their queen; for on restoring her, tranquillity is instantly regained
among them; and, what is very singular, they _recognise_ her: you must
interpret this expression strictly. Substitution of another queen is not
attended with the same effect, if she is introduced into the hive within
the first twelve hours after removal of the reigning one. Here the
agitation continues; and the bees treat the stranger the same as when
the presence of their own leaves them nothing to desire. They surround,
seize, and keep her captive, a very long time, in an impenetrable
cluster; and she commonly dies either from hunger or privation of air.
If eighteen hours elapse before substitution of a stranger queen for the
native one removed, she is at first treated in the same manner, but the
bees leave her sooner; nor is the surrounding cluster so close; they
gradually disperse; and the queen is at last liberated. She moves
languidly; and sometimes expires in a few minutes. However some queens
have escaped in good health from an imprisonment of seventeen hours; and
ended with reigning in the hives where they had originally been ill
received.
If, before substituting the stranger queen, twenty-four hours elapse,
she will be well received, and reign from the moment of her introduction
into the hive. Here I speak of the good reception given to a queen after
an interregnum of twenty-four hours. But as this word reception is very
indefinite, it is proper to enter into some detail for explaining the
exact sense in which I use it. On the 15. of August, I introduced a
fertile queen, eleven months old, into a glass hive. The bees were
twenty-four hours deprived of their queen, and had already begun the
construction of twelve royal-cells, such as described in the preceding
chapter. Immediately on placing this female stranger on the comb, the
workers near her touched her with their antennæ, and, passing their
trunks over every part of her body, they gave her honey. Then these gave
place to others that treated her exactly in the same manner. All
vibrated their wings at once, and ranged themselves in a circle around
their sovereign. Hence resulted a kind of agitation which gradually
communicated to the workers situated on the same surface of the comb,
and induced them to come and reconnoitre, in their turn, what was going
on. They soon arrived; and, having broke through the circle formed by
the first, approached the queen, touched her with the antennæ, and gave
her honey. After this little ceremony they retired; and, placing
themselves behind the others, enlarged the circle. There they vibrated
their wings, and buzzed without tumult or disorder, and as if
experiencing some very agreeable sensation. The queen had not yet moved
from the place where I had put her, but in a quarter of an hour she
began to move. The bees, far from opposing her, opened the circle at
that part to which she turned, followed her, and formed a guard around.
She was oppressed with the necessity of laying, and dropped eggs.
Finally, after four hours abode, she began to deposit male eggs in the
cells she met.
While these events passed on the surface of the comb where the queen
stood, all was quiet on the other side. Here the workers were apparently
ignorant of a queen's arrival in the hive. They laboured with great
activity at the royal cells, as if ignorant that they no longer stood in
need of them: they watched over the royal worms, supplied them with
jelly and the like. But the queen having at length come to this side,
she was received with the same respect that she had experienced from
their companions on the other side of the comb. They encompassed her;
gave her honey; and touched her with their antennæ: and what proved
better that they treated her as a mother, was their immediately
desisting from work at the royal cells; they removed the worms, and
devoured the food collected around them. From this moment the queen was
recognised by all her people, and conducted herself in this new
habitation as if it had been her native hive.
These particulars will give a just idea of the manner that bees receive
a stranger queen; when they have time to forget their own, she is
treated exactly as if she was their natural one, except that there is
perhaps at first greater interest testified in her, or more conspicuous
demonstrations of it. I am sensible of the impropriety of these
expressions, but M. de Reaumur in some respect authorises them. He does
not scruple to say, that bees pay _attention_, _homage_, and _respect_,
to their queen, and from his example the like expressions have escaped
most authors that treat on bees.
Twenty-four or thirty hours absence is sufficient to make them forget
their first queen, but I can hazard no conjecture on the cause.
* * * * *
Before terminating this letter, which is full of combats and disastrous
scenes, I should, perhaps, give you an account of some more pleasing
and interesting facts relative to their industry. However, to avoid
returning to duels and massacres, I shall here subjoin my observations
on the massacre of the males.
You will remember, Sir, it is agreed by all observers, that at a certain
period of the year, the workers kill and expel the drones. M. de Reaumur
speaks of these executions as a horrible massacre. He does not expressly
affirm, indeed, that he has himself witnessed it, but what we have seen
corresponds so well with his account, that there can be no doubt he has
beheld the peculiarities of the massacre.
It is usually in the months of July and August, that the bees free
themselves of the males. Then they are drove away and pursued to the
inmost parts of the hive, where they collect in numbers; and as at the
same time we find many dead drones on the ground before the hives, it is
indubitable that after being expelled, the bees sting them to death.
Yet on the surface of the comb, we do not see the sting used against
them; there the bees are content to pursue and drive them away. You
observe this, Sir, yourself, in the new notes added to _la Contemplation
de la Nature_; and you seem disposed to think, that the drones forced to
retire to the extremity of the hive, perish from hunger. Your conjecture
was extremely probable. Still it was possible the carnage might take
place in the bottom of the hive, and had been unobserved, because that
part is dark, and escapes the observer's eye.
To appreciate the justice of this suspicion, we thought of making the
support of the hive of glass, and of placing ourselves below to see what
passed in the scene of action. Therefore, a glass table was constructed,
on which were put six hives with swarms of the same year; and, lying
under it, we endeavoured to discover how the drones were destroyed. The
invention succeeded to admiration. On the 4 of July, we saw the workers
actually massacre the males, in the whole six swarms, at the same hour,
and with the same peculiarities.
The glass table was covered with bees full of animation, which flew upon
the drones, as they came from the bottom of the hive; seized them by the
antennæ, the limbs, and the wings, and after having dragged them about,
or, so to speak, after quartering them, they killed them by repeated
stings directed between the rings of the belly. The moment that this
formidable weapon reached them, was the last of their existence; they
stretched their wings, and expired. At the same time, as if the workers
did not consider them as dead as they appeared to us, they still stuck
the sting so deep, that it could hardly be withdrawn, and these bees
were obliged to turn upon themselves before the stings could be
disengaged.
Next day, having resumed our former position, we witnessed new scenes of
carnage. During three hours, the bees furiously destroyed the males.
They had massacred all their own on the preceding evening, but now
attacked those which, driven from the neighbouring hives, had taken
refuge amongst them. We saw them also tear some remaining nymphs from
the combs; they greedily sucked all the fluid from the abdomen, and then
carried them away. The following days no drones remained in the hives.
These two observations seem to me decisive. It is incontestible that
nature has charged the workers with the destruction of the males at
certain seasons of the year. But what means does she use to excite their
fury against them? This is a question that I cannot pretend to answer.
However, an observation I have made may one day lead to solution of the
problem. The males are never destroyed in hives deprived of queens, on
the contrary, while a savage massacre prevails in other places, they
there find an asylum. They are tolerated and fed, and many are seen even
in the middle of January. They are also preserved in hives, which,
without a queen properly so called, have some individuals of that
species that lay the eggs of males, and in those whose half fecundated
queens, if I may use the expression, propagate only drones. Therefore,
the massacre takes place but in hives where the queens are completely
fertile, and it never begins until the season of swarming is past.
_PREGNY, 28 August 1791._
LETTER VII.
_SEQUEL OF EXPERIMENTS ON THE RECEPTION OF A STRANGER QUEEN. M. DE
REAUMUR'S OBSERVATIONS ON THE SUBJECT._
I have frequently testified my admiration of M. de Reaumur's
observations on bees. I feel a sensible pleasure in acknowledging that
if I have made any progress in the art of observation, I am indebted for
it to profound study of the works of this naturalist. In general his
authority has such weight, that I can scarcely trust my own experiments
when the results are different from his. Likewise, on finding myself in
opposition to the _historian of bees_, I repeat my experiments. I vary
the mode of conducting them; I examine with the utmost caution all the
circumstances that might mislead me, and never are my labours
interrupted before acquiring the moral certainty of avoiding error. With
the aid of these precautions, I have discovered the justice of M. de
Reaumur's suggestions, and I have a thousand times seen, if certain
experiments seemed to combat them, it was from incorrectness of
execution. Yet I must except some facts where my results have constantly
been different from his. Those respecting the reception of a stranger
queen substituted for the natural one, are of the number.
If, after removing the natural queen, a stranger is immediately
substituted, the usurper is ill received. I never could succeed in
making them adopt her, but by allowing an interval of twenty or
twenty-four hours to elapse. Then they seemed to have forgot their own
queen; and respectfully received any female put in her place. M. de
Reaumur, on the contrary, asserts, that should the original queen be
removed, and another presented, this new one will be perfectly well
received from the beginning. As evidence of this assertion, he gives the
detail of an experiment which must be read in his work, for I shall here
give only an extract of it{L}. He induced four or five hundred bees to
leave their native hive and enter a glass box, containing a small piece
of comb towards the top. At first they were in great agitation; and, to
pacify or console them, he presented a new queen. From this moment, the
tumult ceased, and the stranger queen was received with all respect.
I do not dispute the truth of this experiment; but, in my opinion, it
does not warrant the conclusion that M. de Reaumur deduces from it. His
apparatus removed the bees too much from their natural condition, to
allow him to judge of their instinct and dispositions. In other
situations, he has himself observed, that these animals, reduced to
small numbers, lost their industry and activity, and feebly continued
their ordinary labours. Thus their instinct is affected by every
operation that too much diminishes their number. To render such an
experiment truly conclusive, it must be made in a populous hive; and on
removing the native queen, a stranger must immediately be substituted in
her place. Had this been done, I am fully persuaded, that M. de Reaumur
would have seen the bees imprison the usurper, confine her at least
twelve or fifteen hours among them, and frequently suffocate her: nor
would he have witnessed any favourable reception before an interval of
twenty-four hours after removal of the original queen. No variation has
occurred in my experiments regarding this fact. Their number, and the
attention bestowed on them, make me presume they merit your confidence.
M. de Reaumur, in another passage of the same Memoir, affirms, that
_bees, which have a queen they are satisfied with, are nevertheless
disposed to give the best possible reception to any female that seeks
refuge among them_. In the preceding letter, I have related my
experiments on this head: their success has been very different from
that of M. de Reaumur's. I have proved that the workers never employ
their stings against the queen; but this cannot be called the welcome
reception of a stranger. They retain her within their ranks, and seem to
allow her liberty only when she prepares to combat the reigning queen.
This observation cannot be made except in the thinnest hives. Those used
by M. de Reaumur had always two parallel combs at least, which must
have prevented him from observing some very important circumstances that
influence the conduct of workers when supplied with several females. The
first circles formed around a stranger queen he has taken for caresses;
and, from the little that this queen could advance between the combs, it
must have been impossible for him to observe that the circles, which
always continued contracting, ended in restraint of the females there
inclosed. Had he used thinner hives, he would have discovered that what
he supposed indication of a favourable reception was the prelude of
actual imprisonment.
I feel reluctant to assert that M. de Reaumur was deceived. Yet I cannot
admit that, on certain occasions, bees tolerate a plurality of females
in their hives. The experiment on which this affirmation rests will not
be considered decisive. In the month of December, he introduced a
stranger queen into a glass hive, in his cabinet, and confined her
there. The bees had no opportunity of going out. This stranger was well
received; her presence awakened the workers from their lethargic state,
into which they did not relapse; she excited no carnage; the number of
dead bees on the board of the hive did not sensibly increase; and no
dead queens were found.
Before concluding any thing favourable to the plurality of queens, it
was necessary to ascertain whether the native queen was living when the
new one was introduced into the hive: however the author neglected this;
and it is very probable the hive had lost its queen, since the bees were
languid, and the presence of a stranger restored their activity.
I trust, Sir, that you will pardon this slight criticism. Far from
industriously seeking faults in our celebrated Reaumur, I derive the
greatest pleasure when my observations coincide with his, and still
more, when my experiments justify his conjectures. But I think it
proper to point out those cases where the imperfections of his hives
have led him into error, and to explain from what causes I have not seen
certain facts in the same manner he did. I feel particular anxiety to
merit your confidence, and I am aware that the greatest exertions are
necessary, when I have to combat the historian of bees. I confide in
your judgment; and pray you to be assured of my respect.
_PREGNY, 30. August 1791._
FOOTNOTES:
{L} Edit. 4to, Tom. V. p. 258.
LETTER VIII.
_IS THE QUEEN OVIPAROUS? WHAT INFLUENCE HAS THE SIZE OF THE CELLS, WHERE
THE EGGS ARE DEPOSITED, ON THE BEES PRODUCED?--RESEARCHES ON THE MODE OF
SPINNING THE COCCOONS._
In this letter I shall collect some isolated observations relative to
various points in the history of bees, concerning which you wished me to
engage.
You desired me to investigate whether the queen is really _oviparous_.
M. de Reaumur leaves this question undecided. He observes, that he has
never seen the worm hatched; and he only asserts that worms are found in
those cells where eggs have been deposited three days preceding. If we
attempt to catch the moment when the worm leaves the egg, we must extend
our observations beyond the interior of the hive; for there the
continual motion of the bees obscures what passes at the bottom of
cells. The egg must be taken out, presented to the microscope, and every
change attentively watched. One other precaution is essential. As a
certain degree of heat is requisite to hatch the worms, should the eggs
be too soon deprived of it they wither and perish. The sole method of
succeeding in seeing the worm come out, consists in watching the queen
while she lays, in marking the egg so as to be recognised, and removing
it from the hive to the microscope only an hour or two before the three
days elapse. The worm will certainly be hatched, provided it has been
exposed as long as possible to the full degree of heat. Such is the
course I have pursued; and the following are the results obtained.
In the month of August, we removed several cells containing eggs that
had been three days deposited: we cut off the top of the cell, and put
the pyramidal bottom, where the egg was fixed, on a glass slider. Slight
motions were soon perceptible in the eggs. At first, we could observe no
external organization: the worm was entirely concealed from us by its
pellicle. We then prepared to examine the egg with a powerful magnifier;
however, during the interval, the worm burst its surrounding membrane,
and cast off part of the envelope, which was torn and ragged on
different parts of the body, and more evidently so towards the last
rings. The worm alternately curved and stretched itself, with very
lively action. Twenty minutes were occupied in casting off the spoil;
when this exertion ceased: the worm lay down, curved, and seemed to take
that rest which it required. An egg laid in a worker's cell produced
this animal, which would have become a worker itself.
We next directed our attention to the moment when a male worm would be
hatched. An egg was exposed to the sun on a glass slider; and, with a
good magnifier, nine rings of the worm were perceptible within the
transparent pellicle. This membrane was still entire, and the worm
perfectly motionless. The two longitudinal lines of tracheæ were visible
on the surface, and many ramifications. We never lost sight of the egg a
single instant, and now succeeded in observing the first motions of the
worm. The thick end alternately straightened and curved, and almost
reached the part where the sharp extremity was fixed. These exertions
burst the membrane, first on the upper part, towards the head, then on
the back, and afterwards on all the rest successively. The ragged
pellicle remained in folds on different parts of the body, and then fell
off. Thus it is beyond dispute, that the queen is oviparous.
Some observers affirm, that the workers attend to the eggs before the
worms are hatched; and it is certain that, at whatever time a hive is
examined, we always see some workers with the head and thorax inserted
into cells containing eggs, and remaining motionless several minutes in
this position. It is impossible to discover what they do, for the
interior of the cell is concealed by their bodies; but it is very easily
ascertained that, in this attitude, they are doing nothing to the eggs.
If, at the moment the queen lays, her eggs are put into a grated box,
and deposited in a strange hive, where there is the necessary degree of
heat, the worms come out at the usual time, just as if they had been
left in the cells. Thus no extraordinary aid or attention is required
for their exclusion.
When the workers penetrate the cells, and remain fifteen or twenty
minutes motionless, I have reason to believe, it is only to repose from
their labours. My observations on the subject seem correct. You know,
Sir, that a kind of irregular shaped cells, are frequently constructed
on the panes of the hive. These, being glass on one side, are
exceedingly convenient to the observer, since all that passes within is
exposed. I have often seen bees enter these cells when nothing could
attract them. The cells contained neither eggs nor honey, nor did they
need further completion. Therefore the workers repaired thither only to
enjoy some moments of repose. Indeed, they were fifteen or twenty
minutes so perfectly motionless, that had not the dilatation of the
rings shewed their respiration, we might have concluded them dead. The
queen also sometimes penetrates the large cells of the males, and
continues very long motionless in them. Her position prevents the bees
from paying their full homage to her, yet even then the workers do not
fail to form a circle around her, and brush the part of her belly that
remains exposed.
The drones do not enter the cells while reposing, but cluster together
on the combs; and sometimes retain this position eighteen or twenty
hours without the slightest motion.
As it is important, in many experiments, to know the exact time that the
three species of bees exist before assuming their ultimate form, I shall
here subjoin my own observations on the point.
The worm of workers passes three days in the egg, five in the vermicular
state, and then the bees close up its cell with a wax covering. The worm
now begins spinning its coccoon, in which operation thirty-six hours are
consumed. In three days, it changes to a nymph, and passes six days in
this form. It is only on the twentieth day of its existence, counting
from the moment the egg is laid, that it attains the fly state.
The royal worm also passes three days in the egg, and is five a worm;
the bees then close its cell; and it immediately begins spinning the
coccoon, which occupies twenty-four hours. The tenth and eleventh day it
remains in complete repose, and even sixteen hours of the twelfth. Then
the transformation to a nymph takes place, in which state four days and
a third are passed. Thus it is not before the sixteenth day that the
perfect state of queen is attained.
The male worm passes three days in the egg, six and a half as a worm,
and metamorphoses into a fly on the twenty-fourth day after the egg is
laid.
Though the larvæ of bees are apodal, they are not condemned to absolute
immobility in their cells; for they can move by a spiral motion. During
the first three days, this motion is so slow as scarcely to be
perceptible, but it afterwards becomes more evident. I have then
observed them perform two complete revolutions in an hour and three
quarters. When the period of transformation arrives, they are only two
lines from the orifice of the cells. As their position is constantly the
same, bent in an arc, those in the workers' and drones' cells are
perpendicular to the horizon, while those in the royal cells lie
horizontally. It might be thought, that the difference of position has
much influence on the increment of the different larvæ; yet it has none.
By reversing combs containing common cells full of brood, I have put the
worms in a horizontal position; but they were not injured. I have also
turned the royal cells, so that the worms came into a horizontal
direction; however their increment was neither slower nor less perfect.
* * * * *
I have been much surprised at the mode of bees spinning their coccoons,
and I have witnessed many new and interesting facts. The worms both of
workers and males fabricate _complete_ coccoons in their cells; that
is, close at both ends, and surrounding the whole body. The royal larvæ,
on the other hand, spin imperfect coccoons, open behind, and enveloping
only the head, thorax, and first ring of the abdomen. The discovery of
this difference, which at first may seem trifling, has given me extreme
pleasure, for it evidently demonstrates the admirable art with which
nature connects the various characteristics in the industry of bees.