The Mason-bees
by
J. Henri Fabre
Part 1 out of 4
This etext was prepared by Sue Asscher asschers@dingoblue.net.au
THE MASON-BEES
by J. HENRI FABRE
TRANSLATED BY ALEXANDER TEIXEIRA DE MATTOS, F.Z.S.
TRANSLATOR'S NOTE.
This volume contains all the essays on the Chalicodomae, or Mason-bees
proper, which so greatly enhance the interest of the early volumes of
the "Souvenirs entomologiques." I have also included an essay on the
author's Cats and one on Red Ants--the only study of Ants comprised in
the "Souvenirs"--both of which bear upon the sense of direction
possessed by the Bees. Those treating of the Osmiae, who are also
Mason-Bees, although not usually known by that name, will be found in
a separate volume, which I have called "Bramble-bees and Others" and
in which I have collected all that Fabre has written on such other
Wild Bees as the Megachiles, or Leaf-cutters, the Cotton-bees, the
Resin-bees and the Halicti.
The essays entitled "The Mason-bees, Experiments" and "Exchanging the
Nests" form the last three chapters of "Insect Life", translated by
the author of "Mademoiselle Mori" and published by Messrs. Macmillan,
who, with the greatest courtesy and kindness have given me their
permission to include a new translation of these chapters in the
present volume. They did so without fee or consideration of any kind,
merely on my representation that it would be a great pity if this
uniform edition of Fabre's Works should be rendered incomplete because
certain essays formed part of volumes of extracts previously published
in this country. Their generosity is almost unparalleled in my
experience; and I wish to thank them publicly for it in the name of
the author, of the French publishers and of the English and American
publishers, as well as in my own.
Some of the chapters have appeared in England in the "Daily Mail", the
"Fortnightly Review" and the "English Review"; some in America in
"Good Housekeeping" and the "Youth's Companion"; others now see the
light in English for the first time.
I have again to thank Miss Frances Rodwell for the invaluable
assistance which she has given me in the work of translation and in
the less interesting and more tedious department of research.
ALEXANDER TEIXEIRA DE MATTOS.
Chelsea, 1914.
CONTENTS.
TRANSLATOR'S NOTE.
CHAPTER 1. THE MASON-BEES.
CHAPTER 2. EXPERIMENTS.
CHAPTER 3. EXCHANGING THE NESTS.
CHAPTER 4. MORE ENQUIRIES INTO MASON-BEES.
CHAPTER 5. THE STORY OF MY CATS.
CHAPTER 6. THE RED ANTS.
CHAPTER 7. SOME REFLECTIONS UPON INSECT PSYCHOLOGY.
CHAPTER 8. PARASITES.
CHAPTER 9. THE THEORY OF PARASITISM.
CHAPTER 10. THE TRIBULATIONS OF THE MASON-BEE.
CHAPTER 11. THE LEUCOPSES.
INDEX.
CHAPTER 1. THE MASON-BEES.
Reaumur (Rene Antoine Ferchault de Reaumur (1683-1757), inventor of
the Reaumur thermometer and author of "Memoires pour servir a
l'histoire naturelle des insectes."--Translator's Note.) devoted one
of his papers to the story of the Chalicodoma of the Walls, whom he
calls the Mason-bee. I propose to go on with the story, to complete it
and especially to consider it from a point of view wholly neglected by
that eminent observer. And, first of all, I am tempted to tell how I
made this Bee's acquaintance.
It was when I first began to teach, about 1843. I had left the normal
school at Vaucluse some months before, with my diploma and all the
simple enthusiasm of my eighteen years, and had been sent to
Carpentras, there to manage the primary school attached to the
college. It was a strange school, upon my word, notwithstanding its
pompous title of 'upper'; a sort of huge cellar oozing with the
perpetual damp engendered by a well backing on it in the street
outside. For light there was the open door, when the weather
permitted, and a narrow prison-window, with iron bars and lozenge
panes set in lead. By way of benches there was a plank fastened to the
wall all round the room, while in the middle was a chair bereft of its
straw, a black-board and a stick of chalk.
Morning and evening, at the sound of the bell, there came rushing in
some fifty young imps who, having shown themselves hopeless dunces
with their Cornelius Nepos, had been relegated, in the phrase of the
day, to 'a few good years of French.' Those who had found mensa too
much for them came to me to get a smattering of grammar. Children and
strapping lads were there, mixed up together, at very different
educational stages, but all incorrigibly agreed to play tricks upon
the master, the boy master who was no older than some of them, or even
younger.
To the little ones I gave their first lessons in reading; the
intermediate ones I showed how they should hold their pen to write a
few lines of dictation on their knees; to the big ones I revealed the
secrets of fractions and even the mysteries of Euclid. And to keep
this restless crowd in order, to give each mind work in accordance
with its strength, to keep attention aroused and lastly to expel
dullness from the gloomy room, whose walls dripped melancholy even
more than dampness, my one resource was my tongue, my one weapon my
stick of chalk.
For that matter, there was the same contempt in the other classes for
all that was not Latin or Greek. One instance will be enough to show
how things then stood with the teaching of physics, the science which
occupies so large a place to-day. The principal of the college was a
first-rate man, the worthy Abbe X., who, not caring to dispense beans
and bacon himself, had left the commissariat-department to a relative
and had undertaken to teach the boys physics.
Let us attend one of his lessons. The subject is the barometer. The
establishment happens to possess one, an old apparatus, covered with
dust, hanging on the wall beyond the reach of profane hands and
bearing on its face, in large letters, the words stormy, rain, fair.
'The barometer,' says the good abbe, addressing his pupils, whom, in
patriarchal fashion, he calls by their Christian names, 'the barometer
tells us if the weather will be good or bad. You see the words written
on the face--stormy, rain--do you see, Bastien?'
'Yes, I see,' says Bastien, the most mischievous of the lot.
He has been looking through his book and knows more about the
barometer than his teacher does.
'It consists,' the abbe continues, 'of a bent glass tube filled with
mercury, which rises and falls according to the weather. The shorter
leg of this tube is open; the other...the other...well, we'll see.
Here, Bastien, you're the tallest, get up on the chair and just feel
with your finger if the long leg is open or closed. I can't remember
for certain.'
Bastien climbs on the chair, stands as high as he can on tip-toe and
fumbles with his finger at the top of the long column. Then, with a
discreet smile spreading under the silky hairs of his dawning
moustache:
'Yes,' he says, 'that's it. The long leg is open at the top. There, I
can feel the hole.'
And Bastien, to confirm his mendacious statement, keeps wriggling his
forefinger at the top of the tube, while his fellow-conspirators
suppress their enjoyment as best they can.
'That will do,' says the unconscious abbe. 'You can get down, Bastien.
Take a note of it, boys: the longer leg of the barometer is open; take
a note of it. It's a thing you might forget; I had forgotten it
myself.'
Thus was physics taught. Things improved, however: a master came and
came to stay, one who knew that the long leg of the barometer is
closed. I myself secured tables on which my pupils were able to write
instead of scribbling on their knees; and, as my class was daily
increasing in numbers, it ended by being divided into two. As soon as
I had an assistant to look after the younger boys, things assumed a
different aspect.
Among the subjects taught, one in particular appealed to both masters
and pupils. This was open-air geometry, practical surveying. The
college had none of the necessary outfit; but, with my fat pay--seven
hundred francs a year, if you please!--I could not hesitate over the
expense. A surveyor's chain and stakes, arrows, level, square and
compass were bought with my money. A microscopic graphometer, not much
larger than the palm of one's hand and costing perhaps five francs,
was provided by the establishment. There was no tripod to it; and I
had one made. In short, my equipment was complete.
And so, when May came, once every week we left the gloomy school-room
for the fields. It was a regular holiday. The boys disputed for the
honour of carrying the stakes, divided into bundles of three; and more
than one shoulder, as we walked through the town, felt the reflected
glory of those erudite rods. I myself--why conceal the fact?--was not
without a certain satisfaction as I piously carried that most delicate
and precious apparatus, the historic five-franc graphometer. The scene
of operations was an untilled, flinty plain, a harmas, as we call it
in the district. (Cf. "The Life of the Fly", by J. Henri Fabre,
translated by Alexander Teixeira de Mattos: chapter 1.--Translator's
Note.) Here, no curtain of green hedges or shrubs prevented me from
keeping an eye upon my staff; here--an indispensable condition--I had
not the irresistible temptation of the unripe apricots to fear for my
scholars. The plain stretched far and wide, covered with nothing but
flowering thyme and rounded pebbles. There was ample scope for every
imaginable polygon; trapezes and triangles could be combined in all
sorts of ways. The inaccessible distances had ample elbow-room; and
there was even an old ruin, once a pigeon-house, that lent its
perpendicular to the graphometer's performances.
Well, from the very first day, my attention was attracted by something
suspicious. If I sent one of the boys to plant a stake, I would see
him stop frequently on his way, bend down, stand up again, look about
and stoop once more, neglecting his straight line and his signals.
Another, who was told to pick up the arrows, would forget the iron pin
and take up a pebble instead; and a third deaf to the measurements of
angles, would crumble a clod of earth between his fingers. Most of
them were caught licking a bit of straw. The polygon came to a full
stop, the diagonals suffered. What could the mystery be?
I enquired; and everything was explained. A born searcher and
observer, the scholar had long known what the master had not yet heard
of, namely, that there was a big black Bee who made clay nests on the
pebbles in the harmas. These nests contained honey; and my surveyors
used to open them and empty the cells with a straw. The honey,
although rather strong-flavoured, was most acceptable. I acquired a
taste for it myself and joined the nest-hunters, putting off the
polygon till later. It was thus that I first saw Reaumur's Mason-bee,
knowing nothing of her history and nothing of her historian.
The magnificent Bee herself, with her dark-violet wings and black-
velvet raiment, her rustic edifices on the sun-blistered pebbles amid
the thyme, her honey, providing a diversion from the severities of the
compass and the square, all made a great impression on my mind; and I
wanted to know more than I had learnt from the schoolboys, which was
just how to rob the cells of their honey with a straw. As it happened,
my bookseller had a gorgeous work on insects for sale. It was called
"Histoire naturelle des animaux articules", by de Castelnau (Francis
Comte de Castelnau de la Porte (1812-1880), the naturalist and
traveller. Castelnau was born in London and died at Melbourne.--
Translator's Note.), E. Blanchard (Emile Blanchard (born 1820), author
of various works on insects, Spiders, etc.--Translator's Note.) and
Lucas (Pierre Hippolyte Lucas (born 1815), author of works on Moths
and Butterflies, Crustaceans, etc.--Translator's Note.), and boasted a
multitude of most attractive illustrations; but the price of it, the
price of it! No matter: was not my splendid income supposed to cover
everything, food for the mind as well as food for the body? Anything
extra that I gave to the one I could save upon the other; a method of
balancing painfully familiar to those who look to science for their
livelihood. The purchase was effected. That day my professional
emoluments were severely strained: I devoted a month's salary to the
acquisition of the book. I had to resort to miracles of economy for
some time to come before making up the enormous deficit.
The book was devoured; there is no other word for it. In it, I learnt
the name of my black Bee; I read for the first time various details of
the habits of insects; I found, surrounded in my eyes with a sort of
halo, the revered names of Reaumur, Huber (Francois Huber (1750-1831),
the Swiss naturalist, author of "Nouvelles observations sur les
abeilles." He early became blind from excessive study and conducted
his scientific work thereafter with the aid of his wife.--Translator's
Note.) and Leon Dufour (Jean Marie Leon Dufour (1780-1865), an army
surgeon who served with distinction in several campaigns, and
subsequently practised as a doctor in the Landes, where he attained
great eminence as a naturalist. Fabre often refers to him as the
Wizard of the Landes. Cf. "The Life of the Spider", by J. Henri Fabre,
translated by Alexander Teixeira de Mattos: chapter 1; and "The Life
of the Fly": chapter 1.--Translator's Note.); and, while I turned over
the pages for the hundredth time, a voice within me seemed to whisper:
'You also shall be of their company!'
Ah, fond illusions, what has come of you? (The present essay is one of
the earliest in the "Souvenirs Entomologiques."--Translator's Note.)
But let us banish these recollections, at once sweet and sad, and
speak of the doings of our black Bee. Chalicodoma, meaning a house of
pebbles, concrete or mortar, would be a most satisfactory title, were
it not that it has an odd sound to any one unfamiliar with Greek. The
name is given to Bees who build their cells with materials similar to
those which we employ for our own dwellings. The work of these insects
is masonry; only it is turned out by a rustic mason more used to hard
clay than to hewn stone. Reaumur, who knew nothing of scientific
classification--a fact which makes many of his papers very difficult
to understand--named the worker after her work and called our builders
in dried clay Mason-bees, which describes them exactly.
We have two of them in our district: the Chalicodoma of the Walls
(Chalicodoma muraria), whose history Reaumur gives us in a masterly
fashion; and the Sicilian Chalicodoma (C. sicula) (For reasons that
will become apparent after the reader has learnt their habits, the
author also speaks of the Mason-bee of the Walls and the Sicilian
Mason-bee as the Mason-bee of the Pebbles and the Mason-bee of the
Sheds respectively. Cf. Chapter 4 footnote.--Translator's Note.), who
is not peculiar to the land of Etna, as her name might suggest, but is
also found in Greece, in Algeria and in the south of France,
particularly in the department of Vaucluse, where she is one of the
commonest Bees to be seen in the month of May. In the first species
the two sexes are so unlike in colouring that a novice, surprised at
observing them come out of the same nest, would at first take them for
strangers to each other. The female is of a splendid velvety black,
with dark-violet wings. In the male, the black velvet is replaced by a
rather bright brick-red fleece. The second species, which is much
smaller, does not show this contrast of colour: the two sexes wear the
same costume, a general mixture of brown, red and grey, while the tips
of the wings, washed with violet on a bronzed ground, recall, but only
faintly, the rich purple of the first species. Both begin their
labours at the same period, in the early part of May.
As Reaumur tells us, the Chalicodoma of the Walls in the northern
provinces selects a wall directly facing the sun and one not covered
with plaster, which might come off and imperil the future of the
cells. She confides her buildings only to solid foundations, such as
bare stones. I find her equally prudent in the south; but, for some
reason which I do not know, she here generally prefers some other base
to the stone of a wall. A rounded pebble, often hardly larger than
one's fist, one of those cobbles with which the waters of the glacial
period covered the terraces of the Rhone Valley, forms the most
popular support. The extreme abundance of these sites might easily
influence the Bee's choice: all our less elevated uplands, all our
arid, thyme-clad grounds are nothing but water-worn stones cemented
with red earth. In the valleys, the Chalicodoma has also the pebbles
of the mountain-streams at her disposal. Near Orange, for instance,
her favourite spots are the alluvia of the Aygues, with their carpets
of smooth pebbles no longer visited by the waters. Lastly, if a cobble
be wanting, the Mason-bee will establish her nest on any sort of
stone, on a mile-stone or a boundary-wall.
The Sicilian Chalicodoma has an even greater variety of choice. Her
most cherished site is the lower surface of the projecting tiles of a
roof. There is not a cottage in the fields, however small, but
shelters her nests under the eaves. Here, each spring, she settles in
populous colonies, whose masonry, handed down from one generation to
the next and enlarged year by year, ends by covering considerable
surfaces. I have seen some of these nests, under the tiles of a shed,
spreading over an area of five or six square yards. When the colony
was hard at work, the busy, buzzing crowd was enough to make one
giddy. The under side of a balcony also pleases the Mason-bee, as does
the embrasure of a disused window, especially if it is closed by a
blind whose slats allow her a free passage. But these are popular
resorts, where hundreds and thousands of workers labour, each for
herself. If she be alone, which happens pretty often, the Sicilian
Mason-bee instals herself in the first little nook handy, provided
that it supplies a solid foundation and warmth. As for the nature of
this foundation, she does not seem to mind. I have seen her build on
the bare stone, on bricks, on the wood of a shutter and even on the
window-panes of a shed. One thing only does not suit her: the plaster
of our houses. She is as prudent as her kinswoman and would fear the
ruin of her cells, if she entrusted them to a support which might
possibly fall.
Lastly, for reasons which I am still unable to explain to my own
satisfaction, the Sicilian Mason-bee often changes the position of her
building entirely, turning her heavy house of clay, which would seem
to require the solid support of a rock, into an aerial dwelling. A
hedge-shrub of any kind whatever--hawthorn, pomegranate, Christ's
thorn--provides her with a foundation, usually as high as a man's
head. The holm-oak and the elm give her a greater altitude. She
chooses in the bushy clump a twig no thicker than a straw; and on this
narrow base she constructs her edifice with the same mortar that she
would employ under a balcony or the ledge of a roof. When finished,
the nest is a ball of earth, bisected by the twig. It is the size of
an apricot when the work of a single insect and of one's fist if
several have collaborated; but this latter case is rare.
Both Bees use the same materials: calcareous clay, mingled with a
little sand and kneaded into a paste with the mason's own saliva. Damp
places, which would facilitate the quarrying and reduce the
expenditure of saliva for mixing the mortar, are scorned by the Mason-
bees, who refuse fresh earth for building even as our own builders
refuse plaster and lime that have long lost their setting-properties.
These materials, when soaked with pure moisture, would not hold
properly. What is wanted is a dry dust, which greedily absorbs the
disgorged saliva and forms with the latter's albuminous elements a
sort of readily-hardening Roman cement, something in short resembling
the cement which we obtain with quicklime and white of egg.
The mortar-quarry which the Sicilian Mason-bee prefers to work is a
frequented highway, whose metal of chalky flints, crushed by the
passing wheels, has become a smooth surface, like a continuous
flagstone. Whether settling on a twig in a hedge or fixing her abode
under the eaves of some rural dwelling, she always goes for her
building-materials to the nearest path or road, without allowing
herself to be distracted from her business by the constant traffic of
people and cattle. You should see the active Bee at work when the road
is dazzling white under the rays of a hot sun. Between the adjoining
farm, which is the building-yard, and the road, in which the mortar is
prepared, we hear the deep hum of the Bees perpetually crossing one
another as they go to and fro. The air seems traversed by incessant
trails of smoke, so straight and rapid is the worker's flight. Those
on the way to the nest carry tiny pellets of mortar, the size of small
shot; those who return at once settle on the driest and hardest spots.
Their whole body aquiver, they scrape with the tips of their mandibles
and rake with their front tarsi to extract atoms of earth and grains
of sand, which, rolled between their teeth, become impregnated with
saliva and form a solid mass. The work is pursued so vigorously that
the worker lets herself be crushed under the feet of the passers-by
rather than abandon her task.
On the other hand, the Mason-bee of the Walls, who seeks solitude, far
from human habitations, rarely shows herself on the beaten paths,
perhaps because these are too far from the places where she builds. So
long as she can find dry earth, rich in small gravel, near the pebble
chosen as the site of her nest, that is all she asks.
The Bee may either build an entirely new nest on a site as yet
unoccupied, or she may use the cells of an old nest, after repairing
them. Let us consider the former case first. After selecting her
pebble, the Mason-bee of the Walls arrives with a little ball of
mortar in her mandibles and lays it in a circular pad on the surface
of the stone. The fore-legs and above all the mandibles, which are the
mason's chief tools, work the material, which is kept plastic by the
salivary fluid as this is gradually disgorged. In order to consolidate
the clay, angular bits of gravel, the size of a lentil, are inserted
separately, but only on the outside, in the as yet soft mass. This is
the foundation of the structure. Fresh layers follow, until the cell
has attained the desired height of two or three centimetres. (Three-
quarters of an inch to one inch.--Translator's Note.)
Man's masonry is formed of stones laid one above the other and
cemented together with lime. The Chalicodoma's work can bear
comparison with ours. To economise labour and mortar, the Bee employs
coarse materials, big pieces of gravel, which to her represent hewn
stones. She chooses them carefully one by one, picks out the hardest
bits, generally with corners which, fitting one into the other, give
mutual support and contribute to the solidity of the whole. Layers of
mortar, sparingly applied, hold them together. The outside of the cell
thus assumes the appearance of a piece of rustic architecture, in
which the stones project with their natural irregularities; but the
inside, which requires a more even surface in order not to hurt the
larva's tender skin, is covered with a coat of pure mortar. This inner
whitewash, however, is put on without any attempt at art, indeed one
might say that it is ladled on in great splashes; and the grub takes
care, after finishing its mess of honey, to make itself a cocoon and
hang the rude walls of its abode with silk. On the other hand, the
Anthophorae and the Halicti, two species of Wild Bees whose grubs
weave no cocoon, delicately glaze the inside of their earthen cells
and give them the gloss of polished ivory.
The structure, whose axis is nearly always vertical and whose orifice
faces upwards so as not to let the honey escape, varies a little in
shape according to the supporting base. When set on a horizontal
surface, it rises like a little oval tower; when fixed against an
upright or slanting surface, it resembles the half of a thimble
divided from top to bottom. In this case, the support itself, the
pebble, completes the outer wall.
When the cell is finished, the Bee at once sets to work to victual it.
The flowers round about, especially those of the yellow broom (Genista
scoparia), which in May deck the pebbly borders of the mountain
streams with gold, supply her with sugary liquid and pollen. She comes
with her crop swollen with honey and her belly yellowed underneath
with pollen dust. She dives head first into the cell; and for a few
moments you see some spasmodic jerks which show that she is disgorging
the honey-syrup. After emptying her crop, she comes out of the cell,
only to go in again at once, but this time backwards. The Bee now
brushes the lower side of her abdomen with her two hind-legs and rids
herself of her load of pollen. Once more she comes out and once more
goes in head first. It is a question of stirring the materials, with
her mandibles for a spoon, and making the whole into a homogeneous
mixture. This mixing-operation is not repeated after every journey: it
takes place only at long intervals, when a considerable quantity of
material has been accumulated.
The victualling is complete when the cell is half full. An egg must
now be laid on the top of the paste and the house must be closed. All
this is done without delay. The cover consists of a lid of pure
mortar, which the Bee builds by degrees, working from the
circumference to the centre. Two days at most appeared to me to be
enough for everything, provided that no bad weather--rain or merely
clouds--came to interrupt the labour. Then a second cell is built,
backing on the first and provisioned in the same manner. A third, a
fourth, and so on follow, each supplied with honey and an egg and
closed before the foundations of the next are laid. Each task begun is
continued until it is quite finished; the Bee never commences a new
cell until the four processes needed for the construction of its
predecessor are completed: the building, the victualling, the laying
of the egg and the closing of the cell.
As the Mason-bee of the Walls always works by herself on the pebble
which she has chosen and even shows herself very jealous of her site
when her neighbours alight upon it, the number of cells set back to
back upon one pebble is not large, usually varying between six and
ten. Do some eight grubs represent the Bee's whole family? Or does she
afterwards go and establish a more numerous progeny on other boulders?
The surface of the same stone is spacious enough to provide a support
for further cells if the number of eggs called for them; the Bee could
build there very comfortably, without hunting for another site,
without leaving the pebble to which she is attached by habit and long
acquaintance. It seems to me therefore, exceedingly probable that the
family is a small one and that it is all installed on the one stone,
at any rate when the Mason-bee is building a new home.
The six to ten cells composing the cluster are certainly a solid
dwelling, with their rustic gravel covering; but the thickness of
their walls and lids, two millimetres (.078 inch--Translator's Note.)
at most, seems hardly sufficient to protect the grubs against the
inclemencies of the weather. Set on its pebble in the open air,
without any sort of shelter, the nest will have to undergo the heat of
summer, which will turn each cell into a stifling furnace, followed by
the autumn rains, which will slowly wear away the stonework, and by
the winter frosts, which will crumble what the rains have respected.
However hard the cement may be, can it possibly resist all these
agents of destruction? And, even if it does resist, will not the
grubs, sheltered by too thin a wall, have to suffer from excess of
heat in summer and of cold in winter?
Without arguing all this out, the Bee nevertheless acts wisely. When
all the cells are finished, she builds a thick cover over the group,
formed of a material, impermeable to water and a bad conductor of
heat, which acts as a protection at the same time against damp, heat
and cold. This material is the usual mortar, made of earth mixed with
saliva, but on this occasion with no small stones in it. The Bee
applies it pellet by pellet, trowelful by trowelful, to the depth of a
centimetre (.39 inch--Translator's Note.) over the cluster of cells,
which disappear entirely under the clay covering. When this is done,
the nest has the shape of a rough dome, equal in size to half an
orange. One would take it for a round lump of mud which had been
thrown and half crushed against a stone and had then dried where it
was. Nothing outside betrays the contents, no semblance of cells, no
semblance of work. To the inexperienced eye, it is a chance splash of
mud and nothing more.
This outer covering dries as quickly as do our hydraulic cements; and
the nest is now almost as hard as a stone. It takes a knife with a
strong blade to break open the edifice. And I would add, in
conclusion, that, under its final form, the nest in no way recalls the
original work, so much so that one would imagine the cells of the
start, those elegant turrets covered with stucco-work, and the dome of
the finish, looking like a mere lump of mud, to be the product of two
different species. But scrape away the crust of cement and we shall
easily recognize the cells below and their layers of tiny pebbles.
Instead of building a brand-new nest, on a hitherto unoccupied
boulder, the Mason-bee of the Walls is always glad to make use of the
old nests which have lasted through the year without suffering any
damage worth mentioning. The mortar dome has remained very much what
it was at the beginning, thanks to the solidity of the masonry, only
it is perforated with a number of round holes, corresponding with the
chambers, the cells inhabited by past generations of larvae. Dwellings
such as these, which need only a little repair to put them in good
condition, save a great deal of time and trouble; and the Mason-bees
look out for them and do not decide to build new nests except when the
old ones are wanting.
From one and the same dome there issue several inhabitants, brothers
and sisters, ruddy males and black females, all the offspring of the
same Bee. The males lead a careless existence, know nothing of work
and do not return to the clay houses except for a brief moment to woo
the ladies; nor do they reck of the deserted cabin. What they want is
the nectar in the flower-cups, not mortar to mix between their
mandibles. There remain the young mothers, who alone are charged with
the future of the family. To which of them will the inheritance of the
old nest revert? As sisters, they have equal rights to it: so our code
would decide, since the day when it shook itself free of the old
savage right of primogeniture. But the Mason-bees have not yet got
beyond the primitive basis of property, the right of the first
occupant.
When, therefore, the laying-time is at hand, the Bee takes possession
of the first vacant nest that suits her and settles there; and woe to
any sister or neighbour who shall henceforth dare to contest her
ownership. Hot pursuits and fierce blows will soon put the newcomer to
flight. Of the various cells that yawn like so many wells around the
dome, only one is needed at the moment; but the Bee rightly calculates
that the others will be useful presently for the other eggs; and she
watches them all with jealous vigilance to drive away possible
visitors. Indeed I do not remember ever seeing two Masons working on
the same pebble.
The task is now very simple. The Bee examines the old cell to see what
parts require repairing. She tears off the strips of cocoon hanging
from the walls, removes the fragments of clay that fell from the
ceiling when pierced by the last inhabitant to make her exit, gives a
coat of mortar to the dilapidated parts, mends the opening a little;
and that is all. Next come the storing, the laying of the eggs and the
closing of the chamber. When all the cells, one after the other, are
thus furnished, the outer cover, the mortar dome, receives a few
repairs if it needs them; and the thing is done.
The Sicilian Mason-bee prefers company to a solitary life and
establishes herself in her hundreds, very often in many thousands,
under the tiles of a shed or the edge of a roof. These do not
constitute a true society, with common interests to which all attend,
but a mere gathering, where each works for herself and is not
concerned with the rest, in short, a throng of workers recalling the
swarm of a hive only by their numbers and their eagerness. The mortar
employed is the same as that of the Mason-bee of the Walls, equally
unyielding and waterproof, but thinner and without pebbles. The old
nests are used first. Every free chamber is repaired, stocked and
sealed up. But the old cells are far from sufficient for the
population, which increases rapidly from year to year. Then, on the
surface of the nest, whose chambers are hidden under the old general
mortar covering, new cells are built, as the needs of the laying-time
call for them. They are placed horizontally, or nearly so, side by
side, with no attempt at orderly arrangement. Each architect has
plenty of elbow-room and builds as and where she pleases, on the one
condition that she does not hamper her neighbours' work; otherwise she
can look out for rough handling from the parties interested. The
cells, therefore, accumulate at random in this workyard where there is
no organization. Their shape is that of a thimble divided down the
middle; and their walls are completed either by the adjoining cells or
by the surface of the old nest. Outside, they are rough and display
successive layers of knotted cords corresponding with the different
courses of mortar. Inside, the walls are flat without being smooth;
later on, the grub's cocoon will make up for any lack of polish.
Each cell, as built, is stocked and walled up immediately, as we have
seen with the Mason-bee of the Walls. This work goes on throughout the
best part of May. All the eggs are laid at last; and then the Bees,
without drawing distinctions between what does and what does not
belong to them, set to work in common on a general protection for the
colony. This is a thick coat of mortar, which fills up the gaps and
covers all the cells. In the end, the common nest presents the
appearance of a wide expanse of dry mud, with very irregular
protuberances, thicker in the middle, the original nucleus of the
establishment, thinner at the edges, where as yet there are only newly
built cells, and varying greatly in dimensions according to the number
of workers and therefore to the age of the nest first founded. Some of
these nests are hardly larger than one's hand, while others occupy the
greater part of the projecting edge of a roof and are measured by
square yards.
When working alone, which is not unusual, on the shutter of a disused
window, on a stone, or on a twig in some hedge, the Sicilian
Chalicodoma behaves in just the same way. For instance, should she
settle on a twig, the Bee begins by solidly cementing the base of her
cell to the slight foundation. Next, the building rises, taking the
form of a little upright turret. This first cell, when victualled and
sealed, is followed by another, having as its support, in addition to
the twig, the cells already built. From six to ten chambers are thus
grouped side by side. Lastly, one coat of mortar covers everything,
including the twig itself, which provides a firm mainstay for the
whole.
CHAPTER 2. EXPERIMENTS.
As the nests of the Mason-bee of the Walls are erected on small-sized
pebbles, which can be easily carried wherever you like and moved about
from one place to another, without disturbing either the work of the
builder or the repose of the occupants of the cells, they lend
themselves readily to practical experiment, the only method that can
throw a little light on the nature of instinct. To study the insect's
mental faculties to any purpose, it is not enough for the observer to
be able to profit by some happy combination of circumstances: he must
know how to produce other combinations, vary them as much as possible
and test them by substitution and interchange. Lastly, to provide
science with a solid basis of facts, he must experiment. In this way,
the evidence of formal records will one day dispel the fantastic
legends with which our books are crowded: the Sacred Beetle (A Dung-
beetle who rolls the manure of cattle into balls for his own
consumption and that of his young. Cf. "Insect Life", by J.H. Fabre,
translated by the author of "Mademoiselle Mori": chapters 1 and 2; and
"The Life and Love of the Insect", by J. Henri Fabre, translated by
Alexander Teixeira de Mattos: chapters 1 to 4.--Translator's Note.)
calling on his comrades to lend a helping hand in dragging his pellet
out of a rut; the Sphex (A species of Hunting Wasp. Cf. "Insect Life":
chapters 6 to 12.--Translator's Note.) cutting up her Fly so as to be
able to carry him despite the obstacle of the wind; and all the other
fallacies which are the stock-in-trade of those who wish to see in the
animal world what is not really there. In this way, again, materials
will be prepared which will one day be worked up by the hand of a
master and consign hasty and unfounded theories to oblivion.
Reaumur, as a rule, confines himself to stating facts as he sees them
in the normal course of events and does not try to probe deeper into
the insect's ingenuity by means of artificially produced conditions.
In his time, everything had yet to be done; and the harvest was so
great that the illustrious harvester went straight to what was most
urgent, the gathering of the crop, and left his successors to examine
the grain and the ear in detail. Nevertheless, in connection with the
Chalicodoma of the Walls, he mentions an experiment made by his
friend, Duhamel. (Henri Louis Duhamel du Monceau (1700-1781), a
distinguished writer on botany and agriculture.--Translator's Note.)
He tells us how a Mason-bee's nest was enclosed in a glass funnel, the
mouth of which was covered merely with a bit of gauze. From it there
issued three males, who, after vanquishing mortar as hard as stone,
either never thought of piercing the flimsy gauze or else deemed the
work beyond their strength. The three Bees died under the funnel.
Reaumur adds that insects generally know only how to do what they have
to do in the ordinary course of nature.
The experiment does not satisfy me, for two reasons: first, to ask
workers equipped with tools for cutting clay as hard as granite to cut
a piece of gauze does not strike me as a happy inspiration; you cannot
expect a navvy's pick-axe to do the same work as a dressmaker's
scissors. Secondly, the transparent glass prison seems to me ill-
chosen. As soon as the insect has made a passage through the thickness
of its earthen dome, it finds itself in broad daylight; and to it
daylight means the final deliverance, means liberty. It strikes
against an invisible obstacle, the glass; and to it glass is nothing
at all and yet an obstruction. On the far side, it sees free space,
bathed in sunshine. It wears itself out in efforts to fly there,
unable to understand the futile nature of its attempts against that
strange barrier which it cannot see. It perishes, at last, of
exhaustion, without, in its obstinacy, giving a glance at the gauze
closing the conical chimney. The experiment must be renewed under
better conditions.
The obstacle which I select is ordinary brown paper, stout enough to
keep the insect in the dark and thin enough not to offer serious
resistance to the prisoner's efforts. As there is a great difference,
in so far as the actual nature of the barrier is concerned, between a
paper partition and a clay ceiling, let us begin by enquiring if the
Mason-bee of the Walls knows how or rather is able to make her way
through one of these partitions. The mandibles are pickaxes suitable
for breaking through hard mortar: are they also scissors capable of
cutting a thin membrane? This is the point to look into first of all.
In February, by which time the insect is in its perfect state, I take
a certain number of cocoons, without damaging them, from their cells
and insert them each in a separate stump of reed, closed at one end by
the natural wall of the node and open at the other. These pieces of
reed represent the cells of the nest. The cocoons are introduced with
the insect's head turned towards the opening. Lastly, my artificial
cells are closed in different ways. Some receive a stopper of kneaded
clay, which, when dry, will correspond in thickness and consistency
with the mortar ceiling of the natural nest. Others are plugged with a
cylinder of sorghum, at least a centimetre (.39 inch--Translator's
Note.) thick; and the remainder with a disk of brown paper solidly
fastened by the edge. All these bits of reed are placed side by side
in a box, standing upright, with the roof of my making at the top. The
insects, therefore, are in the exact position which they occupied in
the nest. To open a passage, they must do what they would have done
without my interference, they must break through the wall situated
above their heads. I shelter the whole under a wide bell-glass and
wait for the month of May, the period of the deliverance.
The results far exceed my anticipations. The clay stopper, the work of
my fingers, is perforated with a round hole, differing in no wise from
that which the Mason-bee contrives through her native mortar dome. The
vegetable barrier, new to my prisoners, namely, the sorghum cylinder,
also opens with a neat orifice, which might have been the work of a
punch. Lastly, the brown-paper cover allows the Bee to make her exit
not by bursting through, by making a violent rent, but once more by a
clearly defined round hole. My Bees therefore are capable of a task
for which they were not born; to come out of their reed cells they do
what probably none of their race did before them; they perforate the
wall of sorghum-pith, they make a hole in the paper barrier, just as
they would have pierced their natural clay ceiling. When the moment
comes to free themselves, the nature of the impediment does not stop
them, provided that it be not beyond their strength; and henceforth
the argument of incapacity cannot be raised when a mere paper barrier
is in question.
In addition to the cells made out of bits of reed, I put under the
bell-glass, at the same time, two nests which are intact and still
resting on their pebbles. To one of them I have attached a sheet of
brown paper pressed close against the mortar dome. In order to come
out, the insect will have to pierce first the dome and then the paper,
which follows without any intervening space. Over the other, I have
placed a little brown paper cone, gummed to the pebble. There is here,
therefore, as in the first case, a double wall--a clay partition and a
paper partition--with this difference, that the two walls do not come
immediately after each other, but are separated by an empty space of
about a centimetre at the bottom, increasing as the cone rises.
The results of these two experiments are quite different. The Bees in
the nest to which a sheet of paper was tightly stuck come out by
piercing the two enclosures, of which the outer wall, the paper
wrapper, is perforated with a very clean round hole, as we have
already seen in the reed cells closed with a lid of the same material.
We thus become aware, for the second time, that, when the Mason-bee is
stopped by a paper barrier, the reason is not her incapacity to
overcome the obstacle. On the other hand, the occupants of the nest
covered with the cone, after making their way through the earthen
dome, finding the sheet of paper at some distance, do not even try to
perforate this obstacle, which they would have conquered so easily had
it been fastened to the nest. They die under the cover without making
any attempt to escape. Even so did Reaumur's Bees perish in the glass
funnel, where their liberty depended only upon their cutting through a
bit of gauze.
This fact strikes me as rich in inferences. What! Here are sturdy
insects, to whom boring through granite is mere play, to whom a
stopper of soft wood and a paper partition are walls quite easy to
perforate despite the novelty of the material; and yet these vigorous
housebreakers allow themselves to perish stupidly in the prison of a
paper bag, which they could have torn open with one stroke of their
mandibles! They are capable of tearing it, but they do not dream of
doing so! There can be only one explanation of this suicidal inaction.
The insect is well-endowed with tools and instinctive faculties for
accomplishing the final act of its metamorphosis, namely, the act of
emerging from the cocoon and from the cell. Its mandibles provide it
with scissors, file, pick-axe and lever wherewith to cut, gnaw through
and demolish either its cocoon and its mortar enclosure or any other
not too obstinate barrier substituted for the natural covering of the
nest. Moreover--and this is an important proviso, except for which the
outfit would be useless--it has, I will not say the will to use those
tools, but a secret stimulus inviting it to employ them. When the hour
for the emergence arrives, this stimulus is aroused and the insect
sets to work to bore a passage. It little cares in this case whether
the material to be pierced be the natural mortar, sorghum-pith, or
paper: the lid that holds it imprisoned does not resist for long. Nor
even does it care if the obstacle be increased in thickness and a
paper wall be added outside the wall of clay: the two barriers, with
no interval between them, form but one to the Bee, who passes through
them because the act of getting out is still one act and one only.
With the paper cone, whose wall is a little way off, the conditions
are changed, though the total thickness of wall is really the same.
Once outside its earthen abode, the insect has done all that it was
destined to do in order to release itself; to move freely on the
mortar dome represents to it the end of the release, the end of the
act of boring. Around the nest a new barrier appears, the wall made by
the paper bag; but, in order to pierce this, the insect would have to
repeat the act which it has just accomplished, the act which it is not
intended to perform more than once in its life; it would, in short,
have to make into a double act that which by nature is a single one;
and the insect cannot do this, for the sole reason that it has not the
wish to. The Mason-bee perishes for lack of the smallest gleam of
intelligence. And this is the singular intellect in which it is the
fashion nowadays to see a germ of human reason! The fashion will pass
and the facts remain, bringing us back to the good old notions of the
soul and its immortal destinies.
Reaumur tells us how his friend Duhamel, having seized a Mason-bee
with a forceps when she had half entered the cell, head foremost, to
fill it with pollen-paste, carried her to a closet at some distance
from the spot where he captured her. The Bee got away from him in this
closet and flew out through the window. Duhamel made straight for the
nest. The Mason arrived almost as soon as he did and renewed her work.
She only seemed a little wilder, says the narrator, in conclusion.
Why were you not here with me, revered master, on the banks of the
Aygues, which is a vast expanse of pebbles for three-fourths of the
year and a mighty torrent when it rains? I should have shown you
something infinitely better than the fugitive escaping from the
forceps. You would have witnessed--and in so doing, would have shared
my surprise--not the brief flight of the Mason who, carried to the
nearest room, releases herself and forthwith returns to her nest in
that familiar neighbourhood, but long journeys through unknown
country. You would have seen the Bee whom I carried to a great
distance from her home, to quite unfamiliar ground, find her way back
with a geographical sense of which the Swallow, the Martin and the
Carrier-pigeon would not have been ashamed; and you would have asked
yourself, as I did, what incomprehensible knowledge of the local map
guides that mother seeking her nest.
To come to facts: it is a matter of repeating with the Mason-bee of
the Walls my former experiments with the Cerceris-wasps (Cf. "Insect
Life": chapter 19.--Translator's Note.), of carrying the insect, in
the dark, a long way from its nest, marking it and then leaving it to
its own resources. In case any one should wish to try the experiment
for himself, I make him a present of my manner of operation, which may
save him time at the outset. The insect intended for a long journey
must obviously be handled with certain precautions. There must be no
forceps employed, no pincers, which might maim a wing, strain it and
weaken the power of flight. While the Bee is in her cell, absorbed in
her work, I place a small glass test-tube over it. The Mason, when she
flies away, rushes into the tube, which enables me, without touching
her, to transfer her at once into a screw of paper. This I quickly
close. A tin box, an ordinary botanizing-case, serves to convey the
prisoners, each in her separate paper bag.
The most delicate business, that of marking each captive before
setting her free, is left to be done on the spot selected for the
starting-point. I use finely-powdered chalk, steeped in a strong
solution of gum arabic. The mixture, applied to some part of the
insect with a straw, leaves a white patch, which soon dries and
adheres to the fleece. When a particular Mason-bee has to be marked so
as to distinguish her from another in short experiments, such as I
shall describe presently, I confine myself to touching the tip of the
abdomen with my straw while the insect is half in the cell, head
downwards. The slight touch is not noticed by the Bee, who continues
her work quite undisturbed; but the mark is not very deep and moreover
it is in a rather bad place for any prolonged experiment, for the Bee
is constantly brushing her belly to detach the pollen and is sure to
rub it off sooner or later. I therefore make another one, dropping the
sticky chalk right in the middle of the thorax, between the wings.
It is hardly possible to wear gloves at this work: the fingers need
all their deftness to take up the restless Bee delicately and to
overpower her without rough pressure. It is easily seen that, though
the job may yield no other profit, you are at least sure of being
stung. The sting can be avoided with a little dexterity, but not
always. You have to put up with it. In any case, the Mason-bee's sting
is far less painful than that of the Hive-bee. The white spot is
dropped on the thorax; the Mason flies off; and the mark dries on the
journey.
I start with two Mason-bees of the Walls working at their nests on the
pebbles in the alluvia of the Aygues, not far from Serignan. I carry
them home with me to Orange, where I release them after marking them.
According to the ordnance-survey map, the distance is about two and a
half miles as the crow flies. The captives are set at liberty in the
evening, at a time when the Bees begin to leave off work for the day.
It is therefore probable that my two Bees will spend their night in
the neighbourhood.
Next morning, I go to the nests. The weather is still too cool and the
works are suspended. When the dew has gone, the Masons begin work. I
see one, but without a white spot, bringing pollen to one of the nests
which had been occupied by the travellers whom I am expecting. She is
a stranger who, finding the cell whose owner I myself had exiled
untenanted, has installed herself there and made it her property, not
knowing that it is already the property of another. She has perhaps
been victualling it since yesterday evening. Close upon ten o'clock,
when the heat is at its full, the mistress of the house suddenly
arrives: her title-deeds as the original occupant are inscribed for me
in undeniable characters on her thorax white with chalk. Here is one
of my travellers back.
Over waving corn, over fields all pink with sainfoin, she has covered
the two miles and a half; and here she is, back at the nest, after
foraging on the way, for the doughty creature arrives with her abdomen
yellow with pollen. To come home again from the verge of the horizon
is wonderful in itself; to come home with a well-filled pollen-brush
is superlative economy. A journey, even a forced journey, always
becomes a foraging-expedition.
She finds the stranger in the nest:
'What's this? I'll teach you!'
And the owner falls furiously upon the intruder, who possibly was
meaning no harm. A hot chase in mid-air now takes place between the
two Masons. From time to time, they hover almost without movement,
face to face, with only a couple of inches separating them, and here,
doubtless measuring forces with their eyes, they buzz insults at each
other. Then they go back and alight on the nest in dispute, first one,
then the other. I expect to see them come to blows, to make them draw
their stings. But my hopes are disappointed: the duties of maternity
speak in too imperious a voice for them to risk their lives and wipe
out the insult in a mortal duel. The whole thing is confined to
hostile demonstrations and a few insignificant cuffs.
Nevertheless, the real proprietress seems to derive double courage and
double strength from the feeling that she is in her rights. She takes
up a permanent position on the nest and receives the other, each time
that she ventures to approach, with an angry quiver of her wings, an
unmistakable sign of her righteous indignation. The stranger, at last
discouraged, retires from the field. Forthwith the Mason resumes her
work, as actively as though she had not just undergone the hardships
of a long journey.
One more word on these quarrels about property. It is not unusual,
when one Mason-bee is away on an expedition, for another, some
homeless vagabond, to call at the nest, take a fancy to it and set to
work on it, sometimes at the same cell, sometimes at the next, if
there are several vacant, which is generally the case in the old
nests. The first occupier, on her return, never fails to drive away
the intruder, who always ends by being turned out, so keen and
invincible is the mistress' sense of ownership. Reversing the savage
Prussian maxim, 'Might is right,' among the Mason-bees right is might,
for there is no other explanation of the invariable retreat of the
usurper, whose strength is not a whit inferior to that of the real
owner. If she is less bold, this is because she has not the tremendous
moral support of knowing herself in the right, which makes itself
respected, among equals, even in the brute creation.
The second of my travellers does not reappear, either on the day when
the first arrived or on the following days. I decide upon another
experiment, on this occasion with five subjects. The starting-place is
the same; and the place of arrival, the distance, the time of day, all
remain unchanged. Of the five with whom I experiment, I find three at
their nests next day; the two others are missing.
It is therefore fully established that the Mason-bee of the Walls,
carried to a distance of two and a half miles and released at a place
which she has certainly never seen before, is able to return to the
nest. But why do first one out of two and then two out of five fail to
join their fellows? What one can do cannot another do? Is there a
difference in the faculty that guides them over unknown ground? Or is
it not rather a difference in flying-power? I remember that my Bees
did not all start off with the same vigour. Some were hardly out of my
fingers before they darted furiously into the air, where I at once
lost sight of them, whereas the others came dropping down a few yards
away from me, after a short flight. The latter, it seems certain, must
have suffered on the journey, perhaps from the heat concentrated in
the furnace of my box. Or I may have hurt the articulation of the
wings in marking them, an operation difficult to perform when you are
guarding against stings. These are maimed, feeble creatures, who will
linger in the sainfoin-fields close by, and not the powerful aviators
required by the journey.
The experiment must be tried again, taking count only of the Bees who
start off straight from between my fingers with a clean, vigorous
flight. The waverers, the laggards who stop almost at once on some
bush shall be left out of the reckoning. Moreover, I will do my best
to estimate the time taken in returning to the nest. For an experiment
of this kind, I need plenty of subjects, as the weak and the maimed,
of whom there may be many, are to be disregarded. The Mason-bee of the
Walls is unable to supply me with the requisite number: there are not
enough of her; and I am anxious not to interfere too much with the
little Aygues-side colony, for whom I have other experiments in view.
Fortunately, I have at my own place, under the eaves of a shed, a
magnificent nest of Chalicodoma sicula in full activity. I can draw to
whatever extent I please on the populous city. The insect is small,
less than half the size of C. muraria, but no matter: it will deserve
all the more credit if it can traverse the two miles and a half in
store for it and find its way back to the nest. I take forty Bees,
isolating them, as usual, in screws of paper.
In order to reach the nest, I place a ladder against the wall: it will
be used by my daughter Aglae and will enable her to mark the exact
moment of the return of the first Bee. I set the clock on the
mantelpiece and my watch at the same time, so that we may compare the
instant of departure and of arrival. Things being thus arranged, I
carry off my forty captives and go to the identical spot where C.
muraria works, in the pebbly bed of the Aygues. The trip will have a
double object: to observe Reaumur's Mason and to set the Sicilian
Mason at liberty. The latter, therefore, will also have two and a half
miles to travel home.
At last my prisoners are released, all of them being first marked with
a big white dot in the middle of the thorax.
You do not come off scot-free when handling one after the other forty
wrathful Bees, who promptly unsheathe and brandish their poisoned
stings. The stab is but too often given before the mark is made. My
smarting fingers make movements of self-defence which my will is not
always able to control. I take hold with greater precaution for myself
than for the insect; I sometimes squeeze harder than I ought to if I
am to spare my travellers. To experiment so as to lift, if possible, a
tiny corner of the veil of truth is a fine and noble thing, a mighty
stimulant in the face of danger; but still one may be excused for
displaying some impatience when it is a matter of receiving forty
stings in one's fingers at one short sitting. If any man should
reproach me for being too careless with my thumbs, I would suggest
that he should have a try: he can then judge for himself the pleasures
of the situation.
To cut a long story short, either through the fatigue of the journey,
or through my fingers pressing too hard and perhaps injuring some
articulations, only twenty out of my forty Bees start with a bold,
vigorous flight. The others, unable to keep their balance, wander
about on the nearest bit of grass or remain on the osier-shoots on
which I have placed them, refusing to fly even when I tickle them with
a straw. These weaklings, these cripples, these incapables injured by
my fingers must be struck off my list. Those who started with an
unhesitating flight number about twenty. That is ample.
At the actual moment of departure, there is nothing definite about the
direction taken, none of that straight flight to the nest which the
Cerceris-wasps once showed me in similar circumstances. As soon as
they are liberated, the Mason-bees flee as though scared, some in one
direction, some in exactly the opposite direction. Nevertheless, as
far as their impetuous flight allows, I seem to perceive a quick
return on the part of those Bees who have started flying towards a
point opposite to their home; and the majority appear to me to be
making for those blue distances where their nest lies. I leave this
question with certain doubts which are inevitable in the case of
insects which I cannot follow with my eyes for more than twenty yards.
Hitherto, the operation has been favoured by calm weather; but now
things become complicated. The heat is stifling and the sky becomes
stormy. A stiff breeze springs up, blowing from the south, the very
direction which my Bees must take to return to the nest. Can they
overcome this opposing current and cleave the aerial torrent with
their wings? If they try, they will have to fly close to the ground,
as I now see the Bees do who continue their foraging; but soaring to
lofty regions, whence they can obtain a clear view of the country, is,
so it seems to me, prohibited. I am therefore very apprehensive as to
the success of my experiment when I return to Orange, after first
trying to steal some fresh secret from the Aygues Mason-bee of the
Pebbles.
I have scarcely reached the house before Aglae greets me, her cheeks
flushed with excitement:
'Two!' she cries. 'Two came back at twenty minutes to three, with a
load of pollen under their bellies!'
A friend of mine had appeared upon the scene, a grave man of the law,
who on hearing what was happening, had neglected code and stamped
paper and insisted upon also being present at the arrival of my
Carrier-pigeons. The result interested him more than his case about a
party-wall. Under a tropical sun, in a furnace heat reflected from the
wall of the shed, every five minutes he climbed the ladder bare-
headed, with no other protection against sunstroke than his thatch of
thick, grey locks. Instead of the one observer whom I had posted, I
found two good pairs of eyes watching the Bees' return.
I had released my insects at about two o'clock; and the first arrivals
returned to the nest at twenty minutes to three. They had therefore
taken less than three-quarters of an hour to cover the two miles and a
half, a very striking result, especially when we remember that the
Bees did some foraging on the road, as was proved by the yellow pollen
on their bellies, and that, on the other hand, the travellers' flight
must have been hindered by the wind blowing against them. Three more
came home before my eyes, each with her load of pollen, an outward and
visible sign of the work done on the journey. As it was growing late,
our observations had to cease. When the sun goes down, the Mason-bees
leave the nest and take refuge somewhere or other, perhaps under the
tiles of the roofs, or in little corners of the walls. I could not
reckon on the arrival of the others before work was resumed, in the
full sunshine.
Next day, when the sun recalled the scattered workers to the nest, I
took a fresh census of Bees with a white spot on the thorax. My
success exceeded all my hopes: I counted fifteen, fifteen of the
transported prisoners of the day before, storing their cells or
building as though nothing out of the way had happened. The weather
had become more and more threatening; and now the storm burst and was
followed by a succession of rainy days which prevented me from
continuing.
The experiment suffices as it stands. Of some twenty Bees who had
seemed fit to make the long journey when I released them, fifteen at
least had returned: two within the first hour, three in the course of
the evening and the rest next morning. They had returned in spite of
having the wind against them and--a graver difficulty still--in spite
of being unacquainted with the locality to which I had transported
them. There is, in fact, no doubt that they were setting eyes for the
first time on those osier-beds of the Aygues which I had selected as
the starting-point. Never would they have travelled so far afield of
their own accord, for everything that they want for building and
victualling under the roof of my shed is within easy reach. The path
at the foot of the wall supplies the mortar; the flowery meadows
surrounding my house furnish nectar and pollen. Economical of their
time as they are, they do not go flying two miles and a half in search
of what abounds at a few yards from the nest. Besides, I see them
daily taking their building-materials from the path and gathering
their harvest on the wild-flowers, especially on the meadow sage. To
all appearance, their expeditions do not cover more than a radius of a
hundred yards or so. Then how did my exiles return? What guided them?
It was certainly not memory, but some special faculty which we must
content ourselves with recognizing by its astonishing effects without
pretending to explain it, so greatly does it transcend our own
psychology.
CHAPTER 3. EXCHANGING THE NESTS.
Let us continue our series of tests with the Mason-bee of the Walls.
Thanks to its position on a pebble which we can move at will, the nest
of this Bee lends itself to most interesting experiments. Here is the
first: I shift a nest from its place, that is to say, I carry the
pebble which serves as its support to a spot two yards away. As the
edifice and its base form but one, the removal is performed without
the smallest disturbance of the cells. I lay the boulder in an exposed
place where it is well in view, as it was on its original site. The
Bee returning from her harvest cannot fail to see it.
In a few minutes, the owner arrives and goes straight to where the
nest stood. She hovers gracefully over the vacant site, examines and
alights upon the exact spot where the stone used to lie. Here she
walks about for a long time, making persistent searches; then the Bee
takes wing and flies away to some distance. Her absence is of short
duration. Here she is back again. The search is resumed, walking and
flying, and always on the site which the nest occupied at first. A
fresh fit of exasperation, that is to say, an abrupt flight across the
osier-bed, is followed by a fresh return and a renewal of the vain
search, always upon the mark left by the shifted pebble. These sudden
departures, these prompt returns, these persevering inspections of the
deserted spot continue for a long time, a very long time, before the
Mason is convinced that her nest is gone. She has certainly seen it,
has seen it over and over again in its new position, for sometimes she
has flown only a few inches above it; but she takes no notice of it.
To her, it is not her nest, but the property of another Bee.
Often the experiment ends without so much as a single visit to the
boulder which I have moved two or three yards away: the Bee goes off
and does not return. If the distance be less, a yard for instance, the
Mason sooner or later alights on the stone which supports her abode.
She inspects the cell which she was building or provisioning a little
while before, repeatedly dips her head into it, examines the surface
of the pebble step by step and, after long hesitations, goes and
resumes her search on the site where the home ought to be. The nest
that is no longer in its natural place is definitely abandoned, even
though it be but a yard away from the original spot. Vainly does the
Bee settle on it time after time: she cannot recognize it as hers. I
was convinced of this on finding it, several days after the
experiment, in just the same condition as when I moved it. The open
cell half-filled with honey was still open and was surrendering its
contents to the pillaging Ants; the cell that was building had
remained unfinished, with not a single layer added to it. The Bee,
obviously, may have returned to it; but she had not resumed work upon
it. The transplanted dwelling was abandoned for good and all.
I will not deduce the strange paradox that the Mason-bee, though
capable of finding her nest from the verge of the horizon, is
incapable of finding it at a yard's distance: I interpret the
occurrence as meaning something quite different. The proper inference
appears to me to be this: the Bee retains a rooted impression of the
site occupied by the nest and returns to it with unwearying
persistence even when the nest is gone. But she has only a very vague
notion of the nest itself. She does not recognize the masonry which
she herself has erected and kneaded with her saliva; she does not know
the pollen-paste which she herself has stored. In vain she inspects
her cell, her own handiwork; she abandons it, refusing to acknowledge
it as hers, once the spot whereon the pebble rests is changed.
Insect memory, it must be confessed, is a strange one, displaying such
lucidity in its general acquaintance with locality and such
limitations in its knowledge of the dwelling. I feel inclined to call
it topographical instinct: it grasps the map of the country and not
the beloved nest, the home itself. The Bembex-wasps (Cf. "Insect
Life": chapters 16 to 19.--Translator's Note.) have already led us to
a like conclusion. When the nest is laid open, these Wasps become
wholly indifferent to the family, to the grub writhing in agony in the
sun. They do not recognize it. What they do recognize, what they seek
and find with marvellous precision, is the site of the entrance-door
of which nothing at all is left, not even the threshold.
If any doubts remained as to the incapacity of the Mason-bee of the
Walls to know her nest other than by the place which the pebble
occupies on the ground, here is something to remove them: for the nest
of one Mason-bee, I substitute that of another, resembling it as
closely as possible in respect to both masonry and storage. This
exchange and those of which I shall speak presently are of course made
in the owner's absence. The Bee settles without hesitation in this
nest which is not hers, but which stands where the other did. If she
was building, I offer her a cell in process of building. She continues
the masonry with the same care and the same zeal as if the work
already done were her own work. If she was fetching honey and pollen,
I offer her a partly-provisioned cell. She continues her journeys,
with honey in her crop and pollen under her belly, to finish filling
another's warehouse. The Bee, therefore, does not suspect the
exchange; she does not distinguish between what is her property and
what is not; she imagines that she is still working at the cell which
is really hers.
After leaving her for a time in possession of the strange nest, I give
her back her own. This fresh change passes unperceived by the Bee: the
work is continued in the cell restored to her at the point which it
had reached in the substituted cell. I once more replace it by the
strange nest; and again the insect persists in continuing its labour.
By thus constantly interchanging the strange nest and the proper nest,
without altering the actual site, I thoroughly convinced myself of the
Bee's inability to discriminate between what is her work and what is
not. Whether the cell belong to her or to another, she labours at it
with equal zest, so long as the basis of the edifice, the pebble,
continues to occupy its original position.
The experiment receives an added interest if we employ two
neighbouring nests the work on which is about equally advanced. I move
each to where the other stood. They are not much more than thirty
inches a part. In spite of their being so near to each other that it
is quite possible for the insects to see both homes at once and choose
between them, each Bee, on arriving, settles immediately on the
substituted nest and continues her work there. Change the two nests as
often as you please and you shall see the two Mason-bees keep to the
site which they selected and labour in turn now at their own cell and
now at the other's.
One might think that the cause of this confusion lies in a close
resemblance between the two nests, for at the start, little expecting
the results which I was to obtain, I used to choose the nests which I
interchanged as much alike as possible, for fear of disheartening the
Bees. I need not have taken this precaution: I was giving the insect
credit for a perspicacity which it does not possess. Indeed, I now
take two nests which are extremely unlike each other, the only point
of resemblance being that, in each case, the toiler finds a cell in
which she can continue the work which she is actually doing. The first
is an old nest whose dome is perforated with eight holes, the
apertures of the cells of the previous generation. One of these cells
has been repaired; and the Bee is busy storing it. The second is a
nest of recent construction, which has not received its mortar dome
and consists of a single cell with its stucco covering. Here too the
insect is busy hoarding pollen-paste. No two nests could present
greater differences: one with its eight empty chambers and its
spreading clay dome; the other with its single bare cell, at most the
size of an acorn.
Well, the two Mason-bees do not hesitate long in front of these
exchanged nests, not three feet away from each other. Each makes for
the site of her late home. One, the original owner of the old nest,
finds nothing but a solitary cell. She rapidly inspects the pebble
and, without further formalities, first plunges her head into the
strange cell, to disgorge honey, and then her abdomen, to deposit
pollen. And this is not an action due to the imperative need of
ridding herself as quickly as possible, no matter where, of an irksome
load, for the Bee flies off and soon comes back again with a fresh
supply of provender, which she stores away carefully. This carrying of
provisions to another's larder is repeated as often as I permit it.
The other Bee, finding instead of her one cell a roomy structure
consisting of eight apartments, is at first not a little embarrassed.
Which of the eight cells is the right one? In which is the heap of
paste on which she had begun? The Bee therefore visits the chambers
one by one, dives right down to the bottom and ends by finding what
she seeks, that is to say, what was in her nest when she started on
her last journey, the nucleus of a store of food. Thenceforward she
behaves like her neighbour and goes on carrying honey and pollen to
the warehouse which is not of her constructing.
Restore the nests to their original places, exchange them yet once
again and both Bees, after a short hesitation which the great
difference between the two nests is enough to explain, will pursue the
work in the cell of her own making and in the strange cell
alternately. At last the egg is laid and the sanctuary closed, no
matter what nest happens to be occupied at the moment when the
provisioning reaches completion. These incidents are sufficient to
show why I hesitate to give the name of memory to the singular faculty
that brings the insect back to her nest with such unerring precision
and yet does not allow her to distinguish her work from some one
else's, however great the difference may be.
We will now experiment with Chalicodoma muraria from another
psychological point of view. Here is a Mason-bee building; she is at
work on the first course of her cell. I give her in exchange a cell
not only finished as a structure, but also filled nearly to the top
with honey. I have just stolen it from its owner, who would not have
been long before laying her egg in it. What will the Mason do in the
presence of this munificent gift, which saves her the trouble of
building and harvesting? She will leave the mortar no doubt, finish
storing the Bee-bread, lay her egg and seal up. A mistake, an utter
mistake: our logic is not the logic of the insect, which obeys an
inevitable, unconscious prompting. It has no choice as to what it
shall do; it cannot discriminate between what is and what is not
advisable; it glides, as it were, down an irresistible slope prepared
beforehand to bring it to a definite end. This is what the facts that
still remain to be stated proclaim with no uncertain voice.
The Bee who was building and to whom I offer a cell ready-built and
full of honey does not lay aside her mortar for that. She was doing
mason's work; and, once on that tack, guided by the unconscious
impulse, she has to keep masoning, even though her labour be useless,
superfluous and opposed to her interests. The cell which I give her is
certainly perfect, looked upon as a building, in the opinion of the
master-builder herself, since the Bee from whom I took it was
completing the provision of honey. To touch it up, especially to add
to it, is useless and, what is more, absurd. No matter: the Bee who
was masoning will mason. On the aperture of the honey-store she lays a
first course of mortar, followed by another and yet another, until at
last the cell is a third taller then the regulation height. The
masonry-task is now done, not as perfectly, it is true, as if the Bee
had gone on with the cell whose foundations she was laying at the
moment when I exchanged the nests, but still to an extent which is
more than enough to prove the overpowering impulse which the builder
obeys. Next comes the victualling, which is also cut short, lest the
honey-store swelled by the joint contributions of the two Bees should
overflow. Thus the Mason-bee who is beginning to build and to whom we
give a complete cell, a cell filled with honey, makes no change in the
order of her work: she builds first and then victuals. Only she
shortens her work, her instinct warning her that the height of the
cell and the quantity of honey are beginning to assume extravagant
proportions.
The converse is equally conclusive. To a Mason-bee engaged in
victualling I give a nest with a cell only just begun and not at all
fit to receive the paste. This cell, with its last course still wet
with its builder's saliva, may or may not be accompanied by other
cells recently closed up, each with its honey and its egg. The Bee,
finding this in the place of her half-filled honey-store, is greatly
perplexed what to do when she comes with her harvest to this
unfinished, shallow cup, in which there is no place to put the honey.
She inspects it, measures it with her eyes, tries it with her antennae
and recognizes its insufficient capacity. She hesitates for a long
time, goes away, comes back, flies away again and soon returns, eager
to deposit her treasure. The insect's embarrassment is most evident;
and I cannot help saying, inwardly:
'Get some mortar, get some mortar and finish making the warehouse. It
will only take you a few moments; and you will have a cupboard of the
right depth.'
The Bee thinks differently: she was storing her cell and she must go
on storing, come what may. Never will she bring herself to lay aside
the pollen-brush for the trowel; never will she suspend the foraging
which is occupying her at this moment to begin the work of
construction which is not yet due. She will rather go in search of a
strange cell, in the desired condition, and slip in there to deposit
her honey, at the risk of meeting with a warm reception from the irate
owner. She goes off, in fact, to try her luck. I wish her success,
being myself the cause of this desperate act. My curiosity has turned
an honest worker into a robber.
Things may take a still more serious turn, so invincible, so imperious
is the desire to have the booty stored in a safe place without delay.
The uncompleted cell which the Bee refuses to accept instead of her
own finished warehouse, half-filled with honey, is often, as I said,
accompanied by other cells, not long closed, each containing its Bee-
bread and its egg. In this case, I have sometimes, though not always,
witnessed the following: when once the Bee realises the shortcomings
of the unfinished nest, she begins to gnaw the clay lid closing one of
the adjoining cells. She softens a part of the mortar cover with
saliva and patiently, atom by atom, digs through the hard wall. It is
very slow work. A good half-hour elapses before the tiny cavity is
large enough to admit a pin's head. I wait longer still. Then I lose
patience; and, fully convinced that the Bee is trying to open the
store-room, I decide to help her to shorten the work. The upper part
of the cell comes away with it, leaving the edges badly broken. In my
awkwardness, I have turned an elegant vase into a wretched cracked
pot.
I was right in my conjecture: the Bee's intention was to break open
the door. Straight away, without heeding the raggedness of the
orifice, she settles down in the cell which I have opened for her.
Time after time, she fetches honey and pollen, though the larder is
already fully stocked. Lastly, she lays her egg in this cell which
already contains an egg that is not hers, having done which she closes
the broken aperture to the best of her ability. So this purveyor had
neither the knowledge nor the power to bow to the inevitable. I had
made it impossible for her to go on with her purveying, unless she
first completed the unfinished cell substituted for her own. But she
did not retreat before that impossible task. She accomplished her
work, but in the absurdest way: by injuriously trespassing upon
another's property, by continuing to store provisions in a cupboard
already full to overflowing, by laying her egg in a cell in which the
real owner had already laid and lastly by hurriedly closing an orifice
that called for serious repairs. What better proof could be wished of
the irresistible propensity which the insect obeys?
Lastly, there are certain swift and consecutive actions so closely
interlinked that the performance of the second demands a previous
repetition of the first, even when this action has become useless. I
have already described how the Yellow-winged Sphex (Cf. "Insect Life":
chapters 6 to 9.--Translator's Note.) persists in descending into her
burrow alone, after depositing at its edge the Cricket whom I
maliciously at once remove. Her repeated discomfitures do not make her
abandon the preliminary inspection of the home, an inspection which
becomes quite useless when renewed for the tenth or twentieth time.
The Mason-bee of the Walls shows us, under another form, a similar
repetition of an act which is useless in itself, but which is the
compulsory preface to the act that follows. When arriving with her
provisions, the Bee performs a twofold operation of storing. First,
she dives head foremost into the cell, to disgorge the contents of her
crop; next, she comes out and at once goes in again backwards, to
brush her abdomen and rub off the load of pollen. At the moment when
the insect is about to enter the cell tail first, I push her aside
gently with a straw. The second act is thus prevented. The Bee now
begins the whole performance over again, that is to say, she once more
dives head first to the bottom of the cell, though she has nothing
left to disgorge, as her crop has just been emptied. When this is
done, it is the belly's turn. I instantly push her aside again. The
insect repeats its proceedings, still entering head first; I also
repeat my touch of the straw. And this can go on as long as the
observer pleases. Pushed aside at the moment when she is about to
insert her abdomen into the cell, the Bee goes back to the opening and
persists in going down head first to begin with. Sometimes, she
descends to the bottom, sometimes only half-way, sometimes again she
only pretends to descend, just bending her head into the aperture;
but, whether completed or not, this action, for which there is no
longer any motive, since the honey has already been disgorged,
invariably precedes the entrance backwards to deposit the pollen. It
is almost the movement of a machine whose works are only set going
when the driving-wheel begins to revolve.
CHAPTER 4. MORE ENQUIRIES INTO MASON-BEES.
This chapter was to have taken the form of a letter addressed to
Charles Darwin, the illustrious naturalist who now lies buried beside
Newton in Westminster Abbey. It was my task to report to him the
result of some experiments which he had suggested to me in the course
of our correspondence: a very pleasant task, for, though facts, as I
see them, disincline me to accept his theories, I have none the less
the deepest veneration for his noble character and his scientific
honesty. I was drafting my letter when the sad news reached me: Darwin
was dead; after searching the mighty question of origins, he was now
grappling with the last and darkest problem of the hereafter. (Darwin
died at Down, in Kent, on the 19th of April 1882.--Translator's Note.)
I therefore abandon the epistolary form, which would be unwarranted in
view of that grave at Westminster. A free and impersonal statement
shall set forth what I intended to relate in a more academic manner.
One thing, above all, had struck the English scientist on reading the
first volume of my "Souvenirs entomologiques", namely, the Mason-bees'
faculty of knowing the way back to their nests after being carried to
great distances from home. What sort of compass do they employ on
their return journeys? What sense guides them? The profound observer
thereupon spoke of an experiment which he had always longed to make
with Pigeons and which he had always neglected making, absorbed as he
was by other interests. This experiment, he thought, I might attempt
with my Bees. Substitute the insect for the bird; and the problem
remained the same. I quote from his letter the passage referring to
the trial which he wished made:
'Allow me to make a suggestion in relation to your wonderful account
of insects finding their way home. I formerly wished to try it with
pigeons; namely, to carry the insects in their paper cornets about a
hundred paces in the opposite direction to that which you intended
ultimately to carry them, but before turning round to return, to put
the insects in a circular box with an axle which could be made to
revolve very rapidly first in one direction and then in another, so as
to destroy for a time all sense of direction in the insects. I have
sometimes imagined that animals may feel in which direction they were
at the first start carried.'
This method of experimenting seemed to me very ingeniously conceived.
Before going west, I walk eastwards. In the darkness of their paper
bags, the mere fact that I am moving them gives my prisoners a sense
of the direction in which I am taking them. If nothing happened to
disturb this first impression, the insect would be guided by it in
returning. This would explain the homing of my Mason-bees carried to a
distance of two or three miles amid strange surroundings. But, when
the insects have been sufficiently impressed by their conveyance to
the east, there comes the rapid twirl, first this way round, then
that. Bewildered by all these revolutions first in one direction and
then in another, the insect does not know that I have turned round and
remains under its original impression. I am now taking it to the west,
when it believes itself to be still travelling towards the east. Under
the influence of this impression; the insect is bound to lose its
bearings. When set free, it will fly in the opposite direction to its
home, which it will never find again.
This result seemed to me the more probable inasmuch as the statements
of the country-folk around me were all of a nature to confirm my
hopes. Favier (The author's gardener and factotum. Cf. "The Life of
the Fly": chapter 4.--Translator's Note.), the very man for this sort
of information, was the first to put me on the track. He told me that,
when people want to move a Cat from one farm to another at some
distance, they place the animal in a bag which they twirl rapidly at
the moment of starting, thus preventing the animal from returning to
the house which it has quitted. Many others, besides Favier, described
the same practice to me. According to them, this twirling round in a
bag was an infallible expedient: the bewildered Cat never returned. I
communicated what I had learnt to England, I wrote to the sage of Down
and told him how the peasant had anticipated the researches of
science. Charles Darwin was amazed; so was I; and we both of us almost
reckoned on a success.
These preliminaries took place in the winter; I had plenty of time to
prepare for the experiment which was to be made in the following May.
'Favier,' I said, one day, to my assistant, 'I shall want some of
those nests. Go and ask our next-door neighbour's leave and climb to
the roof of his shed, with some new tiles and some mortar, which you
can fetch from the builder's. Take a dozen tiles from the roof, those
with the biggest nests on them, and put the new ones in their place.'
Things were done accordingly. My neighbour assented with a good grace
to the exchange of tiles, for he himself is obliged, from time to
time, to demolish the work of the Mason-bee, unless he would risk
seeing his roof fall in sooner or later. I was merely forestalling a
repair which became more urgent every year. That same evening, I was
in possession of twelve magnificent rectangular blocks of nest, each
lying on the convex surface of a tile, that is to say, on the surface
looking towards the inside of the shed. I had the curiosity to weigh
the largest: it turned the scale at thirty-five pounds. Now the roof
whence it came was covered with similar masses, adjoining one another,
over a stretch of some seventy tiles. Reckoning only half the weight,
so as to strike an average between the largest and the smallest lumps,
we find the total weight of the Bee's masonry to amount to three-
quarters of a ton. And, even so, people tell me that they have seen
this beaten elsewhere. Leave the Mason-bee to her own devices, in the
spot that suits her; allow the work of many generations to accumulate;
and, one fine day, the roof will break down under the extra burden.
Let the nests grow old; let them fall to pieces when the damp gets
into them; and you will have chunks tumbling on your head big enough
to crack your skull. There you see the work of a very little-known
insect. (The insect is so little known that I made a serious mistake
when treating of it in the first volume of these "Souvenirs." Under my
erroneous denomination of Chalicodoma sicula are really comprised two
species, one building its nests in our dwellings and particularly
under the tiles of outhouses, the other building its nests on the
branches of shrubs. The first species has received various names,
which are, in order of priority: Chalicodoma pyrenaica, LEP.
(Megachile); Chalicodoma pyrrhopeza, GERSTACKER; Chalicodoma
rufitarsis, GIRAUD. It is a pity that the name occupying the first
place should lend itself to misconception. I hesitate to apply the
epithet of Pyrenean to an insect which is much less common in the
Pyrenees than in my own district. I shall call it the Chalicodoma, or
Mason-bee, of the Sheds. There is no objection to the use of this name
in a book where the reader prefers lucidity to the tyranny of
systematic entomology. The second species, that which builds its nests
on the branches, is Chalicodoma rufescens, J. PEREZ. For a like
reason, I shall call it the Chalicodoma of the Shrubs. I owe these
corrections to the kindness of Professor Jean Perez, of Bordeaux, who
is so well-versed in the lore of Wasps and Bees.--Author's Note.)
These treasures were insufficient, not in regard to quantity, but in
regard to quality, for the main object which I had in view. They came
from the nearest house, separated from mine by a little field planted
with corn and olive-trees. I had reason to fear that the insects
issuing from those nests might be hereditarily influenced by their
ancestors, who had lived in the shed for many a long year. The Bee,
when carried to a distance, would perhaps come back, guided by the
inveterate family habit; she would find the shed of her lineal
predecessors and thence, without difficulty, reach her nest. As it is
the fashion nowadays to assign a prominent part to these hereditary
influences, I must eliminate them from my experiments. I want strange
Bees, brought from afar, whose return to the place of their birth can
in no way assist their return to the nest transplanted to another
site.
Favier took the business in hand. He had discovered on the banks of
the Aygues, at some miles from the village, a deserted hut where the
Mason-bees had established themselves in a numerous colony. He
proposed to take the wheelbarrow, in which to move the blocks of
cells; but I objected: the jolting of the vehicle over the rough paths
might jeopardise the contents of the cells. A basket carried on the
shoulder was deemed safer. Favier took a man to help him and set out.
The expedition provided me with four well-stocked tiles. It was all
that the two men were able to carry between them; and even then I had
to stand treat on their arrival: they were utterly exhausted. Le
Vaillant tells us of a nest of Republicans (Social Weaver-birds.--
Translator's Note.) with which he loaded a wagon drawn by two oxen. My
Mason-bee vies with the South-African bird: a yoke of Oxen would not
have been too many to move the whole of that nest from the banks of
the Aygues.
The next thing is to place my tiles. I want to have them under my
eyes, in a position where I can watch them easily and save myself the
worries of earlier days: going up and down ladders, standing for hours
at a stretch on a narrow rung that hurt the soles of my feet and
risking sunstroke up against a scorching wall. Moreover, it is
necessary that my guests should feel almost as much at home with me as
where they come from. I must make life pleasant for them, if I should
have them grow attached to the new dwelling. And I happen to have the
very thing for them.
Under the leads of my house is a wide arch, the sides of which get the
sun, while the back remains in the shade. There is something for
everybody: the shade for me, the sunlight for my boarders. We fasten a
stout hook to each tile and hang it on the wall, on a level with our
eyes. Half my nests are on the right, half on the left. The general
effect is rather original. Any one walking in and seeing my show for
the first time begins by taking it for a display of smoked provisions,
gammons of some outlandish bacon curing in the sun. On perceiving his
mistake, he falls into raptures at these new hives of mine. The news
spreads through the village and more than one pokes fun at it. They
look upon me as a keeper of hybrid Bees:
'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, incapable 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, I stand in the thick of the whirling crowd and never
a prick do I receive. I 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 curiosity 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 nothing
unusual about it. My Bees, far from remaining an object of dread,
became an object of diversion; every one took pleasure in watching 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 standing 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?'
'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 experimenting. The Mason-bees intended
for the journey 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 insects had to be
held in the fingers one after the other; and I was thus exposed to
frequent stings, which 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 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 coloured
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.
Nothing 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 forthwith 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 open the bags.
The whole performance is thus effected without once giving that
distressing squeeze of the fingers.
Another question remains to be solved before 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 that 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 in the
galleries, but with her head at the entrance. Once those old
habitations are in use, however, and the building of new cells begun,
she selects another retreat. In the harmas (The piece of enclosed
waste ground on which the author studies his insects in their natural
state. Cf. "The Life of the Fly": chapter 1.--Translator's Note.), as
I have said elsewhere, are stone heaps, intended for building the
surrounding wall. This is where my Chalicodomae 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 consideration, 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; 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
advisable 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; tomorrow 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 the Bees that return
on the same day.
The question of the rotary machine remains. Darwin advised me to use a
circular box with an axle and a handle. I have nothing 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 insects, each one placed by itself in a paper cornet (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.) or screw, shall be
placed in a tin box; the screws of paper shall be wedged in so as 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 circles; if I spin on my heels at the same time, I am
able to make the process still more complicated by compelling my sling
to trace every known curve. That is what I shall do.
On the 2nd 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 brick-laying; others are
garnering 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 sling. There is a
way-side 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 accomplished in the presence of this unexpected witness. Then I
retrace my steps and walk westward 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 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 insects 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 going two
or three times round my body, a suspicious-looking object which they
wish, apparently, to reconnoitre before starting. A quarter of an hour
later, my eldest daughter, 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 home on the same day,
out of ten scattered abroad.
I resume the experiment next morning. I mark ten Mason-bees with red,
which will enable me to distinguish them from those who returned 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 myself to swinging my box round on leaving and on
arriving. The insects are released at a quarter past eleven. I
preferred the forenoon, 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 myself am back at twelve and,
within a short time, catch three others. I see no more 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 Chalicodomae marked with
blue. The distance to be travelled remains the same. I make the first
rotation after carrying my insects a few hundred steps in the
direction opposite to that which I finally take; in addition, three
rotations 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 moment undecided and
lazy; but, after a short sunbath on a stone where I place them, they
take wing. I am sitting on the ground, facing the south, with Serignan
on my left and Piolenc 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 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 minutes
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 Serignan. Yet I had taken care to
leave the choice free between the two opposite directions: in
particular, I had sent away my Dog, 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 experiment has been repeated often
enough, but it does not conclude as Darwin hoped, as I myself hoped,
especially after what I had 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 twirl my sling with every
complication in the way of whirls and twists that I am able to
imagine; in vain, thinking to increase the difficulties, do I repeat
the rotation as often as five times over: at the start, on the road,
on arriving; it makes no difference: the Mason-bees return; and the
proportion 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 experimenting again, but in a
different way. Hitherto, I had worked on the level. To return to the
nest, my lost Bees had only to cross slight obstacles, the hedges and
spinneys of the tilled fields. To-day, I propose to add to the
difficulties 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 releasing my Chalicodomae in the
thick of the Serignan Woods. How will they escape from that labyrinth,
where, in the early days, I needed a compass to find my way? Moreover,
I shall have an assistant with me, a pair of eyes younger than mine
and better-fitted to follow my insects' first flight. That immediate
start in the direction of the nest has already been repeated very
often and is beginning to interest me more than the return itself. A
pharmaceutical student, spending a few days with my parents, shall be
my eyewitness. With him, I shall feel at ease; science and he are no
strangers.
The trip to the woods takes place on the 16th of May. The weather is
hot and hints at a coming storm. There is a perceptible breeze from
the south, but not enough to upset 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 recognize the direction of the
insects' first flight. 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
curtain 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 insects 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 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 the 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 approaching. 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 returned. 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
condition on leaving my stung and smarting fingers. Besides, the sky
has become overcast, 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 day of fine weather. A splendid morning is swiftly followed
by a fitful afternoon; and my experiments with Mason-bees have often
suffered by these variations. All things considered, I am inclined to
think that the homeward journey across the forest and the mountain 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 another 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 offers 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 Turonian fossils. We next turn
back towards Serignan, by the Piolenc Road. A halt is made by the
stretch of country known as Font-Claire, the distance from which to
the village 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.
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