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The Mason-Bees
J H Fabre
Alan >Stone
THE MASON-BEES
THE MASON-BEES
i.Flx' BY
J. HENRI FABRE
translated by Alexander Teixeira de Mattos
FELLOW OF THE ZOOLOGICAL SOCIETY OF LONDON
Garden City New York^
GARDEN CITY PUBLISHING COMPANY
1925
Copyright, 1914 By DODD, MEAD AND COMPANY
PRINTBD IN THE UNITED STATES OF AMERICA,
CONTENTS
PAGE
translator's note . . . ;. . vii
I THE MASON-BEES I
II EXPERIMENTS ....... 30
III EX'CHANGING THE NESTS . . .56
IV MORE ENQUIRIES INTO MASON-BEES 73 V THE STORY OF MY CATS 1. i. . I09
VI THE RED ANTS 1 24
VII SOME REFLECTIONS UPON INSECT
PSYCHOLOGY . ^. . . . I58
VIII PARASITES 190
IX THE THEORY OF PARASITISM . . 217
X THE TRIBULATIONS OF THE MASON- BEE 250
XI THE LEUCOSPES . ;. ,.. . . 277
INDEX .., ., ,., 1., I., 1. 1 I., i.i I. 311
TRANSLATOR'S NOTE
THIS volume contains all the essays on tKe Challcodomae, or Mason-bees proper, which so greatly enhance the interest of the early volumes of the Souvenirs entO' mologiques. 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 Osmise, 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, Ex- periments and Exchanging the Nests form the last three chapters of Insect Life, translated by the author of Mademoiselle Mori and pub- lished by Messrs. Macmillan, who, with the greatest courtesy and kindness have given me their permission to include a new translation vU
Translator's Note
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 edi- tion 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 Rod- well for the invaluable assistance which she has given me in the work of translation and in the less interesting and more tedious de- partment of research.
Alexander Teixeira de Mattos. Chelsea, 19 14.
CHAPTER I
THE MASON-BEES
REAUMUR' devoted one of his papers to the story of the Challcodoma 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 Car- pentras, 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 en-
iRene Antoine Ferchault de Reaumur (1683-1757), inventor of the Reaumur thermometer and author of Memoires pour servir a I'histoire naturelle des insectes. — Translator's Note.
The Mason-bees
gendered 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 to- gether, 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
The Mason-bees
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 dul- ness from the gloomy room, whose walls dripped melancholy even more than damp- ness, my one resource was my tongue, my one weapon my stick of chalk.
For that matter, there was the same con- tempt 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 prin- cipal of the college was a first-rate man, the worthy Abbe X., who, not caring to dispense beans and bacon himself, had left the com- missariat-department to one of his relatives and had undertaken instead to teach the boys physics.
Let us attend one of his lessons. The sub- ject is the barometer. The establishment happens to possess one, an old apparatus, covered with dust, hanging on the wall be- yond the reach of profane hands and bearing on its face, in large letters, the words stormy, rain, fair.
The Mason-bees
"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, Bas- tien?"
"Yes, I see," says Bastlen, the most mis- chievous 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, Bastlen, 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."
Bastlen 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 4
The Mason-bees
is open at the top. There, I can feel the hole."
And Bastlen, to confirm his mendacious statement, keeps wriggling his forefinger at the top of the tube, while his fellow-conspira- tors 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 im- proved, 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 particu- lar appealed to both master 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 5
The Mason-bees
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 car- ried that most delicate and precious appa- ratus, the historic five-franc graphometer. The scene of operations was an untilled, flinty plain, a harmas,^ as we call it in the dis- trict. Here, no curtain of green hedges or shrubs prevented me from keeping an eye
iCf. T/ie Life of the Fly, by J. Henri Fabre, trans- lated by Alexander Teixeira de Mattos: chap. i. — Trans' tutor's Note.
6
The Mason-bees
upon my staff; here — an indispensable condi- tion— 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 perpendicu- lar to the graphometer's performances.
Well, from the very first day, my atten- tion 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?
The Mason-bees
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 oft the polygon till later. It was thus that I first saw Reaumur's Mason-bee, knowing nothing of her history and, for that matter, knowing 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 di- version 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 learned 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 natu7'elle des animaux articu- 8
The Mason-bees
les, by de Castelnau/ E. Blanchard^ and Lucas, ^ and boasted a multitude of most at- tractive 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 ef- fected. That day my professional emolu- ments 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 learned the name of my black Bee; I read for the first time various details of the habits of Insects; I found, sur- rounded in my eyes with a sort of halo, the
^Francis Comte de Castelnau de la Porte (1812-1880), the naturalist and traveller. Castelnau was born in Lon- don and died at Melbourne. — Translator's Note,
^Emile Blanchard {b. 1820), author of various works on insects, Spiders, etc. — Translator's Note.
^Pierre Hippolyte Lucas {b. 1815), author of works on Moths and Butterflies, Crustaceans, etc. — Translator's Note.
The Mason-bees ,
revered names of Reaumur, Huber^ and Leon Dufour;- 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?^ 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 un- familiar with Greek. The rame Is given to Bees who build their s with mate- rials similar to those ■* i we employ for our own dwellings. work of these
^Fran^ois Huber (1750-1831), tae 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.
2Jean Marie Leon Dufour (1780-1865), an army sur- geon who served with distinction in several campaigns and subsequently practised as a doctor in the Landcs, 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: chap, i; and The Life of the Fly: chap. i. — Translator's Note.
^The present essay is one of the earliest in the Souve- nirs Entomologiques, — Translator's Note. 10
The Mason-bees
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 under- stand— 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 mtiraria) , whose history Reaumur gives us in a masterly fashion; and the Sicilian Chali- codoma (C. sicula),^ 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 de- partment of Vaucluse, where she is one of the commonest Bees to be seen In the month of May. In the former species, the two sexes are so unlike In colouring that a novice, sur- prised at observing them come out of the same nest, would at first take them for strangers to
*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 IV., footnote. — Translator's Note.
II
The Mason-bees
each other. The female is of a splendid vel- vety 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, re- call, but only faintly, the rich purple of the former 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 cov- ered with plaster, which might come off and imperil the future of the ceils. She confides her buildings only to solid foundations, such as bare stone. 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 sup- port. The extreme abundance of these sites
12
The Mason-bees
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 val- leys, 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 want- ing, 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 cher- ished site is the lower surface of the project- ing 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 ma- sonry, 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 13
The Mason-bees
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 pas- sage. But these are popular resorts, where hundreds and thousands of workers labour, each for herself. If she be alone, which hap- pens pretty often, the Sicilian Mason-bee in- stals herself in the first little nook handy, pro- vided that it supplies a solid foundation and warmth. As for the nature of this founda- tion, 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 — haw- thorn, pomegranate, Christ's-thorn — pro-
The Mason-bees
vides 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: calca- reous 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 plas- ter and lime that have long lost their settling- 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, 15
The Mason-bees
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 fix- ing her abode under the eaves of some rural dwelling, she always goes for her building- materials to the nearest path or road, with- out allowing herself to be distracted from her business by the constant traflfic 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 adjoin- ing 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 work- er'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 i6
The Mason-bees
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 forelegs and above all the mandibles, which are the mason's chief tools, work the material, which 17
The Mason-bees
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.^
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 economize la- bour and mortar, the Bee employs coarse ma- terials, 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 con- tribute to the solidity of the whole. Layers of mortar, sparingly applied, hold them to- gether. The outside of the cell thus assumes the appearance of a piece of rustic architect- ure, In which the stones project with their natural Irregularities; but the inside, which requires a more even surface in order not to
^Three-quarters of an inch to one inch. — Translator's Note.
l8
The Mason-bees
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 it- self a cocoon and hang the rude walls of its abode with silk. On the other hand, the An- thophoras 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 up- right or slanting surface, It resembles the half of a thimble divided from top to bottom. In this case, the support itself, the pebble, com- pletes 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
19
The Mason-bees
pebbly borders of the mountain streams with gold, supply her with sugary liquid and pol- len. 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 dis- gorging 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 ab- domen with her two hindlegs and rids her- self 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 cir-
20
The Mason-bees
cumference 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 sup- plied with honey and an egg and closed be- fore 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 con- struction 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 be- tween six and ten. Do some eight grubs represent the Bee's whole family? Or does she afterward go and establish a more numer- ous progeny on other boulders? The surface of the same stone is spacious enough to pro- vide a support for further cells if the num-
21
The Mason-bees
ber of eggs called for them; the Bee could build there very comfortably, without hunt- ing for another site, without leaving the peb- ble 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 boulder, 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 rus- tic gravel covering; but the thickness of their walls and lids, two millimetres^ at most, seems hardly sufficient to protect the grubs against the inclemencies of the weather. Set on Its stone 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 stone- work, and by the winter frosts, which will crumble what the rains have respected. How- ever hard the cement may be, can it possibly resist all these agents of destruction? And, even if it does resist, will not the grubs, shel-
^.078 inch. — Translator's Note. 22
The Mason-bees
tered by top thin a wall, have to suffer from excess of heat in summer and of cold in win- ter?
Without arguing all this out, the Bee nev- ertheless 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 pel- let, trowelful by trowelful, to the depth of a centimetre^ 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.
*.39 inch. — Translator's Note. 23
The Mason-bees
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 outset, those elegant turrets covered with stuccowork, 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, 24
The Mason-bees
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 ex- istence, know nothing of work and do not re- turn to the clay houses except for a brief mo- ment 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 re- vert? 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 va- cant nest that suits her and settles there; and woe to any sister or neighbour who shall 25
The Mason-bees
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 ex- amines the old cell to see what parts require repairing. She tears off the strips of cocoon hanging from the walls, removes the frag- ments 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 fur- nished, the outer cover, the mortar dome, re- ceives 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 26
The Mason-bees
hundreds, very often in many thousands, un- der 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 eager- ness. 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 sur- face 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; other- wise she can look out for rough handling from the parties Interested. The cells, there- 27
The Mason-bees
fore, accumulate at random in this work-yard where there is no organization. Their shape is that of a thimble divided down the mid- dle; 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 correspond- ing with the different courses of mortar. In- side, 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, with- out 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 mor- tar, 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 esta- blishment, thinner at the edges, where as yet there are only newly-built cells, and varying 28
The Mason-bees
greatly In dimensions according to the num- ber 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 Chali- codoma 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 up- right 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.
39
CHAPTER II
EXPERIMENTS
AS THE nests of the Mason-bee of the Walls are erected on small-sized peb- bles, which can be easily carried wherever you like and moved about from one place to an- other, without disturbing either the work of the builder or the repose of the occupants of the cells, they lend themselves readily to prac- tical 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 pro- duce other combinations, vary them as much as possible and to test them by substitution and interchange. Lastly, to provide science with a solid basis of facts, he must experi- ment. In this way, the evidence of formal records will one day dispel the fantastic le- gends with which our books are crowded : the 30
Experiments
Sacred Beetle^ calling on his comrades to lend a helping hand in dragging his pellet out of a rut; the Sphex^ 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 har- vest was so great that the illustrious harvester went straight to what was most urgent, the gathering of the crop, and left his successors
^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: chaps, i. and ii.; and TJie Life and Love of the Insect, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chaps, i. to iv. — Translator's Note.
"A species of Hunting Wasp. Cf. Insect Life: chaps. vi. and xii. — Translator's Note.
31
The Mason-bees
to examine the grain and the ear in detail. Nevertheless, in connection with the Chali- codoma of the Walls, he mentions an experi- ment made by his friend, Duhamel/ He tells us how a Mason-bee's nest was enclosed in a glass funnel, the mouth of which was cov- ered merely with a bit of gauze. From it there issued three males, who, after vanquish- ing 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 pickaxe to do the same work as a dressmaker's scissors. Secondly, the trans- parent glass prison seems to me ill-chosen. As soon as the insect has made a passage through
iHenri Louis Duhamel du Monceau (17001781), a distinguished writer on botany and agriculture. — Trans- lator's Note.
32
Experiments
the thickness of its earthen dome, it finds It- self 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 per- ishes, at last, of exhaustion, without, in its obstinacy, giving a glance at the gauze closing the conical chimney. I must devise a means of renewing the experiment under better con- ditions.
The obstacle which I select is ordinary brown paper, stout enough to keep the insect in the dark and thin enough not to offer seri- ous resistance to the prisoner's efforts. Aa there Is a great difference, in so far as the ac- tual nature of the barrier is concerned, be- tween 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 33
The Mason-bees
capable of cutting a thin membrane? This is tlie 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 toward 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^ 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 mak- ing 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 inter-
1.39 inch. — Translator's Note. 34
Experiments
ference, 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 vege- table 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 hence- forth the argument of incapacity cannot be 35
The Mason-bees
raised when a mere paper barrier is in ques- tion.
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 rest- ing 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 with- out any intervening space. Over the other, I have placed a little brown-paper cone, gummed to the pebble. There is here, there- fore, as in the first case, a double wall — a clay- partition and a paper partition — with this dif- ference, that the two walls do not come im- mediately 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 al- ready seen in the reed cells closed with a lid of the same material. We thug become
Experiments
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 mak- ing their way through the earthen dome, find- ing 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 vigor- our 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-endowtd with 37
The Mason-bees
tools and instinctive faculties for accomplish- ing the final act of its metamorphosis, namely, the act of emerging from the cocoon and from the cell. Its mandibles provide it with scis- sors, file, pickaxe 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, but for which the outfit would be useless — it has, I will not say the will to use those tools, but a secret stimulus invi- ting 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 be- tween them, form but one to the Bee, who passes through them because the act of get- ting 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 38
Experiments
thickness of wall is really the same. Once out- side 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 in- telligence. 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 fore- most, to fill it with pollen-paste, carried her to a closet at some distance from the spot 39
The Mason-be^
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 for three-fourths of the year is a vast expanse of pebbles 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, car- ried to the nearest room, rekises herself and forthwith returns to her nest in that familiar neighbourhood, but long journeys through un- known 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 your- self, as I did, what incomprehensible know- 40
Experiments
ledge of the local map guides that mother seeking her nest.
To come to facts: it is a matter of repeat- ing with the Mason-bee of the Walls my former experiments with the Cerceris-wasps,^ 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 him- self, I make him a present of my manner of operation, which may save him time at the outset. The insect intended for a long jour- ney must obviously be handled with certain precautions. There must be no forceps em- ployed, 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 mark- ing each captive before setting her free, is left
*Cf. Insect Life; chap. xix. — Translator's Note. 41
The Mason-bees
to be done on the spot selected for the starting-point. I use finely-powdered chalk, steeped in a strong solution of gum arable. The mixture, applied to some part of the in- sect 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 de- tach the pollen and is sure to rub It off sooner or later. I therefore make another one, drop- ing 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 over- power her without rough pressure. It Is easily seen that, though the job may yield no other profit, you are at least sure of being 42
Experiments
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. Accord- ing 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 43
The Mason-bees
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 origi- nal occupant are inscribed for me in undenia- ble 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 in- truder, who possibly was meaning no harm. A hot chase in mid-air now takes place be- tween the two masons. From time to time, they hover almost without movement, face to 44
Experiments
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 ex- pect to see them come to blows, to make them draw their stings. But my hopes are disap- pointed: 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 demonstra- tions 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 discour- aged, retires from the field. Forthwith the mason resumes her work, as actively as though she had not just undergone the hard- ships 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, 45
The Mason-bees
some homeless vagabond, to call at the nest, take a fancy to it and set to work on it, some- times 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 in- ferior to that of the real owner. If she is less bold, this is because she has not the tre- mendous 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 reap- pear, either on the day when the first arrived or on the following days. I decide upon an- other 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. 46
Experiments
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 drop- ping 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 diflficult 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 re- quired by the journey.
The experiment must be tried again, tak- 47
The Mason-bees
ing 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. For- tunately, I have at my own place, under the eaves of a shed, a magnificent nest of Chali- codoma 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 daugh- 4»
Experiments
ter 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 com- pare the Instant of departure and of arrival. Things being thus arranged, I carry off my forty captives and go to the identical spot where Chalicodoma tnuraria works, In the peb- bly 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, herefore, 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 hand- ling 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 49
The Mason-bees
corner of the veil of truth is a fine and noble thing, a mighty stimulant in the face of dan- ger; but still one may be excused for display- ing 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 fin- gers 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 fin- gers 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 50
Experiments
the Cercerls-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 di- rection. Nevertheless, as far as their impetu- ous 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 homes ; 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 in- sects 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 com- plicated. 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 con- tinue their foraging; but soaring to lofty regions, whence they can obtain a clear view of the country, is, so it seems to me, pro- Si
The Mason-bees
hibited. 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 ex- citement:
"Two !" she cries. "Two arrived 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 watch- ing the Bees' return.
I had released my Insects at about two o'clock; and the first arrivals returned to the 52
Experiments
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 re- member that the Bees did some foraging on the road, as was proved by their bellies' yel- low pollen, 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 scat- tered workers to the nest, I took a fresh cen- sus 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 hap- pened. The weather had become more and 53
The Mason-bees
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 un- acquainted 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 fur- nish 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 54
Experiments
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 ex- plain it, so greatly does it transcend our own psychology.
CHAPTER III
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 per- formed 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, ex- amines 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 insect takes wing and flies away to 56
Exchanging the Nests
some distance. Her absence is of short dura- tion. 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 in- spections of the deserted spot go on for a long time, a very long time, before the mason is convinced that her nest is gone. She has cert- ainly 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 57
The Mason-bees
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 trans- planted dweUing 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 in- capable 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 im- pression of the site occupied by the nest and S8
Exchanging the Nests
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 her- self 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, re- fusing 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 gen- eral acquaintance with locality and such limi- tations 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^ have already led us to a like conclusion. iWhen the nest is laid open, these Wasps be- come 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 pre- cision is the site of the entrance-door of which nothing at all is left, not even the threshold.
iCf. Insect Life: chaps, xvi. to xtx. — Translator's Note. 59
The Mason-bees
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 set- tles without hesitation in this nest which is not here, but which stands where the other did. If she was building, I offer her a cell in process of building. She continues the ma- sonry 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 an- other'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 work- ing at the cell which is really hers.
After leaving her for a certain time in pos- session of the strange nest, I give her back 60
Exchanging the Nests
her own. This fresh change passes unper- ceived 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 experirrient 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 apart. 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 to choose between them, each Bee, on arriving, settles Immediately on the sub- stituted nest and continues her work there. Change the two nests as often as you please and you shall see the two Mason-bees keep 6i
The Mason-bees
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 con- fusion 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 gen- eration. One of these cells has been restored 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 differ- ences : one with its eight empty chambers and 62
Exchanging the Nests
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 con- sisting 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 there- fore 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 63
The Mason-bees
her nest when she started on her last jour- ney, the nucleus of a store of food. Thence- forward she behaves like her neighbour and goes on carrying honey and pollen to the warehouse which is not of her making.
Restore the nests to their original places, exchange them yet once again and both Bees, after a short hesitation which the great dif- ference 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 provision- ing 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 64
Exchanging the Nests
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 mis- take: our logic is not the logic of the in- sect, 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 be- forehand 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 in- terests. The cell which I give her is cer- tainly perfect, looked upon as a building, in the opinion of the master-builder herself, since 65
The Mason-bees
the Bee from whom I took It was completing the provision of honey. To touch It up, es- pecially 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 than 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 irresistible 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 warn- ing 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 66
Exchanging the Nests
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 67
The Mason-bees
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 desper- ate 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 ware- house, 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 realizes 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 68
Exchanging the Nests
enough to admit a pin's head. I wait longer still. Then I lose patience; and, fully con- vinced that the Bee is trying to open the store- room, I decide to help her to shorten the work. I force the lid with the point of my knife. 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 in- tention 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 un- finished cell substituted for her own. But she did not retreat before that impossible task. She accomplished her work, but in the absurd- est way: by injuriously trespassing upon an- 69
The Mason-bees
other's property, by continuing to store pro- visions in a cupboard already full to overflow- ing, 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 seri- ous repairs. What better proof could be wished of the irresistible propensity which the insect obeys?
Lastly, there are certain swift and consecu- tive actions so closely Interlinked that the performance of the second demands a previ- ous repetition of the first, even when this ac- tion has become useless. I have already described how the Yellow-winged Sphex^ per- sists In descending Into her burrow alone, after depositing at Its edge the Cricket whom I mahclously at once remove. Her re- peated 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 an- other form, a similar repetition of an act which is useless in itself, but which is the com- pulsory preface to the act that follows. When
^Cf. Insect Life: chaps, vi to ix. — Translator's Note. ?0
Exchanging the Nests
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 pre- vented. The Bee now begins the whole per- formance 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 pro- ceedings, 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, some- times again she only pretends to descend, just bending her head into the aperture; but, whether completed or not, this action, for 71
The Mason-bees
which there is no longer any motive, since the honey has already been disgorged, in- variably 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.
7a
X
CHAPTER IV
MORE ENQUIRIES INTO MASON-BEES
THIS chapter and the next were to have taken the form of a letter addressed to Charles Darwin, the illustrious naturalist, who now lies buried beside Newton in Westmin- ster 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 corre- spondence: 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 sci- entific 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 dark- est problem of the hereafter.^ I therefore abandon the epistolary form, which would be unwarranted in view of that grave at West- minster. A free and impersonal statement
'Darwin died on the 19th of April, 1882, at Down, in Kent — Translator's Note.
7^
The Mason-bees
shall set forth what I intended to relate in a more academic manner.
One thing, above all, had struck the Eng- lish scientist on reading the first volume of my Souve?iirs entomologiqiies, namely, the Mason-bees' faculty of knowing the way back to their nests after being carried to great dis- tances 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, ab- sorbed as he was by other interests. This ex- periment, 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 rela- tion to your wonderful account of insects find- ing their way home. I formerly wished to try it with pigeons; namely, to carry the in- sects in their paper cornets about a hundred paces in the opposite direction to that which you intended ultimately to carry them, but 74
More Enquiries into Mason-bees
before turning round to return, to put the In- sects 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 ani- mals may feel In which direction they were at the first start carried."
This method of experimenting seemed to me very ingeniously conceived. Before going wect, I walk eastwards. In the darkness of their paper-bags, the mere fact that I am mov- ing them gives my prisoners a sense of the di- rection 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 re- mains under Its original Impression. I am
75
The Mason-bees
now taking it to the west, when it believes it- self to be still travelling towards the east. Under the influence of this impression, the in- sect 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 con- firm my hopes. Favier,^ the very man for this sort of information, was the first to put me on the track. He told me that, when peo- ple want to move a Cat from one farm to another at some distance, they place the ani- mal in a bag, which they twirl rapidly at the moment of starting, thus preventing the ani- mal from returning to the house which it has quitted. Many others, besides Favier, de- scribed 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
^The authors gardener and factotum. Cf. The Life of the Fly: chap. iv. — Translator's Note. 76
More Enquiries into Mason-bees
amazed; so was I; and we both of us almost reckoned on a success.
These preliminaries took place In the win- ter; I had plenty of time to prepare for tdie experiment which was to be made in the fol- lowing 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 neigh- bour assented with a good grace to the ex- change 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 rectangu- lar 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 Mason-bees
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 accu- mulate, 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 Sowvenirs. Under my erroneous denomination of Chali- codoma 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 vari- ous names, which are, in order of priority: Chalicodoma fyrenaica, Ler. {Megacliile) ; Chalicodoma pyrrhopeza, Gerstacker; Chalicodoma rufitarsis, Giraud. It is a pity 78
More Enquiries into Mason-bees
These treasures were insufficient, not in re- gard 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 in- sects issuing from those nests might be heredi- tarily influenced by their ancestors, who had lived in the shed for many a long year. The Bee, when carried to a distance, would per- haps come back, guided by the inveterate family habit; she would find the shed of her lineal predecessors and thence, without diffi- culty, 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
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 ento- mology. 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 the erudite Professor Jean Perez, of Bordeaux, who is so well-versed in the lore of Wasps and Bees. — Author's Note.
79
rhe Mason-bees
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 them- selves in a numerous colony. He proposed to take the wheel-barrow, in which to move the blocks of cells; but I objected: the jolt- ing of the vehicle over the rough paths might jeopardize 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^ 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
iPrangois Le Vaillant (1753-1824), a distinguished French naturalist, born in Dutch Guiana. "Republicans" are Social Weaver-birds. — Translator's Note.
80
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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 my- self 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 scorch- ing 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 would have them grow attached to the new- dwelling.
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 some- thing 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 8i
The Mason-bees
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:
"I wonder what he's going to make out of that!" say they.
My hives are in full swing before the end of April. When the work is at its height, the swarm becomes a little eddying, buzzing cloud. The arch is a much-frequented passage: it leads to a store-room for various household provisions. The members of my family bully me at first for establishing this dangerous commonwealth within the precincts of our home. They dare not go to fetch things: they would have to pass through a swarm of Bees; and then . . . look out for stings ! There is nothing for it but to prove, once and for all, that the danger does not exist, that mine is a most peaceable Bee, in- capable of stinging so long as she is not startled. I bring my face close to one of the clay nests, so as almost to touch it, while it is black with masons at work; I let my fingers wander through the ranks, I put a few Bees on my hand, 1 stand in the thick of the whirl- ing crowd and never a prick do I receive. I 82
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have long known their peaceful character. Time was when I used to share the common fears, when I hesitated before venturing into a swarm of Anthophorae or Chalicodomae; nowadays, I have quite got over those terrors. If you do not tease the insect, the thought of hurting you will never occur to it. At the worst, a single specimen, prompted by curi' osity rather than anger, will come and hover in front of your face, examining you with some persistency, but employing a buzz as her only threat. Let her be : her scrutiny is quite friendly.
After a few demonstrations, my household were reassured: all, old and young, moved in and out of the arch as though there were no- thing unusual about it. My Bees, far from re- maining an object of dread, became an object of diversion ; every one took pleasure in watch- ing the progress of their ingenious work. I was careful not to divulge the secret to strangers. If any one, coming on business, passed outside the arch while I was stand- ing before the hanging nests, some such brief dialogue as the following would take place:
"So they know you ; that's why they don't sting you?"
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The Mason-bees
"They certainly know me."
"And me?"
"Oh, you : that's another matter !"
Whereupon the intruder would keep at a respectful distance, which was what I wanted.
It is time that we thought of experiment- ing. The Mason-bees intended for the jour- ney must be marked with a sign whereby I may know them. A solution of gum arabic, thickened with a colouring-powder, red, blue or some other shade, is the material which I use to mark my travellers. The variety in hue will save me from confusing the subjects of my different experiments.
When making my former investigations, I used to mark the Bees at the place where I set them free. For this operation, the in- sects had to be held in the fingers one after the other; and I v/as thus exposed to frequent stings, v/hich smarted all the more for being constantly repeated. The consequence was that I was not always quite able to control my fingers and thumbs, to the great detriment of my travellers ; for I could easily warp their wing-joints and thus weaken their flight. It was worth while improving the method of operation, both in my own interest and in that
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of the insect. I must mark the Bee, carry her to a distance and release her, without taking her in my fingers, without once touching her. The experiment was bound to gain by these nice precautions. I will describe the method which I adopted.
The Bee is so much engrossed in her work when she buries her abdomen in the cell and rids herself of her load of pollen, or when she is building, that it is easy, at such times, without alarming her, to mark the upper side of the thorax with a straw dipped in the col- oured glue. The insect is not disturbed by that slight touch. It flies off; it returns laden with mortar or pollen. You allow these trips to be repeated until the mark on the thorax is quite dry, which soon happens in the hot sun necessary to the Bee's labours. The next thing is to catch her and Imprison her in a paper bag, still without touching her. No- thing could be easier. You place a small test- tube over the Bee engrossed in her work; the insect, on leaving, rushes into it and is thence transferred to the paper bag, which is forth- with closed and placed in the tin box that will serve as a conveyance for the whole party. When releasing the Bees, all you have to do is 85
The Mason-bees
to open the bags. The whole performance is thus effected without once giving that di- stressing squeeze of the fingers.
Another question remains to be solved be- fore we go further. What time-limit shall I allow for this census of the Bees that return to the nest? Let me explain what I mean. The dot which I have made in the middle of the thorax with a touch of my sticky straw Is not very permanent : it merely adheres to the hairs. At the same time, it would have been no more lasting if I had held the insect in my fingers. Now the Bee often brushes her back: she dusts it each time she leaves the galleries; besides, she is always rubbing her coat against the walls of the cell, which she has to enter and to leave each time she brings honey. A Mason-bee, so smartly dressed at the start, at the end of her work is in rags; her fur is all worn bare and as tattered as a mechanic's overall.
Furthermore, in bad weather, the Mason- bee of the Walls spends the days and nights in one of the cells of her dome, suspended head downwards. The Mason-bee of the Sheds, as long as there are vacant galleries, does very nearly the same : she takes shelter 86
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in the galleries, but with her head at the en- trance. But once those old habitations are in use and the building of new cells begun, she selects another retreat. In the harmas,^ as I have said, are stone heaps, intended for building the surrounding wall. This is where my Chalicodomce pass the night. Piled up promiscuously, both sexes together, they sleep in numerous companies, in crevices between two stones laid closely one on top of the other. Some of these companies number as many as a couple of hundred. The most common dormitory is a narrow groove. Here they all huddle, as far forward as possible, with their backs in the groove. I see some lying flat on their backs, like people asleep. Should bad weather come on, should the sky cloud over, should the north-wind whistle, they do not stir out.
With all these things to take into consider- ation, I cannot expect my dot on the Bee"'s thorax to last any length of time. By day, the constant brushing and the rubbing against the partitions of the galleries soon wipe it off;
*The waste ground on which the author studies his in- sects in the natural state. Cf. The Life of the Fly: chap. i. — Translator's Note. 87
The Mason-bees
at night, things are worse still, in the narrow sleeping-room where the Mason-bees take refuge by the hundred. After a night spent in the crevice between two stones, it is not ad- visable to trust to the mark made yesterday. Therefore, the counting of the number of Bees that return to the nest must be taken in hand at once; to-morrow would be too late. And so, as it would be impossible for me to recognize those of my subjects whose dots had disappeared during the night, I will take into account only those Bees who return on the same day.
The question of the rotary machine re- mains. Darwin advised me to use a circular box with an axle and a handle. I have no- thing of the kind in the house. It will be simpler and quite as effective to employ the method of the countryman who tries to lose his Cat by swinging him in a bag. My in- sects, each one placed by itself in a paper cornet^ or screw, shall be placed in a tin box; the screws of paper shall be wedged in so as
*A cornet is simply the old "sugar-bag," the funnel- shaped paper bag so common on the continent and still used occasionally by small grocers and tobacconists in England. — Translator's Note.
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to avoid collisions during the rotation; lastly, the box shall be tied to a cord and I will whirl the whole thing round like a sling. With this contrivance, it will be quite easy to obtain any rate of speed that I wish, any variety of inverse movements that I consider likely to make my captives lose their bearings. I can whirl my sling first in one direction and then in another, turn and turn about; I can slacken or increase the pace; if I like, I can make it describe figures of eight, combined with cir- cles; if I spin on my heels at the same time, I am able to make the process still more com- plicated by compelling my sling to trace every known curve. That is what I shall do.
On the 2d of May, 1880, I make a white mark on the thorax of ten Mason-bees busied with various tasks : some are exploring the slabs of clay in order to select a site; others are bricklaying; others are laying in stores. When the mark is dry, I catch them and pack them as I have described. I first carry them a quarter of a mile in the opposite direction to the one which I intend to take. A path skirting my house favours this preliminary manoeuvre ; I have every hope of being alone when the time comes to make play with my 89
The Mason-bees
sling. There is a wayside cross at the end; I stop at the foot of the cross. Here I swing my Bees in every direction. Now, while I am making the box describe inverse circles and loops, while I am pirouetting on my heels to achieve the various curves, up comes a woman from the village and stares at me. Oh, how she stares at me, what a look she gives me ! At the foot of the cross! Acting in such a silly way! People talked about it. It was sheer witchcraft. Had I not dug up a dead body, only a few days before? Yes, I had been to a prehistoric burial-place, I had taken from it a pair of venerable, well-developed tibias, a set of funerary vessels and a few shoulders of horse, placed there as a viaticum for the great journey. I had done this thing; and people knew it. And now, to crown all, the man of evil reputation is found at the foot of a cross indulging in unhallowed antics. No matter — and it shows no small courage on my part — the gyrations are duly accom- plished in the presence of this unexpected wit- ness. Then I retrace my steps and walk west- ward of Serignan. I take the least-frequented paths, I cut across country so as, if possible, to avoid a second meeting. It would be the last 90
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straw if I were seen opening my paper bags and letting loose my insects! When half- way, to make my experiment more decisive still, I repeat the rotation, in as complicated a fashion as before. I repeat it for the third time at the spot chosen for the release.
I am at the end of a flint-strewn plain, with here and there a scanty curtain of almond- trees and holm-oaks. Walking at a good pace, I have taken thirty minutes to cover the ground in a straight line. The distance, therefore, is, roughly, two miles. It is a fine day, under a clear sky, with a very light breeze blowing from the north. I sit down on the ground, facing the south, so that the in- sects may be free to take either the direction of their nest or the opposite one. I let them loose at a quarter past two. When the bags are opened, the Bees, for the most part, circle several times around me and then dart off impetuously in the direction of Serignan, as far as I can judge. It is not easy to watch them, because they fly off suddenly, after go- ing two or three times round my body, a suspicious-looking object which they wish, ap- parently, to reconnoitre before starting. A quarter of an hour later, my eldest daughter,
■31
The Mason-bees
Antonia, who is on the look-out beside the nests, sees the first traveller arrive. On my return, in the course of the evening, two others come back. Total: three of my Masons home on the same day, out of ten scattered abroad.
I resume the experiment next day. I mark ten Mason-bees with red, which will enable me to distinguish them from those who re- turned on the day before and from those who may still return with the white spot uneffaced. The same precautions, the same rotations, the same localities as on the first occasion; only, I make no rotation on the way, confining my- self to swinging my box round on leaving and on arriving. The insects are released at a quarter past eleven. I prefer the morning, as this was the busiest time at the works. One Bee was seen by Antonia to be back at the nest by twenty minutes past eleven. Supposing her to be the first let loose, it took her just five minutes to cover the distance. But there Is nothing to tell me that it is not another, in which case she needed less. It is the fastest speed that I have succeeded in noting. I my- self am back at twelve and, within a short time, catch three others. I see no more 92
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during the rest of the evening. Total: four home, out of ten.
The 4th of May is a very bright, calm, warm day, weather highly propitious for my experiments. I take fifty Chalicodomse marked with blue. The distance to be travel- led remains the same. I make the first ro- tation after carrying my insects a few hun- dred steps in the direction opposite to that which I finally take; in addition, three rota- tions on the road; a fifth rotation at the place where they are set free. If they do not lose their bearings this time, It will not be for lack of twisting and turning. I begin to open my screws of paper at twenty minutes past nine. It Is rather early, for which reason my Bees, on recovering their liberty, remain for a mo- ment undecided and lazy; but, after a short sun-bath on a stone where I place them, they take wing. I am sitting on the ground, facing the south, with Serlgnan on my left and Plolenc on my right. When the flight Is not too swift to allow me to perceive the direction taken, I see my released captives disappear to my left. A few, but only a few, go south; two or three go west, or to right of me. I do not speak of the north, against which I act
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as a screen. All told, the great majority take the left, that Is to say, the direction of the nest. The last is released at twenty minutes to ten. One of the fifty travellers has lost her mark in the paper bag. I deduct her from the total, leaving forty-nine.
According to Antonia, who watches the home-coming, the earliest arrivals appeared at twenty-five minutes to ten, say fifteen min- utes after the first was set free. By twelve o'clock mid-day, there are eleven back; and, by four o'clock In the evening, seventeen. That ends the census. Total: seventeen, out of forty-nine.
I resolved upon a fourth experiment, on the 14th of May. The weather Is glorious, with a light northerly breeze. I take twenty Mason-bees marked in pink, at eight o'clock In the morning. Rotations at the start, after a preliminary backing In a direction opposite to that which I intend to take; two rotations on the road; a fourth on arriving. All those whose flight I am able to follow with my eyes turn to my left, that is to say, towards Serlgnan. Yet I had taken care to leave the choice free between the two opposite direc- tions : In particular, I had sent away my Dog, 94
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who was on my right. To-day, the Bees do not circle round me: some fly away at once; the others, the greater number, feeling giddy perhaps after the pitching of the journey and the rolling of the sling, alight on the ground a few yards away, seem to wait until they are somewhat recovered and then fly off to the left. I perceived this to be the general flight, whenever I was able to observe at all. I was back at a quarter to ten. Two Bees with pink marks were there before me, of whom one was engaged in building, with her pellet of mortar In her mandibles. By one o'clock in the afternoon there were seven arrivals; I saw no more during the rest of the day. Total: seven, out of twenty.
Let us be satisfied with this: the experi- ment has been repeated often enough, but It does not conclude as Darwin hoped, as I my- self hoped, especially after what I have been told about the Cat. In vain, adopting the advice given, do I carry my insects, first In the opposite direction to the place at which I intend to release them; In vain, when about to retrace my steps, do I whirl my sling with every complication In the way of whirls and twists that
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I am able to imagine; in vain, thinking to increase the difliculties, do I repeat the rota- tion as often as five times over: at the start, on the road, on arriving; it makes no differ- ence: the Mason-bees return and the pro- portion of returns on the same day fluctuates between thirty and forty per cent. It goes to my heart to abandon an idea suggested by so famous a man of science and cherished all the more readily inasmuch as I thought it likely to provide a final solution. The facts are there, more eloquent than any number of ingenious views; and the problem remains as mysterious as ever.
In the following year, 1881, I began experi- menting again, but in a different way. Hitherto, I had worked on the level. To re- turn to the nest, my lost Bees had only to cross slight obstacles, the hedges and spin- neys of the tilled fields. To-day, I propose to add to the difliculties of distance those of the ground to be traversed. Discontinuing all my backing- and whirling-tactics, things which I recognize as useless, I think of re- leasing my Chalicodomae in the thick of the Serignan Woods. How will they escape from that labyrinth, where, in the early days, I 96
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needed a compass to find my way? More- over, I shall have an assistant with me, a pair of eyes younger than mine and better-fitted to follow my insects' first flight. That immedi- ate start in the direction of the nest has al- ready been repeated very often and is begin- ning to interest me more than the return it- self. A pharmaceutical student, spending a few days with his parents, shall be my eye- witness. With him, I feel at ease; science and he are no strangers.
The trip to the woods takes place on the 1 6th of May. The weather is hot and hints at a coming storm. There is a perceptible breeze from the south, but not enough to up- set my travellers. Forty Mason-bees are caught. To shorten the preparations, because of the distance, I do not mark them while they are on the nests; I shall mark them at the starting-point, as I release them. It is the old method, prolific of stings; but I prefer it to-day, in order to save time. It takes me an hour to reach the place. The distance, therefore, allowing for windings, is about three miles.
The site selected must permit me to recog- nize the direction of the insects' first flight. 97
The Mason-bees
I choose a clearing in the middle of the copses. All around is a great expanse of dense woods, shutting out the horizon on every side; on the south, in the direction of the nests, a cur- tain of hills rises to a height of some three hundred feet above the spot at which I stand. The wind is not strong, but it is blowing in the opposite direction to that which my in- sects will have to take in order to reach their home. I turn my back on Serignan, so that, when leaving my fingers, the Bees, to return to the nest, will be obliged to fly sideways, to right and left of me; I mark the insects and release them one by one. I begin operations at twenty minutes past ten.
One-half of the Bees seem rather indolent, flutter about for a while, drop to the ground, appear to recover their spirits and then start off. The other half show greater decision. Although the insects have to fight against the soft wind that is blowing from the south, they make straight for the nest. All go south, after describing a few circles, a few loops around us. There is no exception in the case of any of those whose departure we are able to follow. The fact is noted by myself and my colleague beyond dispute or doubt. My 98
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Mason-bees head for the south as though some compass told them which way the wind was blowing.
I am back at twelve o'clock. None of tht strays is at the nest; but, a few minutes later, I catch two. At two o'clock, the number has increased to nine. But now the sky clouds over, the wind freshens and the storm is ap- proaching. We can no longer rely on any further arrivals. Total: nine, out of forty, or twenty-two per cent.
The proportion is smaller than in the former cases, when it varied between thirty and forty per cent. Must we attribute this result to the difficulties to be overcome? Can the Mason-bees have lost their way in the maze of the forest? It is safer not to give an opinion : other causes intervened which may have decreased the number of those who rcturn'ed. I marked the insects at the starting- place; I handled them; and I am not prepared to say that they were all in the best of con- dition on leaving my stung and smarting fingers. Besides, the sky has become over- cast, a storm is imminent. In the month of May, so variable, so fickle, in my part of the world, we can hardly ever count on a whole 99
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day of fine weather. A splendid morning Is swiftly followed by a fitful afternoon; and my experiments with Mason-bees have often suf- fered by these variations. All things con- sidered, I am Inclined to think that the home- ward journey across the forest and the mount- ain Is effected just as readily as across the corn-fields and the plain.
I have one last resource left whereby to try and put my Bees out of their latitude. I will first take them to a great distance; then, describing a wide curve, I will return by an- other road and release my captives when I am near enough to the village, say, about two miles. A conveyance Is necessary, this time. My collaborator of the day in the woods of- fers me the use of his gig. The two of us set off, with fifteen Mason-bees, along the road to Orange, until we come to the viaduct. Here, on the right, is the straight ribbon of the old Roman road, the Via Domitia. We take it, driving north towards the Uchaux Mountains, the classic home of superb Turo- nlan fossils. We next turn back towards Serlgnan, by the Piolenc Road. A halt is made by the stretch of country known as Font- Claire, the distance from which to the village
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is about one mile and five furlongs. The reader can easily follow my route on the ordnance-survey map; and he will see that the loop described measures not far short of five miles and a half.
At the same time, Favier came and joined me at Font-Claire, by the direct road, the one that runs through Piolenc. He brought with him fifteen Mason-bees, intended for purposes of comparison with mine. I am, therefore, in possession of two sets of insects. Fifteen, marked in pink, have taken the five-mile bend; fifteen, marked in blue, have come by the straight road, the shortest road for returning to the nest. The weather is warm, exceedingly bright and very calm; I could not hope for a better day for my experiment. The insects are given their freedom at mid-day.
At five o'clock, the arrivals number seven of the pink Mason-bees, whom I thought that I had bewildered by a long and circuitous drive, and six of the blue Mason-bees, who came to Font-Claire by the direct route. The two proportions, forty-six and forty per cent., are almost equal; and the slight excess in fa- vour of the insects that went the roundabout way Is evidently an accidental result which we
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need not take Into consideration. The bend described cannot have helped them to find their way home ; but it has also certainly not hampered them.
There is no need of further proof. The in- tricate movements of a rotation such as I have described; the obstacle of hills and woods; the pitfalls of a road which moves on, moves back and returns after making a wide circuit: none of these is able to disconcert the Chali- codomse or prevent them from going back to the nest.
I had written to Charles Darwin telling him of my first, negative results, those ob- tained by swinging the Bees round in a box. He expected a success and was much surprised at the failure. Had he had time to experi- ment with his pigeons, they would have be- haved just like my Bees; the preliminary twirling .would not have affected them. The problem called for another method; and what he proposed was this:
"To place the Insect within an Induction- coil, so as to disturb any magnetic or dlamag- netic sensibility which It seems just possible that they may possess."
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To treat an Insect as you would a mag- netic needle and to subject it to the current from an induction-coil in order to disturb Its magnetism or diamagnetism appeared to me, I must confess, a curious notion, worthy of an imagination in the last ditch. I have but little confidence In our physics, when they pre- tend to explain life; nevertheless, my respect for the great man would have made me re- sort to the Induction-coils, If I had possessed the necessai-y apparatus. But my village boasts no scientific resources: If I want an electric spark, I am reduced to rubbing a sheet of paper on my knees. My physics cupboard contains a magnet; and that Is about all. When this penury was realized, another method was suggested, simpler than the first and more certain In Its results, as Darwin him- self considered:
"To mak" a very thin needle Into a mag- net; then breaking It into very short pieces, which would still be magnetic, and fastening one of these pieces with some cement on the thorax of the Insects to be experimented on. I believe that such a little magnet, from its close proximity to the nervous system of the 103
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insect, would affect It more than would the terrestrial currents."
There is still the same idea of turning the insect into a sort of bar magnet. The ter- restrial currents guide it when returning to the nest. It becomes a living compass which, withdrawn from the action of the earth by the proximity of a loadstone, loses its sense of direction. With a tiny magnet fastened on its thorax, parallel with the nervous system and more powerful than the terrestrial mag- netism by reason of its comparative nearness, the insect will lose its bearings. Naturally, in setting down these lines, I take shelter be- hind the mighty reputation of the learned be- getter of the idea. It v/ould not be accepted as serious coming from a humble person like myself. Obscurity cannot afford these auda- cious theories.
The experiment seems easy; it is not be- yond the means at my disposal. Let us at- tempt it. I magnetize a very fine needle by rubbing it with my bar magnet; I retain only the slenderest part, the point, some five or six millimetres long.^ This broken piece is a
*.2 to .23 inch. — Translator's Note. 104
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perfect magnet : it attracts and repels another magnetized needle hanging from a thread. I am a little puzzled as to the best way to fasten it on the insect's thorax. My assistant of the moment, the pharmaceutical student, requisitions all the adhesives in his labora- tory. The best is a sort of cerecloth which he prepares specially with a very fine mate- rial. It possesses the advantage that it can be softened at the bowl of one's pipe when the time comes to operate out of doors.
I cut out of this cerecloth a small square the size of the Bee's thorax; and I insert the magnetized point through a few threads of the material. All that we now have to do is to soften the gum a little and then dab the thing at once on the Mason-bee's back, so that the broken needle runs parallel with the spine. Other engines of the same kind are prepared and due note taken of their poles, so as to enable me to point the south pole at the insect's head in some cases and at the op- posite end In others.
My assistant and I began by rehearsing the
performance; we must have a little practice
before trying the experiment away from
home. Besides, I want to see how the insect
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will behave in its magetic harness. I take a Mason-bee at work in her cell, which I mark. I carry her to my study, at the other end of the house. The magnetized outfit is fastened on the thorax ; and the insect is let go. The moment she is free, the Bee drops to the ground and rolls about, like a mad thing, on the floor of the room. She resumes her flight, flops down again, turns over on her side, on her back, knocks against the things in her way, buzzes noisily, flings herself about de- sperately and ends by daring through the open window in headlong flight.
What does it all mean? The magnet ap- pears to have a curious effect on my patient's system ! What a fuss she makes ! How ter- rified she is! The Bee seemed utterly dis- traught at losing her bearings tinder the in- fluence of my knavish tricks. Let us go to the nests and see what happens. We have not long to wait : my insect returns, but rid of its magnetic tackle. I recognize it by the traces of gum that still cling to the hair of the thorax. It goes back to its cell and resumes its labours.
Always on my guard when searching the unknown, unwilling to draw conclusions be- io6
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fore weighing the arguments for and against, I feel doubt creeping in upon me with regard to what I have seen. Was It really the mag- netic Influence that disturbed my Bee so strangely? When she struggled and kicked on the floor, fighting wildly with both legs and wings, when she fled in terror, was she under the sway of the magnet fastened on her back? Can my appliance have thwarted the guiding Influence of the terrestrial currents on her nervous system? Or was her distress merely the result of an unwonted harness? This Is what remains to be seen and that with- out delay.
I construct a new apparatus, but provide it with a short straw In place of the magnet. The insect carrying It on Its back rolls on the ground, kicks and flings herself about like the first, until the Irksome contrivance Is removed, taking with It a part of the fur on the thorax. The straw produces the same effects as the magnet, in other words, magnetism had no- thing to do with what happened. My inven- tion, In both cases alike. Is a cumbrous tackle of which the Bee tries to rid herself at once by every possible means. To look to her for normal actions so long as she carries an ap- 107
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paratus, magnetized or not, upon her back is the same as expecting to study the natural habits of a Dog after tying a kettle to his tail. The experiment with the magnet is im- practicable. What would it tell us if the in- sect consented to it? In mxy opinion, it would tell us nothing. In the matter of. the homing instinct, a magnet would have no more influ- ence than a bit of straw.
xo8
CHAPTER V
THE STORY OF MY CATS
IF THIS swinging-process fails entirely when its object is to make the insect lose its bearings, what influence can it have upon the Cat? Is the method of whirling the ani- mal round In a bag, to prevent Its return, worthy of confidence? I believed In it at first, so close-allied was it to the hopeful idea suggested by the great Darwin. But my faith is now shaken : my experience with the insect makes me doubtful of the Cat. If the former returns after being whirled, why should not the latter?. I therefore embark upon fresh experiments.
And, first of all, to what extent does the Cat deserve his reputation of being able to return to the beloved home, to the scenes of his amorous exploits, on the tiles and in the hay-lofts? The most curious facts are told of his instinct; children's books on natural his- tory abound with feats that do the greatest credit to his prowess as a pilgrim. I do not 109
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attach much importance to these stones : they come from casual observers, uncritical folk given to exaggeration. It is not everybody who can talk about animals correctly. When some one not of the craft gets on the subject and says to me, "Such or such an animal is black," I begin by finding out if it does not happen to be white ; and many a time the truth Is discovered in the converse proposition. Men come to me and sing the praises of the Cat as a travelling expert. Well and good: we will now look upon the Cat as a poor tra- veller. And that would be the extent of my knowledge If I had only the evidence of books and of people unaccustomed to the scruples of scientific examination. Fortunately, I am acquainted with a few Incidents that will stand the test of my Incredulity. The Cat really de- serves his reputation as a discerning pilgrim. Let us relate these incidents.
One day — it was at Avignon — there ap- peared upon the garden-wall a wretched- looking Cat, with matted cqat and protru- ding ribs; so thin that his back was a jagged ridge. He was mewing with hunger. My children, at that time very young, took pity on his misery. Bread soaked In milk was of-
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The Story of My Cats
fered him at the end of a reed. He took it. And the mouthfuls succeeded one another to such good purpose that he was sated and went off, heedless of the "Puss! Puss!" of his com- passionate friends. Hunger returned; and the starveling reappeared in his wall-top refectory. He received the same fare of bread soaked in milk, the same soft words. He allowed himself to be tempted. He came down from the wall. The children were able to stroke his back. Goodness, how thin he
was!
It was the great topic of conversation. We discussed it at table : we would tame the vagabond, we would keep him, we would make him a bed of hay. It was a most im- portant matter: I can see to this day, I shall always see the council of rattleheads deli- berating on the Cats fate. They were not satisfied until the savage animal remained. Soon he grew into a magnificent Tom. His large round head, his muscular legs, his red- dish fur, flecked with darker patches, re- minded one of a little jaguar. He was christened Ginger because of his tawny hue. A mate joined him later, picked up in almost similar circumstances. Such was the origin
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of my series of Gingers, which I have re- tained for little short of twenty years through the vicissitudes of my various removals.
The first of these removals took place in 1870. A little earlier, a minister who has left a lasting memory in the University, that fine man, Victor Duruy,^ had instituted classes for the secondary education of girls. This was the beginning, as far as was then possi- ble, of the burning question of to-day. 1 very gladly lent my humble aid to this labour of light. I was put to teach physical and natural science. I had faith and was not sparing of work, with the result that I rarely faced a more attentive or interested audience. The days on which the lessons fell were red-letter days, especially when the lesson was botany and the table disappeared from view under the treasures of the neighbouring conserva- tories.
That was going too far. In fact, you can see how heinous my crime was : I taught those young persons what air and water are;
^Jean Victor Duruy (1811-1894), author of a number of historical works, including a well-known Histoire des romains, and minister of public instruction under Napo- leon III. from 1863 to 1869. Cf. The Life of the Fly: chap, XX. — Translator's Note.
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whence the lightning comes and the thunder; by what device our thoughts are transmitted across the seas and continents by means of a metal wire; why fire burns and why we breathe; how a seed puts forth shoots and how a flower blossoms: all eminently hateful things in the eyes of some people, whose fee- ble eyes are dazzled by the light of day.
The little lamp must be put out as quickly as possible and measures taken to get rid of the officious person who strove to keep it alight. The scheme was darkly plotted with the old maids who owned my house and who saw the abomination of desolation in these new educational methods. I had no written agreement to protect me. The bailiff appeared with a notice on stamped paper. It baldly informed me that I must move out within four weeks from date, failing which the law would turn my goods and chattels into the street. I had hurriedly to provide myself with a dwelling. The first house which we found happened to be at Orange. Thus was my exodus from Avignon effected.
We were somewhat anxious about the mo- ving of the Cats. We were all of us attached to them and should have thought it nothing "3
The Mason-bees
short of criminal to abandon the poor crea- tures, whom we had so often petted, to di- stress and probably to thoughtless persecution. The shes and the kittens would travel with- out any trouble: all you have to do is to put them in a basket; they will keep quiet on the journey. But the old Tom-cats were a seri- ous problem. I had two: the head of the family, the patriarch; and one of his descend- ants, quite as strong as himself. We decided to take the grandsire, if he consented to come, and to leave the grandson behind, after find- ing him a home.
My friend Dr. Loriol offered to take charge of the forsaken one. The animal was carried to him at nightfall in a closed hamper. Hardly were we seated at the evening-meal, talking of the good fortune of our Tom-cat, when we saw a dripping mass jump through the window. The shapeless bundle came and rubbed itself against our legs, purring with happiness. It was the Cat.
I learnt his story next day. On arriving at Dr. Loriol's, he was locked up In a bedroom. The moment he saw himself a prisoner in the unfamiliar room, he began to jump about wildly on the furniture, against the window- 114
The Story of My Cats
panes, among the ornaments on the mantel- piece, threatening to make short work of everything. Mme. Loriol was frightened by the Httle lunatic; she hastened to open the window; and the Cat leapt out among the passers-by. A few minutes later, he was back at home. Arjd it was no easy matter : he had to cross the town almost from end to end; he had to make his way through a long laby- rinth of crowded streets, amid a thousand dan- gers, including first boys and next dogs; lastly — and this perhaps was an even more serious obstacle — he had to pass over the Sorgue, a river running through Avignon. There were bridges at hand, many, in fact; but the animal, taking the shortest cut, had used none of them, bravely jumping Into the water, as Its streaming fur showed. I had pity on the poor Cat, so faithful to his home. We agreed to do our utmost to take him with us. We were spared the worry: a few days later, he was found lying stiff and stark under a shrub In the garden. The plucky animal had fallen a victim to some stupid act of spite. Some one had poisoned him for me. Who? It Is not likely that it was a friend!
There remained the old Cat. He was not "5
The Mason-bees
indoors when we started; he was prowling round the hay-lofts of the neighbourhood. The carrier was promised an extra ten francs if he brought the Cat to Orange with one of the loads which he had still to convey. On his last journey he brought him stowed away under the driver's seat. I scarcely knew my old Tom when we opened the moving prison in which he had been confined since the day before. He came out looking a most alarm- ing beast, scratching and spitting, with bristling hair, bloodshot eyes, lips white with foam. I thought him mad and watched him closely for a time. I was wrong : it was merely the fright of a bewildered animal. Had there been trouble with the carrier when he was caught? Did he have a bad time on the journey? History is silent on both points. What I do know is that the very nature of the Cat seemed changed: there was no more friendly purring, no more rubbing against our legs; nothing but a wild expression and the deepest gloom. Kind treatment could not soothe him. For a few weeks longer, he dragged his wretched existence from corner to corner; then, one day, I found him lying dead in the ashes on the hearth. Grief, with ii6
The Story of My Cats
the help of old age, had killed him. Would he have gone back to Avignon, had he had the strength? I would not venture to affirm it. But, at least, I think it very remarkable that an animal should let itself die of home- sickness because the infirmities of age prevent it from returning to its old haunts.
What the patriarch could not attempt, we shall see another do, over a much shorter di- stance, I admit. A fresh move is resolved upon, to give me, at long length, the peace and quiet essential to my work. This time, I hope that it will be the last. I leave Orange for Serignan.
The family of Gingers has been renewed: the old ones have passed away, new ones have come, including a full-grown Tom, worthy in all respects of his ancestors. He alone will give us some difficulty; the others, the babies and the mothers, can be removed without trouble. We put them into baskets. The Tom has one to himself, so that the peace may be kept. The journey is made by car- riage, in company with my family. Nothing striking happens before our arrival. Re- leased from their hampers, the females In- spect the new home, explore the rooms one
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The Mason-bees
by one; with their pink noses they recognize the furniture: they find their own seats, their own tables, their own arm-chairs; but the sur- roundings are dijEferent. They give little sur- prised miaows and questioning glances. A few caresses and a saucer of milk allay all their apprehensions; and, by the next day, the mother Cats are acclimatized.
It is a different matter with the Tom. We house him in the attics, where he will find ample room for his capers; we keep him com- pany, to relieve the weariness of captivity; we take him a double portion of plates to lick; from time to time, we place him in touch with some of his family, to show him that he is not alone in the house ; we pay him a host of at- tentions, in the hope of making him forget Orange. He appears, in fact, to forget it: he is gentle under the hand that pets him, he comes when called, purrs, arches his back. It is well: a week of seclusion and kindly treat- ment have banished all notions of returning. Let us give him his liberty. He goes down to the kitchen, stands by the table like the others, goes out into the garden, under the watchful eye of Aglae, who does not lose sight of him; he prowls all around with the most ii8
The Story of My Cats
innocent air. He comes back. Victory ! The Tom-cat will not run away.
Next morning:
"Puss! Puss!"
Not a sign of him! We hunt, we call. Nothing, Oh, the hypocrite, the hypocrite ! How he has tricked us! He has gone, he is at Orange. None of those about me can be- lieve in this venturesome pilgrimage. I de- clare that the deserter is at this moment at Orange mewing outside the empty house.
Aglae and Claire went to Orange. They found the Cat, as I said they would, and brought him back in a hamper. His paws and belly were covered with red clay; and yet the weather was dry, there was no mud. The Cat, therefore, must have got wet crossing the Aygues torrent; and the moist fur had kept the red earth of the fields through which he had passed. The distance from Serignan to Orange, in a straight line, is four and a half miles. There are two bridges over the Aygues, one above and one below that line, some distance away. The Cat took neither the one nor the other: his instinct told him the shortest road and he followed that road, as his belly, covered with red mud, proved. 119
The Mason-bees
He crossed the torrent In May, at a time when the rivers run high; he overcame his repug- nance to water in order to return to his be- loved home. The Avignon Tom did the same when crossing the Sorgue.
The deserter was reinstated In his attic at Serignan. He stayed there for a fortnight; and at last we let him out. Twenty-four hours had not elapsed before he was back at Orange. We had to abandon him to his un- happy fate. A neighbour living out in the country, near my former house, told me that he saw him one day hiding behind a hedge with a rabbit in his mouth. Once no longer provided with food, he, accustomed to all the sweets of a Cat's existence, turned poacher, taking toll of the farm-yards round about my old home. I heard no more of him. He came to a bad end, no doubt : he had become a rob- ber and must have met with a robber's fate.
The experiment has been made and here is the conclusion, twice proved. Full-grown Cats can find their way home, in spite of the distance and their complete ignorance of the intervening ground. They have, in their own fashion, the instinct of my Mason-bees. A second point remains to be cleared up, that
I20
The Story of My Cats
of the swinging motion in the bag. Are they thrown out of their latitude by this stratagem, or are they not? I was thinking of making some experiments, when more precise infor- mation arrived and taught me that it was not necessary. The first who acquainted me with the method of the revolving bag was telling the story told him by a second person, who repeated the story of a third, a story related on the authority of a fourth; and so on. None had tried it, none had seen it for him- self. It is a tradition of the country-side. One and all extol it as an infallible method, without, for the most part, having attempted it. And the reason which they give for its success is, in their eyes, conclusive. If, say they, we ourselves are blindfolded and then spin round for a few seconds, we no longer know where we are. Even so with the Cat carried off in the darkness of the swinging bag. They argue from man to the animal, just as others argue from the animal to man: a faulty method in either case, if there really be two distinct psychic worlds.
The belief would not be so deep-rooted In the peasant's mind, if facts had not from time to time confirmed it. But we may assume
121
The Mason-bees
that, in successful cases, the Cats made to lose their bearings were young and unemanci- pated animals. With those neophytes, a drop of milk is enough to dispel the grief of exile. They do not return home, whether they have been whirled in a bag or not. People have thought it as well to subject them to the whirl- ing operation by way of an additional precau- tion; and the method has received the credit of a success that has nothing to do with it. In order to test the method properly, it should have been tried on a full-grown Cat, a genu- ine Tom.
I did in the end get the evidence which I wanted on this point. Intelligent and trust- worthy people, not given to jumping to con- clusions, have told me that they have tried the trick of the swinging bag to keep Cats from returning to their homes. None of them succeeded when the animal was full-grown. Though carried to a great distance, into an- other house, and subjected to a conscientious series of revolutions, the Cat always came back. I have in mind, more particularly a destroyer of the Gold-fish in a fountain, who, when transported from Serignan to Piolenc, according to the time-honoured method, re-
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The Story of My Cats
turned to his fish ; who, when carried into the mountain and left in the woods, returned once more. The bag and the swinging round proved of no avail; and the miscreant had to be put to death. I have verified a fair num- ber of similar instances, all under most fa- vourable conditions. The evidence is unani- mous: the revolving motion never keeps the adult Cat from returning home. The popu- lar belief, which I found so seductive at first, is a country prejudice, based upon imperfect observation. We must, therefore, abandon Darwin's idea when trying to explain the ho- ming of the Cat as well as of the Mason-bee.
123
CHAPTER VI
THE RED ANTS
THE Pigeon transported for hundreds of miles is able to find his way back to his Dove-cot; the Swallow, returning from his winter quarters in Africa, crosses the sea and once more takes possession of the old nest. What guides them on these long journeys? Is it sight? An observer of supreme intelli- gence, one who, though surpassed by others in the knowledge of the stuffed animal under a glass case, is almost unrivalled in his know- ledge of the live animal in its wild state, Toussenel,^ the admirable writer of L'Esprit des betes, speaks of sight and metereology as the Carrier-pigeon's guides:
"The French bird," he says, "knows by ex- perience that the cold weather comes from the north, the hot from the south, the dry
'Alphonse Toussenel (i 803-1885), the author of a num- ber of interesting and valuable works on ornithology. — Translator's Note.
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The Red Ants
from the east and the wet from the west. That is enough meteorological knowledge to tell him the cardinal points and to direct his flight. The Pigeon taken In a closed basket from Brussels to Toulouse has certainly no means of reading the map of the route with his eyes; but no one can prevent him from feeling, by the warmth of the atmosphere, that he is pur- suing the road to the south. When restored to hberty at Toulouse, he already knows that the direction which he must follow to regain his dove-cot is the direction of the north. Therefore, he wings straight in that direction and does not stop until he nears those latitudes where the mean temperature is that of the zone which he inhabits. If he does not find his home at the first onset, it is because he has borne a little too much to the right or to the left. In any case, it takes him but a few hours' search in an easterly or westerly direc- tion to correct his mistake."
The explanation is a tempting one when the journey is taken north and south; but it does not apply to a journey east and west, on the same isothermal line. Besides, it has this defect, that it does not admit of gen- 125
The Mason-bees
eralizatlon. One cannot talk of sight and still less of the influence of a change of climate when a Cat returns home, from one end of a town to the other, threading his way through a labyrinth of streets and alleys which he sees for the first time. Nor is it sight that guides my Mason-bees, especially when they are let loose in the thick of a wood. Their low flight, eight or nine feet above the ground, does not allow them to take a panoramic view nor to gather the lie of the land. What need have they of topography? Their hesitation Is short-lived: after describing a few narrow cir- cles around the experimenter, they start in the direction of the nest, despite the cover of the forest, despite the screen of a tall chain of hills which they cross by mounting the slope at no great height from the ground. Sight en- ables them to avoid obstacles, without giving them a general idea of their road. Nor has meteorology aught to do with the case: the climate has not varied in those few miles of transit. My Mason-bees have not learnt from any experiences of heat, cold, dryness and damp: an existence of a few weeks' duration does not allow of this. And, even if they knew all about the four cardinal points, there 126
The Red Ants
is no difference in climate between the spot where their nest lies and the spot at which they are released; so that does not help them to settle the direction in which they arc to travel.
To explain these many mysteries, wc are driven, therefore, to appeal to yet another mystery, that is to say, a special sense denied to mankind. Charles Darwin, whose weighty authority no one will gainsay, arrives at the same conclusion. To ask if the animal be not impressed by the terrestrial currents, to enquire if it be not influenced by the close proximity of a magnetic needle: what is this but the recognition of a magnetic sense? Do we possess a similar faculty? I am speak- ing, of course, of the magnetism of the physi- cists and not of the magnetism of the Mes- mers and Cagliostros. Assuredly we possess nothing remotely like it. What need would the mariner have of a compass were he him- self a compass?
And this is what the great scientist ac- knowledges : a special sense, so foreign to our organism that we are not able to form a con- ception of it, guides the Pigeon, the Swallow, the Cat, the Mason-bee and a host of others 127
The Mason-bees
when away from home. Whether this sense be magnetic or no I will not take upon myself to decide; I am content to have helped, in no small degree, to establish its existence. A new sense added to our number: what an acquisi- tion, what a source of progress ! Why are we deprived of it? It would have been a fine weapon and of great service in the strug- gle for life. If, as is contended, the whole of the animal kingdom, including man, is de- rived from a single mould, the original cell, and becomes self-evolved in the course of time, favouring the best-endowed and leaving the less well-endowed to perish, how comes it that this wonderful sense is the portion of a humble few and that it has left no trace in man, the culminating achievement of the zoo- logical progression? Our precursors were very Ill-advised to let so magnificent an in- heritance go : It was better worth keeping than a vertebra of the coccyx or a hair of the moustache.
Does not the fact that this sense has not
been handed down to us point to a flaw in
the pedigree? I submit the little problem to
the evolutionists; and I should much like to
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The Red Ants
know what their protoplasm and their nucleus have to say to it.
Is this unknown sense localized in a particu- lar part of the Wasp and the Bee? Is it ex- ercised by means of a special organ? We im- mediately think, of the antennae. The antennae are what we always fall back upon when the insect's actions are not quite clear to us ; we gladly put down to them whatever is most necessary to our arguments. For that matter, I had plenty of fairly good reasons for suspecting them of containing the sense of di- rection. When the Hairy Ammophila'^ is searching for the Grey Worm, it is with her antennae, those tiny fingers continually fumbling at the soil, that she seems to recog- nize the presence of the underground prey. Could not those inquisitive filaments, which seem to guide the insect when hunting, also guide it when travelling? This remained to be seen; and I did see.
I took some Mason-bees and amputated their antennas with the scissors, as closely as
*A Sand-wasp, who hunts the Grey Worm, or Cater- pillar of the Turnip-moth, to serve as food for her grubs. For other varieties of the Aramophila, cf. Insect Life: chap. XV. — Translator's Note.
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The Mason-bees
I could. These maimed ones were then car- ried to a distance and released. They returned to the nest with as little difficulty as the others. I once experimented in the same way with the largest of our Cerceres {Cerceris tiihercU' lata) '^ and the Weevil-huntress returned to her galleries. This rids us of one hypothesis: the sense of direction is not exercised by the antennae. Then where is its seat? I do not know.
What I do know is that the Mason-bees without antennae, though they go back to the cells, do not resume work. They persist in flying in front of their masonry, they alight on the clay cup, they perch on the rim of the cell and there, seemingly pensive and forlorn, stand for a long time contemplating the work which will never be finished ; they go off, they come back, they djive away any importunate neighbour, but they fetch and carry no more honey or mortar. The next day, they do not appear. Deprived of her tools, the worker loses all heart in her task. When the Mason- bee is building, the antennae are constantly
'Another Hunting-wasp, who feeds her young on Weevils. Cf. Insect Life: chaps, iv. and v. — Translator's Note.
ISO
The Red Ants
feeling, fumbling and exploring, superintend- ing, as it were, the finishing touches given to the work. They are her instruments of pre- cision ; they represent the builder's compasses, square, level and plumb-line.
Hitherto, my experiments have been con- fined to the females, who are much more faith- ful to the nest by virtue of their maternal re- sponsibilities. What would the males do if they were taken from home ? I have no great confidence in these swains who, for a few days, form a tumultuous throng outside the nests, wait for the females to emerge, quarrel for their possession, amid endless brawls, and then disappear when the works are in full swing. What care they, I ask myself, about returning to the natal nest rather than settling elsewhere, provided that they find some recipi- ent for their amatory declarations? I was mistaken : the males do return to the nest. It is true that, in view of their lack of strength, I did not subject them to a long journey : about half a mile or so. Nevertheless, this repre- sented to them a distant expedition, an un- known country; for I do not see them go on long excursions. By day, they visit the nests or the flowers in the garden; at night, they 131
The Mason-bees
take refuge in the old galleries or in the Inter- stices of the stone-heaps in the harmas.
The same nests are frequented by two Osmia-bees {Osmia tricornis and Osmia Latreillii), who build their cells In the galler- ies left at their disposal by the Chalicodomae. The most numerous is the first, the Three- horned Osmia. It was a splendid opportunity to try and discover to what extent the sense of direction may be regarded as general in. the Bees and Wasps; and I took, advantage of it. Well, the Osmias {Osmia tricornis)^ both male and female, can find their way back to the nest. My experiments were made very quickly, with small numbers and over short distances; but the results agreed so closely with the others that I was convinced. All told, the return to the nest. Including my earlier attempts, was verified in the case of four species: the Chalicodoma of the Sheds, the Chalicodoma of the Walls, the Three- horned Osmia and the Warted Cerceris {Cerceris tiiberciilata) ^ Shall I generalize without reserve and allow all the Hymenop- tera" this faculty of finding their way in un-
^Insect Life: chap. xix. — Translator's Note.
*The Hymenoptera are an order of insects having four
132
The Red Ants
known country? I shall do nothing of the kind ; for here, to my knowledge, is a contra- dictory and very significant result.
Among the treasures of my harmas- laboratory, I place in the first rank an Ant- hill of Polyergus rufescens, the celebrated Red Ant, the slave-hunting Am.azon. Un- able to rear her family, incapable of seeking her food, of taking it even when it is within her reach, she needs servants who feed her and undertake the duties of housekeeping. The Red Ants make a practice of stealing children to wait on the community. They ran- sack the neighbouring Ant-hills,- the home of a different species; they carry away nymphs, which soon attain maturity in the strange house and become willing and industrious servants.
When the hot weather of June and July sets in, I often see the Amazons leave their barracks of an afternoon and start on an ex- pedition. The column measures five or six yards in length. If nothing worthy of atten- tion be met upon the road, the ranks are fairly well maintained; but, at the first suspicion of
membranous wings and include the Bees, Wasp«, Ants, Saw-flies and Ichneumon-flies. — Translator's Note.
133
The Mason-bees
an Ant-hill, the vanguard halts and deploys in a swarming throng, which is increased by the others as they come up hurriedly. Scouts are sent out ; the Amazons recognize that they are on a wrong track; and the column forms again. It resumes its march, crosses the garden-paths, disappears from sight in the grass, reappears farther on, threads its way through the heaps of dead leaves, comes out again and continues its search. At last, a nest of Black Ants is discovered. The Red Ants hasten down to the dormitories where the nymphs lie and soon emerge with their booty. Then we have, at the gates of the under- ground city, a bewildering scrimmage between the defending blacks and the attacking reds. The struggle is too unequal to remain Inde- cisive. Victory falls to the reds, who race back to their abode, each with her prize, a swaddled nymph, dangling from her mandi- bles. The reader who is not acquainted with these slave-raiding habits would be greatly in- terested in the story of the Amazons. I re- linquish it, with much regret : it would take us too far from our subject, namely, the return to the nest.
The distance covered by the nymph- 134
The Red Ants
stealing column varies: it all depends on whether Black Ants are plentiful in the neigh- bourhood. At times, ten or twenty yards suf- fice; at others, it requires fifty, a hundred or more. I once saw the expedition go beyond the garden. The Amazons scaled the sur- rounding wall, which was thirteen feet high at that point, climbed over it and went on a little farther, into a corn-field. As for the route taken, this is a matter of indifference to the marching column. Bare ground, thick grass, a heap of dead leaves or stones, brick- work, a clump of shrubs: all are crossed with- out any marked preference for one sort of road rather than another.
What is rigidly fixed is the path home, which follows the outward track in all its windings and all its crossings, however diffi- cult. Laden with their plunder, the Red Ants return to the nest by the same road, often an exceedingly complicated one, which the exigen- cies of the chase compelled them to take originally. They repass each spot which they passed at first; and this is to them a matter of such imperative necessity that no additional fatigue nor even the gravest danger can make them alter the track.
I3S
The Mason-bees
Let us suppose that they have crossed a thick heap of dead leaves, representing to them a path beset with yawning gulfs, where every moment some one falls, where many are exhausted as they struggle out of the hol- lows and reach the heights by means of sway- ing bridges, emerging at last from the laby- rinth of lanes. No matter: on their return, they will not fail, though weighed down with their burden, once more to struggle through that weary maze. To avoid all this fatigue, they would have but to swerve slightly from the original path, for the good, smooth road is there, hardly a step away. This little devi- ation never occurs to them.
I came upon them one day when they were on one of their raids. They were marching along the inner edge of the stone-work of the garden-pond, where I have replaced the old batrachians by a colony of Gold-fish. The wind was blowing very hard from the north and, taking the column in flank, sent whole rows of the Ants flying into the water. The fish hurried up ; they watched the performance and gobbled up the drowning insects. It was a diflicult bit; and the column was decimated before it had passed. I expected to see the 136
The Red Ants
return journey made by another road, which would wind round and avoid the fatal diff. Not at all. The nymph-laden band resumed the parlous path and the Gold-fish received a double windfall: the Ants and their prizes. Rather than alter its track, the column was decimated a second time.
It is not easy to find the way home again after a distant expedition, during which there have been various sorties, nearly always by different paths; and this difficulty makes it absolutely necessary for the Amazons to re- turn by the same road by which they went. The insect has no choice of route, if it would not be lost on the way : it must come back by the track which it knows and which it has lately travelled. The Processionary Caterpil- lars, when they leave their nest and go to an- other branch, on another tree, in search of a type of leaf more to their taste, carpet the course with silk and are able to return home by following the threads stretched along their road. This is the most elementary method open to the insect liable to stray on its ex- cursions: a silken path brings It home again. The Processionaries, with their unsophisti- cated traffic-laws, are very different from the 137
The Mason-bees
Mason-bees and others, who have a special sense to guide them.
The Amazon, though belonging to the Hymenopteron clan, herself possesses rather limited homing-faculties, as witness her com- pulsory return by her former trail. Can she imitate, to a certain extent, the Procession- aries' method, that is to say, does she leave, along the road trav^ersed, not a series of con- ducting threads, for she is not equipped for that work, but some odorous emanation, for instance, some formic scent, which would allow her to guide herself by means of the olfactory sense? This view is pretty gen- erally accepted. The Ants, people say, are guided by the sense of smell; and this sense of smell appears to have its seat in the antennae, which we see in continual palpita- tion. It is doubtless very reprehensible, but I must admit that the theory does not inspire me with overwhelming enthusiasm. In the first place, I have my suspicions about a sense of smell seated in the antennae : I have given my reasons before; and, next, I hope to prove by experiment that the Red Ants are not guided by a scent of any kind.
To lie in wait for my Amazons, for whole 138
The Red Ants
afternoons on end, often unsuccessfully, meant taking up too much of my time. I engaged an assistant whose hours were not so much occupied as mine. It was my grand- daughter Lucie, a little rogue who liked to hear my stories of the Ants. She had been present at the great battle between the reds and blacks and was much impressed by the rape of the long-clothes babies. Well-coached in her exalted functions, very proud of al- ready serving that august lady. Science, my little Lucie would wander about the garden, when the weather seemed propitious, and keep an eye on the Red Ants, having been commis^ sioned to reconnoitre carefully the road to the pillaged Ant-hill. She had given proof of her zeal; I could rely upon It.
One day, while I was spinning out my daily quota of prose, there came a banging at my study-door:
"It's I, Lucie! Come quick: the reds have gone into the blacks' house. Come quick !"
"And do you know the road they took?"
"Yes, I marked it."
"What! Marked It? And how?"
"I did what Hop-o'-My-Thumb did: I scattered little white stones along the road." 139
The Mason-bees
I hurried out. Things had happened as my six-year-old colleague said. Lucie had se- cured her provision of pebbles In advance and, on seeing the Amazon regiment leave barracks, had followed them step by step and placed her stones at Intervals along the road covered. The Ants had made their raid and were beginning to return along the track of tell-tale pebbles. The distance to the nest was about a hundred paces, which gave me time to make preparations for an experiment pre- viously contemplated.
I take a big broom and sweep the track for about a yard across. The dusty particles on the surface are thus removed and replaced by others. If they were tainted with any odor- ous effluvia, their absence will throw the Ants off the track. I divide the road, in this way, at four different points, a few feet apart.
The colum.n arrives at the first section. The hesitation of the Ants is evident. Some recede and then return, only to recede once more; others wander along the edge of the cutting; others disperse sideways and seem to be trying to skirt the unknown country. The head of the column, at first closed up to a width of a foot or so, now scatters to three 140
The Red Ants
or four yards. But fresh arrivals gather in their numbers before the obstacle ; they form a mighty array, an undecided horde. At last, a few Ants venture Into the swept zone and others follow, while a few have meantime gone ahead and recovered the track by a cir- cuitous route. At the other cuttings, there are the same halts, the same hesitations; ne- vertheless, they are crossed, either In a straight line or by going round. In spite of my snares, the Ants manage to return to the nest; and that by way of the little stones.
The result of the experiment seems to argue In favour of the sense of smell. Four times over, there are manifest hesitations wher- ever the road is swept. Thougii the return takes place, nevertheless, along the original track, this may be due to the uneven work of the broom, which has left certain particles of the scented dust In position. The Ants who went round the cleared portion may have been guided by the sweepings removed to either side. Before, therefore, pronouncing judg- ment for or against the sense of smell. It were ^well to renew the experiment under better conditions and to remove everything contain- ing a vestige of scent. 141
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A few days later, when I have definitely de- cided on my plan, Lucie resumes her watch and soon comes to tell me of a sortie. I was counting on it, for the Amazons rarely miss an expedition during the hot and sultry after- noons of June and July, especially when the weather threatens storm. Hop-o'-My- Thumb's pebbles once more mark out the road, on which I choose the point best-suited to my schemes.
A garden-hose is fixed to one of the feeders of the pond; the sluice is opened; and the Ants' path is cut by a continuous torrent, two or three feet wide and of unlimited length. The sheet of water flows swiftly and plenti- fully at first, so as to wash the ground well and remove anything that may possess a scent. This thorough washing lasts for nearly a quarter of an hour. Then, when the Ants draw near, returning from the plunder, I let the water flow more slowly and reduce its depth, so as not to overtax the strength of the insects. Now we have an obstacle which the Amazons must surmount, if it is absolutely necessary for them to follow the first trail.
This time, the hesitation lasts long and the stragglers have time to come up with the head 142
The Red Ants
of the column. Nevertheless, an attempt Is made to cross the torrent by means of a few bits of gravel projecting above the water; then, failing to find bottom, the more reck- less of the Ants are swept off their feet and, without loosing hold of their prizes, drift away, land on some shoal, regain the bank and renew their search for a ford. A few straws borne on the waters stop and become so many shaky bridges, on which the Ants climb. Dry olive-leaves are converted into rafts, each with its load of passengers. The more venturesome, partly by their own ef- forts, partly by good luck, reach the opposite bank without adventitious aid. I see some who, dragged by the current to one or the other bank, two or three yards off, seem very much concerned as to what they shall do next. Amid this disorder, amid the dangers of drowning, not one lets go her booty. She would not dream of doing so : death sooner than that! In a word, the torrent is crossed somehow or other along the regular track.
The scent of the road cannot be the cause of this, it seems to me, for the torrent not only washed the ground some time before- hand, but also pours fresh water on it all the 143
The Mason-bees
time that the crossing is taking place. Let us now see what will happen when the formic scent, if there really be one on the trail, is replaced by another, much stronger odour, one perceptible to our own sense of smell, which the first is not, at least not under present conditions.
I wait for a third sortie and, at one point in the road taken by the Ants, rub the ground with some handfuls of freshly-gathered mint. I cover the track, a little farther on, with the leaves of the same plant. The Ants, on their return, cross the section over which the mint was rubbed without apparently giving it a thought; they hesitate in front of the section heaped up with leaves and then go straight on.
After these two experiments, first with the torrent of water which washes away all trace of smell from the ground and then with the mint which changes the smell, I think that we are no longer at liberty to quote scent as the guide of the Ants that return to the nest by the road which they took at starting. Further tests will tell us more about it.
Without interfering with the soil, I now lay across the track some large sheets of 144
The Red Ants
paper, newspapers, keeping them in position with a few small stones. In front of this car- pet, which completely alters the appearance of the road, without removing any sort of scent that it may possess, the Ants hesitate even longer than before any of my other snares, including the torrent. They are com- pelled to make manifold attempts, reconnais- sances to right and left, forward movements and repeated retreats, before venturing alto- gether into the unknown zone. The paper straits are crossed at last and the march re- sumed as usual.
Another ambush awaits the Amazons some distance farther on. I have divided the track by a thin layer of yellow sand, the ground itself being grey. This change of colour alone is enough for a moment to disconcert the Ants, who again hesitate in the same way, though not for so long, as they did before the paper. Eventually, this obstacle is overcome like the others.
As 'neither the stretch of sand nor the stretch of paper got rid of any scented effluvia with which the trail may have been impreg- nated, it is patent that, as the Ants hesitated and stopped in the same way as before, they 145
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find their way not by sense of smell, but really land truly by sense of sight; for, every time that I alter the appearance of the track in any way whatever — whether by my destruc- tive broom, my streaming water, my green mint, my paper carpet or my golden sand — the returning column calls a halt, hesitates and attempts to account for the changes that have taken place. Yes, it is sight, but a very dull sight, whose horizon is altered by the shifting of a few bits of gravel. To this short sight, a strip of paper, a bed of mint-leaves, a layer of yellow sand, a stream of water, a furrow made by the broom, or even lesser modifications are enough to transform the landscape; and the regiment, eager to reach home as fast as it can with its loot, halts un- easily on beholding this unfamiliar scenery. If the doubtful zones are at length passed, it is due to the fact that fresh attempts are con- stantly being made to cross the doctored strips and that at last a few Ants recognize well- known spots beyond them. The others, rely- ing on their clearer-sighted sisters, follow.
Sight would not be enough, if the Amazon had not also at her service a correct memory for places. The memory of an Ant 1 What 146
The Red Ants
can that be? In what does it resemble ours? I have no answers to these questions; but a few words will enable me to prove that the insect has a very exact and persistent recollec- tion of places which it has once visited. Here is something which I have often witnessed. It sometimes happens that the plundered Ant- hill offers the Amazons a richer spoil than the invading column is able to carry away. Or, again, the region visited is rich in Ant- hills. Another raid is necessary, to exploit the site thoroughly. In such cases, a second expedition takes place, sometimes on the next day, sometimes two or three days later. This time, the column does no reconnoitring on the way : it goes straight to the spot known to abound in nymphs and travels by the identical path which it followed before. It has some- times happened that I have marked with small stones, for a distance of twenty yards, the road pursued a couple of days earlier and have then found the Amazons proceeding by the same route, stone by stone :
"They will go first here and then there," I said, according to the position of the guide- stones.
And they would, in fact, go first here and
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then there, skirting my line of pebbles, with- out any noticeable deviation.
Can one believe that odoriferous emana- tions diffused along the route are going to last for several days? No one would dare to suggest it. It must, therefore, be sight that directs the Amazons, sight assisted by its mem- ory for places. And this memory is tenacious enough to retain the impression until the next day and later; it is scrupulously faithful, for it guides the column by the same path as on the day before, across the thousand Irregulari- ties of the ground.
How will the Amazon behave when the lo- cality is unknown to her? Apart from topo- graphical memory, which cannot serve her here, the region in which I imagine her being still unexplored, does the Ant possess the Mason-bee's sense of direction, at least within modest limits, and is she able thus to regain her Ant-hill or her marching column?
The different parts of the garden are not all visited by the marauding legions to the same extent : the north side is exploited by preference, doubtless because the forays in that direction are more productive. The Amazons, therefore, generally direct their 148
The Red Ants
troops north of their barracks; I seldom see them in the south. This part of the garden is, if not wholly unknown, at least much less familiar to them than the other. Having said that, let us observe the conduct of the strayed Ant.
I take up my position near the Ant-hill; and, when the column returns from the slave- raid, I force an Ant to step on a leaf which I hold out to her. Without touching her, I carry her two or three paces away from her regiment: no more than that, but in a south- erly direction. It is enough to put her astray^ to make her lose her bearings entirely. I see the Amazon, now replaced on the ground, wander about at random, still, I need hardly say, with her booty in her mandibles; I see her hurry away from her comrades, thinking that she is rejoining them; I see her retrace her steps, turn aside again, try to the right, try to the left and grope in a host of direc- tions, without succeeding in finding her where- abouts. The pugnacious, strong-jawed slave- hunter is utterly lost two steps away from her party. I have in mind certain strays who, after half an hour's searching, had not suc- ceeded in recovering the route and were go-^ 149
The Mason-bees
ing farther and farther from it, still carrying the nymph in their teeth. What became of them? What did they do with their spoil? I had not the patience to follow those dull- witted marauders to the end.
Let us repeat the experiment, but place the Amazon to the north. After more or less prolonged hesitations, after a search now in this direction, now in that, the Ant suc- ceeds in finding her column. She knows the locality.
Here, of a surety, is a Hymenopteron de- prived of that sense of direction which other Hymenoptera enjoy. She has in her favour a memory for places and nothing more. A deviation amounting to two or three of our strides is enough to make her lose her way and to keep her from returning to her people, whereas miles across unknown country will not foil the Mason-bee. I expressed my sur- prise, just now, that man was deprived of 3 wonderful sense wherewith certain animals are endowed. The enormous distance between the two things compared might furnish mat- ter for discussion. In the present case, the distance no longer exists : we have to do with two insects very near akin, two Hymenoptera. 150
The Red Ants
Why, if they issue from the same mould, has one a sense which the other has not, an ad« ditional sense, constituting a much more over- powering factor than the structural details? I will wait until the evolutionists condescend to give me a valid reason.
To return to this memory for places whose tenacity and fidelity I have just recognized: to what degree does it consent to retain im- pressions? Does the Amazon require re- peated journeys in order to learn her geogra- phy, or is a single expedition enough for her? Are the line followed and the places visited engraved on her memory from the first? The Red Ant does not lend herself to the tests that might furnish the reply: the ex- perimenter is unable to decide whether the path followed by the expeditionary column is being covered for the first time, nor is it in his power to compel the legion to adopt this or that different road. When the Amazons go out to plunder the Ant-hills, they take the direction which they please; and we are not allowed to interfere with their march. Let us turn to other Hymenoptera for informa- tion.
I select the Pompili, whose habits we shall 151
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study in detail in a later chapter/ They are hunters of Spiders and diggers of burrows. The game, the food of the coming larva, is first caught and paralyzed; the home is ex- cavated afterwards. As the heavy prey would be a grave encumbrance to the Wasp in search of a convenient site, the Spider is placed high up, on a tuft of grass or brushwood, out of the reach of marauders, especially Ants, who might damage the precious morsel in the law- ful owner's absence. After fixing her booty on the verdant pinnacle, the Pompilus casts around for a favourable spot and digs her burrow. During the process of excavation, she returns from time to time to her Spider; she nibbles at the prize, feels it, touches here and there, as though taking stock of its plump- ness and congratulating herself on the plenti- ful provender; then she returns to her bur- row and goes on digging. Should anything alarm or distress her, she does not merely in- spect her Spider: she also brings her a little closer to her work-yard, but never fails to lay heron the top of a tuft of verdure. These
^For the Wasp known as the Pompilus, or Ringed Calicurgus, cf. The Life and Love of the Insect: chap, xii. — Translator's Note.
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are the manoeuvres of which I can avail myself to gauge the elasticity of the Wasp's memory. While the Pompilus is at work upon the burrow, I seize the prey and place it in an ex- posed spot, half a yard away from its original position. The Pompilus soon leaves the hole to enquire after her booty and goes straight to the spot where she left it. This sureness of direction, this faithful memory for places can be explained by repeated previous visits. I know nothing of what has happened before- hand. Let us take no notice of this first ex- pedition; the others will be more conclusive. For the moment, the Pompilus, without the least hesitation, finds the tuft of grass whereon her prey was lying. Then come marches and counter-marches upon that tuft, minute ex- plorations and frequent returns to the exact spot where the Spider was deposited. At last, convinced that the prize is no longer there, the W^asp makes a leisurely survey of the neigh- bourhood, feeling the ground with her antennae as she goes. The Spider is descried in the exposed spot where I had pl^ed her. Surprise on the part of the Pompilus, who goes forward and then suddenly steps back with a start :
153
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"Is it alive?" she seems to ask. "Is It dead? Is it really my Spider? Let us be wary!"
The hesitation does not last long : the hunt- ress grabs her victim, drags her backwards and places her, still high up, on a second tuft of herbage, two or three steps away from the first. She then goes back to the burrow and digs for a while. For the second time, I remove the Spider and lay her at some dis- tance, on the bare ground. This is the mo- ment to judge of the Wasp's memory. Two tufts of grass have served as temporary resting-places for the game. The first, to which she returned with such precision, the Wasp may have learnt to know by a more or less thorough examination, by reiterated visits that escaped my eye ; but the second has cert- ainly made but a slight impression on her memory. She adopted it without any studied choice; she stopped there just long enough to hoist her Spider to the top; she saw it for the first time and saw it hurriedly, in passing. Is that rapid glance enough to provide an exact recollection? Besides, there are now two localities to be muddled in the insect's mem- ory: the first shelf may easily be confused 154
The Red Ants
with the second. To which will the Pompilus betake herself?
.We shall soon find out: here she comes, leaving the burrow to pay a fresh visit to the Spider. She runs straight to the second tuft, where she hunts about for a long time for her absent.prey. She knows that it was there, when last seen, and no elsewhere; she persists in looking for it there and does not once think of going back to the first perch. The first tuft of grass no longer counts; the second alone interests her. And then the search in the neighbourhood begins again.
On finding her game on the bare spot where I myself have placed it, the Pompilus quickly deposits the Spider on a third tuft of grass; and the experiment is renewed. This time, the Pompilus hurries to the third tuft when she comes to look after her Spider; she hur- ries to it without hesitation, without confusing it in any way with the first two, which she scorns to visit, so sure is her memory. I do the same thing a couple of times more; and the insect always returns to the last perch, without troubling about the others. I stand amazed at the memory of that pigmy. She need but catch a single hurried glimpse of a 155
The Mason-bees
spot that differs In no wise from a host of others in order to remember it quite well, notwithstanding the fact that, as a miner re- lentlessly pursuing her underground labours, she has other matters to occupy her mind. Could our own memory always vie with Hers? It is very doubtful. Allow the Red Ant the same sort of memory; and her peregrinations, her returns to the nest by the same road are no longer difficult to explain.
Tests of this kind have furnished me with some other results worthy of mention. When convinced, by untiring explorations, that her prey is no longer on the tuft where she laid It, the Pompilus, as we were saying, looks for It in the neighbourhood and finds It pretty easily, for I am careful to put It In an ex- posed place. Let us Increase the difficulty to some extent. I dig the tip of my finger into the ground and lay the Spider In the little hole thus obtained, covering her with a tiny leaf. Now the Wasp, while In quest of her lost prey, happens to walk over this leaf, to pass It again and again without suspecting that the Spider lies beneath, for she goes and con- tinues her vain search farther off. Her guide, therefore, is not scent, but sight. Neverthe- is6
The Red Ants
less, she Is constantly feeling the ground with her antennse. What can be the function of those organs ? I do not know, although I as- sert that they are not olfactory organs. The Ammophila, in search of her Grey Worm, had already led me to make the same assertion; I now obtain an experimental proof which seems to me decisive. I would add that the Pompilus has very short sight: often, she passes within a couple of inches of her Spider without seeing her.
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CHAPTER VII
SOME REFLECTIONS UPON INSECT PSY- CHOLOGY
THE laudator tempor'is acti is out of fa- vour just now: the world Is on the move. Yes, but sometimes it moves back- wards. When I was a boy, our twopenny textbooks told us that man was a reasoning animal; nowadays, there are learned volumes to prove to us that human reason is but a higher rung in the ladder whose foot reaches down to the bottommost depths of animal life. There is the greater and the lesser; there are all the intermediary rounds; but no- where does it break off and start afresh. It begins with zero in the glair of a cell and ascends until we come to the mighty brain of a Newton. The noble faculty of which we were so proud is a zoological attribute. All have a larger or smaller share of it, from the live atom to the anthropoid ape, that hideous caricature of man.
It always struck me that those who held 158
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this levelling-theory made facts say more than they really meant ; it struck me that, in order to obtain their plain, they were lowering the mountain-peak, man, and elevating the valley, the animal. Now this levelling of theirs needed proofs, to my mind; and, as I found none in their books, or at any rate only doubt- ful and highly debatable ones, I did my own observing, in order to arrive at a definite con- viction; I sought; I experimented.
To speak with any certainty, it behoves us not to go beyond what we really know.^ I am beginning to have a passable acquaintance with insects, after spending some forty years in their company. Let us question the insect, then: not the first that comes along, but the most gifted, the Hymenopteron. I am giving my opponents every advantage. Where will they find a creature more richly endowed with talent? It would seem as though, in creating it, nature had delighted in bestowing the great- est amount of industry upon the smallest body of matter. Can the bird, wonderful architect that it is, compare its work with that master- piece of higher geometry, the edifice of the Bee? The Hymenopteron rivals man him- self. We build towns, the Bee erects cities; 159
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we have servants, the Ant has hers; we rear domestic animals, she rears her sugar-yielding insects; we herd cattle, she herds her milch- cows, the Aphides; wc have abolished slavery, whereas she continues her nigger-traffic.
Well, does this superior, this privileged being reason? Reader, do not smile: this Is a most serious matter, well worthy of our con- sideration. To devote our attention to ani- mals is to plunge at once into the vexed quest- ion of who we are and whence we come. What, then, passes in that little Hymenop- teron brain? Has it faculties akin to ours, has it the power of thought? What a pro- blem, if we could only solve it; what a chapter of psychology, if we could only write it ! But, at our very first questionings, the mysterious will rise up, impenetrable: we may be con- vinced of that. We are incapable of knowing ourselves; what will it be if we try to fathom the intellect of others? Let us be content if we succeed in gleaning a few grains of truth.
What is reason? Philosophy would give us learned definitions. Let us be modest and keep to the simplest : we are only treating of animals. Reason is the faculty that connects the effect with its cause and directs the act by i6o
Reflections upon Insect Psychology- conforming it to the needs of the accidental. Within these limits, are animals capable of reasoning? Are they able to connect a "be- cause" with a "why" and afterwards to regu- late their behaviour accordingly? Are they able to change their line of conduct when faced with an emergency?
History has but few data likely to be of use to us here; and those which we find scattered in various authors are seldom able to with- stand a severe examination. One of the most remarkable of which I know is supplied by Erasmus Darwin, in his book entitled Zoo- nom'ia. It tells of a Wasp that has just caught and killed a big Fly. The wind is blowing, and the huntress, hampered in her flight by the great area presented by her prize, alights on the ground to amputate the abdomen, the head and the wings; she flies away, carrying with her only the thorax, which gives less hold to the wind. If we keep to the bald facts, this does, I admit, give a semblance of reason. The Wasp appears to grasp the relation be- tween cause and effect. The effect is the re- sistance experienced in the flight; the cause is the dimensions of the prey contending with the air. Hence the logical conclusion: those i6i
The Mason-bees
dimensions must be decreased; the abdomen, the head and, above all, the wings must be chopped off; and the resistance will be les- sened.^
But does this concatenation of Ideas, rudi- mentary though It be, really take place within the insect's brain ? I am convinced of the con-
^I would gladly, if I were able, cancel some rather hasty lines which I allowed myself to pen in the first vol* ume of these Souvenirs; but scripta manent and all that I can do is to make amends now, in this note, for the error into which I fell. Relying on Lacordaire, who quotes this instance from Erasmus Darwin in his own Introduction a I'entomologie, I believed that a Sphex was given as the heroine of the story. How could I do other- wise, not having the original text in front of me? How could I suspect that an entomologist of Lacordaire's standing should be capable of such a blunder as to substi- tute a Sphex for a Common Wasp? Great was my per- plexity, in the face of this evidence! A Sphex capturing a Fly was an impossibility; and I blamed the British scientist accordingly. But what insect was it that Eras- mus Darwin saw? Calling logic to my aid, I declared that it was a Wasp; and I could not have hit the mark more truly. Charles Darwin, in fact, informed me after- wards that his grandfather wrote, "a Wasp," in his Zoonomia. Though the correction did credit to my intel- ligence, I none the less deeply regretted my mistake, for I had uttered suspicions of the observer's powers of discernment, unjust suspicions which the translator's in- accuracy led me into entertaining. May this note serve to mitigate the harshness of the strictures provoked by my overtaxed credulity. I do not scruple to attack ideas which I consider false; but Heaven forfend that I should ever attack those who uphold them! — Author's Note.
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trary; and my proofs are unanswerable. In the first volume of these Souvenirs,^ I demon- strated by experiment that Erasmus Darwin's Wasp was but obeying her instinct, which is to cut up the captured game and to keep only the most nourishing part, the thorax. Whethet the day be perfectly calm or whether the wind blow, whether she be in the shelter of a dense thicket or in the open, I see the Wasp proceed to separate the succulent from the tough; I see her reject the legs, the wings, the head and the abdomen, retaining only the breast as pap for her larvas. Then what value has this dissection as an argument in favour of the insect's reasoning-powers when the wind blows? It has no value at all, for it would take place just the same in absolutely calm weather. Erasmus Darwin jumped too quickly to his conclusion, which was the out- come of his mental bias and not of the logic of things. If he had first enquired into the Wasp's habits, he would not have brought for- ward as a serious argument an incident which had no connection with the important question of animal reason.
^Cf. Insect Life: chap. ix. — Translator's Note. 163
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I have reverted to this case to show the difficulties that beset the mian who confines himself to casual observations, however care- fully carried out. One should never rely upon a lucky chance, which may not occur again. We must multiply our observations, check them one with the other; we must create inci- dents, looking into preceding ones, finding out succeeding ones and working out the relation between them all : then and not till then, with extreme caution, are we entitled to express a few views worthy of credence. Nowhere do I find data collected under such conditions; for which reason, however much I might wish it, It is impossible for me to bring the evidence of others in support of the few conclusions which I myself have formed.
My Mason-bees, with their nests hanging on the walls of the arch which I have men- tioned, lent themselves to continuous experi- ment better than any other Hymenopteron. I had them there, at my house, under my eyes, at all hours of the day, as long as I wished. I was free to follow their actions in full detail and to carry out successfully any experiment, however long. Moreover, their numbers al- lowed me to repeat my attempts until I was 1^4
Reflections upon Insect Psychology
perfectly convinced. The Mason-bees, there*, fore, shall supply me with the materials for this chapter also.
A few words, before I begin, about the works. The Mason-bee of the Sheds utilizes, first of all, the old galleries of the clay nest, a part of which she good-naturedly abandons to two Osmiae, her free tenants: the Three- horned Osmia and Latreille's Osmia. These old corridors, which save labour, are in great demand; but there are not many vacant, as the more