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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 reache
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


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


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,


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


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


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


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


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


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


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


The five upper ones measure between their partitions:

7, 7, 5, 6, 7. (.273, .273, .195, .234, .273 inch.--Translator's


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.)


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


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!