February has its sunny days, heralding spring, to which rude winter will
reluctantly yield place. In snug corners, among the rocks, the great
spurge of our district, the characias of the Greeks, the jusclo of the
Provencals, begins to lift its drooping inflorescence and discreetly
opens a few sombre flowers. Here the first Midges of the year will come
to slake their thirst. By the time that the tip of the stalks reaches
the perpendicular, the worst of the cold weather will be over.
Another eager one, the almond-tree, risking the loss of its fruit,
hastens to echo these preludes to the festival of the sun, preludes
which are too often treacherous. A few days of soft skies and it becomes
a glorious dome of white flowers, each twinkling with a roseate eye.
The country, which still lacks green, seems dotted everywhere with
white-satin pavilions. 'Twould be a callous heart indeed that could
resist the magic of this awakening.
The insect nation is represented at these rites by a few of its more
zealous members. There is first of all the Honey-bee, the sworn enemy
of strikes, who profits by the least lull of winter to find out if some
rosemary is not beginning to open somewhere near the hive. The droning
of the busy swarm fills the flowery vault, while a snow of petals falls
softly to the foot of the tree.
Together with the population of harvesters there mingles another, less
numerous, of mere drinkers, whose nesting-time has not yet begun.
This is the colony of the Osmiae, with their copper-coloured skin and
bright-red fleece. Two species have come hurrying up to take part in the
joys of the almond-tree: first, the Horned Osmia, clad in black velvet
on the head and breast and in red velvet on the abdomen; and, a little
later, the Three-horned Osmia, whose livery must be red and red only.
These are the first delegates despatched by the pollen-gleaners to
ascertain the state of the season and attend the festival of the early
blooms. 'Tis but a moment since they burst their cocoon, the winter
abode: they have left their retreats in the crevices of the old walls;
should the north wind blow and set the almond-tree shivering, they will
hasten to return to them. Hail to you, O my dear Osmiae, who yearly,
from the far end of the harmas (The piece of waste ground in which the
author studied his insects in their natural state. Cf. "The Life of
the Fly" by J. Henri Fabre, translated by Alexander Teixeira de Mattos:
chapter 1.--Translator's Note.), opposite snow-capped Ventoux (A
mountain in the Provencal Alps, near Carpentras and Serignan, 6,271
feet.--Translator's Note.), bring me the first tidings of the awakening
of the insect world! I am one of your friends; let us talk about you a
little.
Most of the Osmiae of my region have none of the industry of their
kinswomen of the brambles, that is to say, they do not themselves
prepare the dwelling destined for the laying. They want ready-made
lodgings, such as the old cells and old galleries of Anthophorae and
Chalicodomae. If these favourite haunts are lacking, then a hiding-place
in the wall, a round hole in some bit of wood, the tube of a reed, the
spiral of a dead Snail under a heap of stones are adopted, according to
the tastes of the several species. The retreat selected is divided into
chambers by partition-walls, after which the entrance to the dwelling
receives a massive seal. That is the sum-total of the building done.
For this plasterer's rather than mason's work, the Horned and the
Three-horned Osmia employ soft earth. This material is different from
the Mason-bee's cement, which will withstand wind and weather for many
years on an exposed pebble; it is a sort of dried mud, which turns
to pap on the addition of a drop of water. The Mason-bee gathers her
cementing-dust in the most frequented and driest portions of the road;
she wets it with a saliva which, in drying, gives it the consistency of
stone. The two Osmiae who are the almond-tree's early visitors are
no chemists: they know nothing of the making and mixing of hydraulic
mortar; they limit themselves to gathering natural soaked earth, mud in
short, which they allow to dry without any special preparation on their
part; and so they need deep and well-sheltered retreats, into which the
rain cannot penetrate, or the work would fall to pieces.
While exploiting, in friendly rivalry with the Three-horned Osmia, the
galleries which the Mason-bee of the Sheds good-naturedly surrenders to
both, Latreille's Osmia uses different materials for her partitions and
her doors. She chews the leaves of some mucilaginous plant, some mallow
perhaps, and then prepares a sort of green putty with which she builds
her partitions and finally closes the entrance to the dwelling. When
she settles in the spacious cells of the Masked Anthophora (Anthophora
personata, ILLIG.), the entrance to the gallery, which is wide enough to
admit one's finger, is closed with a voluminous plug of this vegetable
paste. On the earthy banks, hardened by the sun, the home is then
betrayed by the gaudy colour of the lid. It is as though the authorities
had closed the door and affixed to it their great seals of green wax.
So far then as their building-materials are concerned, the Osmiae whom
I have been able to observe are divided into two classes: one building
compartments with mud, the other with a green-tinted vegetable putty.
The first section includes the Horned Osmia and the Three-horned Osmia,
both so remarkable for the horny tubercles on their faces.
The great reed of the south, the Arundo donax, is often used, in the
country, for rough garden-shelters against the mistral or just for
fences. These reeds, the ends of which are chopped off to make them all
the same length, are planted perpendicularly in the earth. I have often
explored them in the hope of finding Osmia-nests. My search has very
seldom succeeded. The failure is easily explained. The partitions and
the closing-plug of the Horned and of the Three-horned Osmia are made,
as we have seen, of a sort of mud which water instantly reduces to pap.
With the upright position of the reeds, the stopper of the opening would
receive the rain and would become diluted; the ceilings of the storeys
would fall in and the family would perish by drowning. Therefore the
Osmia, who knew of these drawbacks before I did, refuses the reeds when
they are placed perpendicularly.
The same reed is used for a second purpose. We make canisses of it,
that is to say, hurdles, which, in spring, serve for the rearing of
silk-worms and, in autumn, for the drying of figs. At the end of April
and during May, which is the time when the Osmiae work, the canisses
are indoors, in the silk-worm nurseries, where the Bee cannot take
possession of them; in autumn, they are outside, exposing their layers
of figs and peeled peaches to the sun; but by that time the Osmiae have
long disappeared. If, however, during the spring, an old, disused hurdle
is left out of doors, in a horizontal position, the Three-horned Osmia
often takes possession of it and makes use of the two ends, where the
reeds lie truncated and open.
There are other quarters that suit the Three-horned Osmia, who is not
particular, it seems to me, and will make shift with any hiding-place,
so long as it has the requisite conditions of diameter, solidity,
sanitation and kindly darkness. The most original dwellings that I know
her to occupy are disused Snail-shells, especially the house of the
Common Snail (Helix aspersa). Let us go to the slope of the hills thick
with olive-trees and inspect the little supporting-walls which are
built of dry stones and face the south. In the crevices of this insecure
masonry, we shall reap a harvest of old Snail-shells, plugged with earth
right up to the orifice. The family of the Three-horned Osmia is settled
in the spiral of those shells, which is subdivided into chambers by mud
partitions.
Let us inspect the stone-heaps, especially those which come from the
quarry-works. Here we often find the Field-mouse sitting on a grass
mattress, nibbling acorns, almonds, olive-stones and apricot-stones. The
Rodent varies his diet: to oily and farinaceous foods he adds the Snail.
When he is gone, he has left behind him, under the overhanging stones,
mixed up with the remains of other victuals, an assortment of empty
shells, sometimes plentiful enough to remind me of the heap of Snails
which, cooked with spinach and eaten country-fashion on Christmas Eve,
are flung away next day by the housewife. This gives the Three-horned
Osmia a handsome collection of tenements; and she does not fail to
profit by them. Then again, even if the Field-mouse's conchological
museum be lacking, the same broken stones serve as a refuge for
Garden-snails who come to live there and end by dying there. When we see
Three-horned Osmiae enter the crevices of old walls and of stone-heaps,
there is no doubt about their occupation: they are getting free lodgings
out of the old Snail-shells of those labyrinths.
The Horned Osmia, who is less common, might easily also be less
ingenious, that is to say, less rich in varieties of houses. She seems
to scorn empty shells. The only homes that I know her to inhabit are the
reeds of the hurdles and the deserted cells of the Masked Anthophora.
All the other Osmiae whose method of nest-building I know work with
green putty, a paste made of some crushed leaf or other; and none of
them, except Latreille's Osmia, is provided with the horned or tubercled
armour of the mud-kneaders. I should like to know what plants are used
in making the putty; probably each species has its own preferences and
its little professional secrets; but hitherto observation has taught me
nothing concerning these details. Whatever worker prepare it, the putty
is very much the same in appearance. When fresh, it is always a clear
dark green. Later, especially in the parts exposed to the air, it
changes, no doubt through fermentation, to the colour of dead leaves,
to brown, to dull-yellow; and the leafy character of its origin is no
longer apparent. But uniformity in the materials employed must not
lead us to believe in uniformity in the lodging; on the contrary, this
lodging varies greatly with the different species, though there is a
marked predilection in favour of empty shells. Thus Latreille's Osmia,
together with the Three-horned Osmia, uses the spacious structures
of the Mason-bee of the Sheds; she likes the magnificent cells of the
Masked Anthophora; and she is always ready to establish herself in the
cylinder of any reed lying flat on the ground.
I have already spoken of an Osmia (O. cyanoxantha, PEREZ) who elects
to make her home in the old nests of the Mason-bee of the Pebbles. (Cf.
"The Mason-bees": chapter 10.--Translator's Note.) Her closing-plug is
made of a stout concrete, consisting of fair-sized bits of gravel
sunk in the green paste; but for the inner partitions she employs
only unalloyed putty. As the outer door, situated on the curve of an
unprotected dome, is exposed to the inclemencies of the weather,
the mother has to think of fortifying it. Danger, no doubt, is the
originator of that gritty concrete.
The Golden Osmia (O. aurulenta, LATR.) absolutely insists on an empty
Snail-shell as her residence. The Brown or Girdled Snail, the Garden
Snail and especially the Common Snail, who has a more spacious spiral,
all scattered at random in the grass, at the foot of the walls and of
the sun-swept rocks, furnish her with her usual dwelling-house. Her
dried putty is a kind of felt full of short white hairs. It must come
from some hairy-leaved plant, one of the Boragineae perhaps, rich both
in mucilage and the necessary bristles.
The Red Osmia (O. rufo-hirta, LATR.) has a weakness for the Brown Snail
and the Garden Snail, in whose shells I find her taking refuge in April
when the north-wind blows. I am not yet much acquainted with her work,
which should resemble that of the Golden Osmia.
The Green Osmia (O. viridana, MORAWITZ) takes up her quarters, tiny
creature that she is, in the spiral staircase of Bulimulus radiatus. It
is a very elegant, but very small lodging, to say nothing of the fact
that a considerable portion is taken up with the green-putty plug. There
is just room for two.
The Andrenoid Osmia (O. andrenoides, LATR.), who looks so curious, with
her naked red abdomen, appears to build her nest in the shell of the
Common Snail, where I discover her refuged.
The Variegated Osmia (O. versicolor, LATR.) settles in the Garden
Snail's shell, almost right at the bottom of the spiral.
The Blue Osmia (O. cyanea, KIRB.) seems to me to accept many different
quarters. I have extracted her from old nests of the Mason-bee of the
Pebbles, from the galleries dug in a roadside bank by the Colletes (A
short-tongued Burrowing-bee known also as the Melitta.--Translator's
Note.) and lastly from the cavities made by some digger or other in the
decayed trunk of a willow-tree.
Morawitz' Osmia (O. Morawitzi, PEREZ) is not uncommon in the old nests
of the Mason-bee of the Pebbles, but I suspect her of favouring other
lodgings besides.
The Three-pronged Osmia (O. tridentata, DUF. and PER.) creates a home of
her own, digging herself a channel with her mandibles in dry bramble and
sometimes in danewort. It mixes a few scrapings of perforated pith with
the green paste. Its habits are shared by the Ragged Osmia (O. detrita,
PEREZ) and by the Tiny Osmia (O. parvula, DUF.)
The Chalicodoma works in broad daylight, on a tile, on a pebble, on a
branch in the hedge; none of her trade-practises is kept a secret from
the observer's curiosity. The Osmia loves mystery. She wants a dark
retreat, hidden from the eye. I would like, nevertheless, to watch
her in the privacy of her home and to witness her work with the same
facility as if she were nest-building in the open air. Perhaps there are
some interesting characteristics to be picked up in the depths of her
retreats. It remains to be seen whether my wish can be realized.
When studying the insect's mental capacity, especially its very
retentive memory for places, I was led to ask myself whether it would
not be possible to make a suitably-chosen Bee build in any place that I
wished, even in my study. And I wanted, for an experiment of this sort,
not an individual but a numerous colony. My preference leant towards the
Three-horned Osmia, who is very plentiful in my neighbourhood, where,
together with Latreille's Osmia, she frequents in particular the
monstrous nests of the Chalicodoma of the Sheds. I therefore thought
out a scheme for making the Three-horned Osmia accept my study as her
settlement and build her nests in glass tubes, through which I could
easily watch the progress. To these crystal galleries, which might well
inspire a certain distrust, were to be added more natural retreats:
reeds of every length and thickness and disused Chalicodoma-cells taken
from among the biggest and the smallest. A scheme like this sounds mad.
I admit it, while mentioning that perhaps none ever succeeded so well
with me. We shall see as much presently.
My method is extremely simple. All I ask is that the birth of my
insects, that is to say, their first seeing the light, their emerging
from the cocoon, should take place on the spot where I propose to make
them settle. Here there must be retreats of no matter what nature,
but of a shape similar to that in which the Osmia delights. The first
impressions of sight, which are the most long-lived of any, shall bring
back my insects to the place of their birth. And not only will the
Osmiae return, through the always open windows, but they will always
nidify on the natal spot if they find something like the necessary
conditions.
And so, all through the winter, I collect Osmia-cocoons, picked up in
the nests of the Mason-bee of the Sheds; I go to Carpentras to glean a
more plentiful supply in the nests of the Hairy-footed Anthophora, that
old acquaintance whose wonderful cities I used to undermine when I
was studying the history of the Oil-beetles. (This study is not yet
translated into English; but cf. "The Life of the Fly": chapters 2
and 4.--Translator's Note.) Later, at my request, a pupil and intimate
friend of mine, M. Henri Devillario, president of the civil court at
Carpentras, sends me a case of fragments broken off the banks frequented
by the Hairy-footed Anthophora and the Anthophora of the Walls, useful
clods which furnish a handsome adjunct to my collection. Indeed, at the
end, I find myself with handfuls of cocoons of the Three-horned Osmia.
To count them would weary my patience without serving any particular
purpose.
I spread out my stock in a large open box on a table which receives
a bright diffused light but not the direct rays of the sun. The table
stands between two windows facing south and overlooking the garden. When
the moment of hatching comes, those two windows will always remain open
to give the swarm entire liberty to go in and out as it pleases.
The glass tubes and the reed-stumps are laid here and there, in fine
disorder, close to the heap of cocoons and all in a horizontal position,
for the Osmia will have nothing to do with upright reeds. The hatching
of some of the Osmiae will therefore take place under cover of the
galleries destined to be the building-yard later; and the site will be
all the more deeply impressed on their memory. When I have made these
comprehensive arrangements, there is nothing more to be done; and I wait
patiently for the building-season to open.
My Osmiae leave their cocoons in the second half of April. Under the
immediate rays of the sun, in well-sheltered nooks, the hatching would
occur a month earlier, as we can see from the mixed population of
the snowy almond-tree. The constant shade in my study has delayed the
awakening, without, however, making any change in the nesting-period,
which synchronizes with the flowering of the thyme. We now have, around
my working-table, my books, my jars and my various appliances, a buzzing
crowd that goes in and out of the windows at every moment. I enjoin the
household henceforth not to touch a thing in the insects' laboratory, to
do no more sweeping, no more dusting. They might disturb the swarm and
make it think that my hospitality was not to be trusted. I suspect that
the maid, wounded in her self-esteem at seeing so much dust accumulating
in the master's study, did not always respect my prohibitions and came
in stealthily, now and again, to give a little sweep of the broom.
At any rate, I came across a number of Osmiae who seemed to have been
crushed under foot while taking a sunbath on the floor in front of the
window. Perhaps it was I myself who committed the misdeed in a heedless
moment. There is no great harm done, for the population is a numerous
one; and, notwithstanding those crushed by inadvertence, notwithstanding
the parasites wherewith many of the cocoons are infested,
notwithstanding those who may have come to grief outside or been unable
to find their way back, notwithstanding the deduction of one-half which
we must make for the males: notwithstanding all this, during four or
five weeks I witness the work of a number of Osmiae which is much too
large to allow of my watching their individual operations. I content
myself with a few, whom I mark with different-coloured spots to
distinguish them; and I take no notice of the others, whose finished
work will have my attention later.
The first to appear are the males. If the sun is bright, they flutter
around the heap of tubes as if to take careful note of the locality;
blows are exchanged and the rival swains indulge in mild skirmishing
on the floor, then shake the dust off their wings and fly away. I find
them, opposite my window, in the refreshment-bar of the lilac-bush,
whose branches bend with the weight of their scented panicles. Here the
Bees get drunk with sunshine and draughts of honey. Those who have had
their fill come home and fly assiduously from tube to tube, placing
their heads in the orifices to see if some female will at last make up
her mind to emerge.
One does, in point of fact. She is covered with dust and has the
disordered toilet that is inseparable from the hard work of the
deliverance. A lover has seen her, so has a second, likewise a third.
All crowd round her. The lady responds to their advances by clashing her
mandibles, which open and shut rapidly, several times in succession. The
suitors forthwith fall back; and they also, no doubt to keep up their
dignity, execute savage mandibular grimaces. Then the beauty retires
into the arbour and her wooers resume their places on the threshold. A
fresh appearance of the female, who repeats the play with her jaws; a
fresh retreat of the males, who do the best they can to flourish their
own pincers. The Osmiae have a strange way of declaring their passion:
with that fearsome gnashing of their mandibles, the lovers look as
though they meant to devour each other. It suggests the thumps affected
by our yokels in their moments of gallantry.
The ingenious idyll is soon over. By turns greeting and greeted with a
clash of jaws, the female leaves her gallery and begins impassively to
polish her wings. The rivals rush forward, hoist themselves on top of
one another and form a pyramid of which each struggles to occupy the
base by toppling over the favoured lover. He, however, is careful not
to let go; he waits for the strife overhead to calm down; and, when the
supernumeraries realize that they are wasting their time and throw up
the game, the couple fly away far from the turbulent rivals. This is all
that I have been able to gather about the Osmia's nuptials.
The females, who grow more numerous from day to day, inspect the
premises; they buzz outside the glass galleries and the reed dwellings;
they go in, stay for a while, come out, go in again and then fly away
briskly into the garden. They return, first one, then another. They halt
outside, in the sun, on the shutters fastened back against the wall;
they hover in the window-recess, come inside, go to the reeds and give a
glance at them, only to set off again and to return soon after. Thus
do they learn to know their home, thus do they fix their birthplace in
their memory. The village of our childhood is always a cherished spot,
never to be effaced from our recollection. The Osmia's life endures
for a month; and she acquires a lasting remembrance of her hamlet in
a couple of days. 'Twas there that she was born; 'twas there that she
loved; 'tis there that she will return. Dulces reminiscitur Argos. ('Now
falling by another's wound, his eyes He casts to heaven, on Argos thinks
and dies.'--"Aeneid," Book 10 Dryden's translation.)
At last each has made her choice. The work of construction begins; and
my expectations are fulfilled far beyond my wishes. The Osmiae build
nests in all the retreats which I have placed at their disposal. The
glass tubes, which I cover with a sheet of paper to produce the shade
and mystery favourable to concentrated toil, do wonderfully well. All,
from first to last, are occupied. The Osmiae quarrel for the possession
of these crystal palaces, hitherto unknown to their race. The reeds
and the paper tubes likewise do wonderfully. The number provided is
too small; and I hasten to increase it. Snail-shells are recognized as
excellent abodes, though deprived of the shelter of the stone-heap; old
Chalicodoma-nests, down to those of the Chalicodoma of the Shrubs (Cf.
"The Mason-bees": chapters 4 and 10.--Translator's Note.), whose cells
are so small, are eagerly occupied. The late-comers, finding nothing
else free, go and settle in the locks of my table-drawers. There are
daring ones who make their way into half-open boxes containing ends of
glass tubes in which I have stored my most recent acquisitions: grubs,
pupae and cocoons of all kinds, whose evolution I wished to study.
Whenever these receptacles have an atom of free space, they claim the
right to build there, whereas I formally oppose the claim. I hardly
reckoned on such a success, which obliges me to put some order into
the invasion with which I am threatened. I seal up the locks, I shut my
boxes, I close my various receptacles for old nests, in short I remove
from the building-yard any retreat of which I do not approve. And now, O
my Osmiae, I leave you a free field!
The work begins with a thorough spring-cleaning of the home. Remnants
of cocoons, dirt consisting of spoilt honey, bits of plaster from broken
partitions, remains of dried Mollusc at the bottom of a shell: these and
much other insanitary refuse must first of all disappear. Violently the
Osmia tugs at the offending object and tears it out; and then off she
goes, in a desperate hurry, to dispose of it far away from the study.
They are all alike, these ardent sweepers: in their excessive zeal, they
fear lest they should block up the place with a speck of dust which they
might drop in front of the new house. The glass tubes, which I myself
have rinsed under the tap, are not exempt from a scrupulous cleaning.
The Osmia dusts them, brushes them thoroughly with her tarsi and then
sweeps them out backwards. What does she pick up? Not a thing. It makes
no difference: as a conscientious housewife, she gives the place a touch
of the broom nevertheless.
Now for the provisions and the partition-walls. Here the order of the
work changes according to the diameter of the cylinder. My glass tubes
vary greatly in dimensions. The largest have an inner width of a dozen
millimetres (Nearly half an inch.--Translator's Note.); the narrowest
measure six or seven. (About a quarter of an inch.--Translator's Note.)
In the latter, if the bottom suit her, the Osmia sets to work bringing
pollen and honey. If the bottom do not suit her, if the sorghum-pith
plug with which I have closed the rear-end of the tube be too irregular
and badly-joined, the Bee coats it with a little mortar. When this small
repair is made, the harvesting begins.
In the wider tubes, the work proceeds quite differently. At the moment
when the Osmia disgorges her honey and especially at the moment when,
with her hind-tarsi, she rubs the pollen-dust from her ventral brush,
she needs a narrow aperture, just big enough to allow of her passage.
I imagine that, in a straitened gallery, the rubbing of her whole body
against the sides gives the harvester a support for her brushing-work.
In a spacious cylinder, this support fails her; and the Osmia starts
with creating one for herself, which she does by narrowing the channel.
Whether it be to facilitate the storing of the victuals or for any other
reason, the fact remains that the Osmia housed in a wide tube begins
with the partitioning.
Her division is made by a dab of clay placed at right angles to the
axis of the cylinder, at a distance from the bottom determined by the
ordinary length of a cell. This wad is not a complete round; it is more
crescent-shaped, leaving a circular space between it and one side of the
tube. Fresh layers are swiftly added to the dab of clay; and soon the
tube is divided by a partition which has a circular opening at the side
of it, a sort of dog-hole through which the Osmia will proceed to knead
the Bee-bread. When the victualling is finished and the egg laid upon
the heap, the hole is closed and the filled-up partition becomes the
bottom of the next cell. Then the same method is repeated, that is to
say, in front of the just completed ceiling a second partition is built,
again with a side-passage, which is stouter, owing to its distance from
the centre, and better able to withstand the numerous comings and goings
of the housewife than a central orifice, deprived of the direct support
of the wall, could hope to be. When this partition is ready, the
provisioning of the second cell is effected; and so on until the wide
cylinder is completely stocked.
The building of this preliminary party-wall, with a narrow, round
dog-hole, for a chamber to which the victuals will not be brought until
later is not restricted to the Three-horned Osmia; it is also frequently
found in the case of the Horned Osmia and of Latreille's Osmia. Nothing
could be prettier than the work of the last-named, who goes to the
plants for her material and fashions a delicate sheet in which she cuts
a graceful arch. The Chinaman partitions his house with paper screens;
Latreille's Osmia divides hers with disks of thin green cardboard
perforated with a serving-hatch which remains until the room is
completely furnished. When we have no glass houses at our disposal,
we can see these little architectural refinements in the reeds of the
hurdles, if we open them at the right season.
By splitting the bramble-stumps in the course of July, we perceive
also that the Three-pronged Osmia, notwithstanding her narrow gallery,
follows the same practice as Latreille's Osmia, with a difference. She
does not build a party-wall, which the diameter of the cylinder would
not permit; she confines herself to putting up a frail circular pad of
green putty, as though to limit, before any attempt at harvesting,
the space to be occupied by the Bee-bread, whose depth could not be
calculated afterwards if the insect did not first mark out its confines.
Can there really be an act of measuring? That would be superlatively
clever. Let us consult the Three-horned Osmia in her glass tubes.
The Osmia is working at her big partition, with her body outside the
cell which she is preparing. From time to time, with a pellet of mortar
in her mandibles, she goes in and touches the previous ceiling with
her forehead, while the tip of her abdomen quivers and feels the pad in
course of construction. One might well say that she is using the length
of her body as a measure, in order to fix the next ceiling at the
proper distance. Then she resumes her work. Perhaps the measure was
not correctly taken; perhaps her memory, a few seconds old, has already
become muddled. The Bee once more ceases laying her plaster and again
goes and touches the front wall with her forehead and the back wall with
the tip of her abdomen. Looking at that body trembling with eagerness,
extended to its full length to touch the two ends of the room, how can
we fail to grasp the architect's grave problem? The Osmia is measuring;
and her measure is her body. Has she quite done, this time? Oh dear
no! Ten times, twenty times, at every moment, for the least particle of
mortar which she lays, she repeats her mensuration, never being quite
certain that her trowel is going just where it should.
Meanwhile, amid these frequent interruptions, the work progresses and
the partition gains in width. The worker is bent into a hook, with her
mandibles on the inner surface of the wall and the tip of her abdomen
on the outer surface. The soft masonry stands between the two points of
purchase. The insect thus forms a sort of rolling-press, in which the
mud wall is flattened and shaped. The mandibles tap and furnish mortar;
the end of the abdomen also pats and gives brisk trowel-touches. This
anal extremity is a builder's tool; I see it facing the mandibles on
the other side of the partition, kneading and smoothing it all over,
flattening the little lump of clay. It is a singular implement, which
I should never have expected to see used for this purpose. It takes an
insect to conceive such an original idea, to do mason's work with its
behind! During this curious performance, the only function of the legs
is to keep the worker steady by spreading out and clinging to the walls
of the tunnel.
The partition with the hole in it is finished. Let us go back to the
measuring of which the Osmia was so lavish. What a magnificent argument
in favour of the reasoning-power of animals! To find geometry, the
surveyor's art, in an Osmia's tiny brain! An insect that begins by
taking the measurements of the room to be constructed, just as any
master-builder might do! Why, it's splendid, it's enough to cover with
confusion those horrible sceptics who persist in refusing to admit the
animal's 'continuous little flashes of atoms of reason!'
O common-sense, veil your face! It is with this gibberish about
continuous flashes of atoms of reason that men pretend to build up
science to-day! Very well, my masters; the magnificent argument with
which I am supplying you lacks but one little detail, the merest trifle:
truth! Not that I have not seen and plainly seen all that I am relating;
but measuring has nothing to do with the case. And I can prove it by
facts.
If, in order to see the Osmia's nest as a whole, we split a reed
lengthwise, taking care not to disturb its contents; or, better still,
if we select for examination the string of cells built in a glass tube,
we are forthwith struck by one detail, namely, the uneven distances
between the partitions, which are placed almost at right angles to the
axis of the cylinder. It is these distances which fix the size of
the chambers, which, with a similar base, have different heights and
consequently unequal holding-capacities. The bottom partitions, the
oldest, are farther apart; those of the front part, near the orifice,
are closer together. Moreover, the provisions are plentiful in the
loftier cells, whereas they are niggardly and reduced to one-half or
even one-third in the cells of lesser height.
Here are a few examples of these inequalities. A glass tube with a
diameter of 12 millimetres (.468 inch.--Translator's Note.), inside
measurement, contains ten cells. The five lower ones, beginning with the
bottom-most, have as the respective distances between their partitions,
in millimetres:
11, 12, 16, 13, 11. (.429,.468,.624,.507,.429 inch.--Translator's Note.)
The five upper ones measure between their partitions:
7, 7, 5, 6, 7. (.273,.273,.195,.234,.273 inch.--Translator's Note.)
A reed-stump 11 millimetres (.429 inch.--Translator's Note.) across the
inside contains fifteen cells; and the respective distances between the
partitions of those cells, starting from the bottom, are:
13, 12, 12, 9, 9, 11, 8, 8, 7, 7, 7, 6, 6, 6, 7. (.507,.468,.468,
.351,.351,.429,.312,.312,.273,.273,.273,.234,.234,.234, .273
inch.--Translator's Note.)
When the diameter of the tunnel is less, the partitions can be still
further apart, though they retain the general characteristic of being
closer to one another the nearer they are to the orifice. A reed of five
millimetres (.195 inch.--Translator's Note.) in diameter, gives me the
following distances, always starting from the bottom:
22, 22, 20, 20, 12, 14. (.858,.858,.78,.78,.468,.546 inch.--Translator's
Note.)
Another, of 9 millimetres (.351 inch.--Translator's Note.), gives me:
15, 14, 11, 10, 10, 9, 10. (.585,.546,.429,.39,.39,.351,.39
inch.--Translator's Note.)
A glass tube of 8 millimetres (.312 inch.--Translator's Note.) yields:
15, 14, 20, 10, 10, 10. (.585,.546,.78,.39,.39,.39 inch.--Translator's
Note.).
I could fill pages and pages with such figures, if I cared to print all
my notes. Do they prove that the Osmia is a geometrician, employing a
strict measure based on the length of her body? Certainly not, because
many of those figures exceed the length of the insect; because sometimes
a higher number follows suddenly upon a lower; because the same string
contains a figure of one value and another figure of but half that
value. They prove only one thing: the marked tendency of the insect to
shorten the distance between the party-walls as the work proceeds. We
shall see later that the large cells are destined for the females and
the small ones for the males.
Is there not at least a measuring adapted to each sex? Again, not so;
for in the first series, where the females are housed, instead of the
interval of 11 millimetres, which occurs at the beginning and the end,
we find, in the middle of the series, an interval of 16 millimetres,
while in the second series, reserved for the males, instead of the
interval of 7 millimetres at the beginning and the end, we have an
interval of 5 millimetres in the middle. It is the same with the other
series, each of which shows a striking discrepancy in its figures. If
the Osmia really studied the dimensions of her chambers and measured
them with the compasses of her body, how could she, with her delicate
mechanism, fail to notice mistakes of 5 millimetres, almost half her own
length?
Besides, all idea of geometry vanishes if we consider the work in a tube
of moderate width. Here, the Osmia does not fix the front partition in
advance; she does not even lay its foundation. Without any boundary-pad,
with no guiding mark for the capacity of the cell, she busies herself
straightway with the provisioning. When the heap of Bee-bread is judged
sufficient, that is, I imagine, when her tired body tells her that she
has done enough harvesting, she closes up the chamber. In this case,
there is no measuring; and yet the capacity of the cell and the quantity
of the victuals fulfil the regular requirements of one or the other sex.
Then what does the Osmia do when she repeatedly stops to touch the
front partition with her forehead and the back partition, the one in the
course of building, with the tip of her abdomen? I have no idea what
she does or what she has in view. I leave the interpretation of this
performance to others, more venturesome than I. Plenty of theories are
based on equally shaky foundations. Blow on them and they sink into the
quagmire of oblivion.
The laying is finished, or perhaps the cylinder is full. A final
partition closes the last cell. A rampart is now built, at the orifice
of the tube itself, to forbid the ill-disposed all access to the home.
This is a thick plug, a massy work of fortification, whereon the Osmia
spends enough mortar to partition off any number of cells. A whole day
is not too long for making this barricade, especially in view of the
minute finishing-touches, when the Osmia fills up with putty every chink
through which the least atom could slip. The mason completing a wall
smooths his plaster and brings it to a fine surface while it is still
wet; the Osmia does the same, or almost. With little taps of the
mandibles and a continual shaking of her head, a sign of her zest for
the work, she smooths and polishes the surface of the lid for hours at a
time. After such pains, what foe could visit the dwelling?
And yet there is one, an Anthrax, A. sinuata (Cf. "The Life of the Fly":
chapters 2 and 4.--Translator's Note.), who will come later on, in the
height of summer, and succeed, invisible bit of thread that she is, in
making her way to the grub through the thickness of the door and the web
of the cocoon. In many cells, mischief of another kind has already been
done. During the progress of the works, an impudent Midge, one of the
Tachina-flies, who feeds her family on the victuals amassed by the Bee,
hovers in front of the galleries. Does she penetrate to the cells and
lay her eggs there in the mother's absence? I could never catch the
sneak in the act. Does she, like that other Tachina who ravages cells
stocked with game (The cells of the Hunting Wasps.--Translator's Note.),
nimbly deposit her eggs on the Osmia's harvest at the moment when the
Bee is going indoors? It is possible, though I cannot say for certain.
The fact remains that we soon see the Midge's grub-worms swarming around
the larva, the daughter of the house. There are ten, fifteen, twenty or
more of them gnawing with their pointed mouths at the common dish and
turning the food into a heap of fine, orange-coloured vermicelli. The
Bee's grub dies of starvation. It is life, life in all its ferocity
even in these tiny creatures. What an expenditure of ardent labour, of
delicate cares, of wise precautions, to arrive at...what? Her offspring
sucked and drained dry by the hateful Anthrax; her family sweated and
starved by the infernal Tachina.
The victuals consist mostly of yellow flour. In the centre of the heap,
a little honey is disgorged, which turns the pollen-dust into a firm,
reddish paste. On this paste the egg is laid, not flat, but upright,
with the fore-end free and the hind-end lightly held and fixed in the
plastic mass. When hatched, the young grub, kept in its place by its
rear-end, need only bend its neck a little to find the honey-soaked
paste under its mouth. When it grows stronger, it will release itself
from its support and eat up the surrounding flour.
All this is touching, in its maternal logic. For the new-born, dainty
bread-and-honey; for the adolescent, dry bread. In cases where
the provisions are all of a kind, these delicate precautions are
superfluous. The victuals of the Anthophorae and the Chalicodomae
consist of flowing honey, the same throughout. The egg is then laid at
full length on the surface, without any particular arrangement, thus
compelling the new-born grub to take its first mouthfuls at random. This
has no drawback, as the food is of the same quality throughout. But,
with the Osmia's provisions--dry powder on the edges, jam in the
centre--the grub would be in danger if its first meal were not regulated
in advance. To begin with pollen not seasoned with honey would be
fatal to its stomach. Having no choice of its mouthfuls because of its
immobility and being obliged to feed on the spot where it was hatched,
the young grub must needs be born on the central mass, where it has only
to bend its head a little way in order to find what its delicate stomach
calls for. The place of the egg, therefore, fixed upright by its base in
the middle of the red jam, is most judiciously chosen. What a contrast
between this exquisite maternal forethought and the horrible destruction
by the Anthrax and the Midge!
The egg is rather large for the size of the Osmia. It is cylindrical,
slightly curved, rounded at both ends and transparent. It soon becomes
cloudy, while remaining diaphanous at each extremity. Fine lines, hardly
perceptible to the most penetrating lens, show themselves in transverse
circles. These are the first signs of segmentation. A contraction
appears in the front hyaline part, marking the head. An extremely
thin opaque thread runs down either side. This is the cord of tracheae
communicating between one breathing-hole and another. At last, the
segments show distinctly, with their lateral pads. The grub is born.
At first, one would think that there was no hatching in the proper sense
of the word--that is to say, no bursting and casting of a wrapper.
The most minute attention is necessary to show that appearances are
deceptive and that actually a fine membrane is thrown off from front to
back. This infinitesimal shred is the shell of the egg.
The grub is born. Fixed by its base, it curves into an arc and bends its
head, until now held erect, down to the red mass. The meal begins. Soon
a yellow cord occupying the front two-thirds of the body proclaims that
the digestive apparatus is swelling out with food. For a fortnight,
consume your provender in peace, my child; then spin your cocoon: you
are now safe from the Tachina! Shall you be safe from the Anthrax'
sucker later on? Alack!