THE PRIMARY LARVA OF THE OIL-BEETLES
I interrupt the history of the Sitares to speak of the Meloes, those
uncouth Beetles, with their clumsy belly and their limp wing-cases
yawning over their back like the tails of a fat man's coat that is far
too tight for its wearer. The insect is ugly in colouring, which is
black, with an occasional blue gleam, and uglier still in shape and
gait; and its disgusting method of defence increases the repugnance
with which it inspires us. If it judges itself to be in danger, the
Meloe resorts to spontaneous bleeding. From its joints a yellowish,
oily fluid oozes, which stains your fingers and makes them stink. This
is the creature's blood. The English, because of its trick of
discharging oily blood when on the defensive, call this insect the
Oil-beetle. It would not be a particularly interesting Beetle save for
its metamorphoses and the peregrinations of its larva, which are
similar in every respect to those of the larva of the Sitares. In
their first form, the Oil-beetles are parasites of the Anthophorae;
their tiny grub, when it leaves the egg, has itself carried into the
cell by the Bee whose victuals are to form its food.
Observed in the down of various Bees, the queer little creature for a
long time baffled the sagacity of the naturalists, who, mistaking its
true origin, made it a species of a special family of wingless
insects. It was the Bee-louse (_Pediculus apis_) of Linnaeus;[1] the
Triungulin of the Andrenae (_Triungulinus andrenetarum_) of Leon
Dufour. They saw in it a parasite, a sort of Louse, living in the
fleece of the honey-gatherers. It was reserved for the distinguished
English naturalist Newport to show that this supposed Louse was the
first state of the Oil-beetles. Some observations of my own will fill
a few lacunae in the English scientist's monograph. I will therefore
sketch the evolution of the Oil-beetles, using Newport's work where my
own observations are defective. In this way the Sitares and the
Meloes, alike in habits and transformations, will be compared; and the
comparison will throw a certain light upon the strange metamorphoses
of these insects.
[Footnote 1: Carolus Linnaeus (Karl von Linne, 1707-1778), the
celebrated Swedish botanist and naturalist, founder of the Linnaean
system of classification.--_Translator's Note_.]
The same Mason-bee (_Anthophora pilipes_) upon whom the Sitares live
also feeds a few scarce Meloes (_M. cicatricosus_) in its cells. A
second Anthophora of my district (_A. parietina_) is more subject to
this parasite's invasions. It was also in the nests of an Anthophora,
but of a different species (_A. retusa_), that Newport observed the
same Oil-beetle. These three lodgings adopted by _Meloe cicatricosus_
may be of some slight interest, as leading us to suspect that each
species of Meloe is apparently the parasite of diverse Bees, a
suspicion which will be confirmed when we examine the manner in which
the larvae reach the cell full of honey. The Sitares, though less
given to change of lodging, are likewise able to inhabit nests of
different species. They are very common in the cells of _Anthophora
pilipes_; but I have found them also, in very small numbers, it is
true, in the cells of _A. personata_.
Despite the presence of _Meloe cicatricosus_ in the dwellings of the
Mason-bee, which I so often ransacked in compiling the history of the
Sitares, I never saw this insect, at any season of the year, wandering
on the perpendicular soil, at the entrance of the corridors, for the
purpose of laying its eggs there, as the Sitares do; and I should know
nothing of the details of the egg-laying if Godart,[2] de Geer[3] and,
above all, Newport had not informed us that the Oil-beetles lay their
eggs in the earth. According to the last-named author, the various
Oil-beetles whom he had the opportunity of observing dig, among the
roots of a clump of grass, in a dry soil exposed to the sun, a hole a
couple of inches deep which they carefully fill up after laying their
eggs there in a heap. This laying is repeated three or four times
over, at intervals of a few days during the same season. For each
batch of eggs the female digs a special hole, which she does not fail
to fill up afterwards. This takes place in April and May.
[Footnote 2: Jean Baptiste Godart (1775-1823), the principal editor of
_L'Histoire naturelle des lepidopteres de France_.--_Translator's
Note_.]
[Footnote 3: Baron Karl de Geer (1720-1778), the Swedish entomologist,
author of _Memoires pour servir a l'histoire des insectes_
(1752-1778).--_Translator's Note_.]
The number of eggs laid in a single batch is really prodigious. In the
first batch, which, it is true, is the most prolific of all, _Meloe
proscarabaeus_, according to Newport's calculations, produces the
astonishing number of 4,218 eggs, which is double the number of eggs
laid by a Sitaris. And what must the number be, when we allow for the
two or three batches that follow the first! The Sitares, entrusting
their eggs to the very corridors through which the Anthophora is bound
to pass, spare their larvae a host of dangers which the larvae of the
Meloe have to run, for these, born far from the dwellings of the Bees,
are obliged to make their own way to their hymenopterous
foster-parents. The Oil-beetles, therefore, lacking the instinct of
the Sitares, are endowed with incomparably greater fecundity. The
richness of their ovaries atones for the insufficiency of instinct by
proportioning the number of germs in accordance with the risks of
destruction. What transcendent harmony is this, which thus holds the
scales between the fecundity of the ovaries and the perfection of
instinct!
The hatching of the eggs takes place at the end of May or in June,
about a month after they are laid. The eggs of the Sitares also are
hatched after the same lapse of time. But the Meloe-larvae, more
greatly favoured, are able to set off immediately in search of the
Bees that are to feed them; while those of the Sitares, hatched in
September, have to wait motionless and in complete abstinence for the
emergence of the Anthophorae the entrance to whose cells they guard. I
will not describe the young Meloe-larva, which is sufficiently well
known, in particular by the description and the diagram furnished by
Newport. To enable the reader to understand what follows, I will
confine myself to stating that this primary larva is a sort of little
yellow louse, long and slender, found in the spring in the down of
different Bees.
How has this tiny creature made its way from the underground lodging
where the eggs are hatched to the fleece of a Bee? Newport suspects
that the young Oil-beetles, on emerging from their natal burrow, climb
upon the neighbouring plants, especially upon the Cichoriceae, and
wait, concealed among the petals, until a few Bees chance to plunder
the flower, when they promptly fasten on to their fur and allow
themselves to be borne away by them. I have more than Newport's
suspicions upon this curious point; my personal observations and
experiments are absolutely convincing. I will relate them as the first
phase of the history of the Bee-louse. They date back to the 23rd of
May, 1858.
A vertical bank on the road from Carpentras to Bedoin is this time the
scene of my observations. This bank, baked by the sun, is exploited by
numerous swarms of Anthophorae, who, more industrious than their
congeners, are in the habit of building, at the entrance to their
corridors, with serpentine fillets of earth, a vestibule, a defensive
bastion in the form of an arched cylinder. In a word, they are swarms
of _A. parietina_. A sparse carpet of turf extends from the edge of
the road to the foot of the bank. The more comfortably to follow the
work of the Bees, in the hope of wresting some secret from them, I had
been lying for a few moments upon this turf, in the very heart of the
inoffensive swarm, when my clothes were invaded by legions of little
yellow lice, running with desperate eagerness through the hairy
thickets of the nap of the cloth. In these tiny creatures, with which
I was powdered here and there as with yellow dust, I soon recognized
an old acquaintance, the young Oil-beetles, whom I now saw for the
first time elsewhere than in the Bees' fur or the interior of their
cells. I could not lose so excellent an opportunity of learning how
these larvae manage to establish themselves upon the bodies of their
foster-parents.
In the grass where, after lying down for a moment, I had caught these
lice were a few plants in blossom, of which the most abundant were
three composites: _Hedypnois polymorpha_, _Senecio gallicus_ and
_Anthemis arvensis_. Now it was on a composite, a dandelion, that
Newport seemed to remember seeing some young Oil-beetles; and my
attention therefore was first of all directed to the plants which I
have named. To my great satisfaction, nearly all the flowers of these
three plants, especially those of the camomile (_Anthemis_) were
occupied by young Oil-beetles in greater or lesser numbers. On one
head of camomile I counted forty of these tiny insects, cowering
motionless in the centre of the florets. On the other hand, I could
not discover any on the flowers of the poppy or of a wild rocket
(_Diplotaxis muralis_) which grew promiscuously among the plants
aforesaid. It seems to me, therefore, that it is only on the composite
flowers that the Meloe-larvae await the Bees' arrival.
In addition to this population encamped upon the heads of the
composites and remaining motionless, as though it had achieved its
object for the moment, I soon discovered yet another, far more
numerous, whose anxious activity betrayed a fruitless search. On the
ground, in the grass, numberless little larvae were running in a great
flutter, recalling in some respects the tumultuous disorder of an
overturned Ant-hill; others were hurriedly climbing to the tip of a
blade of grass and descending with the same haste; others again were
plunging into the downy fluff of the withered everlastings, remaining
there a moment and quickly reappearing to continue their search.
Lastly, with a little attention, I was able to convince myself that
within an area of a dozen square yards there was perhaps not a single
blade of grass which was not explored by several of these larvae.
I was evidently witnessing the recent emergence of the young
Oil-beetles from their maternal lairs. Part of them had already
settled on the groundsel- and camomile-flowers to await the arrival of
the Bees; but the majority were still wandering in search of this
provisional refuge. It was by this wandering population that I had
been invaded when I lay down at the foot of the bank. It was
impossible that all these larvae, the tale of whose alarming thousands
I would not venture to define, should form one family and recognize a
common mother; despite what Newport has told us of the Oil-beetles'
astonishing fecundity, I could not believe this, so great was their
multitude.
Though the green carpet was continued for a considerable distance
along the side of the road, I could not detect a single Meloe-larva
elsewhere than in the few square yards lying in front of the bank
inhabited by the Mason-bee. These larvae therefore could not have come
far; to find themselves near the Anthophorae they had had no long
pilgrimage to make, for there was not a sign of the inevitable
stragglers and laggards that follow in the wake of a travelling
caravan. The burrows in which the eggs were hatched were therefore in
that turf opposite the Bees' abode. Thus the Oil-beetles, far from
laying their eggs at random, as their wandering life might lead one to
suppose, and leaving their young to the task of approaching their
future home, are able to recognize the spots haunted by the
Anthophorae and lay their eggs in the near neighbourhood of those
spots.
With such a multitude of parasites occupying the composite flowers in
close proximity to the Anthophora's nests, it is impossible that the
majority of the swarm should not become infested sooner or later. At
the time of my observations, a comparatively tiny proportion of the
starving legion was waiting on the flowers; the others were still
wandering on the ground, where the Anthophorae very rarely alight; and
yet I detected the presence of several Meloe-larvae in the thoracic
down of nearly all the Anthophorae which I caught and examined.
I have also found them on the bodies of the Melecta- and
Coelioxys-bees,[4] who are parasitic on the Anthophorae. Suspending
their audacious patrolling before the galleries under construction,
these spoilers of the victualled cells alight for an instant on a
camomile-flower and lo, the thief is robbed! A tiny, imperceptible
louse has slipped into the thick of the downy fur and, at the moment
when the parasite, after destroying the Anthophora's egg, is laying
her own upon the stolen honey, will creep upon this egg, destroy it in
its turn and remain sole mistress of the provisions. The mess of honey
amassed by the Anthophora will thus pass through the hands of three
owners and remain finally the property of the weakest of the three.
[Footnote 4: Cf. _The Mason-bees_: chaps. viii. and ix.--_Translator's
Note_.]
And who shall say whether the Meloe, in its turn, will not be
dispossessed by a fresh thief; or even whether it will not, in the
state of a drowsy, fat and flabby larva, fall a prey to some marauder
who will munch its live entrails? As we meditate upon this deadly,
implacable struggle which nature imposes, for their preservation, on
these different creatures, which are by turns possessors and
dispossessed, devourers and devoured, a painful impression mingles
with the wonder aroused by the means employed by each parasite to
attain its end; and, forgetting for a moment the tiny world in which
these things happen, we are seized with terror at this concatenation
of larceny, cunning and brigandage which forms part, alas, of the
designs of _alma parens rerum_!
The young Meloe-larvae established in the down of the Anthophorae or
in that of the Melecta- and the Coelioxys-bees, their parasites, had
adopted an infallible means of sooner or later reaching the desired
cell. Was it, so far as they were concerned, a choice dictated by the
foresight of instinct, or just simply the result of a lucky chance?
The question was soon decided. Various Flies--Drone-flies and
Bluebottles (_Eristalis tenax_ and _Calliphora vomitoria_)--would
settle from time to time on the groundsel- or camomile-flowers
occupied by the young Meloes and stop for a moment to suck the sweet
secretions. On all these Flies, with very few exceptions, I found
Meloe-larvae, motionless in the silky down of the thorax. I may also
mention, as infested by these larvae, an Ammophila (_A. hirsuta_),[5]
who victuals her burrows with a caterpillar in early spring, while her
kinswomen build their nests in autumn. This Wasp merely grazes, so to
speak, the surface of a flower; I catch her; there are Meloes moving
about her body. It is clear that neither the Drone-flies nor the
Bluebottles, whose larvae live in putrefying matter, nor yet the
Ammophilae who victual theirs with caterpillars, could ever have
carried the larvae which invaded them into cells filled with honey.
These larvae therefore had gone astray; and instinct, as does not
often happen, was here at fault.
[Footnote 5: For the Wasp known as the Hairy Ammophila, who feeds her
young on the Grey Worm, the caterpillar of the Turnip Moth, cf. _The
Hunting Wasps_, chaps. xviii. to xx.--_Translator's Note_.]
Let us now turn our attention to the young Meloes waiting expectant
upon the camomile-flowers. There they are, ten, fifteen or more,
lodged half-way down the florets of a single blossom or in their
interstices; it therefore needs a certain degree of scrutiny to
perceive them, their hiding-place being the more effectual in that the
amber colour of their bodies merges in the yellow hue of the florets.
So long as nothing unusual happens upon the flower, so long as no
sudden shock announces the arrival of a strange visitor, the Meloes
remain absolutely motionless and give no sign of life. To see them
dipping vertically, head downwards, into the florets, one might
suppose that they were seeking some sweet liquid, their food; but in
that case they ought to pass more frequently from one floret to
another, which they do not, except when, after a false alarm, they
regain their hiding-places and choose the spot which seems to them the
most favourable. This immobility means that the florets of the
camomile serve them only as a place of ambush, even as later the
Anthophora's body will serve them solely as a vehicle to convey them
to the Bee's cell. They take no nourishment, either on the flowers or
on the Bees; and, as with the Sitares, their first meal will consist
of the Anthophora's egg, which the hooks of their mandibles are
intended to rip open.
Their immobility is, as we have said, complete; but nothing is easier
than to arouse their suspended activity. Shake a camomile-blossom
lightly with a bit of straw: instantly the Meloes leave their
hiding-places, come up and scatter in all directions on the white
petals of the circumference, running over them from one end to the
other with all the speed which the smallness of their size permits. On
reaching the extreme end of the petals, they fasten to it either with
their caudal appendages, or perhaps with a sticky substance similar to
that furnished by the anal button of the Sitares; and, with their
bodies hanging outside and their six legs free, they bend about in
every direction and stretch as far out as they can, as though striving
to touch an object out of their reach. If nothing offers for them to
seize upon, after a few vain attempts they regain the centre of the
flower and soon resume their immobility.
But, if we place near them any object whatever, they do not fail to
catch on to it with surprising agility. A blade of grass, a bit of
straw, the handle of my tweezers which I hold out to them: they accept
anything in their eagerness to quit the provisional shelter of the
flower. It is true that, after finding themselves on these inanimate
objects, they soon recognize that they have gone astray, as we see by
their bustling movements to and fro and their tendency to go back to
the flower if there still be time. Those which have thus giddily flung
themselves upon a bit of straw and are allowed to return to their
flower do not readily fall a second time into the same trap. There is
therefore, in these animated specks, a memory, an experience of
things.
After these experiments I tried others with hairy materials imitating
more or less closely the down of the Bees, with little pieces of cloth
or velvet cut from my clothes, with plugs of cotton wool, with pellets
of flock gathered from the everlastings. Upon all these objects,
offered with the tweezers, the Meloes flung themselves without any
difficulty; but, instead of keeping quiet, as they do on the bodies of
the Bees, they soon convinced me, by their restless behaviour, that
they found themselves as much out of their element on these furry
materials as on the smooth surface of a bit of straw. I ought to have
expected this: had I not just seen them wandering without pause upon
the everlastings enveloped with cottony flock? If reaching the shelter
of a downy surface were enough to make them believe themselves safe in
harbour, nearly all would perish, without further attempts, in the
down of the plants.
Let us now offer them live insects and, first of all, Anthophorae. If
the Bee, after we have rid her of the parasites which she may be
carrying, be taken by the wings and held for a moment in contact with
the flower, we invariably find her, after this rapid contact, overrun
by Meloes clinging to her hairs. The larvae nimbly take up their
position on the thorax, usually on the shoulders or sides, and once
there they remain motionless: the second stage of their strange
journey is compassed.
After the Anthophorae, I tried the first live insects that I was able
to procure at once: Drone-flies, Bluebottles, Hive-bees, small
Butterflies. All were alike overrun by the Meloes, without hesitation.
What is more, there was no attempt made to return to the flowers. As I
could not find any Beetles at the moment, I was unable to experiment
with them. Newport, experimenting, it is true, under conditions very
different from mine, since his observations related to young Meloes
held captive in a glass jar, while mine were made in the normal
circumstances, Newport, I was saying, saw Meloes fasten to the body of
a Malachius and stay there without moving, which inclines me to
believe that with Beetles I should have obtained the same results as,
for instance, with a Drone-fly. And I did, in fact, at a later date,
find some Meloe-larvae on the body of a big Beetle, the Golden
Rose-chafer (_Cetonia aurata_), an assiduous visitor of the flowers.
After exhausting the insect class, I put within their reach my last
resource, a large black Spider. Without hesitation they passed from
the flower to the arachnid, made for places near the joints of the
legs and settled there without moving. Everything therefore seems to
suit their plans for leaving the provisional abode where they are
waiting; without distinction of species, genus, or class, they fasten
to the first living creature that chance brings within their reach. We
now understand how it is that these young larvae have been observed
upon a host of different insects and especially upon the early Flies
and Bees pillaging the flowers; we can also understand the need for
that prodigious number of eggs laid by a single Oil-beetle, since the
vast majority of the larvae which come out of them will infallibly go
astray and will not succeed in reaching the cells of the Anthophorae.
Instinct is at fault here; and fecundity makes up for it.
But instinct recovers its infallibility in another case. The Meloes,
as we have seen, pass without difficulty from the flower to the
objects within their reach, whatever these may be, smooth or hairy,
living or inanimate. This done, they behave very differently,
according as they have chanced to invade the body of an insect or some
other object. In the first case, on a downy Fly or Butterfly, on a
smooth-skinned Spider or Beetle, the larvae remain motionless after
reaching the point which suits them. Their instinctive desire is
therefore satisfied. In the second case, in the midst of the nap of
cloth or velvet, or the filaments of cotton, or the flock of the
everlasting, or, lastly, on the smooth surface of a leaf or a straw,
they betray the knowledge of their mistake by their continual coming
and going, by their efforts to return to the flower imprudently
abandoned.
How then do they recognize the nature of the object to which they have
just moved? How is it that this object, whatever the quality of its
surface, will sometimes suit them and sometimes not? Do they judge
their new lodging by sight? But then no mistake would be possible; the
sense of sight would tell them at the outset whether the object within
reach was suitable or not; and emigration would or would not take
place according to its decision. And then how can we suppose that,
buried in the dense thicket of a pellet of cotton-wool or in the
fleece of an Anthophora, the imperceptible larva can recognize, by
sight, the enormous mass which it is perambulating?
Is it by touch, by some sensation due to the inner vibrations of
living flesh? Not so, for the Meloes remain motionless on insect
corpses that have dried up completely, on dead Anthophorae taken from
cells at least a year old. I have seen them keep absolutely quiet on
fragments of an Anthophora on a thorax long since nibbled and emptied
by the Mites. By what sense then can they distinguish the thorax of an
Anthophora from a velvety pellet, when sight and touch are out of the
question? The sense of smell remains. But in that case what exquisite
subtlety must we not take for granted? Moreover, what similarity of
smell can we admit between all the insects which, dead or alive, whole
or in pieces, fresh or dried, suit the Meloes, while anything else
does not suit them? A wretched louse, a living speck, leaves us
mightily perplexed as to the sensibility which directs it. Here is yet
one more riddle added to all the others.
After the observations which I have described, it remained for me to
search the earthen surface inhabited by the Anthophorae: I should then
have followed the Meloe-larva in its transformations. It was certainly
_cicatricosus_ whose larvae I had been studying; it was certainly this
insect which ravaged the cells of the Mason-bee, for I found it dead
in the old galleries which it had been unable to leave. This
opportunity, which did not occur again, promised me an ample harvest.
I had to give it all up. My Thursday was drawing to a close; I had to
return to Avignon, to resume my lessons on the electrophorus and the
Toricellian tube. O happy Thursdays! What glorious opportunities I
lost because you were too short!
We will go back a year to continue this history. I collected, under
far less favourable conditions, it is true, enough notes to map out
the biography of the tiny creature which we have just seen migrating
from the camomile-flowers to the Anthophora's back. From what I have
said of the Sitaris-larvae, it is plain that the Meloe-larvae perched,
like the former, on the back of a Bee, have but one aim: to get
themselves conveyed by this Bee to the victualled cells. Their object
is not to live for a time on the body that carries them.
Were it necessary to prove this, it would be enough to say that we
never see these larvae attempt to pierce the skin of the Bee, or else
to nibble at a hair or two, nor do we see them increase in size so
long as they are on the Bee's body. To the Meloes, as to the Sitares,
the Anthophora serves merely as a vehicle which conveys them to their
goal, the victualled cell.
It remains for us to learn how the Meloe leaves the down of the Bee
which has carried it, in order to enter the cell. With larvae
collected from the bodies of different Bees, before I was fully
acquainted with the tactics of the Sitares, I undertook, as Newport
had done before me, certain investigations intended to throw light on
this leading point in the Oil-beetle's history. My attempts, based
upon those which I had made with the Sitares, resulted in the same
failure. The tiny creatures, when brought into contact with
Anthophora-larvae or -nymphs, paid no attention whatever to their
prey; others, placed near cells which were open and full of honey, did
not enter them, or at most ventured to the edge of the orifice;
others, lastly, put inside the cell, on the dry wall or on the surface
of the honey, came out again immediately or else got stuck and died.
The touch of the honey is as fatal to them as to the young Sitares.
Searches made at various periods in the nests of the Hairy-footed
Anthophora had taught me some years earlier that _Meloe cicatricosus_,
like the Sitares, is a parasite of that Bee; indeed I had at different
times discovered adult Meloes, dead and shrivelled, in the Bee's
cells. On the other hand, I knew from Leon Dufour that the little
yellow animal, the Louse found in the Bee's down, had been recognized,
thanks to Newport's investigations, as the larva of the Oil-beetle.
With these data, rendered still more striking by what I was learning
daily on the subject of the Sitares, I went to Carpentras, on the 21st
of May, to inspect the nests of the Anthophorae, then building, as I
have described. Though I was almost certain of succeeding, sooner or
later, with the Sitares, who were excessively abundant, I had very
little hope of the Meloes, which on the contrary are very scarce in
the same nests. Circumstances, however, favoured me more than I dared
hope and, after six hours' labour, in which the pick played a great
part, I became the possessor, by the sweat of my brow, of a
considerable number of cells occupied by Sitares and two other cells
appropriated by Meloes.
While my enthusiasm had not had time to cool at the sight, momentarily
repeated, of a young Sitaris perched upon an Anthophora's egg floating
in the centre of the little pool of honey, it might well have burst
all restraints on beholding the contents of one of these cells. On the
black, liquid honey a wrinkled pellicle is floating; and on this
pellicle, motionless, is a yellow louse. The pellicle is the empty
envelope of the Anthophora's egg; the louse is a Meloe-larva.
The story of this larva becomes self-evident. The young Meloe leaves
the down of the Bee at the moment when the egg is laid; and, since
contact with the honey would be fatal to the grub, it must, in order
to save itself, adopt the tactics followed by the Sitaris, that is to
say, it must allow itself to drop on the surface of the honey with the
egg which is in the act of being laid. There, its first task is to
devour the egg which serves it for a raft, as is attested by the empty
envelope on which it still remains; and it is after this meal, the
only one that it takes so long as it retains its present form, that it
must commence its long series of transformations and feed upon the
honey amassed by the Anthophora. This was the reason of the complete
failure both of my attempts and of Newport's to rear the young
Meloe-larvae. Instead of offering them honey, or larvae, or nymphs, we
should have placed them on the eggs recently laid by the Anthophora.
On my return from Carpentras, I meant to try this method, together
with that of the Sitares, with which I had been so successful; but, as
I had no Meloe-larvae at my disposal and could not obtain any save by
searching for them in the Bees' fleece, the Anthophora-eggs were all
discovered to have hatched in the cells which I brought back from my
expedition, when I was at last able to find some. This lost experiment
is little to be regretted, for, since the Meloes and the Sitares
exhibiting the completest similarity not only in habits but also in
their method of evolution, there is no doubt whatever that I should
have succeeded. I even believe that this method may be attempted with
the cells of various Bees, provided that the eggs and the honey do not
differ too greatly from the Anthophora's. I should not, for example,
count on being successful with the cells of the three-horned Osmia,
who shares the Anthophora's quarters: her egg is short and thick; and
her honey is yellow, odourless, solid, almost a powder and very
faintly flavoured.