by the sun. The species usually selected by the Eumenes is one of the smaller Helices, Helix strigata, frequent on our parched slopes. I have seen nests where this Helix took the place of pebbles almost entirely. They were like boxes made of shells, the work of a patient hand. A comparison suggests itself. Certain Australian birds, notably the Bower-birds, build themselves covered walks or arbours with interwoven twigs and decorate the two entrances to the portico by strewing the threshold with anything that they can find in the shape of glittering, polished or bright- coloured objects. Every doorsill is a cab- II I n The Mason-Wasps inet of curiosities where the collector gathers smooth pebbles, variegated shells, empty Snail-shells, Parrots' feathers, bones that have come to look like sticks of ivory. Even the odds and ends mislaid by man find a home in the bird's museum, where we see pipe-stems, brass buttons, strips of cotton stuff and stone axe-heads. The collection at either entrance to the bower is large enough to fill half a bushel. As these thinjgs are of no use to the bird, its only motive for accumulating them must be an art-lover's hobby. Our common Magpie has similar tastes: any shiny thing that he comes upon he picks up, hides and hoards. Well, the Eumenes, who shares this pas- sion for bright pebbles and empty Snail- shells, is the Bower-bird of the insect world; but she is a more practical collector, knows how to combine the useful and the ornament- al and employs her discoveries in the construc- tion of her nest, which is both a fortress and " museum. When she finds bits of trans- lucent quartz, she rejects everything else: the building will be all the prettier for them. When she comes across a little white shell, she hastens to beautify her dome with it; should fortune smile and empty Snail-shells 12 The Eumenes abound, she encrusts the whole fabric with them, until it becomes the supreme express- ion of her artistic taste. Is this so or not? Who shall decide? The nest of Eumenes pomifortnls is the size of an average cherry and constructed of pure mortar, without any outer pebblework. Its shape is exactly similar to that which we have * 1st described. When built upon a large enough horizontal base, it is a dome with a central neck, funnelled like the mouth of an urn. But, when the foundation is reduced to a mere point, as on the twig of a shrub, the nest becomes a spherical capsule, always, of course, rurmounted by a neck. It is then a miniature specimen of exotic pottery, a big-bellied alcarraza. Its thick- ness is very slight, less than that of a sheet of paper; it crushes under the least finger- pressure. The outside is not quite even. It displays wrinkles and seams, due to the different courses of mortar, or else knotty projections distributed almost concentric- ally. Both Wasps accumulate caterpillars in their coffers, whether domes or jars. Let us give an abstract of the bill of fare. These documents, for all their dryness, possess a value: they will enable whoso 13 The Mason- Wasps I cares to Interest himself In the Eumenes to perceive to what extent instinct modifies the diet, according to place and season. The food is plentiful but lacks variety. It con- sists of tiny caterpillars, by which I mean the grubs of small Butterflies or Moths. This is proclaimed by the structure, for we observe the usual caterpillar organism in the prey selected by either Wasp. The body is composed of twelve segments, not inclu- ding the head. The frst three have true legs, the next twb are legless, then come four segments with prolegs, two legless seg- ments and, lastly, a terminal segment with prolegs. It is exactly the same organization which we saw in the Ammophila's Grey Worm. My old notes give the following descrip- tion of the caterpillars found in the nest of E. Amadei: a pale-green or, less often, yellowish body covered with short white hairs; head wider than the. front segment, dead-black and also bristling with hairs. Length : 1 6 to 1 8 millimetres ; ^ width : about 3 millimetres.' It is more than a quarter of a century since I jotted down this descriptive sketch; and today, at Serignan, I * .63 Inch to .7 inch. — Translator's Note. 2 .12 inch. — Translator's Note. 14 The Eumenes find in the Eumenes' larder the same sort of game that I saw long ago at Carpentras. Time and distance have not altered the nature of the provisions. I know one exception and one alone in this fidelity to the ancestral diet. My ob- servations mention a single dish that differs greatly from those which accompany it. This is a caterpillar of the Looper group * with only three pairs of prolegs, placeid under the eighth, ninth and twelfth segments. The body tapers slightly at either end, is contracted at the junction of the different rings and is pale green with faint blac'c veinings, visible under the magni- fying-glass, and a few sparse black cilia. Length: 15 millimetres ; * width: 2^ milli- metres." E. pomiformis also has her preferences. Her game consists of small caterpillars about 7 millimetres long by 1% wide.* The body is pale green, pretty sharply con- tracted at the junction of the segments. The head h narrower than the rest of the body and is spotted with brown. Pale ocel- 1 Also known as the Measuring-worm, the caterpillar of the Georaetrid Moth. — Translator's Note. * .585 inch.— Translator's Note. « .093 inch.— Translator's Note. *.ij by .50 mdi.^ Translator's Note. IS The Mason- Wasps lated circles are distributed in two trans^ versal rows over the middle segments and have a black dot in the centre, surmounted by a black cilium. On the third and fourth and also on the penultimate segment, each circle has two black dots and two cilia. This is the rule. The exception is supplied by two head of game in the whole course of my observa- tions. These two had a pale yellow body, with five longitudinal brick-red stripes and a few very rare cilia. Head and prothorax brown and shiny; length and diameter as above. The number of pieces served for the meal of each larva interests us more than the quality. In the cells of E. Amadei I find sometimes five caterpillars and sometimes ten, which means a difference of a hundred per cent in the quantity of the food, for the pieces are of exactly the same size in both cases. Why this unequal supply, which gives a double portion to one larva and a single portion to another? The consumers have the same appetite: what one nurseling demands a second must demand, unless there be here a menu differing according to the sexes. In the perfect stage, the males are smaller than the females, are hardly i6 The Eumenes half as much in weight or volume. The amount of victuals, therefore, required to bring them to their final development may be reduced by one-half. In that case, the well-stocked cells belong to females; the others, more meagrely supplied, belong to males. But the egg is laid when the provisions are stored; and this egg has a determined sex, although the most minute examination is not able to discover the differences which will decide the hatching of a female or a male. We are therefore needs driven to this strange conclusion: the mother knows beforehand the sex of the egg which she is about to lay;* and this knowledge enables her to fill the larder according to the appetite of the future grub. What a strange world, so wholly different from ours! We fall back upon a special sense to explain the Ammophila's hunting; what can we fall back upon to account for this intuition of the future? Can the theory of chances play a part in the hazy problem? If nothing is logically arranged with a fore- seen object, how is this clear vision of the in' isible acquired? 1 Of. Bramble-bees and Others, by J. Henri Fabre, trans- lated by Alexander Teixeira de Mattos: chap, iv.— Trans- lator's Note. n The Mason-Wasps ! The capsules of E. potnifortnis are lit- erally crammed with game. It is true that the morsels are very small. My notes speak of fourteen green caterpillars in one cell and sixteen in a second. I have no other information about the integral diet of this Wasp, whom I have neglected some- what, preferring to study her cousin, the builder of rockwork domes. As the two sexes differ in size, though not so greatly as in E. Amadel, I am inclined to think that those two well-filled cells belonged to fe- males and that the males' cells must have a less sumptuous table. Not having seen for myself, I am content to set down this mere suspicion. What I have seen and often seen is the pebbly nest, with the larva inside and the provisions partly consumed. To continue the rearing at home and follow my charges' progress from day to day was a business which I could not resist; besides, so far as I was able to see, it was easily managed. I had had some practice in this foster-father's trade; my association with the Bembex, the Ammophila, the Sphex * and many others had turned me into a passable insect- 1 Cf. The Hunting Wasps: chaps, iv. to viii. and xiii. to sx. — Translator's Note. X8 The Eutnenes breeder. I was no novice in the art of dividing an old pen-box into com- partments in which I laid a bed of sand and on this bed the larva, with her provisions, delicately removed from the maternal cell. Success *vas almost certain at each attempt: I used to watch the larvaj at their meals, I saw my nurselings grow up and spin their cocoons. Relying upon the experience thus gained, I reckoned on suc- cess in raising my Eumenes. The results, however, in no way answered to my expectations. All my endeavours failed; and the larva allowed itself to die a piteour death without touching its provision; I ascribed my reverse to this, that and the other cause : perhaps I had injured the frail grub when demolishing the fortress; per- haps a splinter of masonry bruised it when I forced open the hard dome with my knife ; perhaps a too-sudden exposure to the sun surprised it when I withdrew it from the darkness of its cell, the open air again might have dried up its moisture. I did the best I could to remedy all these pro- bable reasons of failure. I went to work with every possible caution in breaking open the home; I cast the shadow of my body 19 I The Mason-Wasps over the nest, to save the grub from sun- stroke; I at once transferred larva and provisions into a glass tube and placed this tube in a box which I carried in my hand, to minimize the jolting on the journey. Nothing was of avail: the larva, when taken from its dwelling, always pined away and died. For a long time, I persisted in explaining my failure by the difficulties attending the removal. The cell of Eumencs Amadei is a strong casket which cannot be forced with- out sustaining a shock; and the demolition of a work of this kind entails such varied accidents that we are always liable to think that the grub has been bruised by the wreck- age. As for carrying home the nest intact on its support, with a view to opening it with greater care than is permitted by a rough and ready operation in the fields, that is out of the question: the nest nearly always stands on an immovable rock or on some big stone forming part of a wall. If I failed in my attempts at rearing, it was because the larva had suffered when I was breaking up her house. The reason seemed a good one; and I let it go at that. In the end, another idea occurred to me and made me doubt whether my rebuffs 20 ({ eI The Eumenes were always due to clumsy accidents. The Eumenes* cells are crammed with game: there are ten caterpillars in the cell of E. Amadei and fifteen in that of E. pomiformis. These caterpillars, stabbed no doubt, but stabbed in a fashion unknown to me, are not entirely motionless. The mandibles seize upon what is presented to them, the body buckles and unbuckles, the hinder half lashes out briskly when stirred with the point of a needle. At what spot is the egg laid amid that swarming mass, where thirty mandibles can make a hole in it, where a hundred and twenty pair of legs can tear it? When the victuals consist of a single head of game, these perils do not cxi'-.tt and the egg is laid on the victim not at hazard, but upon a judiciously chosen spot. Thus, for instance, the Hairy Am- mophila fixes hers, by one end, across the Grey Worm, on the side of the first pro- legged segment. The egg hangs over the caterpillar's back, away from the legs, whose proximity might be dangerous. The worm, moreover, stung in the greater number of its nerve-centres, lies on its side, motionless and incapable of bodily contor- tions or sudden jerks of its hinder segments. If the mandibles try to snap, if the legs give 21 The Mason-Wasps a kick or two, they find nothing in front of them: the Ammophila's egg is in the op- posite direction. The little grub is thus able, as soon as it hatches, to dig into the giant's belly in full security. How different are the conditions in the Eumenes' cell! The caterpillars are im- perfectly paralysed, perhaps because they have received but a single stab; they toss about when touched with a pin; they are bound to wriggle when bitten by the larva. If the egg is laid on one of them, this first morsel will, I admit, be consumed without danger, on condition that the point of at- tack be wisely chosen; but there remain others which are not deprived of every means of defence. Let a movement take place in the mass; and the egg, shifted from the upper layer, will tumble into a trap of legs and mandibles. The least thing is enough to jeopardize its existence; and this least thing has every chance of being brought about in the disordered heap of caterpillars. The egg, a tiny cylinder, transparent as crystal, is e'^'.remely delicate: a touch withers it; the least pressure crushes it. No, its place is not in the mass of pro- visions, for the caterpillars, I repeat, are 22 The Eumenes not sufficiently harmless. Their paralysis is incomplete, as is proved by theu icntor- tions when I irritate them an-i evidenced moreover by a very important f; ct, I hav. sometimes taken from the cell cf Eumenas Amadei a few head of game half-trans- formed into chrysalids. It is evident that the transformation was effected in the cell itself and therefore after the operation which the Wasp had performed upon them. Whereof does this operation consist? I cannot say precisely, never having seen the huntress at work. The sting most certainly has played its part; but where? And how often? This is what we do not know. What we can declare is that the torpor is not very profound, inasmuch as the patient sometimes retains enough vitality to shed its skin and become a chrysalis. Everything thus tends to make us ask by what stratagem the egg is shielded from danger. This stra igem I longed to discover; I would not be put off by the scarcity of nests, by the irksomeness of the search, by the risk of sunstroke, by the time taken up in the vain breaking open of unsuitable cells; I meant to see and I saw. Here is my method: with the point of a knife and a pair of nippers, I make a side opening, a window, 23 The Mason- Wasps beneath the dome of E. Amadei and E. pomiformis. I work with the greatest care, so as not to injure the recluse. I used to attack the cupola from the top; I now attack it from the side. I stop when the breach is large enough to allow me to see the state of things within. What is this state of things? I pause to give the reader time to reflect and tc think out for himself a means of safety that will protect the egg and afterwards the grub in the perilous conditions which I have set forth. Seek, think and contrive, such of you as have inventive minds. Have you guessed it? Do you give it up? I may as well tell you. The egg is not laid upon the provisions; it hangs from the top of the cupola by a thread which vies with that of a Spider's web for slenderness. The dainty cylinder quivers and swings at the least breath; it reminds me of the famous pendulum hung from the dome of the Pantheon to prove the rotation of the earth. The victuals are heaped up underneath. Second act of this wondrous spectacle. In order to witness it, we must open a window in cell after cell until fortune deigns to smile upon us. The larva is hatched and The Eumenes already fairly large. Like the egg, it hangs perpendicularly, by its rear-end, from the ceiling; but the suspension-cord has gained considerably in length and consists of the original thread eked out by a sort of ribbon. The grub is at dinner : head downwards, it is digging into the limp belly of one of the caterpillars. I touch up the game that is still intact with a straw. The caterpillars grow restless. The grub forthwith retires from the fray. And how? Marvel is added to marvel: what I took for a flat cord, for a ribbon, at the lower end of the suspension-thread, is a sheath, a scabbard, a sort of ascending gallery wherein the grub crawls backwards and makes its way up. The cast shell of the egg, retaining its cyl- indrical form and perhaps lengthened by a special operation on the part of the new- born larva, forms this safety-channel. At the least sign of danger in the heap of cater- pillars, the larva retreats into its sheath and climbs back to the ceiling, where the swarm- ing rabble cannot reach it. When peace is restored, it slides down its case and returns to table, with its head over the viands and its rear upturned and ready to withdraw in case of need. Third and last act. Strength and vigour 25 ri tin 11 i i The Mason-Wasps have come; the larva is sturdy enough not to dread the movements of the caterpillars bodies. Besides, the caterpillars, mortified by fasting and weakened by a prolonged torpor, become more and more incapable of defence. The perils of the tender babe arc succeeded by the security of the lusty strip- ling; and the grub, henceforth scorning its sheathed lift, lets itself drop upon the game that remains. And thus the banquet ends in normal fashion. c u u That is what I saw in the nests of both species of TLumenes, that is what I showed to friends who were even more surprised than I by these ingenious tactics. The egg hanging from the ceiling, at a distance from the provisions, has naught to fear from the caterpillars, which flounder about below. The newly-hatched worm, whose suspen- sion-cord is lengthened by the sheath of the egg, reaches the game and takes a first cau- tious bite at it. If there be danger, it climbs back to the ceiling by retreating inside the scibbard. This explains the failure of my earlier attempts. Not knowing of the safety-thread, so slender and so easily broken, I gathered at one time the egg, at another the young larva, after my inroads at the top had caused them to fall into the 26 The Eumenes midst of the live provisions. Neither of them was able to thrive when brought into direct contact with the dangerous game. If any one of my readers, to whom I ap- pealed just now, has thought out something better than the Eumenes' invention, I beg that he will let me know, for there is a curious parallel to be drawn between the inspirations of reason and those of instinct. I^i! CHAPTER II THE ODYNERI THE Eumenes' suspension-cord and as- cending-sheath are rendered necessary by the large number and the incomplete paralysis of the caterpillars provided for the larva; the object of the ingenious system is to avert danger. This, at least, is how 1 regard the concatenation of causes and ef- fects. But I yield to no one in my distrust of whys and wherefores; I know how slip- pery our footing becomes when we venture on interpretations; and, before declaring the reasons of any fact observed, I seek for a batch of proofs. If the singular installa- tion of the Eumenes' egg is really due to the reasons suggested, then, wherever we find similar conditions of danger, namely, a multiplicity of dishes combined with incom- plete torpor, we must also find a similar method of protection, or some other method having an equivalent effect. The repeti- tion of the act will bear witness to the cor- rectness of the interpretation; and, if it is not reproduced elsewhere, with such varia- 28 The Odyneri tions as may be required, the case of the Eumenes will remain a very curious instance, without acquiring the far-reaching sig- nificance which I suspect it of bearing. Let us generalize, the better to establish the facts. Now not far removed from the Eumenes arc the Odyneri, the Solitary Wasps ob- served by Reaumur.* They have the same costumes, the same wings folded lengthwise, the same predatory instincts and, above all, as the supreme condition, the same accumulations of prey retaining sufficient power of movement to be danger- ous. If my arguments are well-founded, if I am right in my conjectures, the egg of the Odynerus should b^ slung from the ceiling of the cell like the egg of the Eumenes. My conviction, based upon logic, is so positive that I already seem to see this egg, recently laid, quivering at the end of the life-line. Ah, I confess that it needed a robust faith to cherish the audacious hope of discov- ering anything further when the masters had seen nothing! I read and reread Reaumur's essay on the Solitary Wasp. *Reni Antoine Ferchault de Reaumur (1683-1757), in- ventor of the Reaumur thermometer and author of Mimoires pour strvir d I'histoire naturelle des insecta. — Translator's N-ite. 29 'i The Mason-Wasps The Insect's Herodotus gives us a host of particulars, but says nothing, absolutely nothing, about the hanging egg. I consult Leon Dufour,^ who treats subjects of this kind with his usual ^aciness : he has seen the egg; he describes it; but of the suspen- sion-thread not a word. I consult Lepele- tier,^ Audouin,^ Blanchard:* they are abso- lutely silent on the means of protection which I expect to find. Is it possible that a detail of such great importance can have escaped all these observers? Am 1 the dupe of my imagination? Is the protective system, though proved to my mind by close logical reasoning, merely one of my ^Jean Marie L^on Dufour (178c -1865), an army sur- geon who served with distinction in several campaigns and afterwards practised as a doctor in the Landei, where he attained great eminence as a naturalist. Fabre often refers to him as the Wizard of the Landes. Cf. The Life of the Spider, by J. Henri Fabre, translated by Alex- ander Teixeira de Mattos: chap, i; and The Life of the Fly, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chap. i. — Translator's Note. -Amedee Comte Lepeletier de Saint-Fargeau (1769- circa 1850), author of an Histoire naturelle des insectes (18^6-1846) and of the volume on insects in the Encyclo- pidie mithodique. He wra a younger brother of Louis Michel and Felix Lepeletier de Saint-Fargeau, the mem- bers of the Convention. — Translator's Note. 3 Jean Victor Audouin (1797-1841), founder of the An- nales des sciences naturelles and author of a number of works on insects injurious to agriculture. — Translator's Note. ^£mile Blanchard (b. 1820), author of various works on insects. Spiders, etc. — Translator's Note. 30 The Odyneri dream ? Either the Eumenes have lied to me or my hopes are justified. As a disciple rebelling against his masters, a disciple strong in arguments which I believed in- vincible, I set to work investigating, con- vinced that I should succeed. And I did succeed; I found what I wus looking for; I found something better still. Let me set things down in detail. There are various Odyneri established in my neighbourhood. I know one who takes possession of the abandoned nests of Eu- menes Amadei, This nest, a structure of un- usual solidity, is not a ruin when its owner moves away; it loses only its neck. The cu- pola, preserved untouched, is a fortified re- treat of too convenient a nature to remain va- cant. Some Spider adopts the cavern, after lining it with silk; Osmias * take refuge in it in rainy weather, or else make it their dormitory, wherein to spend the night; an Odynerus divides it, by means of clay par- titions, into three or four chambers, which become the cradles of as many larvae. A second species uses the deserted nests of the Pelopajus;* a third, removing the pith from 1 Cf. Bramble-bees and Others: chaps, i. to vii.— Trans- lator's Note. 2 Cf. Chapter III. of the present volume. — Translator's Note. 3« The Mason-Wasps a dry bramblc-stcm, obtains, for the use of her family, a long sheath, which she sub- divides into stories; a fourth bores a gallery in the dead wood of some fig-tree; a fifth digs herself a shaft in the soil of a foot- path and surmounts it with a cylindrical, vertical kerb. All these industries are worth studying, but I should have preferred to discover that which Reaumur and Dufour have rendered famous. On a steep bank of red clay, I at length recognize, in no great profusion, the signs of a village of Odyneri. Here are the characteristic chimneys mentioneJ by the two historians, that is to say, tin curved tubes, with their guilloche-work, that hang at the entrance to the dwelling. The bank is exposed to the heat of the noonday sun. A little tumbledown wall surmounts it; be- hind is a dense screen of pines. The whole forms a warm refuge, such as the Wasp re- quires for setting up house. Moreover, we are now in the second fortnight of the month of May, which is just the working- season, according to the masters. The out- side architecture, the site and the period all agree with what Reaumur and Leon Dufour have told us. Have I really chanced upon one or other of their Odyneri? This re- 32 The Odyncri mains to be seen and without delay. Not one of the ingenious constructors of guilloche porticoes shows herself, not one arrives; I must wait. I take up my position close by, to watch the homing insects. Ah, how long the hours seem, spent mo- tionless, under a burning sun, at the foot of a declivity which sends the heat of an oven beating down upon you! Bull, my inseparable companion, has retired some distance into the shade, under a clump of evergreen oaks. He has found a layer of sand whose depths still retain some traces of the last shower. He digs himself a bed; and in the cool furrow the sybarite stretches himself flat upon his belly. Lolling his tongue and thrashing the boughs with his tail, he keeps his soft, deep gaze fixed upon me: " What are you doing over there, you booby, baking in the heat? Come here, under the foliage; see how comfortable I ami" That is what I seem to read in my com- panion's eyes. "Oh, my Dog, my friend," I should answer, if you could only understand, " man is tormented by a desire for knowledge, whereas your torments are confined to a de- 33 The Mason-Wasps sire for bones and, from time to time, a de- sire for your sweetheart 1 This, notwith. standmg our devoted friendship, creates a certam difference between us, even though people nowadays say that we are more or less related, almost cousins. I feel the need to know thmgs and am content to bake in the heat; you feel no such need and retire into the cool shade." , Vcs, the hours drag when you lie wait- ing for an msect that does not come. In the pinewood hard by, a couple of Hoopoes are chasing each other with the amorous pro- vocations of spring; " Oopoopoo! " cries the cock, in a muf- ned tone. "Oopoopoo!" Latin antiquity called the Hoopoe ^pttpa; Greek antiquity named it "E,ro^. But Phny turned the i into ou and must have -onounced the word Oupoupa, as the cry . tated by the name teaches me to do. Karely have I received a lesson in Latin pronunciation better authenticated than yours,^ you beautiful bird, who provide a diversion for my long hours of weari- ncss. Faithful to your idiom, you say Oopoopoo/" as you said in the days of »The French, it may hardly be neceiiary to exDlain The Odyncri Aristotle and Pliny, as you said when your note sounded for the first time. But our own idioms, our primitive idioms, what has become of them? The scholar cannot even recover their traces. Man alters; animals do not change. At last, here we are at last! See, the Odynerus arrives, with a flight as silent as the Eumenes*. She disappears into the curved cylinder of the vestibule, bringing home a grub beneath her abdomen. I place a small glass test-tube at the entrance to the nest. When the insect emerges, it will be caught. Done! The Wasp is caught and at once decanted into the asphyxiating-flask, with its strips of paper steeped in bisulphide of carbon. And now, my Dog, still lolling your tongue and frisk- ing your tail, we can be off; the day has not been wasted. We will come back to- morrow. Upon investigation, my Odynerus does not correspond with what I expected to see. This is not the species of which Reaumur speaks (O. spinipes); nor is it the species studied by Dufour (O. Reatimurii) ; it is another. (O. reniformis, Latr.), a differ- ent one, though addicted to the same arts. Already the naturalist of the Landes had 35 The Mason-Wasps allowed himself to be deceived by that similarity in architecture, provisions and habits; he thought that he was observing Reaumur's Solitary Wasp, whereas in re- ality his tube-builder presented specific dif- ferences. We know the worker; it remains for us to become acquainted with her work. The entrance to the nest opens in the perpend- icular wall of the bank. It is a round hole, on the edge of which is built a curved tube, with the orifice turned downwards. Made with the materials cleared from the burrow under construction, this tubular vestibule is composed of grains of earth, not arranged m continuous courses, but leaving small vacant intervals. It is a species of open- work, a lacework of clay. Its length is about an inch and its internal diameter a fifth of an inch. This portico is continued by the gallery, of the same diameter, which slants into the soil to a depth of nearly six inches. Here this main gallery branches into short corridors, each giving access to a cell which is independent of its neighbours. Each larva has its chamber, which can be reached by a special passage. I have counted as many as ten of them; and there may be more. These chambers have no- J6 The Odyneri thing remarkable about them, either in con- struction or n capacity; they are just cuts- de-sac ending the corridors that give access to them. Some are horizontal, some more ^xTi. sloping; there is no fixed rule. When a cell contains what it is meant to contam, the egg and the provisions, the Odynerus closes the entrance with a little earthen lid; she then digs another near it, on one side of the principal gallery. Lastly, the common road to the cells is blocked with earth; the tube at the entrance IS demolished, to furnish material for the work done inside the nest; and every vestige of the habitation disappears. The surface of the bank is of clay baked in the sun; it is almost brick. I break into It with difficulty, making use of a small pocket-trowel. Underneath, it is much less hard. How does the frail miner manage to sink a gallery in this brick? She em- ploys, I cannot doubt, the method described by Reaumur. I will therefore reproduce a passage from the master's writings, to give my younger readers a glimpse into the habits of the Odyneri, habits which my very small colony did not enable me to observe in all their details: 27 The Mason-Wasps f " It is at the end of May that these Wasps set to work; and one can see them busily labouring during the whole of June. Though their actual object is only to dig in the sand a hole a few inches deep and not much wider than their bodies, one might suppose that they had another end in view; for, to make this hole, they build on the out- side a hollow tube, which has as its base the circumference of the entrance to the hole and which,! after following a direction perpendicular to the surface containing that aperture, turns downwards. This tube be- comes longer in proportion as the hole be- comes deeper; it is built of the sand drawn from the hole; it is fashioned in coarse filigree, or a sort of guilloche. It is made of big, granular, winding fillets, which do not touch at all points. The gaps left in between make it look as if it were artistic- ally constructed, whereas it is only a sort of scaffolding by means of which the mother's tactics are rendered swifter and surer. " Though I knew these insects* two teeth to be capital instruments, capable of break- ing into very hard substances, the task which they had to perform appeared to me rather severe for them. The sand on which they had to act was scarcely less hard than ordi- 38 The Odyneri nary stone; at least, one's finger-nails made but a poor impression upon its outer layer, which the sun's rays had dried more thor- oughly than the rest. But, when I sue ceeded in observing these workers at the moment when they were beginning to bore a hole, they taught me that they did not need to subject their teeth to so harsh an ordeal. " I saw that the Wasp begins by soften- ing the sand which she proposes to remove. Her mouth discharges upon it a drop or two of water, which is promptly swallowed by the sand, turning it instantly into a soft paste which her teeth scrape and remove without difficulty. Two of her legs, the foremost pair, immediately proceed to gather it into a little pellet, about the size of a currant-seed. It is with this pellet, the first one removed, that the Wasp lays the foundations of the tube which we have de- scribed. She carries her pellet of mortar to the edge of the hole which she has just made by removing it; her teeth and feet turn It about, flatten it and make it stand up higher than it did before. This done, the Wasp again sets about removing sand and loads herself with another pellet of mortar, boon she contrives to have extracted enoueh 39 * The Mason- Wasps sand to make the entrance of the hole per- ceptible and to have laid the foundation of the tube. " But the work can proceed quickly only so long as the Wasp is able to moisten the sand. She is obliged to take trouble to re- new her store of water. I do not know whether she simply went to take in water at some stream, or whether she drew, from some plant or fruit, a more sticky fluid; what I do know is that she returned without delay and set to work with renewed zeal. I observed one Wasp who managed, in about an hour, to sink a hole the length of her body and who raised a chimney as tall as the hole was deep. At the end of a few hours the tube stood two inches high and she was still deepening the hole that lay un- derneath. " It did not appear to me that she had any rule respecting the depth which she gives it. I have found some whose hole ran more than four inches from the orifice; others whose hole measured only two or three inches. Again, over one hole you will find a tube twice or three times as long as that over another. Not all the mortar removed from the hole is invariably em- ployed to prolong it. In cases where the 40 The Odyneri ^n!FA ''"* ^7' ^^' ^^*^ ^ ^^"g*h which she considers sufficient, you see her simply ar- kI?^ l^ ^'^'^ opening to the tube, put her head beyond Its edge and forthwith drop her pellet which falls to the ground. In ° u'S!:^''^.^^ ^^^ foot of certain holes. . The object for which the hole is pierced in a solid mass of mortar or sand cannot appear m doubt: it is plainly intended to re- ceive an egg, together with a store of food- fnH i \r ^^ "°.* '° ^^'^y ^" to what end the mother has built the mortar shaft. By continuing to follow her labours, we shaU discover that it means to her what a stack of welUaid stones means To [he masons building a wall. Not u*.. whole of L„H.T 7*!J'^ '^^ ^^^ excavated is in- tended as a lodging for the larva which will be bom mside; a portion will be quite cT^S u f^ '^ "^^^ necessary that the hole Itfi f "^"^ '° * "^"'^ ^^P^h, in order that the larva may not find itself exposed to too great a heat when the sun's rays fall on the outer layer of sand. It will occupy only the end of the tunnel. The mother knows what space she must leave vacant and this space she retains; but she fills up all the remainder and replaces in the upper 41 The Mason-Wasps portion of the hole as much of the sand removed from it as is necessary to stop it up. It IS to have this mortar within reach that she has built that shaft. Once the egg IS laid and the store of victuals placed withm Its reach, we see the mother come and gnaw the end of the shaft, after first moist- cnmg It, carry the pellet inside and next re- turn for more, in the same manner, until the hole IS blocked right up to the opening." Reaumur goes on to speak of the victuals heaped up in the cells, the " green grubs," as he calls them, heedless of the ugly al- literation. Not having seen the same things, because my Odynerus is of a differ- ent species, I will continue my story. I counted the head of game in three cells only: the colony was a small one; I had to deal tenderly with it if I would follow its history to the end. In one of the cells, before the provisions were broached, I counted twenty- four pieces; in each of the two others, which were likewise intact, I counted twenty-two. Reaumur found only eight to twelve pieces m the larder of his Odynerus; and Dufour, /Reaumur', actual words are "vers verts;" and Fabre 'iSor'lN^U * °^ "'^* '*'*'*'*"' "«>nance."— Traw- 42 The Odyneri in the store-room of his, discovered a batch of ten to twelve. Mine requires twice as many, a coup e of dozen, which may be due to the smaller size of the game No frol"?*!"^ ^'y °^ '"y acquaintance,* apart from the Bembeces,^ who obtain their sup- plies from day to day, approaches this prodigahty m numbers. Two dozen grub- worms to make a meal for only one I How tar removed are we from the single cater- pillar of the Hairy Ammophila! And what delicate precautions must be taken for the safety of the egg in the midst of such a crowd I A scrupulous vigilance is neces- sary here, if we would obtain a true con- ception of the dangers to which the Odynerus egg is exposed and of the means that save it from danger. And, in the first place, what variety of game is this? It consists of worms as thick as a knitting-needle and varying slightly in length. The biggest measure a centi- metre.2 The head is small, of an intense, glossy black. The segments, unlike those ot the caterpillars, have no legs, either true or false, but all, without exception, are turnished with ambulatory organs in the ^ .39 inch.— Translator's Note. 43 The Mason-Wasps shape of a pair of small fleshy nipples. These worms, though of the same species, to judge by their general characteristics, differ in colouring. They are a pale, yel- lowish green, with two wide longitudinal stripes of pale pink in some anc^ of a more or less deep green in others. Between these two stripes, on the back, runs a streak of pale yellow. The whole body is sprinkled with little black tubercles, each bearing a hair on its crest. The absence of legs proves that they are not caterpillars, not the larvae of Butterflies or Moths. Ac- cording to Audouin's experiments, Reau- mur's "green grubs" are the larva? of a Weevil, Phytonomus variabilis, an inhabi- tant of the lucerne-field- Can my worms, pink or green, also belong to some little Weevil? It is quite possible. Reaumur described the grubs composing the victuals of his Odynerus as alive; he tried to rear some, hoping to see a Fly or a Beetle appear from them. Leon Dufour, on his side, called them live caterpillars. The mobility of the game provided escaped neither of the two observers; they had be- fore their eyes grubs that moved about and gave full sign? of life. What they saw I also see. My little 44 The Odyncri larva frisk and fidget; curled at first in the shape of a ring, they uncurl themselves and curl again, if I do no more than slowly turn the small glass tube in which I have im- prisoned them. When touched with the point of a needle, they struggle abruptly. Some succeed in shifting their position. While engaged in rearing the Odynerus* egg, I opened the cell lengthwise, so as to reduce it to a semicylinder; in the little trench thus made, which was kept horizon- tal, I placed a few head of game. Next day usually I found that one of them had fallen out, a proof of movement, of a change of position, even when nothing was disturbing its repose. These larva, I am firmly convinced, have been wounded by the Odynerus' sting, for she would not carry a rapier merely for show. Possessing a weapon, she employs It. However, the wound is so slight that Reaumur and Leon Dufour did not suspect its existence. To their mind the prey was alive; to mine it is very nearly alive. In these conditions we can see to what perils the Odynerus' egg would be exposed but for exquisitely prudent precautions. There they are, those restless grubs, to the number of two dozen in one cell, side by side with 45 The Mason-Wasps the egg, which a mere nothing is enough to endanger. By what means will this very delicate germ escape the perils of the crowd ? As 1 foresaw by my process of reasoning, the egg IS slung from the ceiling of the cell. A very short thread fastens it to the top wall and lets it hang free in space. The hrst time that I saw this egg, quivering at the end of its thread at the least jerk and confirming by its oscillations the correctness of my theoretical views, I experienced one of those moments of inward joy which atone for much vexation and weariness. I was to have many more such moments, as will be seen. If we pursue our investigations in the insect world with loving patience and a practised eye, we always find some marvel in store for us. The egg, I was saying, swings from the ceiling, held by a very short and extremely fine thread. The cell is sometimes horizontal, sometimes slanting. In the first case, the egg hangs perpendicu- larly to the axis of the cell and its lower end approaches to within a twelfth of an inch of the opposite wall; in the second case, the vertical direction of the egg forms a more or less acute angle with that axis. I wished to follow the progress of this 46 J The Odyncri hanging egg at my leisure, with the greater convenience of observation which is possible at home. With the egg of Eumenes Amadei this was all but .mpracticable. because of the cell, which could not be moved together with the block that most often serves as its foundation. A house of this kind demands observation on the spot. The Odynerus' dweUing docs not present the same draw- back. When a ceil is laid bare and found to be m the condition which I desire, I die round It with the point of a knife until I deach a cylinder of earth containing the cell which IS reduced to an open trough, so as to conceal nothing of what is to happen inside. The victuals are extracted piece- meal, with every care, and decanted sepa- rately into a glass tube. I shall thus avoid the accidents that might be occasioned by the swarming heap of grubs during the mevitable shaking of the journey. The egg alone remains, swinging in the empty enclosure. A large tube receives the cyl- inder of earth, which is wedged in position with pads of cotton-wool. I place my booty in a tin box and carry it in my hand in such a position that the egg hangs vert- ically without striking against the walls of the cell. 47 The Mason-Wasps ..^^7V ^^""^ ^ .*^"^*^ * '«'"ov*» which called for such nice precautions. An acci- dental movement might easily break the suspension-thread, which is so delicate that It needs the magnifying-glass to distinguish It; excessive oscillation might bruise the esut against the walls of the cell: I had to be- ware of turning it into a sort of belUlapper dashing against its bronze prison. I walked, therefore, with the stiffness of an automaton all of one piece, with steps methodically calculated. What a misfor- tunc should some acquaintance appear and make me stop a moment, for a chat or a shake of the hand: the least distraction on my part would perhaps ruin my schemes! btiU more embarrassing would it be should Bull, who cannot endure a black look, find himself muzzle to muzzle with a rival and tnroat. I should have to put an end to the tray, to avoid the scandal of a well- brought-up Dog showing intolerance of the village cur. The squabble would end in the breakdown of all my experimental scaffold- mg. And to think that the eager pre- occupations of a person not entirely devoid Do"fi"t?*^ 'on^etimes be dependent on a 48 The Odyneri Lord be praised, the road is deserted! The journey is accoir lished without hindrance; the thread, my great anxiety, does not break; the egg is not bruised; everything is in order. The little clod of earth is put in a place of safety, with the cell in a horizontal position. I distribute near the egg two or three of the grubs which I have collected; the complete allowance of provisions would cause trouble, now that the cell possesses only half its enclosing wall and IS reduced to a semicylinder. Two days later, I find the egg hatched. The young larva, yellow in colour, is hanging by Its hinder end, head downwards. It is busy with Its first grub, whose skin is already growing limp. The suspension^ord con- sists of the short thread that supported the egg, with the addition of the slough, now reduced to a sort of crumpled ribbon. In order to remain sheathed in the end of this hollow ribbon, the hinder end of the new- born larva is at first slightly constricted and then swells into a button. If I disturb it while at rest, or if the victuals move, the larva withdraws, shrinking back upon it- self, but without retreating into the ascend- ing-sheath, as docs the Ermenes' larva. The tethering-cord does not serve as a scab- 49 y I The Mason-Wasps bard, as a refuge into which the larva can retire; it is rather an anchor-chain, which gives it a purchase on the ceiling and enables it to protect itself by shrinking to a safe distance from the heap of victuals. When things are quiet, the larva lengthens out and returns to its grub. Thus do mat- ters happen at the start, according to my observations, of which some were made at home, in my rearing-jars, and others on the spot, when I unearthed cells containing a larva young enough for my purpose. The first grub is devoured in twenty- four hours. The larva thereupon, so it seemed, goes through a moult. For at least some time it remains inactive and contracted; then it releases itself from the cord. It is now free, in contact with the heap of grubs and henceforth unable to step out of the way. The life-line has not lasted long; it protected the egg and safeguarded its hatch- ing; but the larva is still very weak and the peril has not diminished. This means that we shall discover other means of protection. By a very strange exception, whereof so far I know no other instance, the egg is laid before the provisions are stored. I have seen cells which as yet contained absolutely nothing in the way of victuals and which so The Odyncri nevertheless had the egg swinging from the ceiling. I have seen others, also furnished with the egg and so far containing only two or three head of game, a first instalment of the abundant dish of twenty-four. This early egg-laying, so utterly unlike what hap- pens in the case of the other predatory Wasps, has its underlying motive, as we shall see; it has its logic at which we can- not fail to marvel. The egg, laid in the emptv cell, is not fixed at random on the first sp ; that olfers upon the enclosing wall, which is vacant at all sides; it is hung near the far end, oppo- site the entrance. Reaumur had already noted this position of the budding larva, but without insisting on a detail whose import- ance he did not suspect : •' The grub," he says, " is born at the bot- tom of the hole, that is, at the back of the cell." He does not speak of the egg, which he does not appear to have seen. This posi- tion of the grub was so well known to him that, wishing to attempt the rearing of a grub in a glass cell made with his own hands, he placed the larva at the bottom and the victuals on top of it. sx ■liH 1;'! \ I i,.i The Mason-Wasps Why do I linger over a petty detail which the famous historian of the Odyneri tells in half-a-dozen words? A petty detail? It 18 nothing of the kind; on the contrary, it is a circumstance of paramount importance. And this is why: the egg is laid at the back, necessitating an empty cell which will be victualled after the egg is laid. The provisions are now stored, piece by piece, layer upon layer, in front of the egg; the cell IS crammed' with game right up to the entrance, which in the end is sealed. Of all these pieces, the obtaining of which may take several days, which are the earliest m point of date? Those nearest the egg. Which are the latest? Those by • the entrance. Now it is obvious — be- sides, It may be proved, if necessary, by di- rect observation — it is obvious, I say, that the heaped worms lose strength from day to day. The effects of a prolonged fast would be enough to produce this result, to say nothing of the disorders due to a wound which becomes worse as time goes on. The larva born at the back of the cell has there- fore beside it, in its first youth, the less dangerous provisions, the oldest in date and consequently the feeblest. As it works its way through the heap, it finds more recent 5a The Odyneri game, which is also more vigorous; but this is attacked without danger, because the larva's own strength has come. This progress from the more to the less nearly mortified victims presumes that the grubs do not disturb the order in which they have been stacked. That in fact is what happens. Former historians of the Ody- neri have all remarked that the grubs pro- vided for the larva are curled in the shape of a ring: The cell," says Reaumur, " was occu- pied by green rings, to the number of eight or twelve. Each of these rings consisted of a vermiform larva, alive, curled up and with its back fitting exactly against the wall of the hole. These grubs, laid in this way one on top of the other and even pressed together, had no liberty of movement." I, in my turn, remark similar facts in my two dozen grub-worms. They are curled in a ring; they are stacked one upon an- other, but with a certain confusion in the ranks; their backs touch the wall. I will not attribute this circular curve to the effect of the sting which was very probably ad- ministered, for I have never observed it in 53 hi '\\\ lii :il The Mason- Wasps the caterpillars stabbed by the Ammophilx; I believe rather that the position is natural to the grub during inaction, even as it is natural for the luli * to coil themselves into a spiral. In this living bracelet there is a tendency to return to the rectilinear conform- ation; it is a bent bow fighting against the obstacle that surrounds it. By the very fact, therefore, of bein«r curled up, each grub keeps more or less steady by pressing its back a little against the wall; and it re- tains its place even when the cell approaches the vertical. Moreover, the shape of the cell has been calculated with a view to this manner of storing. In the part next the entrance, the part which one might call the store-room, the cell is cylindrical and narrow, so as to afford the living rings as little space as pos- sible ; they are thus kept in position and are unable to slip. It is here that the grubs are stacked, squeezed one against the o^her. At the other end, near the back, the cell expands into an ovoid to give the larva elbow-room. The differences between the two diameters is very perceptible. At the entrance I find only four millimetres:' at * The lulus belongs to the Myriapod family, which in- cludes the Centipedes, etc. — Translator^ Nott. * .156 inch.— Translator's Note. 54 The Odyneri the back I find six.* Thanks to this in- equality of width, the cell comprises two apartments : the provision-store in front and the dining-room behind. The Eumenes' spacious cupola does not permit of this ar- rangement; there the game is heaped up in disorder, the oldest in date promiscuously with the most recent; and each piece is merely bent, not rolled. The ascending- sheath provides a remedy for the disad- vantages of this confusion. Note also that the packing of the victuals is not the same from one end of the Odynerus' skewerful to the other. In the cells whose provisions have not yet or have only recently been broached, I observe this detail: near the egg or the newly-hatched larva, in the part which I have just described as the dining-room, the space is not fully occupied; there are just a few grubs here, three or four, somewhat isolated from the bulk and leaving enough room to ensure the safety of either the egg or the young larva. This is the food supplied for the early meals. If there be danger in the first mouthfuls, which are the most risky of all, the life-line provides a means of with- drawal. More towards the front, the game » .134 inch.— Tramlator's Note. 55 The Mason-Wasps is piled in dose-packed layers, the stack of worms is continuous. Will the larva, now that it possesses a modicum of strength, force itself im- prudently into this heap? Far from it. The victuals arc consumed iji due order, from the bottommost to the topmost. The larva drags towards it, to a little distance, into the dining-room, the first ring that offers, devours it without danger of being inconvenienced* by the others and thus, layer by layer, consumes the batch of two dozen, always in complete security. Let us retrace our steps and end with a brief summary. The large number of grubs provided for a single cell and their very incomplete paralysis jeopardize the security of the Wasp's egg and of her new- bom larva. How is the danger to be averted? This is the problem; and it has several solutions. The Eumenes, with her sheath, which enables the larva to climb back to the ceiling, gives us one; the Odynerus, in her turn, gives us hers, a solu- tion no less ingenious and much more complicated. The egg and also the newly-hatched larva have to be saved from the danger of contact with the game. A suspension-thread solves 56 The Odyncri the difficulty. Up to this point, that is the method adopted by the Eumenes; but soon the young larva, having eaten its first grub, drops off the thread that gave it a support whereby to shrink out of harm's way. A sequence of conditions now begins, all di- rected towards its welfare. Prudence demands that the very young larva shall first attack the most inoffensive of the grubs, that is those most nearly deadened by abstinence, in short, the grubs first placed in the cell; it demands, more- over, that the consumption of these grubs shall proceed from the oldest specimens to the most recent, so that the larva may have fresh game to the end. With this object, a curious exception is made to the general rule: the egg is laid before the victualling is commenced. It is laid at the back of the cell; in this way, the stacked provisions will present themselves to the larva in due order of date. That is not enough : it is important that the grubs shall be unable, in moving, to alter their respective positions. This circumr stance is provided for: the store-room is a narrow cylinder in which change of place is difficult. Even that is not sufficient : the larva must 57 W> '\ Ml i ft ' The Mason- Wasps have room enough to move about at ease. The condition is fulfilled: at the back, the cell forms a comparatively spacious dining- room: Is that all? Not yet. The dining- room must not be encumbered like the rest of the cell. The matter has been seen to: the first course consists of a small number of specimens. Have we done? By no means. It is not of any use to have a narrow cylinder for the larder: if the grubs straighten out, they will slip lengthwise and disturb the nurse- ling in the back-room. This has been remedied: the game selected is a larva which deliberately rolls itself into a bracelet and maintains its position by its own tendency to unbend. It is by the Ingenious removal of this series of difficulties that the Odynerus suc- ceeds in leaving a family. We have seen enough of her exquisite foresight to amaze us. What would it be were nothing to re- main concealed from our dull eyes ! Can the insect have acquired its skill gradually, from generation to generation, by a long series of casual experiments, of blind gropings? Can such order be born of chaos; such foresight of hazard; such S8 .! ;t The Odyncri wisdom of stupidity? Is the world subject to the fatalities of evolution, from the first albuminous atom which coagulated into a cell, or is it ruled by an Intelligence? The more I see and the more I observe, the more does this Intelligence shine behind the mys- tery of things. I know that I shall not fail to be treated as an abominable " final causer." Little do I care 1 A sure sign of being right in the future is to be out of fashion in the present. I, 59 CHAPTER III li'i THE PELOPiEirS QF the several insects that elect to make their home in our houses, certainly the most interesting, for the beauty of its shape, the singularity of its manners and the structure of its nests, is the Pclopaius, a Wasp hardly known even to the people whose fireside she frequents. Her solitary habits and her peaceful occupation of the premises explain why history is silent m her regard. She is so extremely retiring that her host is nearly always ignorant of her presence. Fame is for the noisy, the im- portunate, the noxious. Let us try to rescue the modest creature from oblivion. An extremely chilly mortal, the Pelopseus pitches her tent under the kindly sun which ripens the olive and prompts the Cicada*8 song; and even then she needs for her family the additional warmth furnished by our. dwellings. Her usual refuge is the peasant's lonely cottage, with its old fig-tree shading the well in front of the door. She 60 The Pelopxus chooses one exposed to all the heat of sum- mer and, if possible, boasting a capacious fireplace in which a fire of sticks is fre- quently renewed. The cheerful blaze on winter evenings, when the sacred yule-log burns upon the hearth, is largely responsible for her choice, for the insect knows by the blackness of the chimney that the spot is a likely one. A chimney that is n t well glazed by smoke does not inspire her with confidence: people must shiver with cold in that house. During the dog-days in July and August, the visitor suddenly appears, seeking a place for her nest. She is in no wise disturbed by the bustle and movement of the household : they take no notice of her nor she of them. Spasmodically she examines, now with her sharp eyes, now with her sensitive antenna, the corners of the blackened ceiling, the angles of the rafters, the chimneypiece, the sides of the fireplace in particular and even the interior of the flue. Having finished her inspection and duly approved of the site, she flies away, soon to return with the little pellet of mud which will form the first layer of the edifice. The spot which she adopts varies greatly; often it is an extremely curious one, the one 6i The Mason-Waipi positive condition being that the temper- ature should be mild and equable. A furnace heat appears to suit the Pelopcus' larva; at least, the favourite place it the chimney, on cither side of the flue, up to a height of twenty inches or so. This snug shelter has its drawbacks. The smoke gets to the nests, especially during the winter, when fires are going all day, and gives them a glaze of brown or black similar to that which covers the stonework. They are so like it in appearance that they might well be taken for inequalities in the mortar which have been overlooked by the trowel. This swarthy distempering is not a serious mat- ter, provided that the flames do not lick against the cluster of cells. That would ensure the destruction of the larvae, stewed to death in their clay pots. But this danger appears to be foreseen; and the Pelopaeus entrusts her family only to chimneys which are too wide for anything but smoke to reach their sides; she is suspicious of the narrow ones which allow the flames to fill the whole entrance to the flue. In spite of her caution, one peril remains. While the nest is building, at a moment when the Wasp, urged by the need for lay- ing her eggs, cannot bring herself to cease 6a The Pelopsui working, it lometimes happens that the ap- proach to the dwelling is barred to her for a time, or even for the whole day, either by a curtain of steam rising from a stew- pan or by clouds of smoke resulting from damp firewood. Washing-days are the most risky. From morning to night, th'; housewife keeps the huge cauldron boilin^^ with all the odds and ends of the wood-f IieU . chips, bits of bark, leaves, fuel that l)t*rn. with difficulty and intermittently. The smoke from the hearth, the steam from the cauldron and the reek from the wash-tub form in front of the fireplace a dense mist with very few rifts in it. I have at rare intervals surprised the Pelopseus in the presence of some such obstacle. It is told of the Water-ouzel, the Dipper, that, to get back to his nest, he will fly through the cataract under a mill-weir. The Pelopxus is even more daring: with her pellet of mud in her teeth, she crosses the cloud of smoke and disappears behind it, henceforth invisible, so thick is the screen. A spasmodic chirring, her work- ing-song, alone betrays the mason at her task. The building rises mysteriously be- hind the cloud. The ditty ceases and the Wasp emerges from the steam-flakes, fit 6$ iP! iN! The Mason-Wasps and well, as though coming out of a limpid atmosphere. She has faced the fire, like the fabled Salamander, and she will face it all day, until the cell is built, crammed with victuals and closed. Cases of this kind occur too seldom to satisfy fully the curiosity of a seasoned ob- server. I should have liked to arrange the mist-screen myself and thus to try a few experiments bearing upon the dangerous crossing; but I was a stranger, a spectator by sheer chance ; and all that I could do was to trust to luck, without interfering with the washing-operations and perhaps upsetting them. What a sorry idea the housewife engaged, on that grave business would have had of my intelligence if I had ventured to touch her fire in order to worry a Wasp! " Va petan cieucle: little things please little minds," she would have been sure to think. In the eyes of the peasant, to occupy one'a self with such small fry is a lunatic's game, the amusement of r cracked mind. Once and once only fortune smiled upon me; but I was not ready to profit by it. The thing took place at my own house, by my own fireside and, as it happened, on a v/ashing-day. I had not long been ap- 64 The Pelopsus pointed to the Avignon grammar-school. It was close upon two o'clock; and in a few minutes the roll of the drum would summon me to display the properties of the Leyden jar to an audience of wool-gatherers. I was preparing to start, when I saw a strange, agile insect, with a slender body and a gourd-shaped abdomen slung at the end of a long thread, dart through the reek rising from the wash-tub. It was the Pelopsus, whom I saw for the first time with observant eyes. A novice still and anxious to become better-acquainted with my visitor, I fervently commended the in- sect to the watchful care of the household, begging them not to disturb it in my absence and to manage the fire in such a way as not to inconvenience it in its plucky work of building the walls of its nest right beside the fiame. My wishes were carried out religiously. Things went better than I dared hope. On my return, the Pelopsus was continuing her mason's work behind the steam of the wash-tub, which stood under the mantel of a wide chimney. Eager as I was to witness the construction of the cells, to identify the nature of the provisions, to follow the evolution of the larvx, all of them 65 The Mason-Wasps biological details entirely new to me, I took good ca:e not to raise the experimental oh- stacles which I should not fail to set in the path of instinct to-day : a good nest was the sole object that I coveted. Therefore, so far from creating fresh difficulties for the Pelopaus, I did my utmost to reduce those which she had to overcome. I raked the fire, making it much smaller, so as to de- crease the volume of smoke in the Wasp's building-yard; and for a good two hours I watched her diving through the cloud. Next day, the usual niggardly fire was burn- ing intermitteMly; and there was nothing now to hamper the Pelopaeus, who con- tinued her work for some days and without further impediment completed the well- filled nest which was the object of my wishes. Never again, in the forty years that fol- lowed, was my fireplace honoured with such a visit; and it was only by having recourse to the more fortunate hearths of my neigh- bours that I was able to glean my little bit of information. Nor was it until much later that, profiting by long experience, I had the idea of turning to account the predilection of so many Bees and SVasps for their birthplace and for founding a 66 ifim/t^' The Pclopaeus family in the neighbourhood of the nest where they receive perhaps the strongest of all impressions, the first dawn of light. I took Pelopzus-nests which I had collected more or less everywhere during the winter and fixed them in different places, in my present house, which, judging by the sum total of my observations, I considered suit- able, notably at the entrance to the chimney both of the kitchen and of the study. I put some in the embrasures of the windows, keeping the outside shutters closed to obtain the requisite sultriness; I stuck some to the dimly-lighted corners of the ceilings. It was in these sites of my (Choosing that the new generation was to hatch when summer came; it was here that it would settle: at least I thought so. Then I could have conducted in my own way the experiments which I had in mind. My attempts invariably failed. Not one of my charges returned to the native nest; the less fickle of them contented themselves with brief visits, soon followed by a de- parture for good. The Pelopaeus, it ap- pears, is of a solitary and vagrant disposi- tion: save in exceptionally favourable cir- cumstances, she builds a lonely nest and is quite ready to change her locality ^-om 67 The Mason-Wasps generation to generation. As a matter of fact, though this Wasp is fairly com- mon in my village, her dwellings arc nearly always scattered one by one, with no traces of any old nests near by. The place of her birth leaves no lasting recollection in the nomad's memory; and none comes to build beside the ruins of the maternal home. For that matter, my want of success might well be due to another cause. The Pelopzus certainly is not rare in our south- ern towns; nevertheless she prefers the peasant's smoky house to the townsman's white villa. Nowhere have I seen her so plentiful as in my village, with its tumble- down cottages guiltless of rough-cast and burnt yellow by the sun. My hermitage is not quite so rustic as that: it is a little neater and cleaner; and there is nothing to show that my visitors did not forsake my kitchen and my study, both too sumptuous in their opinion, to go and settle somewhere near in lodgings more to their taste. And so the eagerly desired colonists, who were to have peopled my workroom crammed with books, plants, fossils and entomological cemeteries, took their departure, scorning all that scicn- tific luxury; they wcat away in search of some 68 The Pelopsus dim chamber with a solitary window sport- ing a sprig of wall-flower in an old, cracked stew-pot. Felicities like that arc reserved for the humble; and I am therefore reduced to what I have gained by an occasional piece of good luck, irrespective of any efforts of mine. The little that I have seen, in one direction and another, is after all sufficient evidence of the pluck of the Pelopaeus, who, to reach her nest built in a corner of the hearth, at times passes through a cloud of steam and smoke. Would she dare to cross a thin sheet of flame? That was what I had proposed to see, if my attempts to acclimatize her in my home had met with any success. It is obvious that, in displaying a marked predilection for the chimney as her abode, the Pelopxus is not seeking her own com- fort: the site chosen means work and dangerous work. She seeks the welfare of her family. This family then, in order to prosper, must require a high temperature, such as is not demanded by the other Wasps or Bees, the Chalicodoma and the Osmia, for instance, who find sufficient shelter under a mortar dome or in the hollow of an exposed reed. Let us see what tempera- ture the Pelopaeus finds to her liking. 69 if I! \ ! The Mason-Wasps On the side-wall, under the chimneypiece, I hung a thermometer over a Pelopaeus- nest. During an hour's observation, with a fire giving out a moderate heat, it fluctu- ated between 95° and 105° F. This tem- perature, it is true, does not remain the same during the long larval period; on the contrary, it varies greatly, according to the season of the year and the time of day. I wanted something better and I found it on two occasions. My first observation was made in the engine-room of a silk-factory. The back of the boiler reached nearly to the ceiling, the ^ace between being barely twenty inches. It was against this ceiling, right above the huge cauldron, which was always full of water and stearr at a high tem- perature, that the Pelopztus-nest was fixed. At this spot the thermometer marked 120°. This degree of heat was maintained all through the year; it was only at night and on holidays that it decreased. A country distillery furnished me with the second subject of observation. It combined two excellent conditions for at- tracting Pelopaei: rural quiet and the heat c4 a furnace. The nests therefore were numerous, fixed more or less everywhere on The Pelopseus anything* that came to hand, even down to the pile of account-books in which the ex- cisemen registered their troublesome in- spections of the proof-spirit. One of these, situated quite close to the still, was tested with the thermometer. It measured 113° of heat. These few data prove that the larvae of the Pelopseus are comfortable in a tempera- ture of a hundred degrees or over, a tem- perature not accidental, like that produced by a fire blazing in a chimney, but con- stant, such as obtained by a boiler or a still. Tropical heat is favourable to the grub slumbering for ten months in its mud hole. Any seed, in order to sprout, needs a cer- tain quantum of heat, greater or smaller according to its kind. The larva, a sort of animal .seed out of which the perfect in- sect will come by a process of germination even more wonderful than that which turns an acorn into an oak, the larva also claims its quantum of heat. The larva of the Pelopaeus can cheerfully endure a temper- ature that makes the baobab or the oily palm-tree sprout. What then is the origin of this chilly tribe? A good fire on the hearth, a boiler or a furnace shedding an artificial tropical 71 i irw w^^:^ ' !l! The Mason-Wasps climate around them are useful windfalls, which, however, cannot be relied upon; and the Pelopxus settles in any lodging where she finds warmth and not too garish a light. The corners of a conservatory; a kitchen- ceiling; the embrasure of a window with closed casement and shutters, provided that these furnish some exit-hole; the rafters of a loft, where the warmth of the daily quota of sunshine is preserved by the heaped-up hay and straw; the walls of a cottage bed- room: any of these suit her, so long as the larvjB find a snug shelter in winter. This climatological expert, the daughter of the dog-days, divines the coming peril for her family, that inclement season which she her- self will never see. While she is scrupulous in her choice of a warm spot, on the other hand she is supremely indifferent to the nature of the foundation on which the nest is to be fastened. As a rule, she fixes her groups of cells to the stonework, whether rough- coated or not, and to the timber, whether bare or plastered; but she uses many other supports, some of which are very peculiar. Let us mention a few of these fantastic installations. My notes speak of a nest constructed in- 72 i:'* have shown us. For reasom qua n'ted^w^h T' "'^ ''^'"P^^ '»""»"■ quainted with the paralysers' art, nor dop. her larva know how a bulky piew of „ame may be consumed without danger. She is therefore very happily inspired when she iv. .„ ,.- rrJ,iJ^Xf,o!; "' """""' *''""•• "»P»- 98 p*WiiE»-iaaiw8^ The PelopiEUs' Victuals provides her family with a large number of small game. The restricted capacity of the store-houses is not the main motive that dictates her choice: there would be nothing to deter the potter from making bigger pickle-jars, were there any advantage to be gained. The preservation of dead victuals is of the foremost consequence; and, to achieve it within the brief limits of the feed- ing-period, the huntress fills her bag with none but the smaller Spiders. Better still: if I open cells that have been recently closed, I always find the egg, not on the surface of the heap, on the last Spider supplied, but right at the bottom, on the piece earliest in date, the first to b** stored. Whenever I witness the start of the provisioning, I see the egg lying on the single Spider wherewith the cell is then pro- vided. There is no exception to the rule: the PelopzBus at once fixes her egg on the first morsel served up, before resuming the chase to complete the ration. The Bem- beces deal similarly with their dead Hies: the first carcase stowed away receives the egg. But this conformity of habits goes no farther. The Bembeces continue to bring provisions day by day, as the larva increases 99 The Mason-Wasps ui - 5 in size, a method easily practised in a bur- row closed with a mere screen of loose sand, through which the mother passes easily m either direction. The Pelop*us has not the same facilities of ingress and egress: once the earthen jar is closed and sealed she would have, in order to re- dry and would offer a resistance out of all proportion to the means at the disposal of 1% ty ^""^^o'ned to handling fresh mud Moreover, each of these laborious burglaries would have to be followed by a rebuilding, which also would be an arduous .Jl '^T ^^T^""^^ ^^"^ Pelopsus' practice hoard of^".°^P'"« ^^y ^y ^^y- '"d the nn«;Kl T/""'' '« completed as swiftly as possible If game be not abundant, if the atmospheric conditions be difficult, several days arc required to fill the cell thoroughly. fici/n7°"M ^' weather an afternoon is suf- hcient. No matter what time the hunting may take long or short according to circum- stances, the laying of the egg at the bottom h!nn A - °" '^' ^"^ P'ece served, is a happy device on whose excellence I have already laid stress in my history of the Odynerus. The victuals provided for a cell 100 The PcIopa?u8' Victuals fill it to the brim and arc stacked in the order of acquisition, with the Spiders earliest in date at the bottom and the more recent on the surface. No subsidence, which would lead to a mixture of fresh game and high, is possible, because of the game's long legs, which in most cases scrape against the walls of the cell with their stiff hairs. The larva, at the bottom of the heap and, moreover, in- tent upon the morsel attacked, thus proceeds from the oldest to the less old and always finds in front of its teeth, until the end of the meal, victuals that have not had time to spoil by decomposition. The egg is laid indifferently upon a large joint or a small, according to the chances of the first capture. It is white, cylindrical, slightly curved and measures three milli- metres in length, with a diameter of rather less than one millimetre.* The spot that receives it on the Spider's body varies hardly at all; it is at the beginning of the abdomen, towards the side. The new-born larva, as is usual with the Hunting Wasps, takes its first bite at the point where the pole of the egg containing the head was fixed. Thus, for its first mouthfuls, it has the juiciest and tenderest part, the Spider's * .177 by .039 inch.— Translator's Notr. lOI m W I . N, The Mason-Wasps plump belly. Next comes the thorax, abounding in muscular tissues, and lastly the legs, dry morsels, but not despised. Everything goes down, from the best to "the coarsest; and, when the meal is finished, there is practically nothing left of the whole heap of Spiders. This life of gluttony lasts for eight to ten days. The larva then works at its cocoon, which consists at first of a sack of pure, perfectly white silk, an extremely delicate sack, affording little protection to the re- cluse. This is only a woof, destined to be- come a better stuff, not by additional weav- ing, but by the application of a special lacquer. The spinner is a worker in oiled silk. In the spinning-mills of the carnivorous Wasps, twc methods of manufacture are employed to give the silken fabric greater toughness. On the one hand, the fabric is encrusted with numerous grains of sand, which produces an almost mineral shell wherein the silk has no other function than to serve as a cement for the stony materials. That is how the Bembeces, the Stizi, the Tachytes and the Palari work. On the other hand, the larva elaborates in its 102 The Pelopaeus' Victuals stomach, in its chylific ventricle, a liquid varnish which it disgorges into the meshes of a rudimentary tissue of silk. Di- rectly it trickles into the web, the varnish hardens and becomes a lacquer of exquisite daintiness. The larva next ejects at the base of the cocoon, in the form of a hard stercoral plug, the residue of the chemical process accomplished in its stomach for the elaboration of the varnish. This method is that of the Spheges, the Ammophilas and the Scolia;, who varnish the inner wrapper of their multiple cocoons; and of the Crabro- wasps, the Cerceres and the Philanthi,* whose delicate cocoon consists of only a single thickness. The Pelopajus adopts this last procedure. When finished, her work is an amber-yel- low fabric suggesting the outer skin of an onion in fineness, colour, transparency and the rustling sound which it emits when fingered. Relatively long in comparison with its width, as is demanded by the ca- »For the Cerceris, cf. The Hunting Wasps: chaps, i. to iii; for the Philanthus, or Bee-eating Wasp, cf. Social Life tn the Insect World:^ chap. xiii. Some of the other Wasps mentioned above will forna the subject of chapters in a later volume of this series entitled More Hunting Wasts. — Translator's Note. 103 The Mason-Wasps pacity of the cell and the slender form of the future insect, the cocoon is rounded at the top and suddenly truncated at the base, which is rendered hard and opaque by the stercoral plug, the by-product of the lacquer-factory. The hatching-period varies, of course, ac- cording to the temperature and also accord- ing to certain conditions which I am not yet in a position to specify. One cocoon, woven in July, , gives birth to the perfect insect in the course of August, two or three weeks after the larva's period of activity; another, dating from August, opens a month later, in September; a third, no mat- ter what its date of origin during the sum- mer quarter, goes through the winter and does not burst until the end of June. By combining the birth-certificates recorded, 1 seem to distinguish three generations in the year, generations which are often but not invariably realized. The first appears at the end of June: this is the one whose co- coons have gone through the winter; the second is seen in August and the third in September. So long as the very hot weather lasts, evolution is rapid: three or four weeks suffice to complete the Pelopaeus' cycle. When September arrives, the fall in 104 The Pclopaeus' Victuals temperature puts an end to these precocious broods; and the last larvae have to wait for the return of the hot weather before they can undergo their transformation. los ml CHAPTER V ' ■ i ABERRATIONS OF INSTINCT CO far as the Pelopseus is concerned, my *^ part as an observer is concluded, a part of no great interest, I am the first to admit, if we limit its scope merely to the data which it is able to supply. That the insect fre- quents our dwellings, that it builds a mud nest victualled with Spiders, that it weaves itself a bag which looks as it it were cut out of an onion-skin : all these details matter to us but little. They may please the col- lector who zealously sets down everything, down to the nervation of a wing, in order to throw a little light on his systematic ar- rangements; but the mind nourished with more serious ideas sees nothing in all this but the food of an almost puerile curiosity. Is it really worth while to spend our time, *he time which escapes us so swiftly, this ocuff of life, as Montaigne calls it, in glean- ing facts of indifferent moment and of highly contestable utility? Is it not child- ish to enquire so minutely into an insect's actions? Too many interests of a graver 106 Aberrations of Instinct kind hold us in their grasp to leave us any leisure for these amusements. That is how the harsh experience of age impels us to speak; that is how I should conclude, as I bring my investigations to a close, if I did not perceive, amid the chaos of my obser- vations, a few gleams of light touching the loftiest problems which we are privileged to discuss. Wh. is life? Will it ever be possible for us to trace it to its sources? Shall we ever be permitted to excite, in a drop of albumen, the uncertain quiverings which are the preludes of organization? What is human intelligence? In what respect does it differ from animal intelligence? What is instinct? Are these two mental aptitudes irreducible, or can they both be traced back to a common factor? Are the species connected with one another, are they re- lated by evolution? Or are they, as it were, so many unchangeable medals, each struck from a separate die upon which the tooth of time has no effect, except to destroy it sooner or later? These questions are and always will be the despair of every cul- tivated mind, even though the inanity of our efforts to solve them urges us to cast them into the limbo of the unknowable. 107 The Mason-Wasps The theorists, proudly daring, have an answer nowaday, for 'every qS,tio„Tbut! as a thousand theoretical views are no worth a single fact, thinker, untrammeC by preconceived idea, are far from be- mg convinced. Problem, ,uch as these whether their scientific ,olution be poS ZT'u'Tr "" """"O"' ma,, of well, e, abhshed data, to which entomology, de- ouot'^'f ''""'''' P.™^'""- «•" contr^'te a quota of some vah ,. And that is why I am an observer, why, above all, I am an experimenter. It is something to observe; but it is not enough: we must experiment, that i to say reveal to u, what it would not teU if left to the norma course of events. It, action" marvellously contrived to attain the end pu?! sued, are capable of deceiving „, as to their rea meaning and of makin| us accent in their linked sequence, that Ihich ou?own ogic dictate, to us. It i, not the anima" * t, ant;^ T^ ""'""["^ "P°" 'he nature of hi =« V it "P"" "■* P""'*^' motive, of Its artiyity, but our own opinion,, which ished notion,. A, I have already re- io8 Aberrations of Instinct peatedly shown, observation in itself is often a snare: we interpret its data according to the exigencies of our theories. To bring out the truth, we must needs resort to ex- periment, which alone is able to some extent to fathom the obscure problem of animal intelligence. It has sometimes been denied that zoology is an experimental science. The accusation would be well-founded if zoology confined itself to describing and classifying; but this is the least important part of its function: it has higher aims than that; and, when it consults the animal upon some problem of life, its method of quest- ioning lies in experiment. In my own modest sphere, I should be depriving my- self of the most potent method of study if I were to neglect experiment. Observation sets the problem; experiment solves it, al- ways presuming that it can be solved; or at least, if powerless to yield the full light of truth, it sheds a certain gleam over the edges of the impenetrable cloud. Let u V return to the Pelopaeus, to whom it is time to apply the experimental method. A cell has recently been completed. The huntress arrives with her first Spider. She stores it away and at once fastens her egg upon the Spider's belly. She sets out on a 109 The Mason-Wasps second trip. I take advantage of her ab- sence to remove with my tweezers from the bottom of the cell the head of game and the egg. What will the insect do on its return, confronted with this empty cell, this cell no longer containing the egg, the sole object of her industry as a potter and her skill as a huntress? The disappearance of the egg must be obvious to the Wasp who has been robbed of It, if her poor intelligence possess so much as the rudimentary gleam that enables us to distinguish between a thing's presence and Its absence. The egg, were it alone, being of small dimensions, might escape the mother's vigilance; but it lies upon a com- Pf^atively bulky Spider, of whose presence the Pelopius, on returning to the nest, is undoubtedly apprised by her sense of touch and sight when she deposits the second vic- tim beside the first. If this big object be missing, the egg is missing likewise, so the most elementary trace of reason that it is possible to conceive ought to tell her. Once more, what will the Pelopseus do when confronted with her cell, where the absence of the egg henceforth renders the bringing of provisions useless and absurd, unless and until she repairs the loss by laying a second no Aberrations of Instinct egg? She will do precisely what we have already seen in the Mason-bee of the Sheds, but under less striking conditions: she will act absurdly and wear herself out uselessly. What she does is to bring a second Spider, whom she stores away with the same cheerful zeal as though nothing untoward had occurred; she brings a third, a fourth and others still, each of whom I remove during her absence, so that every time that she returns from the chase the warehouse is found empty. For two days the Pelopaeus' obstinacy in seeking to fill the insatiable jar persisted; for two days my patience in emptying the pot as she stocked it was equally unflagging. With the twentieth victim, persuaded, perhaps, by the fatigue of expeditions repeated beyond all measure, the huntress considered that the game-bag was sufficiently supplied; and she began most conscientiously to close the cell which contained absolutely nothing. The Mason-bees whose cups I used to empty as and when they brushed off the pol- len-dust and disgorged the honey-paste gave pre »f of similar inconsistencies: I would see them laying the egg in the empty cell and then closing the cell forming easy victims, i^or the caterpillar, therefore, this double- acting mouth is a work of the highest im- portance. It has to expend upon it all that >t possesses in foresight, in gleams of rea- son and in art capable of modification when circumstances require; it must in short give proof of the best of which its talents are capable. Let us follow it in its labours; let us interpose the experimental test; and we shall learn some curious facts The cocoon and its opening' are con- structed simultaneously. When it has woven this or that part of the general wall, the caterpillar turns about, if need be, and with Its unbroken thread proceeds to continue the palisade of converging filaments. To 122 Aberrations of Instinct this end it pokes its head to the end of the roughly-defined funnel and then with- draws it, doubling the thread as it goes. Ihis alternation of thrusts and withdraw- als results in a circle of doubled filaments, which do not adhere to one another. The shift is not a long one; when the palisade is a row the richer, the caterpillar resumes its work upon the shell, a task which it again abandons to busy itself with the funnel; and so on, over and over again, the emission of the gummy product being suspended when the threads are to be left free and copiously ettected when they have to be stuck together in order to obtain a solid texture. The exit-funnel is not, as we see, a piece of work executed continuously; the cater- pillar works at it intermittently, as the gen- eral shell progresses. From the beginning to the end of its spinning-period, so long as the reservoirs of silk are not exhausted, it multiplies the tiers without neglecting the rest of the cocoon. These tiers take the fomi of cones enclosed one within the other and of increasingly obtuse angles, until the last to be spun are so flat as to become al- most level surfaces. If nothing happen to disturb the worker, the work is performed with a perfection 123 III The Mason-Wasps that would do credit to a discerning in- dustry capable of realizing the why and wherefore of things. Can the caterpillar V t^^'^ /° ^^^^ ^"y conception, however slight, of the importance of its task, of the future function of its overlapping conical palisades? This is what we are about to learn. I take a pair of scissors and remove the conical extremity while the spinner is work- ing at the other end. The cocoon is now wide open. The caterpillar soon turns about. It thrusts its head into the wide breach which I have just made; it seems to be exploring the outside and enquiring into the accident that has occurred. I ex- pect to see it repair the disaster and en- tirely reconstruct the cone destroyed by my scissors. It does, in fact, work at it for a time; it erects a row of converging threads; then, without paying further heed to the disaster, it applies its spinnerets elsewhere and continues to thicken, the cocoon. Grave doubts come to my mind: the cone built upon the breach consists of sparse filaments; it is, moreover, very flat and does not project anything like so much as the original cone. What I took at first to be a work of repair is merely a work of con- 124 Aberrations of Instinct tinuation. The caterpillar, put to the test by my tricks, has not modified the course of its work; despite the imm'nenc of the danger, it has confined itself i o the tier of threads which it would have fitted inside the preceding tier but for the snip of my scissors. I let things go on for a while; and, when the mouth has once again acquired a cer- tain solidity, I cut it off for the second time. The insect displays the same lack of per- spicacity as before, replacing the absent cone by one with an even more obtuse angle, that is to say, continuing its usual task, without any attempt at a thorough restoration, despite the extreme urgency. If the store of silk were nearly at an end, I should sympathize with the troubles of the sorely-tried caterpillar doing its best to re- pair its house with the scanty materials that remain at its disposal; but I see it foolishly squandering its product on the additional upholstering of a shell which may be strong enough as it is, while economizing to the point of stinginess in the matter of the fence, which, if neglected, will leave the cell and its inhabitant at the mercy of the first thief that comes along. There is no lack of silk: the spinner applies layer upon layer to the las II II' The Mason-Wasps points that arc unhurt; but at the breach it employs only the quantity required under ordinary conditions. This is not economy imposed by shortage; it is blind clinging to custom. And so my commiseration changes to amazement in the presence of such profound stupidity, which applies itself to the superfluous work of upholstery in a dwelling henceforth uninhabitable, instead of attendmg, while there is yet time, to the busmess of repairing the ruins. I make my cut a third time. When the moment has come to resume Lhe series of boxed cones, the caterpillar arms the breach with bristles arranged in a disk, as they appear in the last courses of the un- disturbed structure. This configuration ^ows that the end of the task is at hand. The cocoon is strengthened for a little longer; then rest ensues and the meta- morphosis begins in a dwelling with a nig- gardly fence to it, one which would not strike terror into the puniest invader. To sum up, the caterpillar, incapable of perceiving the dangers attendant upon an incomplete palisade, resumes its work, after each amputation of the cocoon, at the point where it had left it before the accident. Instead of thoroughly restoring the ruined 126 Aberrations of Instinct exit, which its very abundant store of silk would allow it to do; instead of reerecting on the breach a projecting cone of many lay- ers, to replace the one removed by my scis- sors, it runs up layers of threads that be- come gradually flatter and flatter and form a continuation and not a reconstruction of the missing layers. Moreover, this work of fence-building, the need for which would seem imperious to any reasoning creature, does not appear to preoccupy the caterpillar more than usual, for it keeps on alternating this work with that of the cocoon, which is much less urgent. Everything goes by rote, as though the serious incident of the housebreaking had not occurred. In a word, the caterpillar does not begin all over again a thing once made and then de- stroyed; it continues it. The early stages of the work are lacking; no matter: the sequel follows without any modification in the plans. It would be easy for me, if my argument were not already quite clear, to give a host of similar examples showing plainly that the intelligence of the insect is absolutely deficient in rational discernment, even when the great perfection of the work would seem to allow the artisan a certain per- 127 l'i% The Mason-Wasps mentioned The plir/"" ^^'"^ ^ ^"' Spider, for an egg .["fh"' "i"" °" """"g •he perseveres inlli." I ''"" "•"""ed; .re KenX h useTe t'"S,e h""^-'"P.' ""« •liat are destined 1„ • !'°"^' ^'«'«''» multiplies trb«.:,rm wTh":!' '"• larder which i^ fnrfU -u . ^*"*e a '-cezers; Tastl" st'cro'se, ZT" "' ""' ternary care, a coll that n^ 1 ""'' ™»- rfrtonerw^rarthV:''''""^"^ of the F^I 1 . ^ . ''^' ^S^'" the mouth Aberrations of Instinct What arc we to conclude from these fac»s? I would fain believe, for the sake of my insects' reputation, in some distrac- tion on their part, in some individual giddi- ness which would not taint the general per- spicacity; I should liice to regard their aber- rations merely as isolated and exceptional actions, which would not affect their judg- ment as a whole. Alas, a long series of glaring facts would impose silence on my attempts at rehabilitation! Any species, no matter which, when subjected to experi- mental tests, is guilty of similar nconsis- tencies in the course of its disturbed in- dustry. Constrained by the inexorable logic of the facts, I therefore state the de- ductions suggested by observation as fol- lows : the insect is neither free nor conscious in its industry, which in its case is an ex- ternal function with phases regulated al- most as strictly as the phases of an inter- nal function, such as digestion. It builds, weaves, hunts, stabs and paralyses, even as it digests, even as it secretes the poison of its sting, the silk of its cocoon or the wax of its combs, always without the least under- standing of the means or the end. It is ignorant of its wonderful talents just as the stomach is ignorant of its skilful chemistry. 129 4-/* ■ I I'i K1 The Mason-Wasps sub?^vr„yr;Vort' " '""" "- than it is able to incr«se or H' '"'■ u'"T pulsation, of its drarv„:el '""'""' ""^ it n^rit'iir'tras'if- "' t' '"" »««' exercise nf'l.ir " " '" "'« undisturbed modification in the?ond"ct o TtstsT T/ Twakera °^' ""' '"^'' '*■• "- "- -t unToto^sn^r^ts'a'r^ '/t"' ."^ '" speciality, but inep T„ th face ofM 'r .'" "u.abf,T af t'£ i^ B^'t^'t handedVn Jo^ ^ bit tXer^x: "oc Its manner of suckinfr u .u equalJy ignorant of what thev Ir!' ^ "'^ 130 Aberrations of Instinct plished counts as valid by the mere fact that it has been accomplished; the insect does not go back to it, should some accident de- mand; the consequent follows without troubling about the missing antecedent. A blind impulse urges it from one act to a second, from this second to a third and so on until the task is completed; but it is im- possible for the insect to reascend the cur- rent of its activity should accidental condi- tions arise and call for this, however im- peratively. Having passed through the complete cycle, the work is considered to be most logically performed by a worker de- void of all logic. The stimulus to labour is the bait of pleasure, that chief motive-power in the ani- mal. The mother has no foreknowledge whatever of her future larva; she does not build, does not hunt, does not hoard with the conscious aim of rearing a family. The real object of her work is hidden from her; the accessory but exciting aim, the pleasure experienced, is her only guide. The Pelo- paeus feels a keen satisfaction when she crams a cell full with Spiders; and she goes on hunting with imperturbable spirit after the removal of the egg from the cell has made provisions useless. She delights in 131 The Mason-Wasps plastering the outside of her nest with mud and she continues to putty the site of her nest, after it has been detached from the wall, without suspecting the futility of her stucco. And so with the others. To re- proach them for their aberrations we must assume that they possess a tiny glimmer of reason, as Darwin* would have us believe; if they have it not, the reproach falls to the ground and their aberrant acts are the in- evitable result of an unconsciousness di- verted from its normal paths. » Charles Robert Darwin (1809-1882), the author of The Ongtn of Species, had the highest opinion of Fabre and spoke of hira as "that incomparable observer." Fabre, on the other hand, had no faith whatever in Dar- winism, nor was he greatly struck by the views and the suggestions for experiments with which Darwin favoured him from time to time. Cf. The Mason-bees: chaps, iv. and v.— Translator's Note. 132 CHAPTER VI THE SWALLOW AND THE SPARROW '' I ^ HE Pelopaeus sets us a second problem. -■• She frequents our homes, seeks the warmth of our fireplaces. A nest like hers, built of soft mud, which lets in the water, which would be dismantled by a shower and utterly destroyed by prolonged damp, must have a dry shelter; and this can be nowhere better found than in our dwelling-houses. Her susceptibility to cold make' warmth a necessity. Perhaps she is a foreigner not yet fully acclimatized, an emigrant from the shores of Africa, who, after coming from the land of dates to the land of olives, finds the sunshine in the latter insufficient and substitutes for the climate beloved of her race the artificial climate of the fireside. This would explain her habits, so unlike those of the other Wasps, all of whom shun the too-close proximity of man. But through what stages did she pass be- fore becoming our guest? Where did she lodge before quarters built by human in- dustry existed, where did she shelter her 133 m r I* llri The Mason- Wasps brood of grubs before chimneys were thought of? When, on the hills near by, abounding in traces of their sojourn, the aborigines of Serignan were hewing weapons out of flint, scraping Goat-skins into raiment and building huts of mud and branches, did the Pelopajus already frequent their cabins? Did she build in some bulging pot, shaped with the thumb out of half-baked black clay, and by this choice teach her latter-day de- scendants to seek out the peasant*s gourd on the chimneypiece ? Did she think of build- ing in the folds of the garments, the spoils of the Wolf and the Bear, hanging from some set of antlers, the hat-rack of the period, thus trying her hand at a kind of annexation that was to take her at a later date to window-curtains and the labourer's smock? Did she prefer to fix her nest on the rough wall of branches and clay, near the conical orifice which let out the smoke from the primitive fire laid between four stones in the centre of the hut? Though not equal to our present chimneys, it will have served at a pinch. What progress she has made, this Pelopaeus, what a contrast between that mis- erable beginning and he: modern premises, if she is really, in my district, a con- J34 The Swallow and the Sparrow temporary of the aborigines! She too must have profited greatly by civilization: she has managed to turn man's increasing comfort into her own. When the dwelling with a roof, rafters and ceiling was planned and the chimney with side-walls and a flue invented, the chilly creature said to herself: " How pleasant this is ! Let us pitch our tent here." And, notwithstandi.ig the novelty of her surroundings, she hastened to take possess- ion. Let us go back farther still. Before huts existed, before the niche in the rock, before man himself, the last to make his entrance on the world's stage, where did the Pelo- paus build? The question is not devoid of interest, as we shall shortly .^e. Besides, it does not stand alone. Where did the Window-swallow and the Chimney-swallow make their nests before there were windows and chimneys to build in? What retreat did the Sparrow select for his family before there were roofs with tiles and walls with holes to them? "As a sparrow all alone on the house- top," said the Psalmist in his day. In King David's time, the Sparrow squawked mournfully under the eaves in the f^ m The Mason- Wasps summer heat, as he does to this day. The buildings of that period differed but little from ours, at least so far as the Sparrow's convenience was concerned; and the shelter under the tile had been adopted long before. But, when Palestine had nothing more than the camel-hair tent, where did the Sparrow then elect to make his home? When Virgil sings to as of good Evander, who, preceded by his watch, two Sheep-dogs, visits iEneas, his guest, he shows him to us awakened at dawn by the singing of the birds : Evandrum ex humili tecto lux alma Et matutini volucrum sub culmine cantus.^ What could those birds be which, at break of day, twittered under the roof of the old King of Latium? I see only two: the Swallow and the Sparrow, both of them chanticleers of my hermitage and as punc- tual as in the Saturnian days. There was nothing princely about Evander's palace. The poet does not conceal the fact, it was a lowly roof: humili tecto, he says. Be- sides, the furniture enlightens us as to the i"The cheerful morn salutes Evander's eyes; And songs of chirping birds invite to rise. He leaves his lov»ly bed.'" ^neid: booic viii ; Dryden's translation. 136 The Swallow and the Sparrow edifice. The illustrious guest is given a Bear-skin and a heap of leaves for a bed : stratisqtie locavit Effultum foliis et pelle Libystidis ursa.^ Evander's Louvre therefore was a cabin a little larger than the others, made per- haps of tree-trunks laid one on top of the other, perhaps of unhewn stone employed as found, perhaps of reeds and clay. This rustic palace would have a thatched roof, of course. However primitive the habita- tion was, the Swallow and Sparrow were there, at least the poet says so. But where did they stay before they found a lodging in man's abode? * The industry of the Sparrow, the Swal- low, the Pelopsus and many others cannot be subordinate to mankind's : each of them must possess a primordial art of building, one which makes the best use of the site within reach. If better conditions present themselves, they profit thereby; if these con- ditions are lacking, they go back to their ancient customs, whose practice, though 1 " Then underneath a lowly roof he led The weary prince and laid him on a bed; Ihe stuffing leaves with hides of bears o'ersprcad." Anetd: book viii; Dryden's translation. 137 . I: T J • ■ « i I i p.. ! The Mason-Wasps sometimes exacting more labour, is at least always possible. The Sparrow shall tell us first how his nest-building art stood in the days when there were no lodgings in walls and roofs. A hollow in a tree, high enough to shelter him from prying eyes, with a narrow mouth to keep out the rain and a fairly generous cavity, gives him an excellent dwelling, of which he readily avails himself even when there are plenty of old walls and roofs in the neighbourhood. The youngest bird's- nester in my village knows all about it and abuses his knowledge. The hollow tree then is one lodging which the Sparrow em- ployed, long before using Evander's cabin and David's stronghold on the rock of Zion. His architectural resources go even fur- ther. His shapeless mattress, an incoher- ent jumble of feathers, down, flock, straw and other incongruous materials, seems to demand a broad and stable support. The Sparrow laughs at the difficulty and, from time to time, for reasons that remain hid- den from me, he conceives a bold plan: he decides to build a nest having no support but that of three or four tiny branches at the top of a tree. The clumsy maker of 138 The Swallow and the Sparrow mattresses tries to obtain aerial suspension, a swinging house, the prerogative of weav- ers and basket-makers well-versed in the art of plaiting. And he succeeds. In the fork of a few branches he accumu- lates everything suitable for his work that he can pick up near a house: rags, scraps of paper, ends of thread, flocks of wool, bits of hay and straw, dry blades of grass, flax dropped from the distaff, strips of bark retted by lying long in the open; and of his various gleanings, clumsily matted together, he contrives to make a large, hollow ball with a narrow opening in the side. It is bulky to a degree, the thickness of the dome having to be as good a defence against the rain as the shelter of a tile would be; it is very roughly constructed, without any at- tempt at artistry; but, when all is said, it is stout enough to last for a season. This is how the Sparrow must have worked in the beginning, when there was no hollow tree at hand. Nowadays, that primitive art, too costly in time and materials, is seldom prac- tised. My huuse is shaded by two great plane- trees; their branches reach the roof, on which generations of Sparrows, too many for the welfare of my cherries and my peas, 139 -I Pi :i I The Mason-Wasps succeed one another throughout the warm wtathcr. This vast mass of greenery is the first stopping-place after the exodus from the nest begins. Here the young biros assemble and for hours chatter and scream before flying off on their pilfering, expeditions; here the well-filled squads take their stand on returning from the fieMs. Ihe adults meet here to keep an eye on their recently-emancipated offspring, to cau- tion the imprudent and encourage the timid; family-quarrels are fought out here and the events of the day discussed. From morn- mg till evening there is a continual going to and fro between the roof and the plane- trees. Well, in spite of these constant vis- Its, I have only once, in the past twelve years, seen the Sparrow build his nest in the branches. The couple that decided in favour of a mid-air nest on one of the plane-trees were not particularly satisfied, It seems, with the results obtained, for they did not repeat the experiment next year, bince then, none has placed before my eyes for the second time a big ball of a nest paying in the wind at the end of a branch The steadier and less costly shelter of the tile IS preferred. We now know enough about the early art 140 The Swallow and the Sparrow of the Sparrow. What will the Swallows tell us In their turn? Two species fre- quent our dwellings: the Window-swallow (Hirundo urbica) * and the Chimney-swal- low (H. rustica), both of whom are very badly named, both in the scientific and the everyday language. Those epithets of urbica and rustica, which make a town- dweller of the first and a villager of the second, can be applied indifferently to either, since they both take up their abode at one time in the town, at another in the vil- lage. The terms window and chimney pos- sess a precise meaning which is rarely con- firmed and very often contradicted by the facts. For the sake of clearness, the su- preme condition of all tolerable prose, and to confine myself to the habits peculiar to the two species in my part of the world, I will call the first the Wall-swallow and the second the Domestic Swallow. The shape of the nest constitutes the most striking dif- ference. The Wall-swallow gives his the form of a ball, with a round aperture just large enough to admit the bird. The Do- mestic Swallow fashions his into a cup with a wide opening. 1 Also known as the House-swallow, or House-martin. — Trantlator't Note. 141 The Mason- Wasps The Wall-swallow, who it much lets common than the other, never chooses a site within our houses for his structure. It must be outside for him and it must stand high, far removed from inquisitive eyes; but at the same time a shelter against the rain IS mdispensable, for the damp is almost as dangerous for his mud nest as for that of the Pelopajus. He therefore settles by choice under the eaves and cornices of buildings. He visits me every spring. My house pleases him. Just below the roof is a cornice made up of a few courses of ordinary " half-round " coping-tiles, cor- belled out from the face of the wall in such a way as to give a long line of round-headed niches which are sheltered from the rain and enjoy plenty of sunshine on the south front. Among all these nooks, so healthy, so well-protected and moreover so excel- lently adapted to the shape of the nest, the bird has only to choose. There is room for all, however numerous the colony may be- come one day. Apart from sites of this kind, I see none approved by the Swallow in the village, ex- cept the under part of a few cornices of the church, which is the only edifice of a monu- mental character. In short, the support of 142 The Swallow and the Sparrow a wall, in the open air, with some shelter against the rain, is all th the Swallow asks of our buildings. But the natural wall is a perpendicular rock. If the bird here finds overhanging projections, forming a penthouse, it must adopt them as the equivalent of the ledge of our roofs. Ornithologists know, in fact, that in mountainous districts, far removed from human dwellings, the Wall-swallow builds against the vertical sides of the rocks, so long as his ball of clay is under cover of some kind. Near where I live are the Gigondas Mountains, the most curious geological structure that I have ever seen. Their long chain displays so steep a slope that it is almost impossible to stand upright near the summit; and the ascent of the accessible part has to be made on all- fours. You then find yourself at the foot of a perpendicular cliff, an enormous slab of sheer rock which, like some Titanic rampart, tops the pre- cipitous ridge with a jagged crest. The people of the country call this Cyclopean wall Us Dentelles. I was one day bo- tanizing at its base, when my eyes were at- tracted by the evolutions of a flock of birds in front of the rugged face of the rock. I 143 The Mason-Wasps easily recognized the Wall-swallow : his si- lent flight, his white belly and his ball- uu ""^- ^^^^^"^^ 'o the cliff told me all about him. I in my turn now learnt, apart from the books, that this species fixes Its nests to perpendicular rocks when the cornices of our buildings and the ledges of our roofs are missing. Even so must it have nested in the ages that preceded our stone structures. The problem becomes thornier with the second species. The Domestic Swallow, who has much more confidence in our hos- pitality and is also perhaps more susceptible to cold, establishes himself as often as pos- sible inside our houses. The embrasure of a window, the under surface of a balcony will satisfy his requirements at need; but he prefers the shed, the loft, the stable or an empty room. His familiarity even reaches the point of cohabitation with man in the same apartment. No more timid than the Pelopaus in taking possession of the premises, he installs himself in the farm- kitchen and builds upon the peasant's smoke-blacked rafters; more venturesome even than the pot-making insect, he ap- propriates the drawing-room, the study the bedroom or any well-kept chamber 144 The Swallow and the Sparrow that leaves him at liberty to come and go. Each spring I have to defend myself against his bold usurpations. I gladly sur- render to him the shed, the cellar-porch, the Dog's corner, the woodshed and other out- houses. This does not suffice for his am- bitious views: he wants my study. At one time he tries to make his home on the cur- tain-rod, at another on the lintel of the open window. In vain I strive to make him un- derstand, by destroying the foundations of his edifice as he lays them, how dangerous to his nest is the shifting su ort of a case- ment, which must be closed from time to time, at the risk of crushing house and brood alike, and how disagreeable for my cur- tains this dirty business is, with its mud and, later, the excretions of the young birds: I do not succeed in convincing him; and to put an end to his determined enterprise I am compelled to keep the windows shut. If I open them too soon, he returns with his beakful of clay and begins all over again. Instructed by experience, I know what it would cost me to grant the hospitality de- manded so persistently. If I were to leave some precious book open on the table, some drawing of a mushroom, my morning's 145 The Mason-Wasps work and still quite fresh from the brush,* he would not fail, in passing, to drop his muddy seal or his stercoral initials upon it. These little annoyances have made me sus- picious; and I remain obdurate to all my visitor s importunities. Once only I allowed myself to be be- guiled. The nest was placed in a corner of the ceiling and the wall, on some plaster mouldings. Below it stood a marble con- sole-table, usually covered with books which I had to be constantly consulting. In an- ticipation of events, I moved my reference- library away. All went well until the eggs were hatched; but, as soon as the young birds were there, things changed. With their insatiable stomachs, into which the tood had barely passed before it was di- gested and dissolved, the six fledgelings be- came unendurable. Every minute — flick, flack I— It rained guano on the console. If my poor books had been there, oh dear, oh dear I Dust and sweep as I might, my study continued redolent of ammonia. And then what a slave the birds made of me I The room was shut up at night. The father slept .k* ^i" ^*f ''K'. "f '*' ^'>' chap, xvii., in which the au- thor describes his collection of water-colour d.wfnMSf mushroom, done by his own hand— Translator^ nIS 146 The Swallow and the Sparrow out; so did the mother, after the little ones were beginning to grow up. Then, at early dawn, both were at the windows, in a mighty state of distress outside the glass barrier. With eyes still heavy with sleep, I had to get up hurriedly and let the poor things in. No, I shall not allow myself to be persuaded again; never more shall I permit the Swal- low to settle in a room that has to be closed at night and still less in the room where I am describing the misadventures that befel me owing to my too-accommodating kindness. As you see, the Swallow with the nest shaped like a half-cup well deserves his epithet of domestic, inasmuch as he makes his home inside our houses. In this respect, he is among birds what the Pelopa?us is among insects. Here we have once again the question of the Sparrow and the Wall- swallow : where did he live before houses ex- isted? Personally, I have never seen him build his nest elsewhere than in the shelter of our habitations; and the authors whom I consult do not appear to be any wiser on this subject. None of them says a word of the manor occupied by the bird apart from the refuges provided by human in- dustry. Can it be that his long frequenta- tion of our society and the consequent sense H7 :|-.P [A \ -Hi i Eh The Mason-Wasps of comfort have made him forget the primi- tive customs of his race? I find it difficult to believe: animals arc not, to that extent, unmindful of their an- cient habits, when it is necessary to remember them. Somewhere, in our day, the Swallow still works independently of us and of our buildings, even as he did in the beginning. Though observation can tell us nothing con- cerning the site selected, analogy makes up for this silence with a wealth of probabilities. After all, what do our houses represent to the Domestic Svjrallow? Refuges a^^ainst the weather, especially against the rain, which does so much harm to the mud shell. Natural grottoes, caves, the irregularities of crumbling rocks: these are all refuges, less healthy, perhaps, but still well worth u ^'c^' ^* ^^^ *^^^^' beyond a doubt, that the Swallow constructed his nest when he had no human dwellings to build in. Man contemporary with the Mammoth and the Reindeer came and shared his lodging un- der the rock. Intimacy sprang up between the two. Then, step by step, the cave was succeeded by the hut, the hut by the cabin, the cabin by the house; and the bird, aban- doning the less good for the better, fol- lowed man into his improved abode. 148 The Swallow and the Sparrow VVe will now end this digression on the habits of birds and apply the evidence which we have gathered to the Pelopceus. Every species practising its industry in our dwellings must first have practised and, we maintain, must still practise it under condi- tions wholly extraneous to the work of man. The Wall-swallow and the Sparrow have given us proofs which are all that can be desired; the Domestic Swallow, more reti- cent of his secrets, gave us only probabili- ties, which however come very near to cer- tainty. The Pelopacus is almost as obsti- nate as the last-named in refusing to di- vulge her ancient customs and long remained to me an insoluble problem in so far as her original domicile was concerned. Where can the enthusiastic colonist of our chimneys have lived, when far removed from man? Thirty years and more elapsed after I first made her acquaintance; and her history al- ways ended in a note of interrogation. Outside our houses, never a trace of a Pelo- paeus-nest. And all the time I was apply- ing the method of analogy, which provides a very probable answer to the question of the Domestic Swallow; I was pursuing my search in the caves, in the shelters under rocks facing the sun. Not a sign. I was 149 in nvi The Mason-Wasps still continuing my useless investigations, when at last chance, which favours the per^ severing, thrice compensated me, under con- ditions which I did not for a moment sus- pect of being auspicious. The Serignan quarries are rich in accumu- ations of broken stones, refuse that has lain piled up there for centuries. These stone-heaps are the refuge of the Field- mouse, who, on a mattress of dried grass, crunches the almonds, olive-stones and acorns which he picks up all around and varies this farinaceous diet with Snails, whose empty shdls lie packed under some flat stone. Different Bees and Wasps — Osmis, Anthidia, Odyneri - pick out shells to suit them from the heap and build their cells m the spiral. My search for these treasures makes me turn over a few cub^c yards of broken stones every vear. Ihree times, when engaged upon this ^sk, 1 came upon the Pelopaus' work 1 wo nests were placed deep down in the mw; f^'"f ^^°?' ^^'^^y ^'gg^^- than a mans two fists; the third was fixed to the lower surface of a large flat stone, forming n.T7J *^°^\th^ ground. These thref nests, though subject to all the changes of the weather, contained nothing more than 150 The Swallow and the Sparrow riic usual structure found inside our houses. and hat was all. The dangers of the site had suggested no improvement to the archi- tec . the edifice was no different from those bu.lt against the wall of a chimney. One ?Z !l T?^'^h^d' therefore: in my dis! trict, the Pelop^us nidifies sometimes, but very rarely, m stone-heaps and under ground. Thus must she have nidified be- fore becoming the inmate of our dwellings and our fireplaces. * Tht thrlT"^ f °'r '5 °P'" *° discussion. The three nests found under the stones are nnf. ^'''r^'T'^' Soaked with damp, they possess hardly more consistency thai the muddy puddle utilized for their construe! Tt' .h ^^ "'' '?^''"''^ '« ^"^h a degree that they can no longer be handled. The cells are ripped open; the cocoons, easily recognizable by their colour and their transparency, which is that of an onion-skin. larva which I ought to find at the time of my discovery, that is in winter. And yet the three hovels are not old nests ruined by the weather after the emergence of the 151 ' 'A ^ -it ■ The Mason-Wasps perfect insect, for the exit-doors are still closed with their well-fitting plugs. It is at an abnormal place, in the side, that the yawning breach occurs. The escaping in- sect would never use such violence in break- ing through. They are certainly recent nests, nests of the previous summer. Their dilapidation is due to their unpro- tected position. The rain penetrates into the stone-heaps; even under the shelter of a flagstone the air is saturated with damp. If a little snow falls, the mischief is still worse. In this way, the wretched nests crumble and fall to pieces, leaving the cocoons partly exposed. Unprotected by their earthen sheath, the larva; have become the prey of the brigandage that mows down the weak. Some Field-mouse passing by has perhaps feasted on those tender mor- sels. At the sight of these ruins a suspicion oc- curs to me. Is the primitiire art of the Pelopaeus really practicable in my region? iWhen nesting in stone-heaps, does the tiny potter find the security needed for her family, especially during the winter? It is very doubtful. The extreme rarity of the nests in such conditions is evidence of the mother's aversion for these sites; and the 153 The Swallow and the Sparrow dilapidated state of those which I find seems to testify to their dangerous nature. If the inclemency of the climate makes it im- possible for the Pelopaus to practise the in- dustry of her forebears successfully, does not this prove that the insect is a stranger, a colonist from a hotter and drier climate, where there is no persistent rain and above all no snow to be dreaded? I have no difficulty in picturing the Pe- lopaus as of African origin. Far back in the past she came to us, by gradual stages, through Spain and Italy; and the olive-dis- trict IS almost the limit of her extension towards the north. She is an African who has become a Provencal by naturalization. In Africa, in fact, she is said often to nest under the stones, which would not, I think make her despise human habitations, if she found peace and quiet there. We hear of her kinswomen in the Malay Archipelago frequenting houses. They have the same habits as the guest of our homes; they share her singular liking for that unstable fabric, a muslin curtain. From one end of the world to the other, the same taste for Spi- ders, for mud cells, for sheltering under man s roof. If I were in the Malay Ar- chipelago, I should turn over the stone- 153 The Mason-Wasps heaps and should most likely discover one further resemblance: the original nest un- der some flat stone. i. 154 CHAFFER VII INSTINCT AND DISCERNMENT ' I ""HE Pelopjcus gives us a very poor idea '*• of her intellect when she |. 'asters the spot in the wall where the nest which I have removed used to stand, when she persists in cramming her cell with Spiders for the benefit of an egg no longer there and when she dutifully closes a cell which my tweezers, extracting both germ and provisions, have left empty. The Mason-bees, the caterpil- lar of the Great Peacock Moth and many others, when subjected to similar tests, are guilty of the same illogical behaviour: they continue, in the normal order, their series of industrious actions, though an accident has now rendered these useless. Just like mill-stones, which do not cease revolving though there be no corn left to grind, let them once be given the compelling power and they will continue to perform their task despite its futility. Are they then machines? Far be it from me to think anything so foolish. It is impossible to make definite progress 155 f : The Mason-Wasps on the shifting sands of contradictory facts : each step in our interpretation may find us embogged. And yet these facts speak so loudly that I do not hesitate to translate their evidence as I understand it. In insect mentality, we have to distinguish two very different domains. One of these is instinct properly so called, the unconscious impulse that presides over the most wonderful part of what the creature achieves with its in- dustry. Where experience and imitation are of absolutely no avail, instinct lays down its inflexible law. It is instinct and instinct alone that makes the mother build for a family which she will never see; that coun- sels the storing of provisions for the un- known offspring; that directs the sting to- wards the nerve-centres of the prey and skilfully paralyses it, so that the game may keep good; that instigates, in fine, a host of actions wherein shrewd reason and consum- mate science would have their part, were the creature acting through discernment. This faculty is perfect of its kind from the outset; otherwise the insect would have no posterity. Time adds nothing to it and takes nothing from it. Such as it was for a definite species, such it is to-day and such it will remain, perhaps the most settled zoo- is6 Instinct and Discernment logical characterittic of them all. It is not free nor conscious in its practice, any more than is the faculty of the stomach for di- gestion or that of the heart for pulsation. The phases of its operations are prede- termined, necessarily entailed one by an- other; they suggest a system of clockwork wherein one wheel set in motion brin^rs about the movement of the next. Th's if the mechanical side of the insect, the faium. the only thing that is able to explai/. t!ie monstrous illogicality of a Pelopxus nuslcd by my artifices. Is the Lamb when it first grips the teat a free and conscious agent, capable of improvement in its difficult art of taking nourishment? The insect is no more capable of improvement in its art, more difficult still, of giving nourishment. But, with its hide-bound science ignorant of itself, pure instinct, if it stood alone, would leave the insect unarmed in the per- petual conflict of circumstances. No two moments in time are identical; though the background remain the same, the details change; the unexpected rises on every side. In this bewildering confusion, a guide is needed to seek, accept, refuse and select; to show preference for this and indifference to that; to turn to account, in short, anything 1S7 \\i The Mason-Wasps useful that occasion may offer. This guide the insect undoubtedly possesses, to a very manifest degree. It is the second province of its mentality. Here it is conscious and capable of improvement by experience. I dare not speak of this rudimentary faculty as intelligence, which is too exalted a title: I will call it discernment. The insect, in exercising its highest gifts, discerns, differ- entiates between one thing and another, within the sphere of its craft, of course; and that is about all. So long as we confound acts of pure in- stinct and acts of discernment under the same head, we shall fall back into those endless discussions which embitter contro- versy without bringing us one step nearer to the solution of the problem. Is the in- sect conscious of what it does? Yes and no. No, if its action falls within the do- main of instinct; yes, if the action falls within that of discernment. Are the habits of an insect capable of modification? No, de- cidedly not, if the habit in question belongs to the province of instinct; yes, if it belongs to that of discernment. Let us state this fun- damental distinction mere precisely with the aid of a hw examples. The Pelopsus builds her cells with earth 158 Instinct and Discernment already softened, with mud. Here we have instinct, the unalterable characteristic of the worker. She has always built in this way and always will. The passing ages will never teach her, neither the struggle for life nor the law of selection will ever inducii her to imitate the Mason-bee and collect dry dust for her mortar. This mud nest of hers needs a shelter against the rain. The hiding-place under a stone suffices at first. But should she find something better, the potter takes possession of that something better and instals herself in the home of man. There we have discernment, the source of some sort of capacity for improve- ment. The Pelopseus supplies her larvae with provisions in the form of Spiders. There you have instinct. The climate, the lati- tude or longitude, the changing seasons, the abundance or scarcity of game introduce no modification into this diet, though the larva shows itself satisfied with other fare provided by myself. Its forebears were brought up on Spiders; their descendants consumed similar food; and their posterity again will know no other. Not a sinj^le cir- cumstance, however favourable, will ever persuade the Pelopjeus that young Crickets, IS9 The Mason-Wasps for instance, are as good as Spiders and that her family would accept them gladly. In- stinct binds her down to the national diet. But, should the Epeira, the favourite prey, be lacking, must the Pelopseus give up foraging? She will stock her warehouses all the same, because any Spider suits her. There you have discernment, whose ela». ticity makes up, in certain circumstances, for the excessive rigidity of instinct. Amid the innumerable variety of game, the huntress is able to discern between what is Spider and what is not; and in this way she is always prepared to supply her family, without quit- ting the domain of her instinct. The Hairy Ammophila gives her larva a single caterpillar, a large one, paralysed by as many pricks of her sting as it has nerv- ous centres in its thorax and abdomen. Her surgical skill in subduing the monster IS instinct, displayed in a form that quashes any inclination to see in it an acquired habit. In an art that can leave no one to practise It in the future unless that one be perfect at the outset, of what avail are lucky chances, atavistic tendencies, or the mellowing hand of time? But the grey caterpillar, sacrificed one day, may be succeeded on another day by a green, yellow or striped caterpillar. i6o ■« ^fmmm':. Instinct and Discernment There you have discernment, which is quite capable of recognizing the regulation prey under very diverse garbs. The Megachiles^ build their honey-jars with disks cut out of leaves; certain An- thidia make felted cotton wallets; others fashion pots out of resin. There you have instinct. Will any rash mind ever conceive the singular idea that the Leaf-cutter might very well have started working in cotton, that rhe cotton-wool-worker once thought or will one day think of cutting disks out of the leaves of the lilac- or the rose-tree, that the resin-kneader began with clay? Who would dare to indulge in such theories? Each Bee has her art, hfr medium, to which she strictly confines her- self. The first has her leaves; the second her wadding; the third her resin. None of these guilds has ever changed trades with another; and none ever will. There you have instinct, keeping the workers to their specialities. There are no innovations in their workshops, no formulae resulting from experiment, no ingenious devices, no pro- gress from the indifferent to the good, from the good to the excellent. To-day's method »0r Le«f-cuttcrs. Cf. Bramble-bees and Others: chap. vin.— Translator's Note. I6l = * 1 The Mason-Wasps is the facsimile of yesterday's; and to-mor- row will know no other. , But, diough the manufacturing.p ocess is invariable the raw material is subject to change. The plant that supplies the cotton ditters in species according to the locality; the bush out of whose leaves the pieces will be cut IS not the same in the various fields ot operation; the tree that provides the resinous putty may be a pine, a cypress, a jumper, a cedar or a spruce, all very differ- ent m appearance. What will guide the in- sect in Its gleaning? Discernment. These, I think, are sufficient details of the fundamental distinction to be drawn in the insect s mentality, the distinction, that is, be- tween pure instinct and discernment. If people confuse these two provinces, as they nearly always do, any understanding be- comes impossible; the last glimmer of light disappears behind the clouds of inter- minable discussions. From an industrial point of view, let us look upon the insect as a worker thoroughly versed from birth in a craft whose essential principles never vary; let us grant that unconscious worker a gleam of intelligence which will permit it to extricate itself from the inevitable con- ttict of attendant circumstances; and I think 162 Instinct and Discernment that we shall have come as near to the truth as the stafc of our knowledge will allow for the moment. Having thus assigned a due share both to instinct and to its aberrations when the course of its different phases is disturbed, jet us see what discernment is able to do in the sefec^ion om the start, the fleshy plants from the New World suited It quite as well as the trunk of a native tree, i66 Instinct and Discernment The Mason-bcc of the Pebbles (Chali. codoma parietina) has none of this elas- ticity in the choice of a site. In her case, the smooth stone of the parched uplands is the almost invariable foundation of her structures. Elsewhere, under a less clement sky, she prefers the support of a wall, which protects the nest against the prolonged snows. Lastly, the Mason-bee of the Shrubs (C. rufescens, P^rez) fixes her ball of clay to a twig of any ligneous plant, from the thyme, the rock-rose and the heath to the oak, the elm and the pine. The list of the sites that suit her would almost form a complete catalogue of the ligneous flora. The variety of places where the insect installs Itself, so eloquent of the part played by discernment in their selection, becomes still more remarkable when accompanied by a corresponding variety in the architec- ture of the cells. This is more particu- larly the case with the Three-horned Os- mia,* who, as she uses clayey materials very easily affected by the rain, requires, like the Pelopaus, a dry shelter for her cells, a shelter which she finds ready-made and uses nIu!' ^'■*'"*'''*'" '»'"' O'*'"- Pauim.-^ Translator's 167 ' if I •1. 7 t I I i -} , The Mason-Wasps just as it is, after a few touches by way of sweeping and cleansing. The homes which I see her adopt are especially the shells of Snails that have died under the stone-heaps and in the low, unmortared walls which sup- port the cultivated earth of the hills in shelves or terraces. The use of Snail- shells is accompanied by the no less active use of the old cells of both the Mason-bee of the Sheds and of certain Anthophors (A. pilipes, A, parietina and A. perso- nata.) * We must not forget the reed, which is highly appreciated when — a rare find — it appears under the desired conditions. In its natural state, the plant with the mighty hollow cylinders is of no possible use to the Osmia, who knows nothing of the art of perforating a woody wall. The gal- lery of an internode has to be wide open before the Bee can take possession of it. Also, the clean-cut stump must be hori- zontal, otherwise the rain would soften the fragile edifice of clay and soon lay it low; also, the stump must not be lying on the ground and must be kept at ,*c.rc distance from the dampness of the soil. We see » Cf. Bramble-bees and Others: passim j— Translator's Note. i68 Instinct and Discernment therefore that, without the Intervention of man, involuntary in the vast majority of cases and deliberate only on the experi- menter's part, the Osmia would hardly ever find a reed-stump suited to the installation of her famdy. It is to her a casual ac- quisition, a home unknown to her race be- fore men took it into their heads to cut reeds and make them into hurdles for dry- mg figs in the sun. How did the work of man's pruning- knife bring about the abandonment of the natural lodging? How was the spiral staircase of the Snaii-shell replaced by the cylindrical gallery of the reed? Was the change from one kind of house to another effected by gradual transitions, by attempts made, abandoned, resumed, becoming more and more definite in their results as genera- tion succeeded generation? Or did the Osmia, finding the cut reed that answered her requirements, install herself there straightway, scorning her ancient dwelling, the Snail-shell? These questions called for a reply; and they have received one. Let us describe how things happened. Near Serignan are some great quarries of coarse limestone, characteristic of the miocenc formation of the Rhone vallev 169 ^* MICROCOPY RESOUITION TBT CHART (ANSI and ISO TEST CHART No. 2) A /APPLIED IM/IGE Ir 1653 East Main Street Rochester. New York 14609 USA (716) 482 - 0300 - Phone (716) 288-5989 -Fox The Mason-Wasps These have been worked for many genera- tions. The ancient public buildings of Orange, notably the colossal frontage of the theatre whither all the intellectual world once flocked to hear Sophocles' CEdipus Tyrannus, derive most of their material from these quarries. Other evidence con- firms what the similarity of the hewn stone tells us. Among the rubbish that fills up the spaces between the tiers of seats, they occasionally discover the Marseilles obol, a bit of silver stamped with the four-spoked wheel, or a few bronze coins bearing the effigy of Augustus or Tiberius. Scattered also here and there among the monuments of antiquity are heaps of refuse, accumula- tions of broken stones in which various Bees and Wasps, including the Three-horned Osmia in particular, take possession of the dead Snail-shell. The quarries form part of an extensive plateau which is so arid a« to be nearly deserted. In these conditions, the Osmia, at all times faithful to her birth-place, has little or no need to emigrate from her heap of stones and leave the shell for another dwelling which she would be obliged to seek at a distance. Since there are heaps of stone there, she probably has no other 170 Instinct and Discernment dwelling than the Snail-shell. Nothing tells us that the present-day generations are not descended in the direct line from the generations contemporary with the quarry- man who lost his as or his obol at this spot. All the circumstances seem to point to it: the Osmia of the quarries is an inveterate user of Snail-shells; so far as heredity is concerned, she knows nothing whatever of reeds. Well, we must place her in the presence of these new lodgings. I collect during the winter about two dozen well-stocked Snail-shells and install them in a quiet corner of my study, as I did at the time of my enquiries into the dis- tribution of the sexes.i The little hive with its front pierced with forty holes has bits of reed fitted to it. At the foot of the five rows of cylinders I place the inhabited shells and with these I mix a few small stones, the better to imitate the natural con- ditions. I add an assortment of empty Snail-shells, after carefully cleaning the in- terior so as to make the Osmia's stay more pleasant. When the time comes for nest- building, the stay-at-home insect will have, close beside the house of its birth, a choice iCf. Bramble-bees and Others: chaps, iii. and iv.— Translator's Note. 171 li i-i The Mason- Wasps of two habitations: the cylinder, a novelty unknown to its race; and the spiral stair- case, the ancient ancestral home. The nests were finished at the end of May and the Osmiae began to answer my interrogatory. Some of them, the great ma- jority, settled exclusively in the reeds; the others remained faithful to the Snail-shell, or else entrusted their eggs partly to the spirals and partly to the cylinders. With the first, who were the pioneers of cylindri- cal architecture, there was no hesitation that I could perceive: after exploring the stump of reed for a time and recognizing it as serviceable, the insect installs itself there and, an expert from the first touch, without apprenticeship, without groping, without any tendencies bequeathed by the long prac- tice of its predecessors, builds its straight row of cells on a very different plan from that demanded by the spiral cavity of the shell, which increases in size as it goes on. The slow school of the ages, the gradual acquisitions of the past, the legacies of heredity count for nothing, therefore, in the Osmia's education. Without any noviciate on its own part or that of its forebears, the insect is versed straight away in the calling which it has to pursue; it possesses, in- 172 i n Instinct and Discernment separable from its nature, the qualities de- manded by its craft: some which are invari- able and belong to the province of instinct; others which are flexible and belong to the province of discernment. To divide a free lodging into chambers by means of mud partitions; to fill these chambers with a heap of pollen-flour, with a few sups of honey in the central part where the egg is to lie; in short, to prepare board and lodging for the unknown, for a family which the mothers have never seen in the past and will never see in the future: this, in its es- sential features, is the function of the Os- mia's instinct. Here, everything is har- moniously, inflexibly, permanently preor- dained ; the insect has but to follow its blind impulse to attain the goal. But the free lodging offered by chance varies exceedingly in hygienic conditions, in shape and in ca- pacity. Instinct, which does not choose, which does not contrive, would, if it were alone, leave the insect's existence in peril. To help her out of her predicament, in these complex circumstances, the Osmia possesses her little stock of discernment, which dis- tinguishes between the dry and the wet, the solid and the fragile, the sheltered and the exposed; which recognizes the worth or 173 The Mason-Wasps worthlessness of a site and knows how to sprinkle it with cells according to the size and shape of the space at its diposal. Here, slight industrial variations are necessary and inevitable; and the insect excels in them without any apprenticeship, as the experi- ment with the Osmia born in the quarries has proved. Animal resources havs a certain elasticity within narrow limits. What we learn from the animals' industry at a given moment is not always the full measure of their skill. They possess latent powers held in reserve for certain emergencies. Long generations can succeed one another without employing them; but, should some circumstance re- quire it, suddenly those powers burst forth, free of any previous attempts, even as the spark potentially contained in the Hint flashes forth independently of all preceding gleams. Could one who knew nothing of the Sparrow except the nest under the eaves suspect the ball-shaped nest at the top of a tree? Would one who knew nothing of the Osmia save her home in the Snail-shell expect to see her accept as her dwelling a stump of reed, a paper funnel, a glass tube? My neighbour the Sparrow, impulsively taking it into his head to leave the roof for 174 Instinct and Discernment the plane-tree, the Osmia of the quarries, rejecting her natal cabin, the Snail-shell, for my cyhnders, ahke show us how sudden and spontaneous are animals' industrial varia- tions. 175 CHAPTER VIII THE NEST-BUILDING ODYNERUS TF further proofs than those submitted * elsewhere were needful, to demonstrate that the organ does not imply the function, that the implement does not determine the work,* the Odynerus group would furnish us with very remarkable evidence. With a close similarity of organization, not only in the details but also in the aggregate, a simi- larity which makes these insects one of the most natural genera in respect of structure, they possess a great variety of industries, bearing no relation one to the other, though carried on with the same equipment. Apart from the likeness in form, one single characteristic unites this group, whose hab- its are so unlike : all the Odyneri are game- hunters; they victual their families with grubs paralysed with the sting, with little cat- erpillars and small Beetle-larv^. But to achieve this common end, the larder furnished with its egg and stuffed 1 Cf. the essay on the Resin-bees in Bramble-bees and Others: chap, x.— Translator's Note. 17^ The Nest-building Odynerus with game, how many several methods of construction! If we were better-acquainted with the biology of the genus, we should perhaps find architects of almost as many different schools as there are species. My investigations, which were dependent on op- portunity, have as yet borne upon only three of the Odyneri; and these three, with the same implement, the curved, toothed pincers of their mandibles, apply them- selves to the most dissimilar industries. One of them, O. reniformis, whose work I have described in an earlier chapter, digs a deep frallery in a hard soil and with the rubbish constructs, at the mouth of her well, a sort of curved chimney, with a guilloche pattern, the materials of which are after- wards again employed to close the abode. Formerly, when I made her acquaintance in front of a steep loamy bank baked by the sun, I whiled away the long hours of wait- ing by conversing, turn and turn about, with the Hoopoe, who taught me how to pro- nounce Latin, and with my Dog, who, lying in the shade of a leafy thicket, cooling his belly in the moist sand, taught me how to practise patience. The Wasp was rare and by no means prodigal of her returns to the nest where I was watching her skilful tac- 177 I. I 11 The Mason-Wasps tics. Nowadays, every spring, I have a populous colony of her before my eyes in one of the paths of my enclosure. When the period for the works arrives, I surround the hamlet with stakes to mark the site, lest heedless footsteps should destroy the pretty chimneys built of grains of earth. The second, O. alpestris, Sauss., is by trade a resin-worker. Possessing the same tool as her colleague the miner, but not the same skill, she does not dig herself a dwell- ing; she prefers to settle down in borrowed lodgings provided by an empt- Snail-shell. The shells of Helix nemoralis, of H. as- persa,^ when very incompletely developed, and of BuUmiilus radiatus are the only dwellings that I have known her to occupy and also the only ones that would serve her turn under the stone-heaps where, in com- pany with Anthidium bellkosum, she per- forms her labours in July and August. Saved by the Snail from the hard task of excavation, she specializes in mosaic and produces a work of art which is superior in elegance to the miner's temporary guil- loche. Her materials are, on the one hand, resin ; on the other, little bits of gravel. Her method is very unlike that of the two resin- » The Common Snail.— Translator's Note. 178 The Ncst-building Odyncrus the Ed.ble Snail. These two swamp with gum, on the outer surface of the lid, their coarse, angular bricks, which are unequal in size, variable in nature and often of a half.earthy character, so that the uneven- ness of the work, in which the pieces are laid side by side at random, is hidden under a coat of resin. On the inner surface the gum does not fill the gaps and the cemented tragments appear with all their irregular projections and their clumsy arrangement. Remember also that the bits of gravel are kept exclusively for the operculum, or lid. the final covering; the partitions which mark ott the cells are made entirely of resin without any mineral particles. The Alpine Odynerus works on a differ- ent plan : she saves pitch by making better use of stone. A number of round, flinty atoms are set m a bed of still sticky cement, on the outer surface. They fit one against the other, are almost all of th. same size, that of a pms head, and are selected singly by the artist amid the miscellaneous rub- bish that litters the ground. When it is well-executed, as is frequently the case, the result suggests a piece of embroidery worked with roughly.fashioned beads of 179 The Mason- Wasps quartz. The Anthldia of the Snail-shell, rude labourers that they arc, accept all that falls to their mandibles: angular splinters of limestone, morsels of flint, bits of shell, hard particles of earth; the daintier Odynerus as a rule inlays with beads of flmt only. Can this taste for gems be due to the brilliancy, the translucency, the polish of the grain? Can it he that the insect takes /'easure in its casket of precious stones? The answer will be the same as in the case of the ornamental rose-window, the tiny shell sometimes inserted in the centrs of the lid by the two resin-gatherers who inhabit the shell of the Edible Snail: why not? Be this as it may, the gem-collector is so pleased with her pretty pebbles that she puts them everywhere. The partitions that sub- divide the shell into chambers are repro- ductions of the lid: each has a carefully- finished mosaic of translucent flints on the front surface. In this manner three or four cells are contrived in the shell of the Edible Snail; in that of the Bulimulus, two at most. The cells are small but correctly shaped and strongly protected. The protection, for that matter, is not restricted to these multiple paved hangings: i8o The Nest-building Odyncrus Shake .t, you hear a rattie of stones. The Odynerus m fact, i, as familiar a, the An! thidia with the art of fortification by mean, o ^hlT'^Vl , ■"»>' " '""^•' '" 'he side of the Snail-shell and pour out the heap of weenfret/''" ^'•''*' "" -"'*"!' be- tween the last partition and the lid. One deta, should be noted: the materials whi?h • k uYf ""' homogeneous. Small pol- ^hed pebble, predominate, but they ^are b^ts of shell and particle, of earth. The Odynerus, so fastidious in choosing the flint fi?„ "k?°u"'u'' ""P'°>" ^<"- her filling the So rh"^ ,:'*' "■" "T' •» •'»"''• Even ,o do the two resin-gatherers act when barri- cading their Snail-shells. As a conscien- fteap of rubbish i, not always there: an- et'ofThrA-nth-r"'-" -'" •"' "- To my great regret, I can carry the bi- ography of the Alpine Odynerus no farther. Ihe insect appears to me to be very rare w nter, the only season propitious to labor- lous searches in the stone-heaps. With the dwelling and its inhabitant, hatched in my i8i ^ til The Mason-Wasps specimen-jars, I am familiar; but the egg, the larva and the provisions I do not know. In compensation, I possess all the details that could be desired about the third species, O. niJulator, Sauss. This insect, like the just mentioned, is ignorant of the art of laying the foundations of its abode and demands a ready-made lodging. Like the Osmi», the Megachiles and the cotton- spinning Anthidia, it wants a cylindrical gallery, either natural or excavated by mi- ners. Its art consists in partitioning a tun- nel and subdividing it into chambers: plast- erer's art, in short. Here then, in three species, the only ones whose habits I have had the opportunity of learning, we see three very different trades : the miner's, the resin-worker's and the plast- erer's. In these three guilds I find exactly the same equipment of tools; and I defy the most meticulous magnifying-glass to tell us what organic modification suggests to the one insect the pavement of pebbles upon a bed of resin, to the second the mine-shaft with its guilloched chimney, to the third the alien cylinder, partitioned with mud. No and again no: the organ does not con- stitute the function, the tool does not make the workman. With similar implements, 182 The Nest-building Odyneru3 the Odynerus group executes the most dis- similar tasks because each species has its predetermined skill, its art that governs the tool and ,s not governed by it. How plainly this conclusion would appear had I been privileged to review the entire Ody- Tn7L^T "T T'"y '^^^^^^rks remain n,n^-fi ?- '?' 7'^^ ^^" ^°°^ undergoing no modification! I suggest investigaTions on these hnes to whomsoever it may concern, were t only in order to shed a little lighi upon this numerous and difficult group, of which the future will, I trust, givf us^^ lu- od^^classification based upon its industrial .K.^^^?m'T '*""' generalities and pass to nA ^^^""'^^^^^'ory of the Nest-building Odynerus. There are few Wasps with whose private life I am better acquainted; and I owe this abundant information to cir- cumstances which, for me, impart a double value to the facts, because of the pleasant memories evoked. I had often extracted the Nest-building Odynerus' series of cells from the old galleries of the Anthophors; 1 knew that the insect occupies dwellings not dug with Its own mandibles and that its la- bours are confined to the partitions; I knew Its yellow larva and its slender, amber-hued 183 The Mason-Wasps cocoon. I knew nothing of all the rest, when I received from my daughter Claire a bundle of reed-cuttings which filled me with exultation. Brought up in a zoological house, the dear child has retained a vivid memory of our evening talks, in which the insect so often cropped up; and her discerning eye IS able quickly to distinguish, amid her cas- ual discoveries, anything that may assist me in my studies of instinct. Her country home, in the neighbourhood of Orange, boasts a rustic poultry-house constructed partly of reeds laid in horizontal stages. In the middle of June last year (1889), she noticed, when visiting her Hens, certain Wasps making their way in large and busy numbers into the cut reeds, coming out again and soon returning laden with a load of earth or some malodorous little grub. Her attention once aroused, the rest did not take long: she had discovered a magnificent subject for me to study. That very even- ing I received a bundle of reeds, with a let- ter giving me circumstantial details. The Wasp, as Claire called it and as Re- aumur named it of old, when speaking of a species of the same genus out of very dif- ferent habits, the Wasp, so the letter told 184 The Nest-building Odynerus me, hoards in her nests a dumpy head of game, covered with blaclc spots and smell- ing strongly of bitter almonds. I informed my daughter that this game was the larva of the Poplar Leaf-beetle (Chrysomela populi), a Beetle with red wing-cases re- minding one, on a larger scale, of the Coc- dnella, or Common Ladybird. Insect and larva should be found together on the pop- lars of the neighbourhood, browsing pro- miscuously on the leaves. I added that a glorious opportunity had presented itself and that we must profit by it without delay. She therefore received instructions to keep a watch on this, that and the other and to furnish my insect laboratory with reed- stumps as and when they became colonized and with poplar-branches covered with Chry- somela-grubs. A collaboration was thus set up between Orange and Serignan, the facts observed on both sides mutually completing and corroborating each other. Let us come quickly to the bundle of reeds, the first examination of which gratifies my fondest hopes. It contains things that reawaken all the enthusiasm of my youth: cells converted into game-baskets, eggs on the point of hatching beside the victuals, new-born grubs biting into their first victim, 185 Mri The Mason-Wasps larvjE of fuller growth, weavers at work on their cocoons, in fact everything that one could wish for. Never, except with the Scoliae in my heap of garden-mould,^ has fortune served me better. Let us make an orderly inventory of these rich documents. Already various Bees that favour bor- rowed houses have shown us the insect dis- criminating between one dwelling and an- other and selecting the best t'* make their homes in. We now have i' predatory Wasp who, following the example of the Osmiae, the Leaf-cutters and the Cotton- bees, leav-s the ancestral cabin for the cyl- inder of the reed, to which man's pruning- knife has prepared the access. The na- tural shelter, of indifferent quality, is suc- ceeded by the artificial and more convenient refuge. The Odynerus' primit-ve lodging is the abandoned corridor of the Antho- phora, or any other burrow dug in the earth by no matter what miner. The wooden tube, free from damp and bathed in sun- shine, is recognized as preferable; and the insect hastens to adopt it when the oppor- tunity occurs. The tunnel of the reed must be recogni^,ed as an excellent habitation, iCf. The Life and Love of the insect: chap, xi.— Translator's Note. i86 The Nest-building Odynerus superior to all others, for never outside any abode of Anthophorae have I seen a colony of Odyneri so populous as that of the Orange poultry-house. The reeds invaded are laid horizontally, a condition on which the Bees likewise insist, if only to shelter from the rain the house- door, plugged with pervious materials, such as mud, cotton, or round, leafy disks. Their inner diameter attains an average of two-fifths of an inch. The length occupied by the cells varies greatly. So.netimes the Odynerus takes possession only of that fragment of the interval between two knots which the stroke of the pruning-knife has left free, a fragment longer or shorter ac- cording to the chances of the cutting. In that case, a small number of cells is enough to fill the available space. But generally, if the stump be too short and not worth the trouble of working, the insect bores through the partition at the end and thus adds a complete internode to the vestibule with the open entrance. In a lodging of this kind, some eiglit inches long, the number of chambers will amount to fourteen or fifteen. In thus enlarging the house by i cmov- ing a fioor, the Odynerus displays two sepa- rate talents, the plasterer's and the car- 187 il i..m Pi The Mason-Wasps penter's. Her knack for wood-working. moreover, is extremely useful in another circumstance, as we shall see. The Three- horned Osmia, also an enthusiastic parti- tioner of reeds, does not employ this means of obtaining a spacious lodging at small cost. 1 find that she always leaves the first party-wall intact, building the row of cells against it, however short the section may be. 1 o make an opening in a slight barrier is not one of her methods. She could do it If she wished; for to gnaw through the ceil- ing of the cell on hatching and then through the general door of the nest is a more diffi- cult job. She possesses in her mandibles a tool powerful enough for the purpose; bnt she IS not aware that a splendid gallery lies beyond the obstacle. How did the Odvne- rus learn, if she did not know from the' be- ginning, what the Osmia, with her greater experience of the reed, does not know? Apart from the ingenious device of breaking down the party-wall in order to enlarge the premises, the Odynerus is the Usmia s equal as a plasterer and partition- builder The results of the two industries resemble each other so closely that we should easily confuse them if we merely ex- amined the structure. We find in both i88 The Nest-building Odynerus cases, at irregular intervals, the same par- titions, the same round disks of fine earth, of mud gathered wet on the brink of an irrigation-ditch or stream. Judging from the appearance of the materials, I imagine that the Odynerus has fetched her clay from the banks of the neighbouring torrent, the Aygues. Identity of construction is maintained even in details which I had at first regarded as a feat peculiar to the Osmia. Let us recall her compartment-building secret. If the reed be of middling diameter, the cell is first stocked with provisions and next bounded in front with a partition run up then and there, without any pause in its construction. If the reed, without being ex- cessively wide, be of a certain thickness, the Osmia, before stowing away the victuals, gets to work on the front partition, pro- viding it with an opening at the side, a sort of service-hatch, through which the honey is more easily discharged and the egg more easily placed in position. Well, this secret of the service-hatch, which was revealed to me by the glass tube, is as well-known to the Odynerus as to the Osmia. She, too, in the bigger reeds, finds it to her ad- vantage to close the larder in front before 189 i: The Mason-Wasps bringing the game; she shuts the cell with a door provided with a sort of wicket, through which the victualling and the lay- ing are done. When everything is finished inside, a plug of mortar closes the hatch. I did not of course see the Odynerus working at her partition with its wicket- door, as I saw the Osmia performing in my glass tubes; but the work itself speaks quite plainly of the method followed. In the centre of the partitions in the medium reeds there is nothing in particular to be seen; m the centre of the partitions in the larger reeds there is a circular aperture, after- wards filled with a plug, which always dif- fers from the rest of the partition by pro- jecting inwards and sometimes differs in colour. The thing is obvious- the small partitions are made in one spell, whereas the work on the larger ones is interrupted and then resumed. As we see, it would be pretty difficult to distinguish the Odynerus' nest from the Osmia's, if our enquiries were confined to the cells. One characteristic, however, and not the least curious enables an attentive eye to tell the owner without opening the reed. The Osmia closes hei dwelling with a thick plug of earth similar in nature to that em- 190 The Nest-building Odynerus ployed for the partitions. The Odynerus, it goes without saying, does not neglect this means of defence: she, too, makes a solid stopper; but to the unsophisticated method of the Osmia she adds the resources of a more highly-finished art. Over her earthen stopper, a thing liable to be spoilt by frost and damp, she spreads, on the out- side, a good thick layer of a composition of clay and chopped-up woody fibres. It matches the red wax with which we seal the corks of our bottles. These fibres, which resemble the remains of a coarse tow retted by long exposure to the air, I should be inclined to look upon as t.ken from reeds spoilt by the rain and bleached by the sun. The Odynerus planes them off in shavings, which she afterwards crumbles by chewing them. This is how the Common Wasps and the Polistes work on soft dead wood, when gathering the raw material for their brown paper. But the reed-dweller, who has no intention of em- ploying her scrapings for paper-making, does not cut up these fibrous particles any- thing like so finely. She contents herself with breaking them up and unravelling them a little. Mixed with thick mud, the same as that of the partitions and the final plug, 191 I I .Si The Mason-Wasps they make an cxcellf it loam, which is far less liable to go to pieces than unmixed clay would be. The efficacy of this ingenious stucco IS evident. After some months of exposure to the inclemencies of the weather, the Osmia s door, made of earth only, is very much dilapidated, whereas the Ody- nerus door, covered on the outside with a iayer of fibrous composition, remains intact. I^et us credit the Odynerus with inventing and patenting the loam covering and pro- After the nest, the victuals. One sort of game alone is served to the Odynerus' fam- ily; this is the larva of the Poplar Leaf- beetle (Chrysomela populi, Una p.), a larva which, in company with the adult in- sect, ravages the poplar-leaves at the end of spring. Consulted merely by our taste, the Odynerus game is anything but enticing in shape and still less in smell. It is a plump, thickset grub, with a bare, flesh- white skin covered with several lines of glossy black dots. The abdomen, in par- ticular, has thirteen rows of these black spots, namely, four on the top, three on each side and three underneath. The four dorsal rows vary in structure: the two in the middle consist of plain black specks; those 192 The Ncst-building Odynerus on cither side consist of little pimples, each shaped like a truncated cone with a minute opening at the top. One of these cones rises on the right and left of each abdominal segment, except the last two; there is also one on the right and one on the left of the metathorax and mesothorax. These two are larger than the others. There are nine pairs of perforated pimples in all. If we tease the creature, we see welling up from the bottom of these several little craters an opalescent liquid, which runs and spreads all over the larva. It has a strong smell of bitter almonds, or rather of nitro- benzene, commonly known as essence of mirbane, a powerful and most repulsive smell. The discharge of this substance is a means of defence. We have only to tickle the insect with a straw or to grip one of its legs with the tweezers and the eighteen scent-bottles at once begin to work. Whoso handles the grub will find his fingers stink and will throw away the noisome perfumer in disgust. If the Chrysomela- larva's object in placing nine pairs of nitro- benzene-stills on its back was to repel man, It has, I admit, thoroughly succeeded. But man is the least of its enemies. Far more formidable is the Odynerus, who 193 The Mason-Wasps patches It w.th a few stings. This wa; the bandit against whom, above all, it should have defended itself; and the poor grub has not been happily inspired in*^ this%espect Considering the huntress' exclusive taste for this sort of game, we must presume that the Chrysomela's drug-shop possesses a ddicious aroma in the Odynerus' opinion. The defensive secretion becomes a deadly tection: each advantage invariably has some corresponding disadvantage. r.l- ^'^c "u"^; ' ^^''«*^' ^^^«' the story of certain South-American Butterflies, some of whom tasted bitter, other, not. The firs were respected by the birds because of the bitterness; the second .ere eagerly swal lowed What did the persecuted 'inslct do? Unable to acquire the disagreeable tated their shape and their costume. And the birds were taken in by the fraud. This was put forward as a striking proof 1 am repeating the story more or less cor- for I have never attached more import' The Ncst-building Odynerus ance than they deserve to pretty inventions of this kind. Is it really certain that the pungent Butterflies escaped destruction be* cause of their taste? Might there not be, among the birds, a few passionate lovers of bitters, to whom the defensive flavour was, on the contrary, an added lure? My two acres of pebbles tell me nothing of things Brazilian; nevertheless I learn within their four walls that a grub of detest* able flavour, of the most repulsive aroma, has, like the others, its appointed consumers and very zealous consumers at that. If the struggle for life made it acquire its scent- bottles, then the struggle for life is a fool: it should have left the creature without them. In this way the enemy most to be feared, the Odynerus, who is attracted by the smell, would have been avoided. The non-pungent Butterflies teach us something more. In order to protect themselves from the birds, they have imi- tated the pungent ones' costume. Pray, then, let some one tell us why, among so many naked larvae on which the little birds feast, not one has thought of assuming the 'Chrysomela's black-buttoned overall. Un- able to provide themselves with stinking re- torts, they should at least possess a colour- 195 The Mason- Wasps able imitr. jn, in order to put their per- secutors otf. The simple creatures 1 It never entered their heads to protect them- selves by mimesis! We will not blame them; it is not their fault. They are what they are; and no bird's beak will make them change their costume. The Chrysomela's defensive fluid has a look of essential oil: it discolours paper with a semitransparent stain which disappears by evaporation. Its colour is opalescent; its Havour -s hor-ble; its odour is excessively strong and may be compared with that ot the nitrobenzene of our laboratories. Were it not that I lack the leisure and the apparatus, I would gladly undertake a little research-work into this singular product of animal chemistry, which, I think, is quite as worthy of exploration by our tests as the milky exudations of the Salamander or the load. Meanwhile I commend the problem to the chemists. In addition to the eighteen flasks of es- sential oil, the grub possesses yet another protective device, which is at once defensive and locomotory. The end of the intestine expands, at the insect's pleasure, into a large amber-coloured pimple, whence oozes a colourless or very pale-yellow liquid. I 196 The Nest-building Odynerus find it difficult to distinguish the odour of this hquid, because the strip of paper on which I collect it is always infected by the creature's mere touch. Nevertheless I seem to recognize, in a fainter degree, the smell of nitrobenzene. Can there be any connection between the product of the dorsal flask and that of the intestinal pimple? There very well may be. I suspect, also, that it possesses special virtues, for the Odynerus, who is a fine judge in such mat- ters, will tell us presently how greatly she appreciates this liquid. Before taking the evidence of the hunt- ress, let us note that the grub employs its anal pimple to move along with. Too short in the legs, it is a sort of cripple using Its inflated stern as a lever. Another fact, whose interest will appear at the proper time, IS that, at the moment of the meta- morphosis, the larva fastens itself by the anus to a poplar-leaf. The larval skin is pushed back while it remains clinging; and the nymph appears half-sheathed in this slough. The nymph in its turn splits; the perfect insect releases itself; and the two cast-off suits of clothes, one partly enclosed within the other, retain their place on the leaf, fastened to it by the anal extremity. 197 The Mason-Wasps The nymphosis takes about twelve days in all. It would be irrelevant to linger any longer over the larva of the Chrysomela; the little which it is expedient to say must not exceed the limits of my subject, which is the story of the Odynerus. We know the game grazing on its poplar- leaf in the sun; let us see it stowed away in the larder. I count the number of head in a reed-stump occupied by seventeen cells, with their stores of food complete, or nearly so, some still containing the egg, the others a young larva attacking its first morsel. In the best-provisioned cells ten grubs are packed together; in those least well-supplied there are only three. I perceive, more- over, that, generally speaking, the abund- ance of provisions diminishes in the upper and increases in the lower stories, though the order of progression is not always very exact. The varying ration of the two sexes is probably responsible: the males, which are smaller and more forward, are given the upper chambers, with a frugal bill of fare; the females, which are larger and more backward, are given the lower chambers, with a plentiful table. Another reason, I think, contributes to these varia- tions in number, namely, the size of the 198 The Ncst-building Odynerus game, which is more or less young, more or less plump. Whether big or small, all the head of game are absolutely motionless. Armed with a magnifying-glass, I watch in vain for any oscillation of the palpi, any quivering of the tarsi, any pulsation of the ibdomen, symptoms of life so frequently observed in the victims of the predatory Wasps. .uu^\ "°J^'"^' ^^^^- C^" the larvs stabbed by the Odynerus be really dead? ean the provisions consist of actual corpses? iiy no means: their profound inertia does not preclude a remnant of life. The proofs are striking. *^ To begin with, inspected cell by cell, my bundle of reeds tells me that the big larvs, those whicn have acquired their full de' velopment, very often adhere by their hinder part to the walls of the cell. The meaning of this detail is evident. Cap- ured when the metamorphosis was at hand, the grub, despite the blows of the stiletto, has made its usual preparations: it has hung Itself firmly to the adjoining support, the earthen partition or the tube of the reed just as it fastens itself to the poplar-leaf! The creature is so fresh in appearance and Its anal adhesion is so accurate that I ac- 199 The Mason- Wasps tually hope to see the victim's skin split and the nymph appear. My hope is not at all exaggerated; it is based on facts no less curious which I shall describe later. Events did not respond to the probabilities on which I all but relied. When removed from the charnel-house with their point of support and put in a safe place, none of the larvae settled for the nymphosis went be- yond the preparatory action. This action in itself, however, is eloquent enough: it tells us that a remnant of life faintly ani- mates the grub, since it retains power to make the necessary arrangements for the transformation. That the grub is no corpse is revealed in another manner. I place in glass tubes, with a plug of cotton, twelve larvae removed from the Odynerus' larders. The sign of latent life is the creature's freshness and its hue, a soft pinky white; the sign of death and corruption is a brown colouring. Well, eighteen days later one of the grubs be- gins to turn brown. A second is seen to be dead in iiiirty-one days. In forty-four days, six are still fresh and full. Finally, the last continues in good condition for two months, from the i6th of June to the 15th of August. It goes without saying that, 200 The Nest-building Odynerus r«lW !?" ""V""!' ''°"'' '"''» "hich are "a £:;*';:""""" °' '"■"'"' ""^ ''™- As I should have expected, the lavinB- pecuhanties of the Nest-building OdTnc- ru8 are precisely identical with those of servatlT'i' ""•°'''^'' "^ "^ '"^'" "b- f!.r- .u ' *8^'" '■"""»• "i'h the satis- taction that results from verifying an in- tcresfng fact, *e curious arrangement" 1 ready described. The egg is laid first ILflV^' back of the c!fl. Next comeJ the stackmg of the provisions in the order of capture. I„ this way the eating pro- ceeds from the oldest to'the most decent 1 was above all anxious to ascertain whether the egg was pendulous, that so say, whether it hung by a thrUd at one pomt of the ceU, in accordance with what O. remformis. A kmswoman of the latter 7^'lt\ «?'" beforehand, conform to the method of the suspension-cord ; but fro™ n" """" '° f'" that the journey from Orange and the jolting of the cart Ln. i • '"'' »'«'«'«. m minute precau- tions, dunng the removal of the cells with 201 Pi The Mason-Wasps the egg of O. reniformis swinging from the ceiling. The cart, ignorant of its precious burden, might have undone everything. Bjt no, to my great surprise. In most of the cells which were sufficiently recent I find the egg In place, slung sometimes from the arched roof of the reed, sometimes from the upper edge of the partition, by a thread which is just visible and about one twenty- fifth of an inch long. The egg Is itself cylindrical and measures about an eighth of an inch. The reeds, opened wide and placed in glass tubes, enable me to witness the hatching, which takes place three days after the closing of the cell and probably four days after the laying. I see the new-born grub enclosed almost wholly, head downwards, in the sheath pro- vided by the pellicle of the egg. Very slowly it slides forward in this scabbard and the suspension-cord stretches to the same ex- tent. It is extremely fine in the part con- sisting of the original thread, but very much thicker in the portion resulting from the slough of the egg. The grub's head reaches the nearest piece of game at one point or another; and the fragile creature takes its first mouthful. If anything startles it, if I tap the reed, it lets go and 202 I The Nest-building Odynerus withdraws a little way into the sheath of the egg ; then, reassured, it once more glides forward and resumes the point attacked. At other times a jerk leaves it indifferent. This suspension-stage of the new-born larva continues for about twenty-four hours, after which the grub, now somewhat fortified, lets itself drop and eats in the ordinary manner. The victuals last it for twelve days. Im- mediately afterwards comes the working of the cocoon, in which the insect remains, a yellow larva, until next May. It would be tedious to follow the Odynerus in its career of eating and weaving. The consumption of dishes highly spiced with nitrobenzene and the spinning of the cocoon, of a fine amber- coloured fabric, involve nothing so remark- able as to deserve special mention. Before leaving this subject, I will state a problem which the pendulous egg sets to the embryogenist. Every insect's egg, if cyl- indrical in form, has two poles, the front and back, the cephalic and the anal pole. By which of the two docj the insect see the light? By the hinder pole, the Eumenes and the Odyneri tell us. The end of the egg fas- tened to the wall of the cell was evidently the first to issue from the oviduct, in view 203 The Mason-Wasps of the irother's absolute need first to glue the suspension-thread somewhere, before abandoning her egg to space. In the ova- rian tubes and in the oviduct, which are too narrow to allow of an inversion, the anal pole therefore passes first. Pointing in the same direction as the egg, the new- born grub will thus hang head downwards, with its hinder end uppermost, at the end of its thread. By the front pole, the Scoliae, the Spheges and the Ammophilae in their turn reply, as do all the Hunting Wasps that fix the egg to some portion of the victim. It is, indeed, always by the cephalic end that the egg ad- heres to the prey, at a definite point selected by the mother's prudence; for the safety of the nurseling and the preservation of the vic- tuals demand that the first bites shall be taken here and here only. For the same reasons as above, the extremity fastened to the game has emerged into the light of day before the other. Both these opposite testimonies are equally truthful. According as its destiny is to be glued to the wall of the cell or to be kept away from it on another support, the egg takes its plunge into life by the front pole or the rear pole, which requires 204 The Nest-building Odynerus an Inverse direction In the ovaries and the oviduct. In this manner the new-born grub always has its food under Its mandibles; and its utter lack of experience does not ex- pose it to the danger of death from in- anition In front of a heap of provisions which its mouth would not yet be able to seek and find. There is the problem. I beg and entreat the embryogenists to solve it, without reference to preordination, with the sole aid of protoplastic energy. To know the Odynerus in the privacy of her home was not enough: the thing was to see her also at work as a huntress. How does she capture her game? How does she operate on it, in order to keep it fresh while deprived of life and movement? What is her surgical method? As, for the moment, I knew of no smallest colony of the Chry- somela's persecutor in my neighborhood, I put the matter to Claire. She was on the spot. In daily contact with the Hen-house where the memorable events that form the subject of this essay occurred ; and — a most important circumstance — I knew her to be both quIck-F tted and willing. She accepted the burdensome task with en- thusiasm. I, on my side, was, if possible, to attempt certain observations with the cap- 205 The Mason- Wasps tivc insect. So as not to influence each other in our appreciation of facts which, by their rapidity, might leave room for doubt, we each agreed to keep our results secret until we were both certain of our data. Fully instructed as to what to do, Claire begins. She soon discovers on the banks of the Aygues some poplars covered with Chrysomela-larvae. From time to time an Odynerus arrives, alights upon a leaf and goes off again with her capture in her legs. But things are happening too high up; de- tailed inspection of the struggle between the huntress and the victim is impracticable. Moreover, the appearances of the Ody- nerus on the tree which was being watched among so many others, all equally pro- pitious to the chase, occur at long intervals, which try the patience beyond all bounds. Tenacious in her desire to see, to learn and to be useful to me, my zealous collaborator bethinks herself oJF an ingenious expedient. A young poplar, with a wealth of Chryso- mela, is pulled up, together with the lump of earth clinging to it. Lavish precautions are taken to avoid the shocks which, du- ring the uprooting and the removal, mii?ht cause the herd of larvae to drop off. The business is so successfully done that the tree 206 The Nest-building Odynerus arrives without a hitch at its destination, in front of the Hen-house. It is put back in the earth immediately facing the reeds wherein the Odynerus makes her dwelling. No matter whether it takes root again or not, provided that the little tree keep fresh for a few days with abundant watering: that is all that is wanted. After installing her observatory, Claire proceeds to lie in wait, hiding behind some branches beside the poplar, whose foliage is in full view. She watches in the morning; she watches when the heat of the day has come; she watches in the afternoon. Next day, she begins again; on t^ ? day after that, she is still at it; and so si continues until at last fortune smiles upon her. O blessed patience, of what are you not capable ! The swarm of Odyneri, out in search of larvae, were, on their return, warned by the smell of nitrobenzene of the presence of the trans- planted and game-laden poplar. Why make distant expeditions when the quarry abounds outside one's door? The little tree was extensively f^xploited. Under such condi- tions the huntress was not long in revealing the secret of her tactics. Over and over again Claire witnessed the act of murder by the dagger. But she paid dearly for satisfy- ao7 The Mason-Wasps ing our common curiosity; she had to keep her room for several days as a result of sun- stroke. For that matter, she was prepared for the misadventure, well knowing, from my own example, that this is the assured re- ward of observations made beneath an im- placable sun. May the eulogies of science repay her for a little headache I The re- sults of her watches agreed at all points with those of my own. 1 shall explain them by telling what I saw myself. Now for my turn. When the bundle of reeds selected by the Odyneri reached me, I was occupied with a most interesting quest- ion, as will be proved by the details reserved for another chapter.* I was endeavouring to make the various Hunting Wasps, the species of whose prey was known to me, operate under a wire cover in my insect laboratory. This would determine the pre- cise spots into which the sting was driven. My captives, confronted with their ordinary game, for tlu most part refused to un- sheathe their weapons; others, less intent upon outdoor hunting, accepted the offer and stabbed their victims under my magnifying- glass. Why should not the Nest-building Odynerus be among these bold ones ? » Not yet publifhed in Engliih.— Translator's Note. 208 The Nest-building Odynerus We will try. I have plenty of Chryio- mela-grub*, received from Orange; I keep them under a wire-gauze dome, with an eye to their metamorphoses and their perfume- stills. The game is at hand; the huntress it lackmg. Where shall I catch her? I have only to ask Claire, who will hasten to send her. This is a sure expedient, but I hesi- tate to employ it: I fear lest the insect should reach me demoralized by the jolting of the cart and the tedium of a long cap- tivity. To this bored and wearied creature an encounter with the Chrysomela will al- most surely be a matter of indifference. I must have something better: I want the in- sect captured that moment with its aptitudes in their prime. In front of my door is a field of yellow fennel-flower, an ingredient of that ill- famed liquor, absinthe. From its umbels Wasps, Bees and Flies of all sorts drink Mieir fill. Let us take the net and see. The banqueters are numerous. I inspect the rows of plants amid the drinking-songs, the buzzmg and the shrilling of the insects. Praise the Lord, here is the Odynerus 1 I catch one, I catch two, I catch six of them and I hurry back to my workroom. Fate is favouring me beyond my desires: my 209 The Mason-Wasps six captures belong to the Nest-building Odynerus and all the six are females. Any one passionately interested in a pro- blem and suddenly discovering the data re- quired for its solution will understand my emotion. The joy of the moment has its anxious side: who knows what turn things will take between the huntress and the quarry? I shift an Odynerus and a Chry- somela-larva into a bell-glass. To stimu- late the assassin's ardour, I set the glass cage in the sun. Here is the story of the drama, told in detail. For a good quarter of an hour, the cap- tive clambers up the sides of the bell-glass, crawls down again and up again, seeking an outlet whereby to escape, and seems to pay no attention to the game. I was already despairing of success when suddenly the huntress falls upon the larva, turns it over, belly upwards, clasps it and stings it thrice in succession in the thorax, particularly un- der the neck, in the median region, a point at which the sting is more insistent than elsewhere. The close-clasped larva does its utmost to protest, emptying its scent-bottles and oiling itself with petrol; but these de- fensive tactics have no effect. Indifferent to the heady perfume, the Odynerus performs 210 The Nest-building Odynerus her operation, wielding her lancet with the same certainty as if the patient were scent- less. Thrice the sting is driven in, to kill the motor nerves in the three ganglia of the thorax. I repeat the experiment with other subjects. Few refuse to attack the prey; and each time three stings are admin- istered with marked insistence at the point under the neck. What I saw under arti- ficial conditions Claire, on her side, saw un- der conditions of liberty, in the open air, on the leaves of the transplanted pophr. The two collaborators, she and I, arrived at pre- cisely the same result. The operation is rapidly performed. Then the Odynerus, while dragging her prey along, belly to belly, munches at its neck for a considerable time, but without causing any wound. This action may well be equivalent to the pracHce of the Lan- guedocian Sphex and th Hairy Ammo- phila,^ when, without inflicting a bruise, the one nibbles at the neck of her Ephippiger and the other at that of her Grey Worm, in or- der to compress and paralyse the cervical ganglia. I of course take possession of the torpid larvae. The victim is absolutely in- 211 The Mason-Wasps crt, save for a slight quivering of the legs, which soon ceases. When laid upon its back, the larva no longer stirs. It is not dead, however; that I have been able to prove. Its dull vitality is affirmed in an- other manner. During the first few days of this lethargy which knows no awakening, droppings are ejected until the intestine is empty. On renewing my experiments, I witness something so singular that I am at first baffled. This time the prey is seized by the anal extremity and the sting is driven sev- eral times into the last segments, under- neath the abdomen. This is the usual op- eration reversed and performed upon the hinder segments, instead of those of the thorax. The surgeon and the patient, who are head to head in the normal method, are in the present instance head to tail. Can it be by inadvertence that the operator is con- fusing the two ends of the grub and sting- ing the tip of the abdomen under the im- pression that she is stinging the neck? I believe it for a moment, but am soon unde- ceived. Instinct does not make mistakes of this sort. For now, having finished thrusting with her sting, the Odynerus clasps the creature 3ia The Nest-building Odynerus mandibles, to munch the last three seg- gluttony accompanies these bites: all the mouth-parts are brought into play, „ though the .nsect were feasting on some ex thTn%'\ M-^^^hile the frub, bitTen to the quick, desperately works its short legs, whose activity ,s not at all diminished by the sting, administered behind; it struggles vio- I ntly, protesting with its head and man- dible . The other takes no notice and con- tinues gnawing at the larva's rump This iandi/".*'" "^fifteen minutes, Then the bandit releases the sufferer and leaves it where ,t l.es, without troubling about it any 7hTnZ i'^ *° r""^ 8""" '"''""I'd for the nest Soon afterwards, the Odynerus begins to lick her fingers, as though she had after time she passes her tarsi between her mandibles; she is washing her hands after rising rom table. What has she been eat' Queeze Tl °""t ""'.""'h the epicure squeeze the juice from the rump. Iittl/nL""'^'"^' ■'•'"''''"^ *'t I P"«i« a other, operate on the ChrysomelaJarvs, at The Mason-Wasps one time in front, as game for the family, at another behind, as a little addition to their own diet. The honey with which I serve them on spikes of lavender does not make them forget this horrible treat. The tac- tics employed in obtaining it, though the same in the general aspect, vary in detail. The larva is always seized by the hinder end and the stings are administered in succession from back to front, on the ventral surface. Sometimes th,e abdomen only is attacked, sometimes the thorax also, when the victim is deprived of all movement. Evidently the object of these stings is not the immo- bility of the larva, since the latter can move quite well, ambling along, wounded though it be, when the sting has not gone higher than the abdomen. Inertia is indispensable only in the case of victuals intended for the cells. If th^ Odynerus is working on her own behalf and not for her family, it mat- ters little to her whether the grubs whose dainties she covets struggle or not; it is enough if all resistance in the part to be exploited is abolished by paralysis. This paralysis, moreover, is quite accessory; and each huntress neglects or practises it at will, bearing more or less forward, without any fixed rule. When the sated Odynerus re- 214 The Nest-building Odynerus leases the grub whose rump she has been chewing, It IS sometimes therefore inert, like those intended for the cells, and sometimes endowed with almost as much activity as the untouched grubs, from which it differs only nL K^ u""". °i '*' ""'^ P'^^PJ^' »ts sup. a bowl """" "' °^ ^ ^''^^^^ ''"'"« '" I examine the helpless ones. The anal blister has disappeared, nor can I make it reappear by squeezing the tip of the abdomen Tf i- Ir "^'"- ^°' ^^^ ^«f' '" the place of this blister my pocket-lens shows me torn, rugged tissues; the end of the intestine is in tatters. Every elsewhere all around are bruises and contusions, but no gaping wounds It IS with the contents of thf bhster then that the Odynerus so deliciously slakes her thirst. When she munches the last two or three segments, she is milking the grub after a fashion; by means of the pressure, which favours the paralysis of the abdomen, she makes the rectal humour flow into the pocket, which she then rips open in order to sip the contents. What is this humour? Some special product, some mixture of nitrobenzene? I cannot say for certain. I know only that the insect employs it in self-defence. When 215 sfea The Mason-Wasps frightened, it exudes it to ward off the as- sailant. The anal reservoir begins to work when the first little drop appears from the scent-bottles. What shall we say of this protective device which becomes the cause of excruciating torture? Unsophisticated crea- tures, acquire the power of stinking, after this; distil benzene ; become bitter if you were not bitter before: you will always find a devourer to scrunch you, an epicure to nibble your rumpl South-American butterflies, pray take note I I will not close the lamentable history of the Chrysomela-grub without telling what becomes of the creature after this horrible mutilation. The complete inertia produced by the thoracic injuries has nothing to teach us that we do not already know from the facts perceived in the larvae destined for the cells. We will therefore consider the case in which the grub is stung three or four times at the tip of the abdomen only. I secure the crea- ture when the Odynerus abandons it, after greedily munching the last three segments and scraping out the end of the intestine, whose defensive and locomotory pimple has disappeared. These three segments are bruised and of a sickly colour; but I cannot discover the least rent in the skin. The ab- 216 The Nest-building Odynerus domcn is paralysed. The insect no longer uses Its anal lever when walking. The lees are perfectly mobile and the grub employs them: it crawls, ,t drags itself along, pro- gressing with a vigour which would be nor- mal but for the obstruction of the hind- quarters. The head also moves; the mouth-parts snap as usual. Apart from the paralysis of the abdomen and the mutilation of the rectum, the victim is in every respect the same as the luscy larva, browsing peace- fully on the poplar-leaf. We have here a magnificent demonstration of the principle hnuJL f'u '"'u"'" P'"^''^ objections are bound to fall to the ground: the effect of the sting ,s not felt, at least not at first, except at the points attacked. The sting strikes the nerve-centres of the abdomen and the abdomen ,s paralysed; it spares the thorax and the legs and head both remain active. Ten hours after the operation, I examine the grubs agam. The hind-legs are tremu- ous and are no longer of use for locomo- tion. Faralysis is overtaking them. Next day, they are inert; so are the middle legs. The head and the fore-legs are still work- ing. On the day after, the whole grub is Motionless, except the head. Lastly, on the fourth day, the creature is dead, really 217 iMi The Mason- Wasps dead, for it shrivels, dries up and goes black, while the larvs subjected to the tho- racic operation with a view to being used for provisions remain full and fresh-col- oured for weeks and months. Did the grub die of its stings in the abdomen? No, for the others, stung in the thorax, do not die. It is the Odynerus' cruel tooth and not the sting that killed it. With the tip of the abdomen crushed under the man- dibles and the intestinal capsule pulled out by the roots, life has ceased to be possible. fli8 CHAPTER IX INSECT GEOMETRY TpHE industry of insects, especially that of •* the Bees and Wasps, abounds in tiny marvels. Newly manufactured with the cotton supplied by various fluff-covered plants, the nest of certain Anthidia forms an exquisitely graceful pouch. It is accur- ately fashioned, white as snow, pleasing to the eye and softer to the touch than Swan's- down. The Humming-bird's nest, a bowl hardly half the size of an apricot, is by comparison a piece of clumsy felt. But this perfection is of brief duration. The artist is hampered by the exigencies of the space at her disposal. Her workshop IS a chance shelter, a tunnel incapable of modification, which she has to use as she finds it. In this narrow retreat, therefore, the cotton purses are placed in a row, each compressing the others and distorting their form; they are welded at either end to their neighbours, till the whole becomes a lumpy pillar moulded to the volume of the con- tainer. For lack of space, the weaver has 219 li The Mason-Wasps been unable to continue her textile fabric in accordance with the exquisite design dic- tated by her instinct. A length of rope, of indifferent merit, takes the place of the 8uperb masterpiece of felt which the An- thidium would have created had she been working at isolated cells. The Chalicodoma of the Walls, when building on a pebble, first raises a turret of faultless geometrical proportions. The dust scraped from the hardest spots in the highways and kneaded with saliva provides the mortar. To make a more solid job of things and also to economize cement, which takes a long time to collect and prtpare, tiny bits of gravel are encrusted in the outer surface before the material sets. In this way the initial building becomes a rus- tic rockwork fortress, which is quite pretty tc look at. , , 1 Using her trowel freely, the Mason-bc< has builded after the prototype of her art the cylinder adorned with a mosaic pattern But other cells, at least a dozen, are to fol low. Necessities now obtrude themselve! from which the first piece of work was ey empt; that which will soon be building i subordinated to that which is already buill The solidity of the whole requires tha 320 Insect Geometry the turrets leaning one against the other shall form a solid mass; and economy of material demands that the same partition- wall shall serve for two adjoining cells. These two conditions are incompatible with the regulation architecture, for grouped cylmders touch only along a line, affording no appreciable area of common partition- wall; they leave between them unoccupied mtervals, which would prejudice the general stability. What does the builder do to remedy these two defects? She abandons the normal outline and modifies it according to the space at her disposal. She alters the shape of the cyl- inder, not as regards the interior, which is still kept rounded to suit the convenience of the larva, the future inhabitant, but as re- gards the outer envelope, which becomes ir- regjjlar and polygonal, filling the interstices with Its angles. The exquisite geometry promised by the turret first constructed is perforce aban- doned when the complete edifice has to consist of a mass of cells in juxtaposition. Inexactness follows exactness even more no- ticeably at the end of the task. Anxious to strengthen her work and enable it to resist the attacks of the weather, the mason plas- 221 ■M The Mason-Wasps ters it with a thick layer of mortar. Mo- saic encrustations, round mouths, closed with a lid, and cylindrical bastions: all these disappear, submerged by the defensive cas- ing. To look at, there is nothing left but a clod of dried mud. The simplest of round bodies, the cyl- inder, stands likewise as the model for the jam-pot wherein the Pelopaeus stacks her Spiders. With mud collected from the edge of a ppol, the huntress begins by build- ing a turret ornamented with diagonal loz- enges. Unhampered by its surroundings, this structure, the first of the group, is of a perfection that gives us a high opinion of the builder's talent. It is fashioned like a segment of a twisted column. But other cells follow which, leaning one against the other, prod', a mutual distortion. For the same rea jns, namely, economy of ma- terial and general solidity, the beautiful or- donnance promised at the outset is wanting; crowding leads to irregularity. A thick layer of cement ends by deforming the structure altogether. Let us next consider the Agenia, who rivals the Pelopaeus as a huntress and a worker in clay. She encloses the one Spider who forms her larva's ration in an 222 Insect Geometry earthenware shell hardly as large as a cherry-stone and embellished on the outside with a tiny milled pattern. This little gem of ceramics is an ellipsoid truncated at one end. When the structure stands alone, its accuracy of form is perfect. But the potter's ware does not end with this. The place of refuge discovered in some crevice in a sunny wall is a valuable site, where the whole family will take up its abode. More prescrve-jars are therefore fashioned, sometimes arranged in a row, sometimes collected in a group. Though constructed according to a fixed type, the ellipsoid, the new structures depart, some more, some less, from the ideal model. Welded together, end to end, they lose the smooth nipple of the ellipse and replace it by the sudden truncation of the barrel. When they are joined lengthwise, the belly of the barrel becomes flattened; when they arc massed together anyhow, they become al- most unrecognizable. Nevertheless, as the Agenia, unlike the Pelopseus, never covers her collection of pots with a casing, her work retains its distinctive features fairly well, thanks to the thoroughness with which the artist has stamped her trade-mark upon It. ^ 223 iiTrr !| I, ;! The Mason-Wasps The pottery of the Eumenes is of a higher order: it favours a bulging cupola, lilce that of the Turkish kiosk or the Mo- scow basilica. At the summit of the dome is a short opening, like the mouth of an amphora, through which the caterpillars in- tended for the larva's consumption are intro- duced. When the larder is full and the egg slung from the ceiling by a thread, the bell- mouthed neck of the cell is closed with a clay stopper. As a rule, in these parts, E. Amadei builds on a big pebble. She adorns her cu- pola with angular bits of gravel, half buried in the plaster; on the stopper closing the mouth she places a little flat stone, or even a Snail-shell, selected from among the small- est. The earthenware casemate, well-baked by the sun, is supremely graceful. Well, this elegant structure is doomed to disappear. Around her cupola the Eume- nes builds others, using as walls what she has already built. Henceforth the exact circular form is no longer practicable. In order to occupy the reentrant angles, the new cells themselves become angular and assume an undecided, polyhedral form. Only the edges of the mass and the top re- tain traces of the regulation plan. The 224 Insect Geometry nest as a whole shows a nip*>led surface en- crusted with broken flint. Hach nipple cor- responds with a cell, which may always be known by its amphora-like mouth, a part which is not misshapen, because it has been fashioned without impediment. In the ab- sence of this certificate of origin, we should hesitate before recognizing the work of an expert dome-builder in the shapeless blob. E. unguiculata does worse. After build- ing, on some big stone, a group of cells which, in shape, ornamental encrustation and bell-mouthed neck, rival those of £. Amadei, she buries the whole under a layer of mortar. She imitates the Chalicodoma and the Pelopjeus, who, for reasons of do- mestic safety, follow up artistic daintiness with the uncouthness of the fortress. In- spired by a system of esthetics which no- thing is able to evade, both insects begin by creating beauty; dominated by the fear of danger, they end by creating ugliness. Other Eumenes, on the contrary, of smaller size, build cells which are always isolated and which often have the twig of a shrub for a support. The structure is a cupola, similar to those already mentioned, and, like them, provided with a graceful neck, but without the gravel mosaic. The 225 m m' r Mi The Mason- Wasps tiny fabric, no bigger than a cherry, does not admit of this rustic ornamentation. The potter replaces it by a few specks of clay distributed here and there. The Eumenes who build a succession of cells in groups are compelled to deform the chamber under construction according to the space left by those preceding it; for the beautiful curve of their original design they substitute, by force of circumstances, the un- pleasing broken line. The others, those who build each cell in isolation, are far from perpetrating such inaccuracies. From first to last, as many as the establishment of the larvae requires, now on this twig, now on that, the cells are built of an identical shape, just as though they had issued from the same mould. Now that nothing hinders the exact application of the rules, order re- turns and produces a series of structures which are no less perfect at the end than at the beginning. If the insect were to build a general shel- ter, in which each larva had its individual box, what would this building, this common home of the family, be? On condition, of course, that no obstacle intervene, the work will always be correct in its geometry, which will vary according to the builder's speci- 226 Insect Geometry ality. I could draw you a child's balloon than which none prettier was ever inflated in toyland, or, for that matter, in fairyland ; and it would be exactly like the nest of a Median Wasp (Vespa media, De Geer). The per- son who gave me this marvel found it hang- ing from the lower edge of a shutter which was left open for the greater part of the year. Possessing liberty of action in all direc- tions, except at the point of contact with the shutter, the Wasp followed the rules of her art without impediment. With a paper of her own manufacture, tough and flexible as the silk papers of China and Japan, she contrived to expand her work into a seg- ment of an ellipsoid, with a cone added to it by means of a gentle curve. A like as- sociation of forms artistically combined is found in the Sacred Beetle's pears.* The slender Wasp and the heavy Dung-beetle, employing dissimilar tools and materials, work after the same pattern. Ill-defined spiral bands tell us how the Wasp went to work. With her pellet of pa- per-pulp in her mandibles, she moved down- wards in a slanting direction, following the 1 Cf. The Sacred Beetle and Others, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chap. vr. — Translator's Note. 227 i ■ >. i i ■■imam rl The Mason-Wasps margin of the part already constructed and leaving as she went a ribbon of her material, still quite soft and impregnated with saliva. The work was discontinued and resumed hundreds and hundreds of times, for the supply was soon exhausted. The Wasp had to go to some woody stem hard by, a stem retted by the moist air and bleached by the sun, and scrape it with her teeth; she had to tear out its fibres, to divide them, un- ravel them and work them up into a plastic felt. When the pellet was removed, the Wasp hastened back to resume her inter- rupted ribbon. There was even the collaboration of sev- eral builders. The foundress of the city, the mother, alone at the outset and ab- sorbed by family cares, was able only to make a rough beginning of the roof; but offspring arrived, neuters,^ eager assistants henceforth charged with the continuing and enlarging of the dwelling, in order to provide the one mother with a lodging to contain the whole of her eggs. This gang of pa- per-makers, coming one by one to take part in the labour, or perhaps working with- out any common agreement, several at a time, at different points, so far fiom pro- * Sexually undeveloped females. — Translator's Note, 228 Insect Geometry ducing confusion, achieves perfect regularity. By slow degrees the spacious dome of the summit decreases in diameter; by degrees it tapers into a cone and ends in a graceful neck. Individual and almost independent efforts result in an harmonious whole. Why? Because these building insects possess an innate geometry, an order of architecture v/hich is known without being taugat and which is constant in the same group, while varying as between one group and another. Just as much as the details of the organism, or perhaps even more so, this propensity to build according to certain determined rules characterizes the corporations known by the name of species. The Chalicodoma of the Walls has her earthen tower, the Pelopaeus her twisted clay cylinder, the Agenia her urn, the Anthidium her cotton wallet, the Eumenes her open-mouthed cupola and the Wasp her paper balloon. And so with the others : each has her own art. Our builders contrive and calculate be- fore they set to work. The insect di- spenses with these preliminaries; it knows nothing of the hesitations of apprentice- ship. Frdm the laying of the first stone it IS a past master of its craft. It builds with 229 I> \ The Mason-Wasps the same accuracy and the same uncon- sciousness as those displayed by the mollusc, which coils its shell in a scientific spiral; if nothing hinders its aims, it always achieves a graceful and wisely economical structure. But, when a number of cells mutually hamper one another, the regulation plan, without being abandoned, undergoes altera- tions imposed by lack of space. Massing leads to irregularity. Here, as with us, liberty makes for order and constraint for disorder. ; We will now open the nest of the balloon- building Wasp. Here is something that we did not expect. Instead of one en- velope there are two, one enclosed within the other, with a slight interval between. There would have been even more, three or four of them, had not impatient hands, eager to bring me the masterpiece, culled it before it reached perfection. The nest is incomplete, as is proved by the single story of cells. A perfect Wasps'-nest woulc contain several stories. No matter : such as it is, this work shows us that the chilly Wasp was acquainted with the art of preserving heat before we were Physics teaches us the efficacy of a cushior of air, motionless between two walls, as j 230 Insect Geometry preventive against cooling; it recommends the use of double windows to maintain a mild temperature in our houses in winter Long before the days of human science, the little Wasp, that passionate lover of warmth, knew the secret of multiple enve- lopes containing layers of air. With its three or four balloons, fitting within one another, her nest, hanging in the sun, must turn into a vapour-bath. These paper containers are merely de- fensive works; the actual city, for which all the rest has been built, occupies the top of the dome It consists at present of a single layer of hexagonal cells, open below. Later on, other, similar layers would have been added, descending in stages and each connected with its predecessor by little papter mdche columns. The aggregate of these layers, or combs, would supply not far short of a hundred cells, the lodgings of as many larva. ^ c T*;^,!S«^^od of rearing imposes on the bocial Wasps rules unknown to the other builders. These latter store in each cell provisions -- honey or game — apportioned to the grubs needs. The egg once laid, they close the cell. The rest does not concern them: the immured larva will find 231 The Mason- Wasps all around it the wherewithal to nourish ii self and to thrive without outside hel{ Under these conditions, the irregular groui ing of the cells is of trifling importance disorder even is admissible, provided thi the whole group be in a place of safety, need be under the cover of a protective ca ing. Richly supplied with provender an tranquil in its crypt, none of the reclus< expects anything from the outer world. Among the Social Wasps a very differc order of things obtains. Here the larv; from the beginning to the end of the growth, are incapable of sufficing unto thei selves. Like little birds in the nest, thi are fed by mouth; like babies in the cradl they need constant attention. The workei who are celibates expressly appointed perform household labours, come and ] incessantly, from bed-chamber to be chamber; they awaken the sleepy larv wash them with a lick of the tongue ai disgorge, from mouth to mouth, the rati' of the moment. So long as the larval sti continues there is no end to these alimenta kisses between the nurselings gaping wi hunger and the nurses returning from t fields, their crops swollen with pap. Nurseries of this kind, which, in t 232 Insect Geometry case of various Social Wasps, number their cradles by the thousand, require ease of inspection, quickness of attendance and therefore perfect order. Whereas it makes no difference to the Chalicodom«, the Eumenes and the Pelopsi whether their cells be grouped without any great pre- cision, since, once provisioned and sealed, they will not be visited again, it is important to the Social Wasps that theirs should be arranged methodically, for otherwise the enormous household, degenerating into a tur- Dulent mob, could not possibly be served. lo lodge the mother's inexhaustible sup- ply of eggs, they have to build for her, within a limited space, the greatest possible number of cells, all of a capacity determined by the ultimate size of the larva. This con- dition exacts a strict economy of the available building-site No empty gaps, therefore, which would take up unnecessary room and moreover compromise the general solidity of the structure. hir^df •' '^'' *"' ^^^ b"siness.man says to " Time is money." The Wasp, no less busy, says to herself: . ^ ','"«,;? paper ; paper means a more spa- cious dweUmg, holding a larger population. 233 The Mason- Wasps Let us not waste our materials. Each par- tition must serve two neighbouring apart- ments." How will the insect set about solving its problem? To begin with, it abandons any circular form. The cylinder, the urn, the cup, the sphere, the gourd, the cupola and the other little structures of their customary art cannot be grouped together without leav- ing gaps; they supply no party-walls. Only flat surfaces, adjusted according to certain rules, can give the desired economy of space and material. The cells therefore will be prisms, of a length calculated by that of the larvae. It remains to decide what form of polygon will serve as the base of these prisms. First of all, it is evident that this polygon will be regular, because the capacity of the cells has to be constant. Once the condition obtains that the grouping must be effected without gaps, figures that were not regular would be subject to variation and would give different capacities in one cell and another. Now of the indefinite number of regular polygons only three can be constructed continuously, with- out leaving unoccupied spaces. These three are the equilateral triangle, the square, and the hexagon. Which are we to choose? 234 Insect Geometry The one that will approximate most closely to the circumference of a circle and hence be best adapted to the cylindrical form of the larva; the one that, with a containing wall of the same extent, will yield the great- est capacity, a condition essential to the free growth of the grubs. Of the three regular figures that can be assembled without vacant intervals, our geometry suggests the hexagon; and it is the hexagon and none other that is chosen by the geometry of the Wasps. The cells are hexagonal prisms. Every high and harmonious achievement finds supersubtle minds that strive to degrade it. What has not been said on the subject of hexagonal cells, above all on the subject of the Bee's, which are arranged in a double layer and united at the base? Reasons of economy of both wax and space demand that this base shall be a pyramid formed of three rhombs with angles of fixed value. Scientific calculations tell us the value of these angles in degrees, minutes and seconds. The gonio- meter subjects the work of the Bee to exami- nation and finds that the value is precisely calculated to degrees, minutes and seconds. The insect's work is in perfect agreement with the nicest speculations of our own geo- metry. 235 The Mason- Wa-ps There is no room for the glorious problem of the Bee-hive in these elementary essays. Let us confine ourselves to the Wasps. It has been said : *' Fill a bottle with dried peas and add a little water. The peas, in swelling, will be- come polyhedrons by mutual pressure. Even so with the Wasps' cells. The builders work in a crowd. Each builds at her own will, placing her work in juxtaposition to her neighbours'; and the reciprocal thrusts pro- duce the hexagon." A preposterous explanation, which no one would venture to suggest if only he had con- descended to make use of his eyes. Good people, why not look into the early stages of the Wasp's work? This is quite easy in the case of the Polistes, who builds in the open, on a twig of some hedge-plant. In the spring, when the Wasps'-nest is founded, the mother is alone. She is not surrounded by collaborators who, vying with her in zeal, would place partition against partition. She sets up her first prism. There is nothing to hamper her, nothing to impose one form upon her rather than another; and the ori- ginal cell, free from contact in every direc- tion, is as perfect an hexagonal prism as the rest will be. The faultless geometry of 236 Iniect Geometry the structure asserts itself from the outset. Look again when the comb of the Polistes or any Social Wasp that you please is more or less advanced, when numbers of builders are at work upon it. The cells at the edge, mi at of them still incomplete, are free as regards their outer halves. So far as this part is concerned there is no contact with the preced- ing row of cells; no limit is imposed; and yet the hexagonal configuration appears as plainly here as elsewhere. Let us abandon the theory of mutual pressure: a single glance of the least discernment contradicts it flatly. Others, with more scientific, that is to say, less intelligible ostentation, substitute for the contact of the swollen peas the contact of spheres which, with their intersections and by virtue of an unseeing mechanism, lead to the superb structure of the Bees. The theory of an order emanating from an Intelligence watchful over all things is, to their thinking, a childish supposition ; the riddle of things is explained by the mere potentialities of chance. To these profound philosophers, who deny the geometrical Idea Which rules the forms of things, let us propound the problem of the Snail. The humble mollusc coils its shell accord- 337 I ll •'" The Mason- Wasps ing to the laws of a curve known as the loga- rithmic spiral, a transcendental curve com- pared with which the hexagon is extremely simple. The study of this line, with its re- markable properties, has long delighted the meditations of the geometricians. How did the Snail take it as a guide for his winding staircase? Did he arrive at it by means of intersecting spheres, or other combinations of forms dove-tailed one into the other? The foolish notion is not worth stopping to consider. With the Snail there is no conflict between fellow-work- ers, no interpenetration of similar, adjoining structures. Quite alone, completely isolated, peacefully and unconsciously he achieves his transcendental spiral with the aid of glaire- ous matter charged with lime. Did the Snail even invent this cunning curve himself ? No, for all the molluscs with turbinate shells, those which dwell in the sea and those which live in fresh water or on land, obey the same laws, with variations of detail as to the conoid on which the typical spiral is projected. Did the present-day builders accomplish it by gradually improv- ing on an ancient and less exact curve? No, for the spiral of abstract science has presided over the scrollwork of their shells ever since 238 Insect Geometry the earliest ages of the globe. The Cera- tites, the Ammonites and other molluscs prior in date to the emergence of our conti- nents coil their shells in the same fashion as the Piano rbes * of our books. The logarithmic spiral of the mollusc is as old as the centuries. It proceeds from the sovran Geometry Which rules the world, at- tentive alike to the Wasp's cell and to the Snail's spiral. "God," says Plato, "is ever the great geometer : *Aet o dcoc yeo/uTpd." Here truly is the solution of the proble^-i of the Wasps. »A wide|)r<^y "'HI die The females whose end is near are easilv d.s mgu,shed from the others by the disorder of the,r appearance. Their backs are dusty h^ve'taS t^- '"'^ r' ''""y- <>"« "W saucer of h ' "■"?' ?" ">= ^""> of the saucer of honey, settle in the sun and dust themselves without ceasing. There^s an in w?tr.entir'""«°' ""^ "'^S' and abdomen"," Cs rf!'/?"'"'"" "''"^i""' of the hind: legs, the fore-legs repeated y stroke the head co"stu™ '-"T- ^''"^ 'he blacktd fellow costume ,s kept perfectly glossy. Those who are ailing, careless of cleanliness stand motionless in the sun or wander irn'^M^ This iLi^ "" '°"S",'"-"»h their clothes ihis mdifference to dress is a bad siirn Two or three days later, in fact, the dS female leaves the nest for the last dme and MtiM The Mason- Wasps goes on the roof, to enjoy yet a little of the sunlight ; then, her nerveless claws relinquish- ing their hold, she slides quietly to the ground and does not get up again. She de- clines to die in her beloved paper home, where the code of the Wasps ordains abso- lute cleanliness. If the neuters, those fierce hygienists, were still there, they would seize the helpless crea- ture and drag her outside. Themselves the first victims of the winter evil, they are lack- ing; and the dying Wasp proceeds to per- form her own funeral rites by dropping her- self into the charnel-pit at the bottom of the cavern. For reasons of health, an indi- spensable condition with such a multitude, these stoics refuse to die in the actual house, among the combs. The last survivors re- tain this repugnance to the very end. For them it is a law which never falls into disuse, however greatly reduced the population may be. No corpse can be allowed to remain in the babies' dormitory. My cage becomes emptier day by day, not- withstanding the mild temperature of the room, notwithstanding the saucer of honey at which the able-bodied come to sip. At Christmas I have only a dozen females left. 266 The Common Wasp On the 6th of January, with snow out of doors, the last of them perishes. Whence arises this mortality, which mows down the whole of my Wasps? My atten- tions have preserved them from the calami- ties which at first sight might appear to cause their death under the usual conditions. Fed upon honey and grapes, they have not suf- fered from famine: warmed by the heat of my fire, they have not suffered from cold; cheered almost daily by the sun's rays and hvmg in their own nest, they have not suf- fered from homesickness. Then what have they died of? I can understand the disappearance of the males. These are henceforth useless; the pairing has taken place and the eggs are fertile. I can less easily explain the death of the neuters, who, on the return of spring, would be of such great assistance when new colonies are founded. What I do not un- derstand at all is the death of the females. I had nearly a hundred; and not one has sur- vived the first few days of the new year. Having left their nymphal cells in October and November, they still possessed the vigor- ous attributes of youth ; they represented the future; yet this sacred quality of prospective 267 SI I, m The Mason-Wasps motherhood has not saved them. Even as the feeble males retired from business, even as the workers exhausted by labour, they too have succumbed. We must not blame their internment un- der wire for their death. The same thing happens in the open country. The various nests inspected at the end of December all reveal a nmilar mortality. The females die almost as rapidly as the rest of the popula- tion. This was to be expected. The number of females who are daughters of the same nest is unknown to me. However, the profusion of their dead bodies in the charnel-pit of the colony tells me that they must be counted by the hundred, perhaps by the thousand. One female is enough to found a city of thirty thousand inhabitants. If all were to pro- sper, what a scourge I The Wasps would tyrannize over the country-side. The order of things demands that the vast majority shall die, killed not by an accidental epidemic and the inclemency of the season, but by an inevitable destiny, which performs Its work of destruction with the same en- ergy as that which it displays in the task of procreation. One question thereupon arises: since a single female, preserved in 26S The Common Wasp one way or another, is enough to maintain the species, why does a Wasps'-nest contain so many aspirant mothers? Why a multi- tude m place of one? Why so many vie- timsi; A perturbing problem, in which our intelligence fails to see its way. 269 ^. V v'|,f, IF CHAPTER XI THE COMMON WASP {continued) QF the calamities that befall the Wasp when winter arrives, the worst remains to be told. Foreseeing the approach of fail- ing power, the neuters, hitherto the tendcrest of nurses, become savage exterminators: " Let us leave no orphans," they say to themselves; " no one would tend them after we are gone. Let us kill everything, belated eggs and larva alike. A violent end is preferable to slow death by starvation." A massacre of the innocents ensues. Seized by the scruff of the neck and brutally extirpated from their cells, the larvae are dragged out of the nest and thrown into the vat at the bottom of the crypt; the eggs, those delicate morsels, are ripped open and de- voured. Will it be possible for me to wit- ness this tragic end of the city, not in the fulness of its horror — that ambition is too far beyond my resources — but at least in some of its scenes? Let us try. In October, I place under cover a few fragments of a nest which have been saved 270 The Common Wasp from asphyxiation. By moderating the dose of petrol I can easily obtain a number of Wasps afflicted merely with a passing torpor, which enables me to collect them wifhout^be! ing stung and which disappears as the suffer- ers are exposed to the air. Note also that. able of killing all the adults, the larv« do not succumb. Mere digesting bellies, they hoM out when the more delicately-organized adults perish Safe from misadven^tu"!! have been able m this way to establish i,^ a cage a portion of a nest rich in eggs and JeSts"" '°"'' ^"""^"^ neuters as at- To facilitate my inspection, I separate the combs and place them side by side, with the openings of the cells turned upwards. This arrangement, which reverses the norma does not appear to annoy my captives who soon recovenng from their 'disturbanerse; to work as if nothing unusual had occurred a slip of soft wood to draw upon. Lastly, I feed them with honey, poured into a pool on a strip of paper and renewed daily. The underground cavern is represented by a large earthen pan surmounted by a wire-eauze cover. A cardboard dome, placed over the 271 I-. The Mason-Wasps cover or removed at will, provides alter- nately the obscurity demanded by the Wasps' labours and the light needed for my observa- tions. The work is continued from one day to an- other. The Wasps attend at the same time to the larva and to the house. The builders begin to erect a wall round the most thickly, colonized combs. Do they intend to repair the disaster and build a new envelope, which will replace the vanished enclosing wall? The progress of the operation seems to tell us no. They are simply continuing the work which my terrible flask and my spade have inter- upted. Over an area embracing hardly a third of the comb, they erect an arched roof of paper scales which would have been joined to the envelope of the nest had it been intact. They are not beginning again; they are continuing. In any case, the sort of tent thus obtained shelters but a small part of the disk of cells. This is not for lack of materials. To begin with, there is the slip of wood, providing, in my opinion, an excellent supply of fibrous scraps. But the Wasps do not touch it. Perhaps I have chosen the wrong sort of piece, being but ill-versed in the secrets of Vespian paper-making. 272 The Common Wasp To these raw materials, which are troublesome to work, they prefer the old ce s now fallen into disuse. In t: ese the telted hbres are ready prepared and have only to be reduced to pulp again. With a slight expenditure of saliva and a little grind- ing in the mandibles, it yields a product of the highest quality. The uninhabited cells, therefore, are demolished by degrees, nibbled and razed to their foundations. Out of the rums a sort of canopy is built. New cells would be constructed in the same way if thev were needed. This confirms what the upper stories with demolished cells made us fore- see: the Wasps build new cells with old. Ihe feeding of the grubs deserves exami- nation even more than this roofing-work. One would never weary of the spectacle of these rough fighters converted into tender """l"' ,T!1^ barracks are turned into a creche. What care, what vigilance in the rearing of the grubs ! Let us watch one of the busy Wasps. Her crop swollen with honey, she halts in front of a cell; almost pensively she bends her head into the orifice- she questions the recluse with the tip of her antenna. The larva wakes and gapes at her like the fledgeling when the mother-bird re- turns to the nest with food. 273 % 'I H ",1 18 The Mason-Wasps For a moment, the awakened larva swings its head to and fro: it is blind and is trying to feel the pap brought to it. The two mouths meet; a drop of syrup passes from the nurse's mouth to the nurseling's. That is enough for the moment. Now for the next. The Wasp moves on, to continue her duties elsewhere. The larva, on its side, licks the base of its neck for a few seconds. There is here, at the moment when the grub is being served with food, a sort of projecting bib, a tempo- rary dewlap which forms a porringer and receives what trickles from the lips. After swallowing the bulk of the ration, the larva finishes its meal by gathering up the crumbs which have fallen on its bib. Then the swelling disappears; and the grub, withdraw- ing a little way into its cell, resumes its sweet slumbers. The better to watch this curious fashion of eating, I happen by good luck to have a few powerful Hornet-larva;. I slip them singly into paper sheaths, which will repre- sent their natal cells. Thus swaddled, my fat babies lend themselves excellently to ob- servation when I myself distribute their rations. In my young days, we had a trick of tap- 274 The Common Wasp ping with our finger the incipient tail of the bparrow whom we were rearing. The pupil at once yawned, ready to receive his food. I like to imagine that this system of bird- traimng is still in vogue. But there is no need of these stimulating preliminaries to arouse the appetite of the Hornet's offspring. 1 hey yawn of their own accord at the least touch that I give to their cell. The lucky creatures have ever-ready stomachs. Taking a piece of straw with a drop of honey hanging from it, I place the delicious ration between the grub's mandibles. There IS too much for a single mouthful. But the breast swells into a dewlap which catches the surplus. Here the grub will take a few more sips, at Its leisure, after swallowing the spoonful which it received direct. When there is no more left, when the pectoral plat- ter IS licked clean, the swelling disappears and the larva resumes its immobility. 1 hanks to this short-lived swelling, suddenly flung out and as suddenly withdrawn, the diner has its table spread beneath its chin; without assistance from others, it finishes its meal alone. When fed in my cage, the Wasps' grubs have their heads up; and what escapes their lips collects upon the dewlap. When fed 275 Pi 0 -Id 8li.ii The Mason-Wasps normally, in the Wasps'-nest, they have their heads down. In this pcsition is the pro- tuberance on the breast of any service? I cannot doubt it. By slightly bending its head, the larva can always deposit on its projecting bib a por- tion of the copious mouthful, which adheres to It by reason of its stickiness. Further, there is nothing to tell u,^ that the nurse does not herself deposit the surplus of her help- ing on this spot. Whether it be above or below the mouth, right way up or upside down, the pectoral porringer fulfils its office because of the sticky nature of the food. It is a temporary saucer which shortens the work of serving and enables the grub to feed m a more or less leisurely fashion and with- out too much gluttony. In the cage my Wasps are fed with honey, which they disgorge for the larvae, once their crops are full. Both nurses and nurselings seem to thrive on this diet. Nevertheless, I know that the usual food is game. I have described elsewhere the hunting of the Eristahs by the Common Wasp and of the Hive-bee by the Hornet.^ The moment she IS caught, the big Fly in particular is dis- nIu!' ^*' '^"""'"^ ^'"'P'- chap. vlu-Translator't 276 The Common Wasp membered; the htad, wings, legs and belly, those meagre portions, are cut off with snips of the shears. There remains the breast, which IS rich in muscular tissues. This is the booty which, minced small upon the spot and reduced to a pill, is carried to the nest as a feast for the larvae. To honey, therefore, let us add game. I slip a few Ei:istales under the wire dome. At ftrst the newcomers are not molested. 1 he turbulent Flies, fluttering, buzzing, but- ting their heads against the wire-gauze, create no sensation in the cage. The in- mates take no notice of them. If one of them pass too near to a Wasp, the Wasp just raises her head, as though in threat. Ihat is quite enough; the Fly decamps. Matters become more serious around the strip of paper covered with honey. The re- fectory is assiduously frequented by the Wasps If the Eristalis, watching jealously from afar, venture to approach, one of the banqueters separates from the group, rushes headlong at the daring one, catches her by the leg and sends her to the right-about. 1 he encounter is not really grave except when the I-Iy commits the imprudence of alightinc on a comb. Then the Wasps fling them- selves upon the hapless intruder, roll her over 277 .* ''• il "t V III 1; 1, '[ -^1 , The Mason- Wasps and over, cuff her and drub her and drag her outside crippled or, as often as not, dead. Ifte body is disdainfully rejected. I renew my attempts in vain; I cannot re- produce the scenes which I used to witness on the aster-blossoms: the capture of the liristahs and her reduction to mincemeat for the larva. Perhaps this strong animal fare is distributed only on certain occasions which are not realized in my cage; or perhaps — and I more incline to favour this idea — honey is judged to be better than meat. My prisoners have plenty of it, served up fresh daily. The nurselings thrive on this diet; and the salmis of Flies is rejected in conse- quence. But in the open country, in the late au- tumn, fruit is scarce; and, in the absence of 'J"^/?iP.' ?^^ ^^" ^^^^^ "Pon game. Minced Eristahs may well be only a sec- ondary resource of the Wasps. Their re- fusal of my offerings seems to prove it. We will now consider the Polistes. Her absolutely Wasp-like shape and costume take nobody in for a moment. She is at once re- cognized and is mobbed as the Eristalis was. If she dare approach the honey whereat the Wasps are sipping. On neither side, how- ever is there any attempt at stinging: these 278 The Common Wasp table-quarrels are not worth the drawing of a dagger. Realizing that she is the weaker and that she is not at home, the Polistes re- tires. She will come back again and so per- sistently that the diners end by allowing her to take her seat beside them, a concession very rarely made to the Eristalis. This toleration does not last long: if the Polistes but venture on the combs, this alone arouses a terrible anger and brings about the death of the in- truder. No, it is not a good thing to enter the Wasps'-nest, even when the stranger wears the same uniform, pursues the same in- dustry and is almost a fellow-member of the corporation. Let us now try the Bumble-bee. Here is a male, quite a small one, clad in russet. The poor little beggar is threatened and even hustled, but no more, each time that he passes near a Wasp. Now, however, the scatter- brain comes tumbling from the top of the trelliswork and drops on a comb, in the midst of the busy nurses. I am all eyes as I follow the tragedy. One of them seizes the Bum- ble-bec by the neck and stabs him in the breast. A few convulsions of the legs fol- low; and the Bumble-bee is dead. Two other Wasps come to the murderess' assis- tance and help her drag the deceased out- 279 *'"! I ', 'fl I'" The Mason-Wasps side. Once more, I remark, it is not a good thmg to enter the Wasps' nest, even by acci- dent and without any bad intention. Here are a few more examples of the savage welcome given to strangers. I do not select my victims; I use them as they happen to come. A rose-tree outside my door supplies me with Hylotoma-larvaB,^ larva shaped like caterpillars. I place one in the midst of the Wasps, who are busy with their cells. Great surprise on the part of the workers confronted by this sort of green drag' :,, spotted with black 1 They come near; tUy withdraw; they again come near. One snaps at it boldly, inflicting a bleeding wound. Others follow her example, bite and endeavour to haul away the wounded creature The dragon resists, holding now by Its fore-legs and now by its hind-legs. Ihe burden is not too heavy, but the insect struggles indefatigably, anchored by its hooks. However, after numerous attempts, the grub, enfeebled by its wounds, is torn from the comb and dragged, all bleeding, to the refuse-pit. It has taken a couple of hours to dislodge it. With the Hylotoma-larva the Wasps did XIT^k""* '■"'*' '''? ^"""^-^y *»' '''« R°se- Cf. Chapter XII. of the present volume.— Translator's Note. 280 The Common Wasp not use the sting, which would have so promptly put an end to all resistance. Per- haps they deemed the wretched grub un- worthy of ceremonial death. The expedl tious method of the poisoned dagger appe^^^^^^ n° 'I TT'i ^^^ ^^^^^ occasions.^Thu penshed the Bumble-bee and the Polistes SaDerd"! ^"'-'^ ^ ^'''' °^ '^' Scalar; mn^ ; /" imposmg grub extracted that moment /rom under the bark of a dead cherry-tree. I fling it on one of the combs. The mnnT "'' ^ul'^^ "'^"'^^ ^y ^he fall of the monster, which goes into vigorous con- ZhlL^!^^ '"^ '' '"^ ^^^" Packing it ^ruh 7TF' u ^" " ^°"P^^ «^ minutes the grub, stabbed through and through, no longer st.rs As for carrying the hu|e deaS body out of the nest that is another matter ; hi W '^'^y' "^H5? too heavy. What wil the Wasps do? Unable to shift the grub, hey eat ,t where it lies, or rather they drain It dry, drmkmg its blood. An hour later? flaccid now and greatly diminished in weight walls.""' '°'P'' '' ^'"^^'^ outside the Nou. ^ -^"^ °' ^^^ P««« yolumc- Translator's 281 .V( The Mason-Wasps The rest of my notes would only repeat the same results. If he keep a certain di- stance, the stranger is tolerated, no matter what his race, his costume or his habits. If he pass near a Wasp, a threat warns him and puts him to flight. If he go to the pool of honey, when the refectory is already occupied by the Wasps, it seldom happens that the daring intruder is not molested and driven from the banquet. So far, blows of no great gravity suffice. But, if he have the misfortune to enter the actual nest, he comes to a bad end, pierced by the Wasps' stings or at least disembowelled by the fangs of their mandibles. His corpse goes to join the other refuse in *^he basement. Protected with this fierce vigilance against the invasion of all intruders and deliciously spoon-fed on honey, on that excellent honey which causes Fly-mea*- to be forgotten, the larvae prosper greatly in my breeding-cage, though of course not all. In the Wasps'- nest, as everywhere, there are weaklings who are cut down before their time. I see these puny sufferers refuse their food and slowly pine away. The nurses perceive it even more clearly. They bend their heads over the sorely-tried grub, they sound it with their antennae, they pronounce it incurable. 282 The Common Wasp Then the creature at point of death, often of a sickly brown, is torn ruthlessly from its cell and dragged outside the nest. In the brutal commonwealth of the Wasps, the invalid is merely a clout, to be got rid of as quickly as possible, for fear of contagion. Woe to the sick among these rude profes- sors of hygiene ! Any and every cripple is expelled and thrown to the maggot waiting to eat him in the catacombs below. Should the experimenter intervene, matters take an even more atrocious turn. I remove from their cells a few larvs and nymphs in excel- lent heahh and place them on the surface of the combs. Once outside the cells, where the nymphs were maturing under a silken cupola, while the larva; were being spoon- fed with the utmost tenderness, the delicate creatures are mere hateful obstacles and use- less encumbrances. Ferociously the work- ers tug at them, disembowel them and even eat a little of them. After this cannibal re- past, the victims are carted outside the nest. Incapable of reentering their cradles, even with assistance, larvae and nymphs, stripped bare, perish, slain by their nurses. In the cage, however, the grubs generally display a well-fed, glossy skin, a certificate of good health. But see what happens on the 283 III lU The Mason-Wasps advent of the first cold nights of November. The building proceeds with diminished en- thusiasm ; the visits to the pool of honey are less assiduous. Household duties are re- laxed. Grubs gaping with hunger receive tardy relief, or are even neglected. Pro- found uneasiness seizes upon the nurses. Their former devotion is succeeded by in- difference, which soon turns to aversion. What is the use of continuing attentions which presently will become impossible ? In view of the imminent famine, our beloved nurselings must die a tragic death. The neuters, in fact, grab the late-born larvae, these to-day, those to-morrow, sooner or later the rest, and root them out of theii cells with the same violence which they would employ against a stranger or a lifeless body; they tug at them, savagely rend them; and all this poor flesh is sent down to the pit. Before much longer, the neuters them- selves, the executioners, are languidly drag- ging what remains of their lives. At length they also succumb, killed by the weather. November is not yet past; and nothing is left alive in my cage. The final massacre of the tardy larvs* must take place underground in more or less the same manner, but on a larger scale. 284 The Common Wasp ,.-^*y af^cr day the catacombs of the Wasps -nest receive the dead and dying hurled down from above, sickly larva and such AVasps as have been injured by accident. Rare in the prosperous season, these falls into the charnel-heap become increasingly frequent as winter approaches. When the late-born grubs are being exterminated and above all at the moment of the final cata- strophe, when the adults, males, females and neuters, are dying in their thousands, the manna descends in a copious downfall daily. The host of devourers has hastened up, receiving only a little at first, but foreseeing great junketings in the future. By the end of November, the bottom of the crypt is a swarming hostelry, dominated numerically by the grubs of certain Flies, those under- takers of the Wasps'-nests. I gather great numbers of the larva of the Volucella, who deserves a chapter to herself, by reason of her fame. I find here, poking its tapering head Into the bellies of the corpses, a naked, white, pointed maggot, smaller than that of the Lucihae.i It works promiscuously with a second, even smaller grub, brown and clad in a pricUy smock. I come upon a dwarf -V^;„?/rW/i "^^ ^'" "'^' "f '*' '^'- ^^^^' - 28s Jill # The Mason-Wasps which, looping and unlooping, wriggles about like the Cheese-mites. All of them are dissecting, dismembering and disembowelling with so much zeal that, when February arrives, they have not yet had time to shrink into pup:e. It is so pleas- ant here, sheltered against the inclemencies of the weather, in the snug basement, with provisions in abundance! Why hurry? These smug eaters expect to consume the heap of victuals before hardening their skin into a barrel. They linger so long over their banquet that I forget to secure them for my rearing-phials; and I can say no more about their history. In the charnel-houses of Moles and Snakes in my aerial retting-vats,' I used to note, from time to time, the arrival of the largest of our Staphylini,* S. maxillosus, who, in passing, would make a brief stay under the putrid mass and then proceed to pursue her business elsewhere. The Wasps' char- nel-house similarly has short-winged Beetles among its habitual visitors. I often come upon Quedius fulgidas, Fab., there, the one with the red wing-cases. But this time it is not a temporary hostelry; it is a family es- » Ch The Life of the Fly: chap, ix.- 2 Rove-beetles.— Translator's Note. 286 Translator's Note. The Common Wasp tablishment, for the adult Staphylinus is ac- companied by her larva. I also find Wood- lice and Millipedes, of the genus Polydesma, both inferior trenchermen, feeding probably on the humours oozing from the dead. Let us also mention one of the outstanding insect-eaters, the tiniest of our mammals, the Shrew, who is smaller than the Common Mouse. At the time of the final cata- strophe, when sickness has calmed the ag- gressive fury of the Wasps, the visitor with the pointed muzzle steals into the nest. Ex- ploited by a pair of Shrew-mice, the dying crowd is soon reduced to a heap of remnants which the maggots end by clearing out. The ruins themselves will perish. A cat- erpillar that develops later into a mean-look- ing, whitish Moth; a Cryptophagus, a tiny reddish Beetle; and a larva of one of the Dermestes * (Attagenus pellio), clad in scaly gold velvet, gnaw the floors of the stages and crumble the whole dwelling. A few pinches of dust, a few shreds of brown paper are all that remains, by the return of spring, of the Vespian city and its thirty thousand in- habitants. » Bacon-beetles.— Translator's Note. i 'ili ! * : 2^ B CHAPTER XII THE VOLUCELLA TJNDERNEATH the brown-papcr manor- y^ house, let us once more say, the ground is channelled into a sort of drain for the refuse of che nest. Here are shot the dead or weakly larva: which a continual inspection roots out from the cells to make room for fresh occupants; here, at the time of the autumn massacre, are flung the backward grubs; here, lastly, lies a good part of the crowd killed by the first touch of winter. During the rack and ruin of November and December, this sewer becomes crammed with animal matter. Such riches will not remain unemployed. The world's great law which says that no- thing edible shall be wasted provides for the consumption of a mere ball of hair dis- gorged by the Owl. How shall it be with the vast stores of a ruined Wasps'-nestl If they have not come yet, the consumers whose task it is to salv* this abundant wreckage for nature's markets, they will not tarry in com- ing and waiting for the manna that will soon 288 The VoluccIIa dcfccnd from above. That public granary, lavishly stocked by death, will become a busy factory of fresh life. Who arc the guests summoned to the banquet ? If the Wasps flew away, carrying the dead or sickly grubs with them, and dropped them on the ground round about their home, those banqueters would be, first and foremost, the msect-eatmg birds, the Warblers, all of whom are lovers of small game. In this connection, we will allow ourselves a brief digression. Everybody knows with what jealou- -■- tolerance the Nightingales occupy eac' own cantonment. Neighbourly intercou among them is tabooed. The males fre- quently exchange defiant couplets at a di- stance; but, should the challenged party draw near, the challenger makes him dear off. Now, not far from my house, in a scanty clump of holly-oaks which would barely give a wood-cutter the wherewithal to make a dozen faggots, I used, all through the spring, to hear such full-throated warbling of Night- ingales that the songs of these virtuosi, all giving voice at once and with no attempt at ° mil ^5?f^"^'"»^ed into a deafening hubbub. Why did those passionate devotees of soli- tude come and settle in such large numbers 289 The Mason- Wasps at a spot where custom decrees that there is just room for one household only? What reasons have turned the recluse into a congre- gation? I asked the owner of the spinney about the matter. ••It's like that every year," he said. ine clump is overrun by Nightingales." •And the reason? " " The reason is that there is a stand of hives close by, behind that wall." I looked at the man in amazement, un- able to understand what connection there could be between a stand of hives and the thronging Nightingales. /'Why, yes," he added, "there are a lot Of Nightingales because there are a lot of Bees. T ^^^^^^^ questioning look from my side. 1 did not yet understand. The explanation came: "The Bees," he said, " throw out their dead grubs. The front of the stand is strewn with them in the mornings; and the INightingales come and collect them for themselves and their families. Thev are very fond of them." This time I had solved the puzzle. De- licious food, abundant and fresh each day, had brought the songsters together. Con- 290 The Volucella trary to their habit, numbers of Nightingales are living on friendly terms in a cluster of bushes, in order to be near the hives and to have a larger share in the morning di- stribution of plump dainties. In the same way, the Nightingale and his gastronomical rivals would haunt the neigh- bourhood of the Wasps'-nests, if the dead grubs were cast out on the surface of the soil; but these delicacies fall inside the bur- row and no little bird would dare to enter the murky cave, even if the entrance were not too small to admit it. Other consumers are needed here, small in size and great in dar- ing; the Fly is called for and her maggot, the king of the departed. What the Green- bottles, Bluebottles and Flesh-flies » do in the open air, at the expense of every kind of corpse, other Flies, narrowing their province, do underground at the Wasps' expense. Let us turn our attention, in September, to the wrapper of a Wasps'-nest. On the outer surface and there alone, this wrapper is strewn with a multitude of big, white, oval dots, firmly fixed to the brown paper and measuring roughly one-tenth of an inch long by one-sixteenth of an inch wide. Flat * Cf. The Lift of the Fly: chaps, ix., x. and xiv. to xvi. — Translator's Note. 291 The Mason-Wasps below, convex above and of a lustrous white, these dots resemble very neat drops from a tallow candle. Lastly, their backs are streaked with faint transversal lines, an elegant detail perceptible only with the lens. These curious objects are scattered all over the surface of the wrapper, sometimes at a distance from one another, sometimes gath- ered into mpre or less dense groups. They are the eggs of the Volucella, or Bumble-bee Fly (V. zonaria, Lin). Also stuck to the brown paper of the outer envelope and mixed up with the Volucella's are a large number of other eggs, chalk- white, spear-shaped and ridged lengthwise with seven or eight thin ribs, afte- the man- ner of the seeds of certain Umbelli ferae. The finishing touch to their delicate beauty h the fine stippling all over the surface. They are smaller by half than the others. I have seen grubs come out of them which might easily be the earliest stage of some pomted maggots which I have already no- ticed in the burrows. My attempts to rear them failed; and I am not able to say to which Fly these eggs belong. Enough for us to note the nameless one in passing. There are plenty of others, which we riiust make up our minds to leave unlabelled, in view of the 29a The Volucella lumbled crowd of feasters in the ruined Wasps-nest. We will concern ourselves only with the most remarkable, in the front rank of which stands the Volucella. She is a gorgeous and powerful Fly; and her costume, with its brown and yellow bands, shows a v gue resemblance to that of the Wasps. Our fashionable theorists have fn !:•! .i V 'f ^"^'f, °^ *^'^ ^^°^" ^"d yellow to cite the Volucella as a striking instance of own behalf, at least on that of her family, to introduce herself as a parasite into the trickery and craftily dons her victim's livery. Once ins.de the Wasps'.nest, she is taken for The simplicity of the Wasp, duped bv a very clumsy imitation of her garb, and the depravity of the Fly, concealing her idendty under a counterfeit presentment, exceed the mits of my credulity. The Wasp is not so silly nor the Volucella so clever as we are assured f the latter really meant to de! aZti" 7i"Z^^ her appearance, we must admit that her disguise is none too successful, bellow sashes round the abdomen do not make a Wasp. It would need more than 293 '■f i , f I li 1! f t The Mason- Wasps that and, above all, a slender figure and a nimble carriage; and the Volucella is thick- set and corpulent and sedate in her move- ments. Never will the Wasp take that un- wieldly insect for one of her own kind. The difference is too great. Poor Volucella, mimesis has not taught you enough 1 You ought — this is the essen- tial point — to have adopted a Wasp's shape and you forgot to do so ; you remained a fat Fly, far too easily recognized. Neverthe- less, you penetrate into the terrible cavern; you are able to stay there for a long time, without danger, as the eggs profusely strewn on the wrapper of the Wasps'-nest show. How do you set about it? Let us, first of all, remember that the Volucella does not enter the enclosure in which the combs are stacked: she keeps to the outer surface of the paper rampart and there lays her eggs. Let us, on the other hand, recall the Polistes placed in the com- pany of the Wasps in my breeding-cage. Here of a surety is one who need not have recourse to mimicry to find acceptance. She belongs to the guild, she is a Wasp herself. Any of us that had not the trained eye of the entomologist would confuse the two species. Well, this stranger, so long as she does not 294 The Volucella !!,7°"l^*?° [mportunate, is quite readily olerated by the caged Wasps. None seeks ZFtA ! *^"l'"^ T'/^ ^''' S^^ '^ even ad. mitted to the table, the strip of paper smeared with honey. But she is doomed if she inadvertently sets foot upon the combs. Her costume her shape, her size, which tally ahaost exact y with the costume, shape and size of the Wasp, do not save her from her tate. t>he is at once recognized as a stranger and attacked and slaughtered with the same vigour as the larva of the Hylotoma and the Saperda, neither of which Wa?s^"^ outward resemblance to the .J^^u'v'7 ""^ l^^^^ ^"^ ^"^^"'"e do not save the Polistes, how will the Volucella fare with her clumsy imitation? The Wasp's eye, which IS able to discern the dissimilar in the hke, will refuse to be caught. The mo- ment she is recognized, the stranger is killed on the spot. As to that there is not the shadow of a doubt. In the absence of Volucella at the moment of experimenting, I employ another Fly, Mtlesta fulmtnans, who, thanks to her slim figure and her handsome yellow bands presents a much more striking likeness to the Wasp than does the fat F. zonaria. De- 295 1^ W.t\ 1 r i| The Mason-Wasps spite this resemblance, if she rashly ven- ture on the combs, she is stabbed and slain. Her yellow sashes, her slender abdomen de- ceive nobody. The stranger is recognized behind the features of a double. My experiments under wire-gauze, which vary according to the captures which I hap- pen to make, all lead me to this conclusion : so long as there is mere propinquity, even around the honey, the other prisoners are tolerated fairly well; but, if they touch the cells, they are assaulted and often killed, without distinction of shape or costume. The grubs' dormitory is the sanctum sanc- torum which no outsider must enter under pain of death. With these caged captives I experiment by daylight, whereas the free Wasps work in the absolute darkness of their crypt. Where light is absent, colour goes for nothing. Once, therefore, that she has entered the cavern, the Volucella derives no benefit from her yellow bands, which arc supposed to be her safeguard. Whether garbed as she is or otherwise, it is easy for her to effect her pur- pose in the dark, on condition that she avoid the tumultuous interior of the Wasps'-nest. So long as she has the prudence not to hustle the passers-by, she can dab her eggs, 396 The Volucella thing i, to cross Crrestold^'Ahe'bfrr Now docs the entrance of the Volucella 'nto r:a^^?°v\^w^;7-i.suchr, cWe. the one'th^Sraralterla^d'sTo- pensh under a bell-glass in the sun gave „" the opportunity for prolonged obKrvalfo^s but wuhout any result uponihe subTecIo mv appear. The period for her visits haH doubtless passed; for I found plen y of her grubs when the nest was dug up. I faw'somT 'Z'"^"^ "" ^°^ "y "'id-ity. need h,T~" ' '•"Pwtful distance, I need hardy say — entering the burrow They were insignificant in sizf and of a daT ThUu'T ""' ""'"'' "'=" "f the House!fly' icry Nevi«h ? ° 1'™ '" P™*«tive mim- home Sni '''V" *°"8'' "'<'y «''« " nome. So long as there was not too ereat alone m "''i°°'' "'' ^asps left fhem alone. When there was anything of a 297 i'ff The Mason-Wasps crowd, the grey visitors waited near the threshold for a less busy moment. No harm came to them. Inside the establishment, the same peace- ful relations prevail. In this respect I have the evidence of my excavations. In the un- derground charnel-house, so rich in Fly- grubs, I find no corpses of adult Flies. If the strangers were slaughtered in passing through the entrance-hall or lower down, they would fall to the bottom of the burrow promiscuously with the other rubbish. Now in this charnel-pit, as I said, there are never any dead Volucellae, never a Fly of any sort. The incomers, therefore, are respected. Having done their business, they go out un- scathed. This tolerance on the part of the Wasps is surprising. And a suspicion comes to one's mind: can it be that the Volucella and the rest are not what the accepted theories of natural history call them, namely, enemies, grub-killers sacking the Wasps'-nest? We will look into this by examining th-m when they are hatched. Nothing is easier, in Sep- tember and October, than to collect the Volucella's eggs in such numbers as we please. They abound on the outer surface of the Wasps'-nest. Moreover, as with the 298 The Volucella larva of the Wasp, it Is some time before they are suffocated by the petrol; and the great majority are sure to hatch. I take my scissors, cut the most densely-populated bits trom the paper wall of the nest and fill a jar with them. This is the warehouse from which I shall daily, for the best part of the next two months, draw my supply of infant grubs. The Volucella's egg remains where it is, with Its white colouring strongly marked against the grey background of the support. Ihe shell wrinkles and collapses; and the fore-end tears open. From it there issues a pretty little white grub, thin in front, widening slightly in the rear and bristling all over with fleshy papilla. These papilla are set, on the creature's sides, like the teeth of a comb; at the rear, they lengthen and spread into a fan; on the back, they are shorter and arranged in four longitudinal rows. The last segment but one carries two short, bright-red breathing-tubes, standing a: ant and joined to each other. The fore- part, near the pointed mouth, is of a darker, brownish colour. This is the biting- and motor-apparatus, seen through the skin and consisting of two fangs. Taken all round, the grub is a comely little thing, with its 299 !* The Mason- Wasps bristling whiteness, which gives it the appear- ance of a tiny snow-flake. But this elegance does not last long: grown big and strong, the Volucella's grub becomes soiled with sanies, turns russet-brown and crawls about in the guise of a hulking Porcupine. What becomes of it when it leaves the egg? This my warehousing-jar tells me, partly. Unable to keep its balance on slop- ing surfaces, it drops to the bottom of the receptacle, where I find it daily, as and when hatched, restlessly wandering. Things must happen likewise at the Wasps'. Incapable of standing on the slant of the paper wall, the new-born grubs slide to the bottom of the underground cavity, which contains, especi- ally at the end of the summer, a plentiful provender of deceased Wasps and dead larvae removed from the cells and flung out- side, all nice and gamy, as proper maggot's- food should be. The Volucella's offspring, themselves mag- gots, notwithstanding their snowy apparel, find in this charnel-house victuals to their liking, incessantly renewed. Their fall from the high walls might well be not accidental but rather a means of reaching, quickly and without searching, the good things down at the bottom of the cavern. Perhaps, also, 300 The Volucclla some of the white grubs, thanks to the holes that make the wrapper resemble a spongy cover, manage to slip inside the Wasps'-nest. Still, most of the Volucella's larva, at what- ever stage of their development, are in the basement of the burtow, among the carrion w*"*'"*' ^^^ °'*^*"' ***°*« ""^««7 Mason-bee of the Walls, 6, 9, 16$, 167, aao-aaa, 339. >33 Measuring - worm (see Looper) Medium Wasp, 337-339, '47 Megachile, 161-163, 183, 186, 346 Miall, Bernard, vi, a;> Milesia fulminans, a9S'a96 Millipede, 387 Mole, 346, 359, 386 Moth (see also Great Pea- cock Moth), 14, 44, 117, 387 Mouse, I30, 387 Mulberry Bombyx, 1 18-119 Mule, 77-78 Myriapod, 54* N Narbonne Lycosa, 90, 94, 96 Nest-building Odynerus) 176-318 Nightingale, 389-391 Noctua segetum (see Grey Worm) Odynerus (see also the va- rieties below), a8-s9, >50. i7< Odynerus alpeslris (see Al- Jtine Odynerus) ynerus nidulator (see Neit-building Odynerus) Odynerus Reaumurii, 35 Odynerus reniformis, 3$- 59. «77-«7«. 30i-3o$ Odynerus s pint pes, 3$ Osmia (see also three- horned Osmia), 31-33, 69, 150, 168-169, 183, 186 Owl (see also Screech- owl), 388 Palarus, io3 Parrrc, 13 Pelopaus, 31, 60-135, 137, ^iSt 158-160, 165, 333- 333, 335, aa9, 333 Philanthus, 103 Phytonomus variabilis, 44 Planorbis, 339 Plato, 339 Pliny, 34 Polistes, 191, a36-337, 378- 379, 381, 394-395 Polydesma, 387 Pompilus, 90, 94, 96 Quedius fulgidus, 386 316 Reaumur, Ren^ Antoine ^ti-H 1 1 Index Perchiuft de, 19-ja, ,5, J7-4*. 44-45. 51-5!. li4. - »4«-a43. aj9 Kinged Calicurgui {see Pommlui) Rodwell, France!, vi Rove-beetle (see Slaphyli- nua) Sacred Beetle, 2*7 Salamander, 65, 196 Saperda (see Scalary Sa- perda) Saw-fly of the Rose (jee Hylotoma roiae) Scalary Saperda, a8i, 306. 309 Scolia, 98, 103, ao4 Screech-owl, 343 Segeatria, 89 Shrew, 387 Silkworm (see Mulberry Bombyx) Snail {see also Bulimulus, Edible Snail, Helix), 11- 13. i«8, 178, 337-239 Snake, 286 Solitary Wa»p {see Ody- nerus) Sophoclei, 170 Sparrow. 135-154. 174. 275 ophex {see also Languedo- cian Sphex), 18, 98, 103, 304 Spider {see also the vari- eties), 34, 81-83, 86, 89- to2, io«, 109-iit, 113, 159-160, 323 Staphylinus maxillosus, 286-387 Stizua, 103 Zi7 Swallow {see also Chlm- ney-.wallow, Wlndow- swailow), 135-154 Tarantula {see Narbonne Lycota ) Tachytes, 103 Tegenana domestica {see House-spider) Teixeira de Mattos, Alex- ander, 3». 4«, l^H, 3o», 39ni, ii7«, 337« Therid'toH lugubre, 90 Three-horned Osmia, 167- 168, 170-175, 188-192 Tiberius, the Emperor, 170 Toad, ir< Turkey, .j3, 355 Turnip Moth {see Gtty Worm) Unwin, Mr. T. Fisher, vi V ^espa erabro (see Hornet) yespa media {see Median Wasp) Fespa vulgaris (see Com- mon Wasp) Virgil, 136-137 Vitruvius, 3 Volucella zonaria, 385-286. 288-311 W Wall-swallow (see Win- dow-swallow) Index Warbler, 289 Wasp {see also Common Wasp, Median Wasp), 65-67, 69, 95. 101-ioa, 150, 170, 209, ax9 Water-ouzel, 63 Weevil, 44 Window-swallow, 135, 141- 143, 145-146, I47-H9 Wolf, 134 Wood-louse, 287 318 15. 141- -149