By J. Henri Fabre
Translated By Alexander Teixeira De Mattos
This volume contains all the essays on the Chalicodomae, or Mason-bees proper, which so greatly enhance the interest of the early volumes of the "Souvenirs entomologiques." I have also included an essay on the author's Cats and one on Red Ants—the only study of Ants comprised in the "Souvenirs"—both of which bear upon the sense of direction possessed by the Bees. Those treating of the Osmiae, who are also Mason-Bees, although not usually known by that name, will be found in a separate volume, which I have called "Bramble-bees and Others" and in which I have collected all that Fabre has written on such other Wild Bees as the Megachiles, or Leaf-cutters, the Cotton-bees, the Resin-bees and the Halicti.
The essays entitled "The Mason-bees, Experiments" and "Exchanging the Nests" form the last three chapters of "Insect Life", translated by the author of "Mademoiselle Mori" and published by Messrs. Macmillan, who, with the greatest courtesy and kindness have given me their permission to include a new translation of these chapters in the present volume. They did so without fee or consideration of any kind, merely on my representation that it would be a great pity if this uniform edition of Fabre's Works should be rendered incomplete because certain essays formed part of volumes of extracts previously published in this country. Their generosity is almost unparalleled in my experience; and I wish to thank them publicly for it in the name of the author, of the French publishers and of the English and American publishers, as well as in my own.
Some of the chapters have appeared in England in the "Daily Mail", the "Fortnightly Review" and the "English Review"; some in America in "Good Housekeeping" and the "Youth's Companion"; others now see the light in English for the first time.
I have again to thank Miss Frances Rodwell for the invaluable assistance which she has given me in the work of translation and in the less interesting and more tedious department of research.
ALEXANDER TEIXEIRA DE MATTOS.
CHAPTER 1. THE MASON-BEES.
CHAPTER 2. EXPERIMENTS.
CHAPTER 3. EXCHANGING THE NESTS.
CHAPTER 4. MORE ENQUIRIES INTO MASON-BEES.
CHAPTER 5. THE STORY OF MY CATS.
CHAPTER 6. THE RED ANTS.
CHAPTER 7. SOME REFLECTIONS UPON INSECT PSYCHOLOGY.
CHAPTER 8. PARASITES.
CHAPTER 9. THE THEORY OF PARASITISM.
CHAPTER 10. THE TRIBULATIONS OF THE MASON-BEE.
CHAPTER 11. THE LEUCOPSES.
CHAPTER 1. THE MASON-BEES.
Reaumur (Rene Antoine Ferchault de Reaumur (1683-1757), inventor of the Reaumur thermometer and author of "Memoires pour servir a l'histoire naturelle des insectes."—Translator's Note.) devoted one of his papers to the story of the Chalicodoma of the Walls, whom he calls the Mason-bee. I propose to go on with the story, to complete it and especially to consider it from a point of view wholly neglected by that eminent observer. And, first of all, I am tempted to tell how I made this Bee's acquaintance.
It was when I first began to teach, about 1843. I had left the normal school at Vaucluse some months before, with my diploma and all the simple enthusiasm of my eighteen years, and had been sent to Carpentras, there to manage the primary school attached to the college. It was a strange school, upon my word, notwithstanding its pompous title of 'upper'; a sort of huge cellar oozing with the perpetual damp engendered by a well backing on it in the street outside. For light there was the open door, when the weather permitted, and a narrow prison-window, with iron bars and lozenge panes set in lead. By way of benches there was a plank fastened to the wall all round the room, while in the middle was a chair bereft of its straw, a black-board and a stick of chalk.
Morning and evening, at the sound of the bell, there came rushing in some fifty young imps who, having shown themselves hopeless dunces with their Cornelius Nepos, had been relegated, in the phrase of the day, to 'a few good years of French.' Those who had found mensa too much for them came to me to get a smattering of grammar. Children and strapping lads were there, mixed up together, at very different educational stages, but all incorrigibly agreed to play tricks upon the master, the boy master who was no older than some of them, or even younger.
To the little ones I gave their first lessons in reading; the intermediate ones I showed how they should hold their pen to write a few lines of dictation on their knees; to the big ones I revealed the secrets of fractions and even the mysteries of Euclid. And to keep this restless crowd in order, to give each mind work in accordance with its strength, to keep attention aroused and lastly to expel dullness from the gloomy room, whose walls dripped melancholy even more than dampness, my one resource was my tongue, my one weapon my stick of chalk.
For that matter, there was the same contempt in the other classes for all that was not Latin or Greek. One instance will be enough to show how things then stood with the teaching of physics, the science which occupies so large a place to-day. The principal of the college was a first-rate man, the worthy Abbe X., who, not caring to dispense beans and bacon himself, had left the commissariat-department to a relative and had undertaken to teach the boys physics.
Let us attend one of his lessons. The subject is the barometer. The establishment happens to possess one, an old apparatus, covered with dust, hanging on the wall beyond the reach of profane hands and bearing on its face, in large letters, the words stormy, rain, fair.
'The barometer,' says the good abbe, addressing his pupils, whom, in patriarchal fashion, he calls by their Christian names, 'the barometer tells us if the weather will be good or bad. You see the words written on the face—stormy, rain—do you see, Bastien?'
'Yes, I see,' says Bastien, the most mischievous of the lot.
He has been looking through his book and knows more about the barometer than his teacher does.
'It consists,' the abbe continues, 'of a bent glass tube filled with mercury, which rises and falls according to the weather. The shorter leg of this tube is open; the other...the other...well, we'll see. Here, Bastien, you're the tallest, get up on the chair and just feel with your finger if the long leg is open or closed. I can't remember for certain.'
Bastien climbs on the chair, stands as high as he can on tip-toe and fumbles with his finger at the top of the long column. Then, with a discreet smile spreading under the silky hairs of his dawning moustache:
'Yes,' he says, 'that's it. The long leg is open at the top. There, I can feel the hole.'
And Bastien, to confirm his mendacious statement, keeps wriggling his forefinger at the top of the tube, while his fellow-conspirators suppress their enjoyment as best they can.
'That will do,' says the unconscious abbe. 'You can get down, Bastien. Take a note of it, boys: the longer leg of the barometer is open; take a note of it. It's a thing you might forget; I had forgotten it myself.'
Thus was physics taught. Things improved, however: a master came and came to stay, one who knew that the long leg of the barometer is closed. I myself secured tables on which my pupils were able to write instead of scribbling on their knees; and, as my class was daily increasing in numbers, it ended by being divided into two. As soon as I had an assistant to look after the younger boys, things assumed a different aspect.
Among the subjects taught, one in particular appealed to both masters and pupils. This was open-air geometry, practical surveying. The college had none of the necessary outfit; but, with my fat pay—seven hundred francs a year, if you please!—I could not hesitate over the expense. A surveyor's chain and stakes, arrows, level, square and compass were bought with my money. A microscopic graphometer, not much larger than the palm of one's hand and costing perhaps five francs, was provided by the establishment. There was no tripod to it; and I had one made. In short, my equipment was complete.
And so, when May came, once every week we left the gloomy school-room for the fields. It was a regular holiday. The boys disputed for the honour of carrying the stakes, divided into bundles of three; and more than one shoulder, as we walked through the town, felt the reflected glory of those erudite rods. I myself—why conceal the fact?—was not without a certain satisfaction as I piously carried that most delicate and precious apparatus, the historic five-franc graphometer. The scene of operations was an untilled, flinty plain, a harmas, as we call it in the district. (Cf. "The Life of the Fly", by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chapter 1.—Translator's Note.) Here, no curtain of green hedges or shrubs prevented me from keeping an eye upon my staff; here—an indispensable condition—I had not the irresistible temptation of the unripe apricots to fear for my scholars. The plain stretched far and wide, covered with nothing but flowering thyme and rounded pebbles. There was ample scope for every imaginable polygon; trapezes and triangles could be combined in all sorts of ways. The inaccessible distances had ample elbow-room; and there was even an old ruin, once a pigeon-house, that lent its perpendicular to the graphometer's performances.
Well, from the very first day, my attention was attracted by something suspicious. If I sent one of the boys to plant a stake, I would see him stop frequently on his way, bend down, stand up again, look about and stoop once more, neglecting his straight line and his signals. Another, who was told to pick up the arrows, would forget the iron pin and take up a pebble instead; and a third deaf to the measurements of angles, would crumble a clod of earth between his fingers. Most of them were caught licking a bit of straw. The polygon came to a full stop, the diagonals suffered. What could the mystery be?
I enquired; and everything was explained. A born searcher and observer, the scholar had long known what the master had not yet heard of, namely, that there was a big black Bee who made clay nests on the pebbles in the harmas. These nests contained honey; and my surveyors used to open them and empty the cells with a straw. The honey, although rather strong-flavoured, was most acceptable. I acquired a taste for it myself and joined the nest-hunters, putting off the polygon till later. It was thus that I first saw Reaumur's Mason-bee, knowing nothing of her history and nothing of her historian.
The magnificent Bee herself, with her dark-violet wings and black-velvet raiment, her rustic edifices on the sun-blistered pebbles amid the thyme, her honey, providing a diversion from the severities of the compass and the square, all made a great impression on my mind; and I wanted to know more than I had learnt from the schoolboys, which was just how to rob the cells of their honey with a straw. As it happened, my bookseller had a gorgeous work on insects for sale. It was called "Histoire naturelle des animaux articules", by de Castelnau (Francis Comte de Castelnau de la Porte (1812-1880), the naturalist and traveller. Castelnau was born in London and died at Melbourne.—Translator's Note.), E. Blanchard (Emile Blanchard (born 1820), author of various works on insects, Spiders, etc.—Translator's Note.) and Lucas (Pierre Hippolyte Lucas (born 1815), author of works on Moths and Butterflies, Crustaceans, etc.—Translator's Note.), and boasted a multitude of most attractive illustrations; but the price of it, the price of it! No matter: was not my splendid income supposed to cover everything, food for the mind as well as food for the body? Anything extra that I gave to the one I could save upon the other; a method of balancing painfully familiar to those who look to science for their livelihood. The purchase was effected. That day my professional emoluments were severely strained: I devoted a month's salary to the acquisition of the book. I had to resort to miracles of economy for some time to come before making up the enormous deficit.
The book was devoured; there is no other word for it. In it, I learnt the name of my black Bee; I read for the first time various details of the habits of insects; I found, surrounded in my eyes with a sort of halo, the revered names of Reaumur, Huber (Francois Huber (1750-1831), the Swiss naturalist, author of "Nouvelles observations sur les abeilles." He early became blind from excessive study and conducted his scientific work thereafter with the aid of his wife.—Translator's Note.) and Leon Dufour (Jean Marie Leon Dufour (1780-1865), an army surgeon who served with distinction in several campaigns, and subsequently practised as a doctor in the Landes, 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 Alexander Teixeira de Mattos: chapter 1; and "The Life of the Fly": chapter 1.—Translator's Note.); and, while I turned over the pages for the hundredth time, a voice within me seemed to whisper:
'You also shall be of their company!'
Ah, fond illusions, what has come of you? (The present essay is one of the earliest in the "Souvenirs Entomologiques."—Translator's Note.)
But let us banish these recollections, at once sweet and sad, and speak of the doings of our black Bee. Chalicodoma, meaning a house of pebbles, concrete or mortar, would be a most satisfactory title, were it not that it has an odd sound to any one unfamiliar with Greek. The name is given to Bees who build their cells with materials similar to those which we employ for our own dwellings. The work of these insects is masonry; only it is turned out by a rustic mason more used to hard clay than to hewn stone. Reaumur, who knew nothing of scientific classification—a fact which makes many of his papers very difficult to understand—named the worker after her work and called our builders in dried clay Mason-bees, which describes them exactly.
We have two of them in our district: the Chalicodoma of the Walls (Chalicodoma muraria), whose history Reaumur gives us in a masterly fashion; and the Sicilian Chalicodoma (C. sicula) (For reasons that will become apparent after the reader has learnt their habits, the author also speaks of the Mason-bee of the Walls and the Sicilian Mason-bee as the Mason-bee of the Pebbles and the Mason-bee of the Sheds respectively. Cf. Chapter 4 footnote.—Translator's Note.), who is not peculiar to the land of Etna, as her name might suggest, but is also found in Greece, in Algeria and in the south of France, particularly in the department of Vaucluse, where she is one of the commonest Bees to be seen in the month of May. In the first species the two sexes are so unlike in colouring that a novice, surprised at observing them come out of the same nest, would at first take them for strangers to each other. The female is of a splendid velvety black, with dark-violet wings. In the male, the black velvet is replaced by a rather bright brick-red fleece. The second species, which is much smaller, does not show this contrast of colour: the two sexes wear the same costume, a general mixture of brown, red and grey, while the tips of the wings, washed with violet on a bronzed ground, recall, but only faintly, the rich purple of the first species. Both begin their labours at the same period, in the early part of May.
As Reaumur tells us, the Chalicodoma of the Walls in the northern provinces selects a wall directly facing the sun and one not covered with plaster, which might come off and imperil the future of the cells. She confides her buildings only to solid foundations, such as bare stones. I find her equally prudent in the south; but, for some reason which I do not know, she here generally prefers some other base to the stone of a wall. A rounded pebble, often hardly larger than one's fist, one of those cobbles with which the waters of the glacial period covered the terraces of the Rhone Valley, forms the most popular support. The extreme abundance of these sites might easily influence the Bee's choice: all our less elevated uplands, all our arid, thyme-clad grounds are nothing but water-worn stones cemented with red earth. In the valleys, the Chalicodoma has also the pebbles of the mountain-streams at her disposal. Near Orange, for instance, her favourite spots are the alluvia of the Aygues, with their carpets of smooth pebbles no longer visited by the waters. Lastly, if a cobble be wanting, the Mason-bee will establish her nest on any sort of stone, on a mile-stone or a boundary-wall.
The Sicilian Chalicodoma has an even greater variety of choice. Her most cherished site is the lower surface of the projecting tiles of a roof. There is not a cottage in the fields, however small, but shelters her nests under the eaves. Here, each spring, she settles in populous colonies, whose masonry, handed down from one generation to the next and enlarged year by year, ends by covering considerable surfaces. I have seen some of these nests, under the tiles of a shed, spreading over an area of five or six square yards. When the colony was hard at work, the busy, buzzing crowd was enough to make one giddy. The under side of a balcony also pleases the Mason-bee, as does the embrasure of a disused window, especially if it is closed by a blind whose slats allow her a free passage. But these are popular resorts, where hundreds and thousands of workers labour, each for herself. If she be alone, which happens pretty often, the Sicilian Mason-bee instals herself in the first little nook handy, provided that it supplies a solid foundation and warmth. As for the nature of this foundation, she does not seem to mind. I have seen her build on the bare stone, on bricks, on the wood of a shutter and even on the window-panes of a shed. One thing only does not suit her: the plaster of our houses. She is as prudent as her kinswoman and would fear the ruin of her cells, if she entrusted them to a support which might possibly fall.
Lastly, for reasons which I am still unable to explain to my own satisfaction, the Sicilian Mason-bee often changes the position of her building entirely, turning her heavy house of clay, which would seem to require the solid support of a rock, into an aerial dwelling. A hedge-shrub of any kind whatever—hawthorn, pomegranate, Christ's thorn—provides her with a foundation, usually as high as a man's head. The holm-oak and the elm give her a greater altitude. She chooses in the bushy clump a twig no thicker than a straw; and on this narrow base she constructs her edifice with the same mortar that she would employ under a balcony or the ledge of a roof. When finished, the nest is a ball of earth, bisected by the twig. It is the size of an apricot when the work of a single insect and of one's fist if several have collaborated; but this latter case is rare.
Both Bees use the same materials: calcareous clay, mingled with a little sand and kneaded into a paste with the mason's own saliva. Damp places, which would facilitate the quarrying and reduce the expenditure of saliva for mixing the mortar, are scorned by the Mason-bees, who refuse fresh earth for building even as our own builders refuse plaster and lime that have long lost their setting-properties. These materials, when soaked with pure moisture, would not hold properly. What is wanted is a dry dust, which greedily absorbs the disgorged saliva and forms with the latter's albuminous elements a sort of readily-hardening Roman cement, something in short resembling the cement which we obtain with quicklime and white of egg.
The mortar-quarry which the Sicilian Mason-bee prefers to work is a frequented highway, whose metal of chalky flints, crushed by the passing wheels, has become a smooth surface, like a continuous flagstone. Whether settling on a twig in a hedge or fixing her abode under the eaves of some rural dwelling, she always goes for her building-materials to the nearest path or road, without allowing herself to be distracted from her business by the constant traffic of people and cattle. You should see the active Bee at work when the road is dazzling white under the rays of a hot sun. Between the adjoining farm, which is the building-yard, and the road, in which the mortar is prepared, we hear the deep hum of the Bees perpetually crossing one another as they go to and fro. The air seems traversed by incessant trails of smoke, so straight and rapid is the worker's flight. Those on the way to the nest carry tiny pellets of mortar, the size of small shot; those who return at once settle on the driest and hardest spots. Their whole body aquiver, they scrape with the tips of their mandibles and rake with their front tarsi to extract atoms of earth and grains of sand, which, rolled between their teeth, become impregnated with saliva and form a solid mass. The work is pursued so vigorously that the worker lets herself be crushed under the feet of the passers-by rather than abandon her task.
On the other hand, the Mason-bee of the Walls, who seeks solitude, far from human habitations, rarely shows herself on the beaten paths, perhaps because these are too far from the places where she builds. So long as she can find dry earth, rich in small gravel, near the pebble chosen as the site of her nest, that is all she asks.
The Bee may either build an entirely new nest on a site as yet unoccupied, or she may use the cells of an old nest, after repairing them. Let us consider the former case first. After selecting her pebble, the Mason-bee of the Walls arrives with a little ball of mortar in her mandibles and lays it in a circular pad on the surface of the stone. The fore-legs and above all the mandibles, which are the mason's chief tools, work the material, which is kept plastic by the salivary fluid as this is gradually disgorged. In order to consolidate the clay, angular bits of gravel, the size of a lentil, are inserted separately, but only on the outside, in the as yet soft mass. This is the foundation of the structure. Fresh layers follow, until the cell has attained the desired height of two or three centimetres. (Three-quarters of an inch to one inch.—Translator's Note.)
Man's masonry is formed of stones laid one above the other and cemented together with lime. The Chalicodoma's work can bear comparison with ours. To economise labour and mortar, the Bee employs coarse materials, big pieces of gravel, which to her represent hewn stones. She chooses them carefully one by one, picks out the hardest bits, generally with corners which, fitting one into the other, give mutual support and contribute to the solidity of the whole. Layers of mortar, sparingly applied, hold them together. The outside of the cell thus assumes the appearance of a piece of rustic architecture, in which the stones project with their natural irregularities; but the inside, which requires a more even surface in order not to hurt the larva's tender skin, is covered with a coat of pure mortar. This inner whitewash, however, is put on without any attempt at art, indeed one might say that it is ladled on in great splashes; and the grub takes care, after finishing its mess of honey, to make itself a cocoon and hang the rude walls of its abode with silk. On the other hand, the Anthophorae and the Halicti, two species of Wild Bees whose grubs weave no cocoon, delicately glaze the inside of their earthen cells and give them the gloss of polished ivory.
The structure, whose axis is nearly always vertical and whose orifice faces upwards so as not to let the honey escape, varies a little in shape according to the supporting base. When set on a horizontal surface, it rises like a little oval tower; when fixed against an upright or slanting surface, it resembles the half of a thimble divided from top to bottom. In this case, the support itself, the pebble, completes the outer wall.
When the cell is finished, the Bee at once sets to work to victual it. The flowers round about, especially those of the yellow broom (Genista scoparia), which in May deck the pebbly borders of the mountain streams with gold, supply her with sugary liquid and pollen. She comes with her crop swollen with honey and her belly yellowed underneath with pollen dust. She dives head first into the cell; and for a few moments you see some spasmodic jerks which show that she is disgorging the honey-syrup. After emptying her crop, she comes out of the cell, only to go in again at once, but this time backwards. The Bee now brushes the lower side of her abdomen with her two hind-legs and rids herself of her load of pollen. Once more she comes out and once more goes in head first. It is a question of stirring the materials, with her mandibles for a spoon, and making the whole into a homogeneous mixture. This mixing-operation is not repeated after every journey: it takes place only at long intervals, when a considerable quantity of material has been accumulated.
The victualling is complete when the cell is half full. An egg must now be laid on the top of the paste and the house must be closed. All this is done without delay. The cover consists of a lid of pure mortar, which the Bee builds by degrees, working from the circumference to the centre. Two days at most appeared to me to be enough for everything, provided that no bad weather—rain or merely clouds—came to interrupt the labour. Then a second cell is built, backing on the first and provisioned in the same manner. A third, a fourth, and so on follow, each supplied with honey and an egg and closed before the foundations of the next are laid. Each task begun is continued until it is quite finished; the Bee never commences a new cell until the four processes needed for the construction of its predecessor are completed: the building, the victualling, the laying of the egg and the closing of the cell.
As the Mason-bee of the Walls always works by herself on the pebble which she has chosen and even shows herself very jealous of her site when her neighbours alight upon it, the number of cells set back to back upon one pebble is not large, usually varying between six and ten. Do some eight grubs represent the Bee's whole family? Or does she afterwards go and establish a more numerous progeny on other boulders? The surface of the same stone is spacious enough to provide a support for further cells if the number of eggs called for them; the Bee could build there very comfortably, without hunting for another site, without leaving the pebble to which she is attached by habit and long acquaintance. It seems to me therefore, exceedingly probable that the family is a small one and that it is all installed on the one stone, at any rate when the Mason-bee is building a new home.
The six to ten cells composing the cluster are certainly a solid dwelling, with their rustic gravel covering; but the thickness of their walls and lids, two millimetres (.078 inch—Translator's Note.) at most, seems hardly sufficient to protect the grubs against the inclemencies of the weather. Set on its pebble in the open air, without any sort of shelter, the nest will have to undergo the heat of summer, which will turn each cell into a stifling furnace, followed by the autumn rains, which will slowly wear away the stonework, and by the winter frosts, which will crumble what the rains have respected. However hard the cement may be, can it possibly resist all these agents of destruction? And, even if it does resist, will not the grubs, sheltered by too thin a wall, have to suffer from excess of heat in summer and of cold in winter?
Without arguing all this out, the Bee nevertheless acts wisely. When all the cells are finished, she builds a thick cover over the group, formed of a material, impermeable to water and a bad conductor of heat, which acts as a protection at the same time against damp, heat and cold. This material is the usual mortar, made of earth mixed with saliva, but on this occasion with no small stones in it. The Bee applies it pellet by pellet, trowelful by trowelful, to the depth of a centimetre (.39 inch—Translator's Note.) over the cluster of cells, which disappear entirely under the clay covering. When this is done, the nest has the shape of a rough dome, equal in size to half an orange. One would take it for a round lump of mud which had been thrown and half crushed against a stone and had then dried where it was. Nothing outside betrays the contents, no semblance of cells, no semblance of work. To the inexperienced eye, it is a chance splash of mud and nothing more.
This outer covering dries as quickly as do our hydraulic cements; and the nest is now almost as hard as a stone. It takes a knife with a strong blade to break open the edifice. And I would add, in conclusion, that, under its final form, the nest in no way recalls the original work, so much so that one would imagine the cells of the start, those elegant turrets covered with stucco-work, and the dome of the finish, looking like a mere lump of mud, to be the product of two different species. But scrape away the crust of cement and we shall easily recognize the cells below and their layers of tiny pebbles.
Instead of building a brand-new nest, on a hitherto unoccupied boulder, the Mason-bee of the Walls is always glad to make use of the old nests which have lasted through the year without suffering any damage worth mentioning. The mortar dome has remained very much what it was at the beginning, thanks to the solidity of the masonry, only it is perforated with a number of round holes, corresponding with the chambers, the cells inhabited by past generations of larvae. Dwellings such as these, which need only a little repair to put them in good condition, save a great deal of time and trouble; and the Mason-bees look out for them and do not decide to build new nests except when the old ones are wanting.
From one and the same dome there issue several inhabitants, brothers and sisters, ruddy males and black females, all the offspring of the same Bee. The males lead a careless existence, know nothing of work and do not return to the clay houses except for a brief moment to woo the ladies; nor do they reck of the deserted cabin. What they want is the nectar in the flower-cups, not mortar to mix between their mandibles. There remain the young mothers, who alone are charged with the future of the family. To which of them will the inheritance of the old nest revert? As sisters, they have equal rights to it: so our code would decide, since the day when it shook itself free of the old savage right of primogeniture. But the Mason-bees have not yet got beyond the primitive basis of property, the right of the first occupant.
When, therefore, the laying-time is at hand, the Bee takes possession of the first vacant nest that suits her and settles there; and woe to any sister or neighbour who shall henceforth dare to contest her ownership. Hot pursuits and fierce blows will soon put the newcomer to flight. Of the various cells that yawn like so many wells around the dome, only one is needed at the moment; but the Bee rightly calculates that the others will be useful presently for the other eggs; and she watches them all with jealous vigilance to drive away possible visitors. Indeed I do not remember ever seeing two Masons working on the same pebble.
The task is now very simple. The Bee examines the old cell to see what parts require repairing. She tears off the strips of cocoon hanging from the walls, removes the fragments of clay that fell from the ceiling when pierced by the last inhabitant to make her exit, gives a coat of mortar to the dilapidated parts, mends the opening a little; and that is all. Next come the storing, the laying of the eggs and the closing of the chamber. When all the cells, one after the other, are thus furnished, the outer cover, the mortar dome, receives a few repairs if it needs them; and the thing is done.
The Sicilian Mason-bee prefers company to a solitary life and establishes herself in her hundreds, very often in many thousands, under the tiles of a shed or the edge of a roof. These do not constitute a true society, with common interests to which all attend, but a mere gathering, where each works for herself and is not concerned with the rest, in short, a throng of workers recalling the swarm of a hive only by their numbers and their eagerness. The mortar employed is the same as that of the Mason-bee of the Walls, equally unyielding and waterproof, but thinner and without pebbles. The old nests are used first. Every free chamber is repaired, stocked and sealed up. But the old cells are far from sufficient for the population, which increases rapidly from year to year. Then, on the surface of the nest, whose chambers are hidden under the old general mortar covering, new cells are built, as the needs of the laying-time call for them. They are placed horizontally, or nearly so, side by side, with no attempt at orderly arrangement. Each architect has plenty of elbow-room and builds as and where she pleases, on the one condition that she does not hamper her neighbours' work; otherwise she can look out for rough handling from the parties interested. The cells, therefore, accumulate at random in this workyard where there is no organization. Their shape is that of a thimble divided down the middle; and their walls are completed either by the adjoining cells or by the surface of the old nest. Outside, they are rough and display successive layers of knotted cords corresponding with the different courses of mortar. Inside, the walls are flat without being smooth; later on, the grub's cocoon will make up for any lack of polish.
Each cell, as built, is stocked and walled up immediately, as we have seen with the Mason-bee of the Walls. This work goes on throughout the best part of May. All the eggs are laid at last; and then the Bees, without drawing distinctions between what does and what does not belong to them, set to work in common on a general protection for the colony. This is a thick coat of mortar, which fills up the gaps and covers all the cells. In the end, the common nest presents the appearance of a wide expanse of dry mud, with very irregular protuberances, thicker in the middle, the original nucleus of the establishment, thinner at the edges, where as yet there are only newly built cells, and varying greatly in dimensions according to the number of workers and therefore to the age of the nest first founded. Some of these nests are hardly larger than one's hand, while others occupy the greater part of the projecting edge of a roof and are measured by square yards.
When working alone, which is not unusual, on the shutter of a disused window, on a stone, or on a twig in some hedge, the Sicilian Chalicodoma behaves in just the same way. For instance, should she settle on a twig, the Bee begins by solidly cementing the base of her cell to the slight foundation. Next, the building rises, taking the form of a little upright turret. This first cell, when victualled and sealed, is followed by another, having as its support, in addition to the twig, the cells already built. From six to ten chambers are thus grouped side by side. Lastly, one coat of mortar covers everything, including the twig itself, which provides a firm mainstay for the whole.
CHAPTER 2. EXPERIMENTS.
As the nests of the Mason-bee of the Walls are erected on small-sized pebbles, which can be easily carried wherever you like and moved about from one place to another, without disturbing either the work of the builder or the repose of the occupants of the cells, they lend themselves readily to practical experiment, the only method that can throw a little light on the nature of instinct. To study the insect's mental faculties to any purpose, it is not enough for the observer to be able to profit by some happy combination of circumstances: he must know how to produce other combinations, vary them as much as possible and test them by substitution and interchange. Lastly, to provide science with a solid basis of facts, he must experiment. In this way, the evidence of formal records will one day dispel the fantastic legends with which our books are crowded: the Sacred Beetle (A Dung-beetle who rolls the manure of cattle into balls for his own consumption and that of his young. Cf. "Insect Life", by J.H. Fabre, translated by the author of "Mademoiselle Mori": chapters 1 and 2; and "The Life and Love of the Insect", by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chapters 1 to 4.—Translator's Note.) calling on his comrades to lend a helping hand in dragging his pellet out of a rut; the Sphex (A species of Hunting Wasp. Cf. "Insect Life": chapters 6 to 12.—Translator's Note.) cutting up her Fly so as to be able to carry him despite the obstacle of the wind; and all the other fallacies which are the stock-in-trade of those who wish to see in the animal world what is not really there. In this way, again, materials will be prepared which will one day be worked up by the hand of a master and consign hasty and unfounded theories to oblivion.
Reaumur, as a rule, confines himself to stating facts as he sees them in the normal course of events and does not try to probe deeper into the insect's ingenuity by means of artificially produced conditions. In his time, everything had yet to be done; and the harvest was so great that the illustrious harvester went straight to what was most urgent, the gathering of the crop, and left his successors to examine the grain and the ear in detail. Nevertheless, in connection with the Chalicodoma of the Walls, he mentions an experiment made by his friend, Duhamel. (Henri Louis Duhamel du Monceau (1700-1781), a distinguished writer on botany and agriculture.—Translator's Note.) He tells us how a Mason-bee's nest was enclosed in a glass funnel, the mouth of which was covered merely with a bit of gauze. From it there issued three males, who, after vanquishing mortar as hard as stone, either never thought of piercing the flimsy gauze or else deemed the work beyond their strength. The three Bees died under the funnel. Reaumur adds that insects generally know only how to do what they have to do in the ordinary course of nature.
The experiment does not satisfy me, for two reasons: first, to ask workers equipped with tools for cutting clay as hard as granite to cut a piece of gauze does not strike me as a happy inspiration; you cannot expect a navvy's pick-axe to do the same work as a dressmaker's scissors. Secondly, the transparent glass prison seems to me ill-chosen. As soon as the insect has made a passage through the thickness of its earthen dome, it finds itself in broad daylight; and to it daylight means the final deliverance, means liberty. It strikes against an invisible obstacle, the glass; and to it glass is nothing at all and yet an obstruction. On the far side, it sees free space, bathed in sunshine. It wears itself out in efforts to fly there, unable to understand the futile nature of its attempts against that strange barrier which it cannot see. It perishes, at last, of exhaustion, without, in its obstinacy, giving a glance at the gauze closing the conical chimney. The experiment must be renewed under better conditions.
The obstacle which I select is ordinary brown paper, stout enough to keep the insect in the dark and thin enough not to offer serious resistance to the prisoner's efforts. As there is a great difference, in so far as the actual nature of the barrier is concerned, between a paper partition and a clay ceiling, let us begin by enquiring if the Mason-bee of the Walls knows how or rather is able to make her way through one of these partitions. The mandibles are pickaxes suitable for breaking through hard mortar: are they also scissors capable of cutting a thin membrane? This is the point to look into first of all.
In February, by which time the insect is in its perfect state, I take a certain number of cocoons, without damaging them, from their cells and insert them each in a separate stump of reed, closed at one end by the natural wall of the node and open at the other. These pieces of reed represent the cells of the nest. The cocoons are introduced with the insect's head turned towards the opening. Lastly, my artificial cells are closed in different ways. Some receive a stopper of kneaded clay, which, when dry, will correspond in thickness and consistency with the mortar ceiling of the natural nest. Others are plugged with a cylinder of sorghum, at least a centimetre (.39 inch—Translator's Note.) thick; and the remainder with a disk of brown paper solidly fastened by the edge. All these bits of reed are placed side by side in a box, standing upright, with the roof of my making at the top. The insects, therefore, are in the exact position which they occupied in the nest. To open a passage, they must do what they would have done without my interference, they must break through the wall situated above their heads. I shelter the whole under a wide bell-glass and wait for the month of May, the period of the deliverance.
The results far exceed my anticipations. The clay stopper, the work of my fingers, is perforated with a round hole, differing in no wise from that which the Mason-bee contrives through her native mortar dome. The vegetable barrier, new to my prisoners, namely, the sorghum cylinder, also opens with a neat orifice, which might have been the work of a punch. Lastly, the brown-paper cover allows the Bee to make her exit not by bursting through, by making a violent rent, but once more by a clearly defined round hole. My Bees therefore are capable of a task for which they were not born; to come out of their reed cells they do what probably none of their race did before them; they perforate the wall of sorghum-pith, they make a hole in the paper barrier, just as they would have pierced their natural clay ceiling. When the moment comes to free themselves, the nature of the impediment does not stop them, provided that it be not beyond their strength; and henceforth the argument of incapacity cannot be raised when a mere paper barrier is in question.
In addition to the cells made out of bits of reed, I put under the bell-glass, at the same time, two nests which are intact and still resting on their pebbles. To one of them I have attached a sheet of brown paper pressed close against the mortar dome. In order to come out, the insect will have to pierce first the dome and then the paper, which follows without any intervening space. Over the other, I have placed a little brown paper cone, gummed to the pebble. There is here, therefore, as in the first case, a double wall—a clay partition and a paper partition—with this difference, that the two walls do not come immediately after each other, but are separated by an empty space of about a centimetre at the bottom, increasing as the cone rises.
The results of these two experiments are quite different. The Bees in the nest to which a sheet of paper was tightly stuck come out by piercing the two enclosures, of which the outer wall, the paper wrapper, is perforated with a very clean round hole, as we have already seen in the reed cells closed with a lid of the same material. We thus become aware, for the second time, that, when the Mason-bee is stopped by a paper barrier, the reason is not her incapacity to overcome the obstacle. On the other hand, the occupants of the nest covered with the cone, after making their way through the earthen dome, finding the sheet of paper at some distance, do not even try to perforate this obstacle, which they would have conquered so easily had it been fastened to the nest. They die under the cover without making any attempt to escape. Even so did Reaumur's Bees perish in the glass funnel, where their liberty depended only upon their cutting through a bit of gauze.
This fact strikes me as rich in inferences. What! Here are sturdy insects, to whom boring through granite is mere play, to whom a stopper of soft wood and a paper partition are walls quite easy to perforate despite the novelty of the material; and yet these vigorous housebreakers allow themselves to perish stupidly in the prison of a paper bag, which they could have torn open with one stroke of their mandibles! They are capable of tearing it, but they do not dream of doing so! There can be only one explanation of this suicidal inaction. The insect is well-endowed with tools and instinctive faculties for accomplishing the final act of its metamorphosis, namely, the act of emerging from the cocoon and from the cell. Its mandibles provide it with scissors, file, pick-axe and lever wherewith to cut, gnaw through and demolish either its cocoon and its mortar enclosure or any other not too obstinate barrier substituted for the natural covering of the nest. Moreover—and this is an important proviso, except for which the outfit would be useless—it has, I will not say the will to use those tools, but a secret stimulus inviting it to employ them. When the hour for the emergence arrives, this stimulus is aroused and the insect sets to work to bore a passage. It little cares in this case whether the material to be pierced be the natural mortar, sorghum-pith, or paper: the lid that holds it imprisoned does not resist for long. Nor even does it care if the obstacle be increased in thickness and a paper wall be added outside the wall of clay: the two barriers, with no interval between them, form but one to the Bee, who passes through them because the act of getting out is still one act and one only. With the paper cone, whose wall is a little way off, the conditions are changed, though the total thickness of wall is really the same. Once outside its earthen abode, the insect has done all that it was destined to do in order to release itself; to move freely on the mortar dome represents to it the end of the release, the end of the act of boring. Around the nest a new barrier appears, the wall made by the paper bag; but, in order to pierce this, the insect would have to repeat the act which it has just accomplished, the act which it is not intended to perform more than once in its life; it would, in short, have to make into a double act that which by nature is a single one; and the insect cannot do this, for the sole reason that it has not the wish to. The Mason-bee perishes for lack of the smallest gleam of intelligence. And this is the singular intellect in which it is the fashion nowadays to see a germ of human reason! The fashion will pass and the facts remain, bringing us back to the good old notions of the soul and its immortal destinies.
Reaumur tells us how his friend Duhamel, having seized a Mason-bee with a forceps when she had half entered the cell, head foremost, to fill it with pollen-paste, carried her to a closet at some distance from the spot where he captured her. The Bee got away from him in this closet and flew out through the window. Duhamel made straight for the nest. The Mason arrived almost as soon as he did and renewed her work. She only seemed a little wilder, says the narrator, in conclusion.
Why were you not here with me, revered master, on the banks of the Aygues, which is a vast expanse of pebbles for three-fourths of the year and a mighty torrent when it rains? I should have shown you something infinitely better than the fugitive escaping from the forceps. You would have witnessed—and in so doing, would have shared my surprise—not the brief flight of the Mason who, carried to the nearest room, releases herself and forthwith returns to her nest in that familiar neighbourhood, but long journeys through unknown country. You would have seen the Bee whom I carried to a great distance from her home, to quite unfamiliar ground, find her way back with a geographical sense of which the Swallow, the Martin and the Carrier-pigeon would not have been ashamed; and you would have asked yourself, as I did, what incomprehensible knowledge of the local map guides that mother seeking her nest.
To come to facts: it is a matter of repeating with the Mason-bee of the Walls my former experiments with the Cerceris-wasps (Cf. "Insect Life": chapter 19.—Translator's Note.), of carrying the insect, in the dark, a long way from its nest, marking it and then leaving it to its own resources. In case any one should wish to try the experiment for himself, I make him a present of my manner of operation, which may save him time at the outset. The insect intended for a long journey must obviously be handled with certain precautions. There must be no forceps employed, no pincers, which might maim a wing, strain it and weaken the power of flight. While the Bee is in her cell, absorbed in her work, I place a small glass test-tube over it. The Mason, when she flies away, rushes into the tube, which enables me, without touching her, to transfer her at once into a screw of paper. This I quickly close. A tin box, an ordinary botanizing-case, serves to convey the prisoners, each in her separate paper bag.
The most delicate business, that of marking each captive before setting her free, is left to be done on the spot selected for the starting-point. I use finely-powdered chalk, steeped in a strong solution of gum arabic. The mixture, applied to some part of the insect with a straw, leaves a white patch, which soon dries and adheres to the fleece. When a particular Mason-bee has to be marked so as to distinguish her from another in short experiments, such as I shall describe presently, I confine myself to touching the tip of the abdomen with my straw while the insect is half in the cell, head downwards. The slight touch is not noticed by the Bee, who continues her work quite undisturbed; but the mark is not very deep and moreover it is in a rather bad place for any prolonged experiment, for the Bee is constantly brushing her belly to detach the pollen and is sure to rub it off sooner or later. I therefore make another one, dropping the sticky chalk right in the middle of the thorax, between the wings.
It is hardly possible to wear gloves at this work: the fingers need all their deftness to take up the restless Bee delicately and to overpower her without rough pressure. It is easily seen that, though the job may yield no other profit, you are at least sure of being stung. The sting can be avoided with a little dexterity, but not always. You have to put up with it. In any case, the Mason-bee's sting is far less painful than that of the Hive-bee. The white spot is dropped on the thorax; the Mason flies off; and the mark dries on the journey.
I start with two Mason-bees of the Walls working at their nests on the pebbles in the alluvia of the Aygues, not far from Serignan. I carry them home with me to Orange, where I release them after marking them. According to the ordnance-survey map, the distance is about two and a half miles as the crow flies. The captives are set at liberty in the evening, at a time when the Bees begin to leave off work for the day. It is therefore probable that my two Bees will spend their night in the neighbourhood.
Next morning, I go to the nests. The weather is still too cool and the works are suspended. When the dew has gone, the Masons begin work. I see one, but without a white spot, bringing pollen to one of the nests which had been occupied by the travellers whom I am expecting. She is a stranger who, finding the cell whose owner I myself had exiled untenanted, has installed herself there and made it her property, not knowing that it is already the property of another. She has perhaps been victualling it since yesterday evening. Close upon ten o'clock, when the heat is at its full, the mistress of the house suddenly arrives: her title-deeds as the original occupant are inscribed for me in undeniable characters on her thorax white with chalk. Here is one of my travellers back.
Over waving corn, over fields all pink with sainfoin, she has covered the two miles and a half; and here she is, back at the nest, after foraging on the way, for the doughty creature arrives with her abdomen yellow with pollen. To come home again from the verge of the horizon is wonderful in itself; to come home with a well-filled pollen-brush is superlative economy. A journey, even a forced journey, always becomes a foraging-expedition.
She finds the stranger in the nest:
'What's this? I'll teach you!'
And the owner falls furiously upon the intruder, who possibly was meaning no harm. A hot chase in mid-air now takes place between the two Masons. From time to time, they hover almost without movement, face to face, with only a couple of inches separating them, and here, doubtless measuring forces with their eyes, they buzz insults at each other. Then they go back and alight on the nest in dispute, first one, then the other. I expect to see them come to blows, to make them draw their stings. But my hopes are disappointed: the duties of maternity speak in too imperious a voice for them to risk their lives and wipe out the insult in a mortal duel. The whole thing is confined to hostile demonstrations and a few insignificant cuffs.
Nevertheless, the real proprietress seems to derive double courage and double strength from the feeling that she is in her rights. She takes up a permanent position on the nest and receives the other, each time that she ventures to approach, with an angry quiver of her wings, an unmistakable sign of her righteous indignation. The stranger, at last discouraged, retires from the field. Forthwith the Mason resumes her work, as actively as though she had not just undergone the hardships of a long journey.
One more word on these quarrels about property. It is not unusual, when one Mason-bee is away on an expedition, for another, some homeless vagabond, to call at the nest, take a fancy to it and set to work on it, sometimes at the same cell, sometimes at the next, if there are several vacant, which is generally the case in the old nests. The first occupier, on her return, never fails to drive away the intruder, who always ends by being turned out, so keen and invincible is the mistress' sense of ownership. Reversing the savage Prussian maxim, 'Might is right,' among the Mason-bees right is might, for there is no other explanation of the invariable retreat of the usurper, whose strength is not a whit inferior to that of the real owner. If she is less bold, this is because she has not the tremendous moral support of knowing herself in the right, which makes itself respected, among equals, even in the brute creation.
The second of my travellers does not reappear, either on the day when the first arrived or on the following days. I decide upon another experiment, on this occasion with five subjects. The starting-place is the same; and the place of arrival, the distance, the time of day, all remain unchanged. Of the five with whom I experiment, I find three at their nests next day; the two others are missing.
It is therefore fully established that the Mason-bee of the Walls, carried to a distance of two and a half miles and released at a place which she has certainly never seen before, is able to return to the nest. But why do first one out of two and then two out of five fail to join their fellows? What one can do cannot another do? Is there a difference in the faculty that guides them over unknown ground? Or is it not rather a difference in flying-power? I remember that my Bees did not all start off with the same vigour. Some were hardly out of my fingers before they darted furiously into the air, where I at once lost sight of them, whereas the others came dropping down a few yards away from me, after a short flight. The latter, it seems certain, must have suffered on the journey, perhaps from the heat concentrated in the furnace of my box. Or I may have hurt the articulation of the wings in marking them, an operation difficult to perform when you are guarding against stings. These are maimed, feeble creatures, who will linger in the sainfoin-fields close by, and not the powerful aviators required by the journey.
The experiment must be tried again, taking count only of the Bees who start off straight from between my fingers with a clean, vigorous flight. The waverers, the laggards who stop almost at once on some bush shall be left out of the reckoning. Moreover, I will do my best to estimate the time taken in returning to the nest. For an experiment of this kind, I need plenty of subjects, as the weak and the maimed, of whom there may be many, are to be disregarded. The Mason-bee of the Walls is unable to supply me with the requisite number: there are not enough of her; and I am anxious not to interfere too much with the little Aygues-side colony, for whom I have other experiments in view. Fortunately, I have at my own place, under the eaves of a shed, a magnificent nest of Chalicodoma sicula in full activity. I can draw to whatever extent I please on the populous city. The insect is small, less than half the size of C. muraria, but no matter: it will deserve all the more credit if it can traverse the two miles and a half in store for it and find its way back to the nest. I take forty Bees, isolating them, as usual, in screws of paper.
In order to reach the nest, I place a ladder against the wall: it will be used by my daughter Aglae and will enable her to mark the exact moment of the return of the first Bee. I set the clock on the mantelpiece and my watch at the same time, so that we may compare the instant of departure and of arrival. Things being thus arranged, I carry off my forty captives and go to the identical spot where C. muraria works, in the pebbly bed of the Aygues. The trip will have a double object: to observe Reaumur's Mason and to set the Sicilian Mason at liberty. The latter, therefore, will also have two and a half miles to travel home.
At last my prisoners are released, all of them being first marked with a big white dot in the middle of the thorax.
You do not come off scot-free when handling one after the other forty wrathful Bees, who promptly unsheathe and brandish their poisoned stings. The stab is but too often given before the mark is made. My smarting fingers make movements of self-defence which my will is not always able to control. I take hold with greater precaution for myself than for the insect; I sometimes squeeze harder than I ought to if I am to spare my travellers. To experiment so as to lift, if possible, a tiny corner of the veil of truth is a fine and noble thing, a mighty stimulant in the face of danger; but still one may be excused for displaying some impatience when it is a matter of receiving forty stings in one's fingers at one short sitting. If any man should reproach me for being too careless with my thumbs, I would suggest that he should have a try: he can then judge for himself the pleasures of the situation.
To cut a long story short, either through the fatigue of the journey, or through my fingers pressing too hard and perhaps injuring some articulations, only twenty out of my forty Bees start with a bold, vigorous flight. The others, unable to keep their balance, wander about on the nearest bit of grass or remain on the osier-shoots on which I have placed them, refusing to fly even when I tickle them with a straw. These weaklings, these cripples, these incapables injured by my fingers must be struck off my list. Those who started with an unhesitating flight number about twenty. That is ample.
At the actual moment of departure, there is nothing definite about the direction taken, none of that straight flight to the nest which the Cerceris-wasps once showed me in similar circumstances. As soon as they are liberated, the Mason-bees flee as though scared, some in one direction, some in exactly the opposite direction. Nevertheless, as far as their impetuous flight allows, I seem to perceive a quick return on the part of those Bees who have started flying towards a point opposite to their home; and the majority appear to me to be making for those blue distances where their nest lies. I leave this question with certain doubts which are inevitable in the case of insects which I cannot follow with my eyes for more than twenty yards.
Hitherto, the operation has been favoured by calm weather; but now things become complicated. The heat is stifling and the sky becomes stormy. A stiff breeze springs up, blowing from the south, the very direction which my Bees must take to return to the nest. Can they overcome this opposing current and cleave the aerial torrent with their wings? If they try, they will have to fly close to the ground, as I now see the Bees do who continue their foraging; but soaring to lofty regions, whence they can obtain a clear view of the country, is, so it seems to me, prohibited. I am therefore very apprehensive as to the success of my experiment when I return to Orange, after first trying to steal some fresh secret from the Aygues Mason-bee of the Pebbles.
I have scarcely reached the house before Aglae greets me, her cheeks flushed with excitement:
'Two!' she cries. 'Two came back at twenty minutes to three, with a load of pollen under their bellies!'
A friend of mine had appeared upon the scene, a grave man of the law, who on hearing what was happening, had neglected code and stamped paper and insisted upon also being present at the arrival of my Carrier-pigeons. The result interested him more than his case about a party-wall. Under a tropical sun, in a furnace heat reflected from the wall of the shed, every five minutes he climbed the ladder bare-headed, with no other protection against sunstroke than his thatch of thick, grey locks. Instead of the one observer whom I had posted, I found two good pairs of eyes watching the Bees' return.
I had released my insects at about two o'clock; and the first arrivals returned to the nest at twenty minutes to three. They had therefore taken less than three-quarters of an hour to cover the two miles and a half, a very striking result, especially when we remember that the Bees did some foraging on the road, as was proved by the yellow pollen on their bellies, and that, on the other hand, the travellers' flight must have been hindered by the wind blowing against them. Three more came home before my eyes, each with her load of pollen, an outward and visible sign of the work done on the journey. As it was growing late, our observations had to cease. When the sun goes down, the Mason-bees leave the nest and take refuge somewhere or other, perhaps under the tiles of the roofs, or in little corners of the walls. I could not reckon on the arrival of the others before work was resumed, in the full sunshine.
Next day, when the sun recalled the scattered workers to the nest, I took a fresh census of Bees with a white spot on the thorax. My success exceeded all my hopes: I counted fifteen, fifteen of the transported prisoners of the day before, storing their cells or building as though nothing out of the way had happened. The weather had become more and more threatening; and now the storm burst and was followed by a succession of rainy days which prevented me from continuing.
The experiment suffices as it stands. Of some twenty Bees who had seemed fit to make the long journey when I released them, fifteen at least had returned: two within the first hour, three in the course of the evening and the rest next morning. They had returned in spite of having the wind against them and—a graver difficulty still—in spite of being unacquainted with the locality to which I had transported them. There is, in fact, no doubt that they were setting eyes for the first time on those osier-beds of the Aygues which I had selected as the starting-point. Never would they have travelled so far afield of their own accord, for everything that they want for building and victualling under the roof of my shed is within easy reach. The path at the foot of the wall supplies the mortar; the flowery meadows surrounding my house furnish nectar and pollen. Economical of their time as they are, they do not go flying two miles and a half in search of what abounds at a few yards from the nest. Besides, I see them daily taking their building-materials from the path and gathering their harvest on the wild-flowers, especially on the meadow sage. To all appearance, their expeditions do not cover more than a radius of a hundred yards or so. Then how did my exiles return? What guided them? It was certainly not memory, but some special faculty which we must content ourselves with recognizing by its astonishing effects without pretending to explain it, so greatly does it transcend our own psychology.
CHAPTER 3. EXCHANGING THE NESTS.
Let us continue our series of tests with the Mason-bee of the Walls. Thanks to its position on a pebble which we can move at will, the nest of this Bee lends itself to most interesting experiments. Here is the first: I shift a nest from its place, that is to say, I carry the pebble which serves as its support to a spot two yards away. As the edifice and its base form but one, the removal is performed without the smallest disturbance of the cells. I lay the boulder in an exposed place where it is well in view, as it was on its original site. The Bee returning from her harvest cannot fail to see it.
In a few minutes, the owner arrives and goes straight to where the nest stood. She hovers gracefully over the vacant site, examines and alights upon the exact spot where the stone used to lie. Here she walks about for a long time, making persistent searches; then the Bee takes wing and flies away to some distance. Her absence is of short duration. Here she is back again. The search is resumed, walking and flying, and always on the site which the nest occupied at first. A fresh fit of exasperation, that is to say, an abrupt flight across the osier-bed, is followed by a fresh return and a renewal of the vain search, always upon the mark left by the shifted pebble. These sudden departures, these prompt returns, these persevering inspections of the deserted spot continue for a long time, a very long time, before the Mason is convinced that her nest is gone. She has certainly seen it, has seen it over and over again in its new position, for sometimes she has flown only a few inches above it; but she takes no notice of it. To her, it is not her nest, but the property of another Bee.
Often the experiment ends without so much as a single visit to the boulder which I have moved two or three yards away: the Bee goes off and does not return. If the distance be less, a yard for instance, the Mason sooner or later alights on the stone which supports her abode. She inspects the cell which she was building or provisioning a little while before, repeatedly dips her head into it, examines the surface of the pebble step by step and, after long hesitations, goes and resumes her search on the site where the home ought to be. The nest that is no longer in its natural place is definitely abandoned, even though it be but a yard away from the original spot. Vainly does the Bee settle on it time after time: she cannot recognize it as hers. I was convinced of this on finding it, several days after the experiment, in just the same condition as when I moved it. The open cell half-filled with honey was still open and was surrendering its contents to the pillaging Ants; the cell that was building had remained unfinished, with not a single layer added to it. The Bee, obviously, may have returned to it; but she had not resumed work upon it. The transplanted dwelling was abandoned for good and all.
I will not deduce the strange paradox that the Mason-bee, though capable of finding her nest from the verge of the horizon, is incapable of finding it at a yard's distance: I interpret the occurrence as meaning something quite different. The proper inference appears to me to be this: the Bee retains a rooted impression of the site occupied by the nest and returns to it with unwearying persistence even when the nest is gone. But she has only a very vague notion of the nest itself. She does not recognize the masonry which she herself has erected and kneaded with her saliva; she does not know the pollen-paste which she herself has stored. In vain she inspects her cell, her own handiwork; she abandons it, refusing to acknowledge it as hers, once the spot whereon the pebble rests is changed.
Insect memory, it must be confessed, is a strange one, displaying such lucidity in its general acquaintance with locality and such limitations in its knowledge of the dwelling. I feel inclined to call it topographical instinct: it grasps the map of the country and not the beloved nest, the home itself. The Bembex-wasps (Cf. "Insect Life": chapters 16 to 19.—Translator's Note.) have already led us to a like conclusion. When the nest is laid open, these Wasps become wholly indifferent to the family, to the grub writhing in agony in the sun. They do not recognize it. What they do recognize, what they seek and find with marvellous precision, is the site of the entrance-door of which nothing at all is left, not even the threshold.
If any doubts remained as to the incapacity of the Mason-bee of the Walls to know her nest other than by the place which the pebble occupies on the ground, here is something to remove them: for the nest of one Mason-bee, I substitute that of another, resembling it as closely as possible in respect to both masonry and storage. This exchange and those of which I shall speak presently are of course made in the owner's absence. The Bee settles without hesitation in this nest which is not hers, but which stands where the other did. If she was building, I offer her a cell in process of building. She continues the masonry with the same care and the same zeal as if the work already done were her own work. If she was fetching honey and pollen, I offer her a partly-provisioned cell. She continues her journeys, with honey in her crop and pollen under her belly, to finish filling another's warehouse. The Bee, therefore, does not suspect the exchange; she does not distinguish between what is her property and what is not; she imagines that she is still working at the cell which is really hers.
After leaving her for a time in possession of the strange nest, I give her back her own. This fresh change passes unperceived by the Bee: the work is continued in the cell restored to her at the point which it had reached in the substituted cell. I once more replace it by the strange nest; and again the insect persists in continuing its labour. By thus constantly interchanging the strange nest and the proper nest, without altering the actual site, I thoroughly convinced myself of the Bee's inability to discriminate between what is her work and what is not. Whether the cell belong to her or to another, she labours at it with equal zest, so long as the basis of the edifice, the pebble, continues to occupy its original position.
The experiment receives an added interest if we employ two neighbouring nests the work on which is about equally advanced. I move each to where the other stood. They are not much more than thirty inches a part. In spite of their being so near to each other that it is quite possible for the insects to see both homes at once and choose between them, each Bee, on arriving, settles immediately on the substituted nest and continues her work there. Change the two nests as often as you please and you shall see the two Mason-bees keep to the site which they selected and labour in turn now at their own cell and now at the other's.
One might think that the cause of this confusion lies in a close resemblance between the two nests, for at the start, little expecting the results which I was to obtain, I used to choose the nests which I interchanged as much alike as possible, for fear of disheartening the Bees. I need not have taken this precaution: I was giving the insect credit for a perspicacity which it does not possess. Indeed, I now take two nests which are extremely unlike each other, the only point of resemblance being that, in each case, the toiler finds a cell in which she can continue the work which she is actually doing. The first is an old nest whose dome is perforated with eight holes, the apertures of the cells of the previous generation. One of these cells has been repaired; and the Bee is busy storing it. The second is a nest of recent construction, which has not received its mortar dome and consists of a single cell with its stucco covering. Here too the insect is busy hoarding pollen-paste. No two nests could present greater differences: one with its eight empty chambers and its spreading clay dome; the other with its single bare cell, at most the size of an acorn.
Well, the two Mason-bees do not hesitate long in front of these exchanged nests, not three feet away from each other. Each makes for the site of her late home. One, the original owner of the old nest, finds nothing but a solitary cell. She rapidly inspects the pebble and, without further formalities, first plunges her head into the strange cell, to disgorge honey, and then her abdomen, to deposit pollen. And this is not an action due to the imperative need of ridding herself as quickly as possible, no matter where, of an irksome load, for the Bee flies off and soon comes back again with a fresh supply of provender, which she stores away carefully. This carrying of provisions to another's larder is repeated as often as I permit it. The other Bee, finding instead of her one cell a roomy structure consisting of eight apartments, is at first not a little embarrassed. Which of the eight cells is the right one? In which is the heap of paste on which she had begun? The Bee therefore visits the chambers one by one, dives right down to the bottom and ends by finding what she seeks, that is to say, what was in her nest when she started on her last journey, the nucleus of a store of food. Thenceforward she behaves like her neighbour and goes on carrying honey and pollen to the warehouse which is not of her constructing.
Restore the nests to their original places, exchange them yet once again and both Bees, after a short hesitation which the great difference between the two nests is enough to explain, will pursue the work in the cell of her own making and in the strange cell alternately. At last the egg is laid and the sanctuary closed, no matter what nest happens to be occupied at the moment when the provisioning reaches completion. These incidents are sufficient to show why I hesitate to give the name of memory to the singular faculty that brings the insect back to her nest with such unerring precision and yet does not allow her to distinguish her work from some one else's, however great the difference may be.
We will now experiment with Chalicodoma muraria from another psychological point of view. Here is a Mason-bee building; she is at work on the first course of her cell. I give her in exchange a cell not only finished as a structure, but also filled nearly to the top with honey. I have just stolen it from its owner, who would not have been long before laying her egg in it. What will the Mason do in the presence of this munificent gift, which saves her the trouble of building and harvesting? She will leave the mortar no doubt, finish storing the Bee-bread, lay her egg and seal up. A mistake, an utter mistake: our logic is not the logic of the insect, which obeys an inevitable, unconscious prompting. It has no choice as to what it shall do; it cannot discriminate between what is and what is not advisable; it glides, as it were, down an irresistible slope prepared beforehand to bring it to a definite end. This is what the facts that still remain to be stated proclaim with no uncertain voice.
The Bee who was building and to whom I offer a cell ready-built and full of honey does not lay aside her mortar for that. She was doing mason's work; and, once on that tack, guided by the unconscious impulse, she has to keep masoning, even though her labour be useless, superfluous and opposed to her interests. The cell which I give her is certainly perfect, looked upon as a building, in the opinion of the master-builder herself, since the Bee from whom I took it was completing the provision of honey. To touch it up, especially to add to it, is useless and, what is more, absurd. No matter: the Bee who was masoning will mason. On the aperture of the honey-store she lays a first course of mortar, followed by another and yet another, until at last the cell is a third taller then the regulation height. The masonry-task is now done, not as perfectly, it is true, as if the Bee had gone on with the cell whose foundations she was laying at the moment when I exchanged the nests, but still to an extent which is more than enough to prove the overpowering impulse which the builder obeys. Next comes the victualling, which is also cut short, lest the honey-store swelled by the joint contributions of the two Bees should overflow. Thus the Mason-bee who is beginning to build and to whom we give a complete cell, a cell filled with honey, makes no change in the order of her work: she builds first and then victuals. Only she shortens her work, her instinct warning her that the height of the cell and the quantity of honey are beginning to assume extravagant proportions.
The converse is equally conclusive. To a Mason-bee engaged in victualling I give a nest with a cell only just begun and not at all fit to receive the paste. This cell, with its last course still wet with its builder's saliva, may or may not be accompanied by other cells recently closed up, each with its honey and its egg. The Bee, finding this in the place of her half-filled honey-store, is greatly perplexed what to do when she comes with her harvest to this unfinished, shallow cup, in which there is no place to put the honey. She inspects it, measures it with her eyes, tries it with her antennae and recognizes its insufficient capacity. She hesitates for a long time, goes away, comes back, flies away again and soon returns, eager to deposit her treasure. The insect's embarrassment is most evident; and I cannot help saying, inwardly:
'Get some mortar, get some mortar and finish making the warehouse. It will only take you a few moments; and you will have a cupboard of the right depth.'
The Bee thinks differently: she was storing her cell and she must go on storing, come what may. Never will she bring herself to lay aside the pollen-brush for the trowel; never will she suspend the foraging which is occupying her at this moment to begin the work of construction which is not yet due. She will rather go in search of a strange cell, in the desired condition, and slip in there to deposit her honey, at the risk of meeting with a warm reception from the irate owner. She goes off, in fact, to try her luck. I wish her success, being myself the cause of this desperate act. My curiosity has turned an honest worker into a robber.
Things may take a still more serious turn, so invincible, so imperious is the desire to have the booty stored in a safe place without delay. The uncompleted cell which the Bee refuses to accept instead of her own finished warehouse, half-filled with honey, is often, as I said, accompanied by other cells, not long closed, each containing its Bee-bread and its egg. In this case, I have sometimes, though not always, witnessed the following: when once the Bee realises the shortcomings of the unfinished nest, she begins to gnaw the clay lid closing one of the adjoining cells. She softens a part of the mortar cover with saliva and patiently, atom by atom, digs through the hard wall. It is very slow work. A good half-hour elapses before the tiny cavity is large enough to admit a pin's head. I wait longer still. Then I lose patience; and, fully convinced that the Bee is trying to open the store-room, I decide to help her to shorten the work. The upper part of the cell comes away with it, leaving the edges badly broken. In my awkwardness, I have turned an elegant vase into a wretched cracked pot.
I was right in my conjecture: the Bee's intention was to break open the door. Straight away, without heeding the raggedness of the orifice, she settles down in the cell which I have opened for her. Time after time, she fetches honey and pollen, though the larder is already fully stocked. Lastly, she lays her egg in this cell which already contains an egg that is not hers, having done which she closes the broken aperture to the best of her ability. So this purveyor had neither the knowledge nor the power to bow to the inevitable. I had made it impossible for her to go on with her purveying, unless she first completed the unfinished cell substituted for her own. But she did not retreat before that impossible task. She accomplished her work, but in the absurdest way: by injuriously trespassing upon another's property, by continuing to store provisions in a cupboard already full to overflowing, by laying her egg in a cell in which the real owner had already laid and lastly by hurriedly closing an orifice that called for serious repairs. What better proof could be wished of the irresistible propensity which the insect obeys?
Lastly, there are certain swift and consecutive actions so closely interlinked that the performance of the second demands a previous repetition of the first, even when this action has become useless. I have already described how the Yellow-winged Sphex (Cf. "Insect Life": chapters 6 to 9.—Translator's Note.) persists in descending into her burrow alone, after depositing at its edge the Cricket whom I maliciously at once remove. Her repeated discomfitures do not make her abandon the preliminary inspection of the home, an inspection which becomes quite useless when renewed for the tenth or twentieth time. The Mason-bee of the Walls shows us, under another form, a similar repetition of an act which is useless in itself, but which is the compulsory preface to the act that follows. When arriving with her provisions, the Bee performs a twofold operation of storing. First, she dives head foremost into the cell, to disgorge the contents of her crop; next, she comes out and at once goes in again backwards, to brush her abdomen and rub off the load of pollen. At the moment when the insect is about to enter the cell tail first, I push her aside gently with a straw. The second act is thus prevented. The Bee now begins the whole performance over again, that is to say, she once more dives head first to the bottom of the cell, though she has nothing left to disgorge, as her crop has just been emptied. When this is done, it is the belly's turn. I instantly push her aside again. The insect repeats its proceedings, still entering head first; I also repeat my touch of the straw. And this can go on as long as the observer pleases. Pushed aside at the moment when she is about to insert her abdomen into the cell, the Bee goes back to the opening and persists in going down head first to begin with. Sometimes, she descends to the bottom, sometimes only half-way, sometimes again she only pretends to descend, just bending her head into the aperture; but, whether completed or not, this action, for which there is no longer any motive, since the honey has already been disgorged, invariably precedes the entrance backwards to deposit the pollen. It is almost the movement of a machine whose works are only set going when the driving-wheel begins to revolve.
CHAPTER 4. MORE ENQUIRIES INTO MASON-BEES.
This chapter was to have taken the form of a letter addressed to Charles Darwin, the illustrious naturalist who now lies buried beside Newton in Westminster Abbey. It was my task to report to him the result of some experiments which he had suggested to me in the course of our correspondence: a very pleasant task, for, though facts, as I see them, disincline me to accept his theories, I have none the less the deepest veneration for his noble character and his scientific honesty. I was drafting my letter when the sad news reached me: Darwin was dead; after searching the mighty question of origins, he was now grappling with the last and darkest problem of the hereafter. (Darwin died at Down, in Kent, on the 19th of April 1882.—Translator's Note.) I therefore abandon the epistolary form, which would be unwarranted in view of that grave at Westminster. A free and impersonal statement shall set forth what I intended to relate in a more academic manner.
One thing, above all, had struck the English scientist on reading the first volume of my "Souvenirs entomologiques", namely, the Mason-bees' faculty of knowing the way back to their nests after being carried to great distances from home. What sort of compass do they employ on their return journeys? What sense guides them? The profound observer thereupon spoke of an experiment which he had always longed to make with Pigeons and which he had always neglected making, absorbed as he was by other interests. This experiment, he thought, I might attempt with my Bees. Substitute the insect for the bird; and the problem remained the same. I quote from his letter the passage referring to the trial which he wished made:
'Allow me to make a suggestion in relation to your wonderful account of insects finding their way home. I formerly wished to try it with pigeons; namely, to carry the insects in their paper cornets about a hundred paces in the opposite direction to that which you intended ultimately to carry them, but before turning round to return, to put the insects in a circular box with an axle which could be made to revolve very rapidly first in one direction and then in another, so as to destroy for a time all sense of direction in the insects. I have sometimes imagined that animals may feel in which direction they were at the first start carried.'
This method of experimenting seemed to me very ingeniously conceived. Before going west, I walk eastwards. In the darkness of their paper bags, the mere fact that I am moving them gives my prisoners a sense of the direction in which I am taking them. If nothing happened to disturb this first impression, the insect would be guided by it in returning. This would explain the homing of my Mason-bees carried to a distance of two or three miles amid strange surroundings. But, when the insects have been sufficiently impressed by their conveyance to the east, there comes the rapid twirl, first this way round, then that. Bewildered by all these revolutions first in one direction and then in another, the insect does not know that I have turned round and remains under its original impression. I am now taking it to the west, when it believes itself to be still travelling towards the east. Under the influence of this impression; the insect is bound to lose its bearings. When set free, it will fly in the opposite direction to its home, which it will never find again.
This result seemed to me the more probable inasmuch as the statements of the country-folk around me were all of a nature to confirm my hopes. Favier (The author's gardener and factotum. Cf. "The Life of the Fly": chapter 4.—Translator's Note.), the very man for this sort of information, was the first to put me on the track. He told me that, when people want to move a Cat from one farm to another at some distance, they place the animal in a bag which they twirl rapidly at the moment of starting, thus preventing the animal from returning to the house which it has quitted. Many others, besides Favier, described the same practice to me. According to them, this twirling round in a bag was an infallible expedient: the bewildered Cat never returned. I communicated what I had learnt to England, I wrote to the sage of Down and told him how the peasant had anticipated the researches of science. Charles Darwin was amazed; so was I; and we both of us almost reckoned on a success.
These preliminaries took place in the winter; I had plenty of time to prepare for the experiment which was to be made in the following May.
'Favier,' I said, one day, to my assistant, 'I shall want some of those nests. Go and ask our next-door neighbour's leave and climb to the roof of his shed, with some new tiles and some mortar, which you can fetch from the builder's. Take a dozen tiles from the roof, those with the biggest nests on them, and put the new ones in their place.'
Things were done accordingly. My neighbour assented with a good grace to the exchange of tiles, for he himself is obliged, from time to time, to demolish the work of the Mason-bee, unless he would risk seeing his roof fall in sooner or later. I was merely forestalling a repair which became more urgent every year. That same evening, I was in possession of twelve magnificent rectangular blocks of nest, each lying on the convex surface of a tile, that is to say, on the surface looking towards the inside of the shed. I had the curiosity to weigh the largest: it turned the scale at thirty-five pounds. Now the roof whence it came was covered with similar masses, adjoining one another, over a stretch of some seventy tiles. Reckoning only half the weight, so as to strike an average between the largest and the smallest lumps, we find the total weight of the Bee's masonry to amount to three-quarters of a ton. And, even so, people tell me that they have seen this beaten elsewhere. Leave the Mason-bee to her own devices, in the spot that suits her; allow the work of many generations to accumulate; and, one fine day, the roof will break down under the extra burden. Let the nests grow old; let them fall to pieces when the damp gets into them; and you will have chunks tumbling on your head big enough to crack your skull. There you see the work of a very little-known insect. (The insect is so little known that I made a serious mistake when treating of it in the first volume of these "Souvenirs." Under my erroneous denomination of Chalicodoma sicula are really comprised two species, one building its nests in our dwellings and particularly under the tiles of outhouses, the other building its nests on the branches of shrubs. The first species has received various names, which are, in order of priority: Chalicodoma pyrenaica, LEP. (Megachile); Chalicodoma pyrrhopeza, GERSTACKER; Chalicodoma rufitarsis, GIRAUD. It is a pity that the name occupying the first place should lend itself to misconception. I hesitate to apply the epithet of Pyrenean to an insect which is much less common in the Pyrenees than in my own district. I shall call it the Chalicodoma, or Mason-bee, of the Sheds. There is no objection to the use of this name in a book where the reader prefers lucidity to the tyranny of systematic entomology. The second species, that which builds its nests on the branches, is Chalicodoma rufescens, J. PEREZ. For a like reason, I shall call it the Chalicodoma of the Shrubs. I owe these corrections to the kindness of Professor Jean Perez, of Bordeaux, who is so well-versed in the lore of Wasps and Bees.—Author's Note.)
These treasures were insufficient, not in regard to quantity, but in regard to quality, for the main object which I had in view. They came from the nearest house, separated from mine by a little field planted with corn and olive-trees. I had reason to fear that the insects issuing from those nests might be hereditarily influenced by their ancestors, who had lived in the shed for many a long year. The Bee, when carried to a distance, would perhaps come back, guided by the inveterate family habit; she would find the shed of her lineal predecessors and thence, without difficulty, reach her nest. As it is the fashion nowadays to assign a prominent part to these hereditary influences, I must eliminate them from my experiments. I want strange Bees, brought from afar, whose return to the place of their birth can in no way assist their return to the nest transplanted to another site.
Favier took the business in hand. He had discovered on the banks of the Aygues, at some miles from the village, a deserted hut where the Mason-bees had established themselves in a numerous colony. He proposed to take the wheelbarrow, in which to move the blocks of cells; but I objected: the jolting of the vehicle over the rough paths might jeopardise the contents of the cells. A basket carried on the shoulder was deemed safer. Favier took a man to help him and set out. The expedition provided me with four well-stocked tiles. It was all that the two men were able to carry between them; and even then I had to stand treat on their arrival: they were utterly exhausted. Le Vaillant tells us of a nest of Republicans (Social Weaver-birds.—Translator's Note.) with which he loaded a wagon drawn by two oxen. My Mason-bee vies with the South-African bird: a yoke of Oxen would not have been too many to move the whole of that nest from the banks of the Aygues.
The next thing is to place my tiles. I want to have them under my eyes, in a position where I can watch them easily and save myself the worries of earlier days: going up and down ladders, standing for hours at a stretch on a narrow rung that hurt the soles of my feet and risking sunstroke up against a scorching wall. Moreover, it is necessary that my guests should feel almost as much at home with me as where they come from. I must make life pleasant for them, if I should have them grow attached to the new dwelling. And I happen to have the very thing for them.
Under the leads of my house is a wide arch, the sides of which get the sun, while the back remains in the shade. There is something for everybody: the shade for me, the sunlight for my boarders. We fasten a stout hook to each tile and hang it on the wall, on a level with our eyes. Half my nests are on the right, half on the left. The general effect is rather original. Any one walking in and seeing my show for the first time begins by taking it for a display of smoked provisions, gammons of some outlandish bacon curing in the sun. On perceiving his mistake, he falls into raptures at these new hives of mine. The news spreads through the village and more than one pokes fun at it. They look upon me as a keeper of hybrid Bees: