L Edit. 4to, Tom. V. p. 258.
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.
You will remember, Sir, the evidence I gave you of the mutual aversion of queens, of the combats in which they engage, and the animosity that leads them to destroy one another. Of several royal nymphs in a hive, the first transformed attacks the rest, and stings them to death. But were these nymphs enveloped in a complete coccoon, she could not accomplish it. Why? because the silk is of so close a texture, the sting could not penetrate, or if it did, the barbs would be retained by the meshes of the coccoon, and the queen, unable to retract it, would become the victim of her own fury. Thus, that the queen might destroy her rivals, it was necessary the last rings of the body should remain uncovered, therefore the royal nymphs must only form imperfect coccoons. You will observe, that the last rings alone should be exposed, for the sting can penetrate no other part: the head and thorax are protected by connected shelly plates which it cannot pierce.
Hitherto, philosophers have claimed our admiration of nature in her care of preserving and multiplying the species. But from the facts I relate, we must admire her precautions in exposing certain individuals to a mortal danger.
The detail on which I have just entered clearly indicates the final cause of the opening left by the royal worms in their coccoons; but it does not shew whether it is in consequence of a particular instinct that they leave this opening, or whether the wideness of their cells prevents them from stretching the thread up to the top. This question interested me very much; the only method of deciding it was to observe the worms while spinning, which cannot be done in their opaque cells. It then occurred to me to dislodge them from their own habitations, and introduce them into glass tubes, blown in exact imitation of the different kind of cells. The most difficult part of the operation consisted in extracting worms and introducing them here; but my assistant accomplished it with much address. He opened several sealed royal cells, where we knew the larvæ were about to begin their coccoons, and, taking them gently out, introduced one into each of my glass cells without the smallest injury.
They soon prepared to work; and commenced by stretching the anterior part of the body in a straight line, while the other was bent in a curve. This formed a curve of which the longitudinal sides of the cells were tangents, and afforded two points of support. The head was next conducted to the different parts of the cell which it could reach, and it carpeted the surface with a thick bed of silk. We remarked that the threads were not carried from one side to another, and that this would have been impracticable, for the worms being obliged to support themselves, and to keep the posterior rings curved, the free and moveable part of the body was not long enough for the mouth to reach the sides diametrically opposite, and fix the threads to them. You will remember, Sir, that the royal cells are of a pyramidal form, with a wide base, and a long contracted top. These cells hang perpendicularly in the hive, the point downwards, from which position the royal worm can be supported in the cell, only when the curvature of the posterior part forms two points of support; and that it cannot obtain this support without resting on the lower part, or towards the extremity. Therefore if it attempted to stretch out and spin towards the wide end of the cell, it could not reach both sides from being too distant. One part would be touched by its extremity, the other by its back, and it would consequently tumble down. I have particularly ascertained the fact in glass cells that were too large, and of which the diameter was greater towards the point than is usual in cells; there they were unable to support themselves.
These first experiments obviated the suspicion of any particular instinct in the royal worms. They proved, if the worms spun incomplete coccoons, it was because they were forced to do so by the figure of their cells. However, I wished to have evidence still more direct. I put them into cylindrical glass cells, or portions of glass tubes resembling common cells, and I had the satisfaction of seeing them spin complete coccoons, as the worms of workers do. Lastly, I put common worms in very wide cells, and they left the coccoon open. Thus it is demonstrated, that the royal worms, and those of workers, have the same instinct and the same industry, or in other words, when situated in the same circumstances, the course they follow is the same. I may here add, that the royal worms artificially lodged in cells, where they can spin complete coccoons, undergo all their metamorphoses equally well. Thus the necessity imposed on them by nature, of having the coccoons open, is not necessary for their increment; nor has it any other object than that of exposing them to the certainty of perishing by the wounds of their natural enemy; an observation new and truly singular.
I ought to relate my experiments on the influence that the size of the cells has on bees. It is to you, Sir, that I am indebted for suggesting them.
As we sometimes find males smaller than they ought to be, and also queens more diminutive than usual, it was desirable to obtain a general explanation, to what degree the cells, where bees pass the first period of their existence, influence their size. With this view, you have advised me to remove all the combs composed of common cells, and to leave those consisting of large cells only. It was evident if the common eggs which the queen would lay in these large cells produced workers of larger size, we were bound to conclude that the size of the cells had a sensible influence on the size of the bees. The first time I made this experiment, it did not succeed, because weevils lodged in the hive discouraged the bees. But I repeated it afterwards, and the result was very remarkable.
I removed the whole comb, consisting of common cells, from one of my best glass hives, and left that composed of males' cells alone: and to avoid vacuities, I supplied others of the same kind. This was in June, the season most favourable to bees. I expected that the bees would quickly have repaired the ravages produced by this operation in their dwelling; that they would labour at the breaches, and unite the new combs to the old. But I was very much surprised to see that they did not begin to work. Expecting they would resume their activity, I continued observing them several days; however, my hopes were disappointed. Their homage to the queen was not interrupted indeed; but except in this, their conduct to the queen was quite different from what it usually is; they clustered on the combs without exciting any sensible heat. A thermometer among them rose only to 81°, though standing at 77° in the open air. In a word, they appeared in a state of the greatest despondency.
The queen herself, though very fertile, and though she must have been oppressed by her eggs, hesitated long before depositing them in the large cells; she chose rather to drop them at random than lay in cells unsuitable. However, on the second day, we found six that had been deposited there with all regularity. The worms were hatched three days afterwards, and then we began to study their history. Though the bees provided them with food, they did not carefully attend to it; yet I was in hopes they might be reared. I was again disappointed; for next morning all the worms had disappeared, and their cells were left empty. Profound silence reigned in the hive; few bees left it, and these returned without pellets of wax on the limbs; all was cold and inanimate. To promote a little motion, I thought of supplying the hive with a comb, composed of large cells, full of male brood of all ages. The bees, which had twelve days obstinately refused working in wax, did not unite this comb to their own. However, their industry was awakened in a way that I had not anticipated. They removed all the brood from this comb, cleaned out the whole cells, and prepared them for receiving new eggs. I cannot determine whether they expected the queen to lay, but it is certain if they did so they were not deceived. From this moment, she no longer dropped her eggs; but laid such a number in the new comb, that we found five or six together in the same cell. I then removed all the combs composed of large cells to substitute small cells in their place, an operation which restored complete activity among the bees.
The peculiarities of this experiment seem worthy of attention. It proves that nature does not allow the queen the choice of the eggs she is to lay. It is ordained that, at a certain time of the year, she shall produce those of males, and at another time the eggs of workers, and this order cannot be inverted. We have seen that another fact led me to the same consequence; and as that was extremely important, I am delighted to have it confirmed by a new observation. Let me repeat, therefore, that the eggs are not indiscriminately mixed in the ovaries of the queen, but arranged so that, at a particular season, she can lay only a certain kind. Thus, it would be vain at that time of the year, when the queen should lay the eggs of workers, to attempt forcing her to lay male eggs, by filling the hives with large cells; for, by the experiment just described, we learn, that she will rather drop the workers eggs by chance than deposit them in an unsuitable place; and that she will not lay the eggs of males. I cannot yield to the pleasure of allowing this queen discernment or foresight, for I observe a kind of inconsistency in her conduct. If she refused to lay the eggs of workers in large cells, because nature has instructed her that their size is neither proportioned to the size nor necessities of common worms, would not she also have been instructed not to lay several eggs in one cell? It seems much easier to rear a worker's worm in a large cell, than to rear several of the same species in a small one. Therefore, the supposed discrimination of bees is not very conspicuous. Here the most prominent feature of industry appears in the common bees. When I supplied them with a comb of small cells, full of male brood, their activity was awakened; but instead of bestowing the necessary care on this brood, as they would have done in every other situation, they destroyed the whole nymphs and larvæ, and cleaned out their cells, that the queen, now oppressed with the necessity of laying, might suffer no delay in depositing her eggs. Could we allow them either reason or reflection, this would be an interesting proof of their affection for her.
The experiment, now detailed at length, not having fulfilled my object in determining the influence of the size of the cells on that of the worms, I invented another which proved more successful.
Having selected a comb of large cells, containing the eggs and worms of males, I removed all the worms from their farina, and my assistant substituted those of workers a day old in their place. Then he introduced this comb into a hive that had the queen. The bees did not abandon these substituted worms; they covered their cells with a top almost flat, a kind quite different from what is put on the cells of males; which proves, that they were well aware that these, though inhabiting large cells, were not males. This comb remained eight days in the hive, counting from the time the cells were sealed. I then removed it to examine the included nymphs, which proved those of workers in different stages of advancement; but, as to size and figure, they perfectly resembled what had grown in the smallest cells. I thence concluded, that the larvæ of workers do not acquire greater size in large than in small cells. Although this experiment was made only once, it seems decisive. Nature has appropriated cells of certain dimensions for the worms of workers while in their vermicular state; undoubtedly she has ordained that their organs should be fully expanded, and there is sufficient space for that purpose; therefore more would be useless. Their expansion ought to be no greater in the most spacious cells than in those appropriated for them. If some cells smaller than common ones are found in combs, and the eggs of workers are deposited there, the size of the bees will probably be less than that of common workers, because they have been cramped in the cells; but it does not thence ensue, that a larger cell will admit of them growing to a greater size.
The effect produced on the size of drones by the size of the cells their worms inhabit, may serve as a rule for what should happen to the larvæ of workers in the same circumstances. The large cells of males are sufficiently capacious for the perfect expansion of their organs. Thus, although reared in cells of still greater capacity, they will grow no larger than common drones. We have had evidence of this in those produced by queens whose fecundation has been retarded. You will remember, Sir, that they sometimes lay male eggs in the royal cells. Now, the males proceeding from them, and reared in cells much more spacious than nature has appropriated for them, are no larger than common males. Therefore it is certain, that whatever be the size of the cells where the worms acquire their increment, the bees will attain no greater size than is peculiar to their species. But if, in their primary form, they live in cells smaller than they should be, as their growth will be checked, they will not attain the usual size, of which there is proof in the following experiment. I had a comb consisting of the cell of large drones, and one with those of workers, which also served for the male worms. Of these, my assistant took a certain number from the smallest cells, and deposited them on a quantity of food purposely prepared in the large ones; and in return he introduced into the small cells the worms that had been hatched in the other, and then committed both to the care of the workers in a hive where the queen laid the eggs of males only. The bees were not affected by this change; they took equal care of the worms; and when the period of metamorphosis arrived, gave both kinds that convex covering usually put on those of the males. Eight days afterwards, we removed the combs, and found, as I had expected, nymphs of large males in the large cells, and those of small males in the small ones.
You suggested another experiment which I carefully made, but it met with an unforeseen obstacle. To appreciate the influence of the royal food on the expansion of the worms, you desired me to supply the worm of a worker in a common cell with it. Twice I have attempted this operation without success. Nor do I think it can ever succeed. If bees get the charge of worms, in whose cells the royal food is deposited, and if at the same time they have a queen, they soon remove the worms and greedily devour the food. When, on the contrary, they are deprived of a queen, they change the cells containing worms into cells of the largest kind. Then the worms will infallibly be converted to queens.
But there is another situation where we can judge of the influence of the royal food administered to worms in common cells. I have spoken at great length in my letter on the existence of fertile workers. You cannot forget, Sir, that the expansion of their sexual organs is owing to the reception of some particles of royal jelly, while in the vermicular form. For want of new observations, I must refer you to what is previously said on the subject.
Pregny, 4 September 1791.
I can add but a few facts to the information M. de Reaumur has communicated relative to swarms.
A young queen, according to this celebrated naturalist, is always or almost always at the head of a swarm; but he does not assert the fact positively, and had some doubts on the subject. "Is it certain," says he "as we have hitherto supposed, in coincidence with all who have treated of bees, that the new colony is always conducted by a young mother? May not the old mother be disgusted with her habitation? or may she not be influenced by some particular circumstances to abandon all her possessions to the young female? I wish it had been in my power to solve this question otherwise than by mere probabilities, and that some misfortune had not befallen all the bees whose queen I had marked red on the thorax."
These expressions seem to indicate, that M. de Reaumur suspected that the old queens sometimes conducted the young swarms. By the following details, you will observe, that his suspicions are fully justified.
In the course of spring and summer, the same hive may throw several swarms. The old queen is always at the head of the first colony; the others are conducted by young queens. Such is the fact which I shall now prove; and the peculiarities attending it shall be related.
But previous to entering on this subject, I should repeat what has already been frequently observed, that the leaf or flat hives are indispensible in studying the industry and instinct of bees. When they are left at liberty to conduct several rows of parallel combs, we can no longer observe what is continually passing between them, or they must be dislodged by water or smoke, for examining what has been constructed; a violent proceeding, which has a material influence on their instinct, and consequently exposes an observer to the risk of supposing simple accidents permanent laws.
I now proceed to experiments proving that an old queen always conducts the first swarm.
One of my glass hives consisted of three parallel combs, placed in squares that opened like the leaves of a book. It was well peopled and abundantly provided with honey, wax, and brood, of every age. On the fifth of May 1788, I removed the queen, and on the sixth, transferred all the bees into another hive, with a fertile queen at least a year old. They entered easily and without fighting, and were in general well received. The old inhabitants of the hive, which, since privation of their queen, had begun twelve royal cells, also gave the fertile queen a good reception; they presented her with honey, and formed regular circles around her. However, there was a little agitation in the evening, but confined to the surface of the comb where we had put the queen, and which she had not quitted. All was perfectly quiet on the other side of this comb.
In the morning of the seventh, the bees had destroyed the twelve royal cells, but, independent of that, order continued prevalent in the hive; the queen laid the eggs of males in the large cells, and those of workers in the small ones, respectively.
Towards the twelfth, we found the bees occupied in constructing twenty-two royal cells, of the same species described by M. de Reaumur, that is the bases not in the plane of the comb, but appended perpendicularly by pedicles or stalks of different length, like stalactites, on the edge of the passage made by the bees through their combs. They bore considerable resemblance to the cup of an acorn, and the longest were only about two lines and a half in depth from the bottom to the orifice.
On the thirteenth, the queen seemed already more slender than when introduced into the hive; however she still laid some eggs, both in common cells and those of males. We also surprised her this day laying in a royal cell: she first dislodged the worker there employed, by pushing it away with her head, and then supported herself by the adjoining cells while depositing the egg.
On the fifteenth, the queen was still more slender: the bees continued their attention to the royal cells, which were all unequally advanced; some to three or four lines in height, while others were already an inch long; which proved that the queen had not laid in the whole at the same time.
At the moment when least expected, the hive swarmed on the nineteenth; we were warned of it by the noise in the air; and hastened to collect and put the bees into a hive purposely prepared. Though we had overlooked the facts attending the departure of the swarm, the object of this experiment was fulfilled; for, on examination of all the bees, we were convinced they had been conducted by the old queen; by that we introduced on the sixth of the month, and which had been deprived of one of the antennæ. Observe, there was no other queen in this colony. In the hive she had left, we found seven royal cells close at the top, but open at the side, and quite empty. Eleven more were sealed; and some others newly begun; no queen remained in the hive.
The new swarm next became the object of our attention: we observed it during the rest of the year, during winter and the subsequent spring; and, in April, we had the satisfaction of seeing a new swarm depart with the same queen at its head that had conducted the former swarm in May the preceding year.
You will remark, Sir, that this experiment is positive. We put an old queen in a glass hive while laying the eggs of males. The bees received her well, and at that time began to construct royal cells; she laid in one of them before us; and in the last place led forth the swarm.
We have several times repeated the same experiment with equal success. Thus it appears incontestible, that the old queen always conducts the first swarm; but never quits the hive before depositing eggs in the royal cells, from which other queens will proceed after her departure. The bees prepare these cells only while the queen lays male eggs; and a remarkable fact attends it, that after this laying terminates, her belly being considerably diminished, she can easily fly, whereas, her belly is previously so heavy she can hardly drag it along. Therefore it is necessary she should lay in order to be in a condition for undertaking her journey, which may sometimes be very long.
But this single condition is not enough. It is also requisite that the bees be very numerous: they should even be superabundant, and a person might say they are aware of it: for, if the hive is thin, no royal cells are constructed when the male eggs are laid, which is solely at the period that the queen is able to conduct a colony. This fact was proved by the following experiment on a large scale.
On the third of May 1788, we divided eighteen hives into two portions; all the queens were about a year old. Thus each portion of the hives had but half the bees that were originally there. Eighteen halves wanted queens, but the other eighteen had very fertile ones. They soon began to lay the eggs of males; but, the bees being few, they did not construct royal cells, and none of the hives threw a swarm.—Therefore, if the hive containing the old queen is not very populous, she remains in it until the subsequent spring; and if the population is then sufficient, royal cells will be constructed: the queen will begin to lay male eggs, and, after depositing them, will issue forth at the head of a colony, before the young queens are produced.
Such is a very brief abstract of my observations on swarms conducted by old queens. You must excuse the long detail on which I am about to enter, concerning the history of the royal cells left by the queen in the hive. Every thing relative to this part of the history of bees has hitherto been very obscure. A long course of observations, protracted even during several years, was necessary to remove, in some degree, the veil that concealed these mysteries. I have been indemnified for the trouble, indeed, by the pleasure of seeing my experiments reciprocally confirmed; but, considering the assiduity required in these researches, they were truly very laborious.
Having established in 1788 and 1789, that queens a year old conducted the first swarm, and that they left worms or nymphs in the hive to transform into queens in their turn; I endeavoured, in 1790, to profit by the goodness of the spring, to study all that related to these young queens; and I shall now extract the chief experiments from my journal.
On the fourteenth of May, we introduced two portions of bees, from the straw hives, into a large glass hive very flat; and allowed them only one queen of the preceding year, and which had already commenced laying in its native hive. We introduced her on the fifteenth. She was very fertile. The bees received her well, and she soon began to lay in large and small cells alternately.
On the twentieth, we saw the formation of twelve royal cells, all on the edges of the communications, or passages through the combs, and shaped liked stalactites.
On the twenty-seventh, ten were much but unequally enlarged; but none so long as when the worms are hatched.
On the twenty-eighth, previous to which the queen had not ceased laying, her belly was very slender, and she began to exhibit signs of agitation. Her motion soon became more lively, yet she still continued examining the cells as when about to lay; sometimes introducing half her belly, but suddenly withdrawing it, without having laid. At other times she deposited an egg, which lay in an irregular position, on one side of the hexagon, and not fixed by an end to the bottom of the cell. The queen produced no distinct sound in her course, and we heard nothing different from the ordinary humming of bees. She passed over those in her way; sometimes when she stopped, the bees meeting her also stopped; and seemed to consider her. They advanced briskly, struck her with their antennæ, and mounted on her back. She then went on carrying some of the workers on her back. None gave her honey, but she voluntarily took it from the cells in her way. The bees no longer inclosed and formed regular circles around her. The first, aroused by her motions, followed her running in the same manner, and in their passage excited those still tranquil on the combs. The way the queen had traversed was evident after she left it, by the agitation created, which was never afterwards quelled: she had soon visited every part of the hive, and occasioned a general agitation; if some places still remained tranquil, the bees in agitation arrived, and communicated their motion. The queen no longer deposited her eggs in cells; she let them fall fortuitously: nor did the bees any longer watch over the young; they ran about in every different direction; even those returning from the fields, before the agitation came to its height, no sooner entered the hive than they participated in these tumultuous motions. They neglected to free themselves of the waxen pellets on their limbs, and ran blindly about. At last the whole rushed precipitately towards the outlets of the hive, and the queen along with them.
As it was of much consequence to see the formation of new swarms in this hive, and, for that reason, as I wished it to continue very populous, I removed the queen, at the moment she came out, that the bees might not fly too far, and that they might return. In fact, after losing their female, they did return to the hive. To increase the population still more, I added another swarm, which had come from a straw hive on the same morning, and removed its queen also.
All these facts were certain, and appeared susceptible of no error. Notwithstanding this, I was particularly earnest to learn whether old queens always followed the same course; which induced me, on the twenty-ninth, to replace, in the glass hive, the queen a year old, which had hitherto been the subject of my experiments, and had just began to lay the eggs of males. On the same day, we found one of the royal cells left by the preceding queen larger than the rest; and, from its length, supposed the included worm two days old: the egg had, therefore, been laid on the twenty-fourth by that queen, and the worm was hatched on the twenty-seventh. On the thirtieth, the queen laid a great deal in the large and small cells alternately. Now, and the two following days, the bees enlarged several royal cells, but unequally, which proved that they included larvæ of different ages. One was closed on the first of June, and on the second another. The bees also commenced some new ones. All was perfectly quiet at eleven in the morning; but, at mid-day, the queen, from the utmost tranquillity, became evidently agitated; and her agitation insensibly communicated to the workers in every part of their dwelling. In a few minutes they precipitately crowded to the entrances, and, along with the queen, left the hive. After they had settled on the branch of a neighbouring tree, I sought for the queen; thinking that, by removing her, the bees might return to the hive, which actually ensued. Their first care seemed to consist in seeking the female; they were still in great agitation, but gradually calmed; and in three hours complete tranquillity was restored.
They had resumed their usual occupations on the third: they attended to the young, worked within the open royal cells, and also watched on those that were shut. They made a waved work on them, not by applying wax cordons, but by removing wax from the surface. Towards the top this waved work is almost imperceptible; it becomes deeper above, and the workers excavate it still more from thence to the base of the pyramid. The cell, when once shut, also becomes thinner; and is so much so, immediately preceding the queen's metamorphosis from a nymph, that all its motions are perceptible through the thin covering of wax on which the waved work is founded. It is a very remarkable circumstance, that in making the cells thinner, from the moment they are closed, the bees know to regulate their labour so that it terminates only when the nymph is ready to undergo its last metamorphosis.
On the seventh day the coccoon is almost completely unwaxed, if I may use the expression, at the part next to the head and thorax of the queen. This operation facilitates her exit; for she has nothing to do but cut the silk that forms the coccoon. Most probably the object is, to promote evaporation of the superabundant fluids of the nymph. I have made some direct experiments to ascertain the fact, but they are yet unfinished. A third royal cell was closed by the bees on the same day, the third of June, twenty-four hours after closing the second. The like was done to other royal cells successively, during the subsequent days.
Every moment of the seventh, we expected the queen to leave the royal cell shut on the thirtieth of May. The seven days had elapsed. The waving of her cell was so deep, that what passed within was pretty perceptible; we could discern that the silk of the coccoon was cut circularly, a line and a half from the extremity; but the bees being unwilling that she should yet quit her cell, they had soldered the covering to it with some particles of wax. What seemed most singular was, that this female emitted a very distinct sound, or clacking from her prison. It was still more audible in the evening, and even consisted of several monotonous notes in rapid succession.
The same sound proceeded from the royal cell on the eighth. Several bees kept guard round each royal cell.
The first cell opened on the ninth. The young queen was lively, slender, and of a brown colour. Now, we understood why bees retain the female captive in their cells, after the period for transformation has elapsed; it is, that they may be able to fly the instant they are hatched. The new queen occupied all our attention. When she approached the other royal cells, the bees on guard pulled, bit her, and chased her away; they seemed to be greatly irritated against her, and she enjoyed tranquillity only when at a good distance from these cells. This procedure was frequently repeated through the day. She twice emitted the sound; in doing so she stood, her thorax against a comb, and the wings crossed on her back; they were in motion but without being unfolded or further opened. Whatever might be the cause of her assuming this attitude, the bees were affected by it; all hung down their heads, and remained motionless.
The hive presented the same appearances on the following day. Twenty-three royal cells yet remained, assiduously guarded by a great many bees. When the queen approached, all the guards became agitated, surrounded her on all sides, bit, and commonly drove her away; sometimes when in these circumstances, she emitted her sound, assuming the position just described, from that moment the bees became motionless.
The queen confined in the second cell had not yet left it, and was heard to hum several times. We accidentally discovered how the bees fed her. On attentive examination, a small aperture was perceptible in the end of the coccoon which she had cut to escape, and which her guards had again covered with wax, to confine her still longer. She thrust her trunk through the cleft; at first the bees did not observe it alternately thrust out and drawn in, but one at length perceiving it, came to apply its trunk to that of the captive queen, and then gave way to others that also approached her with honey. When satisfied she retracted her trunk, and the bees again closed up the opening with wax.
The queen this day between twelve and one became extremely agitated. The royal cells had multiplied very much; she could go no where without meeting them, and on approaching she was very roughly treated. Then she fled, but to obtain no better reception. At last, these things agitated the bees; they precipitately rushed through the outlets of the hive, and settled on a tree in the garden. It singularly happened that the queen was herself unable to follow or conduct the swarm. She had attempted to pass between two royal cells before they were abandoned by the bees guarding them, and she was so confined and maltreated as to be incapable of moving. We then removed her into a separate hive prepared for a particular experiment; the bees, which had clustered on a branch, soon discovered their queen was not present, and returned of their own accord to the hive. Such is an account of the second colony of this hive.
We were extremely solicitous to ascertain what would become of the other royal cells. Four of the close ones had attained complete maturity, and the queens would have left them had not the bees prevented it. They were not open either previous to the agitation of the swarms, or at the moment of swarming.
None of the queens were at liberty on the eleventh. The second should have transformed on the eighth; thus she had been three days confined, a longer period than the first which formed the swarm. We could not discover what occasioned the difference in their captivity.
On the twelfth, the queen was at last liberated, as we found her in the hive. She had been treated exactly as her predecessor; the bees allowed her to rest in quiet, when distant from the royal cells, but tormented her cruelly when she approached them. We watched this queen a long time, but not aware that she would lead out a colony, we left the hive for a few hours. Returning at mid-day, we were greatly surprised to find it almost totally deserted. During our absence, it had thrown a prodigious swarm, which still clustered on the branch of a neighbouring tree. We also saw with astonishment the third cell open, and its top connected to it as by a hinge. In all probability the captive queen, profiting by the confusion that preceded the swarming, escaped. Thus, there was no doubt of both queens being in the swarm. We found it so; and removed them, that the bees might return to the hive, which they did very soon.
While we were occupied in this operation, the fourth captive queen left her prison, and the bees found her on returning. At first they were very much agitated, but calmed towards the evening, and resumed their wonted labours. They formed a strict guard around the royal cells, and took great care to remove the queen whenever she attempted to approach. Eighteen royal cells now remained to be guarded.
The fifth queen left her cell at ten at night; therefore two queens were now in the hive. They immediately began fighting, but came to disengage themselves from each other. However they fought several times during the night without any thing decisive. Next day, the thirteenth, we witnessed the death of one, which fell by the wounds of her enemy. This duel was quite similar to what is said of the combats of queens.
The victorious queen now presented a very singular spectacle. She approached a royal cell, and took this moment to utter the sound, and assume that posture, which strikes the bees motionless. For some minutes, we conceived, that taking advantage of the dread exhibited by the workers on guard, she would open it, and destroy the young female; also she prepared to mount the cell; but in doing so she ceased the sound, and quitted that attitude which paralyses the bees. The guardians of the cell instantly took courage; and, by means of tormenting and biting the queen, drove her away.
On the fourteenth, the sixth young queen appeared, and the hive threw a swarm, with all the concomitant disorder before described. The agitation was so considerable, that a sufficient number of bees did not remain to guard the royal cells, and several of the imprisoned queens were thus enabled to make their escape. Three were in the cluster formed by the swarm, and other three remained in the hive. We removed those that had led the colony, to force the bees to return. They entered the hive, resumed their post around the royal cells, and maltreated the queens when approaching.
A duel took place in the night of the fifteenth, in which one queen fell. We found her dead next morning before the hive; but three still remained, as one had been hatched during night. Next morning we saw a duel. Both combatants were extremely agitated, either with the desire of fighting, or the treatment of the bees, when they came near the royal cells. Their agitation quickly communicated to the rest of the bees, and at mid-day they departed impetuously with the two females. This was the fifth swarm that had left the hive between the thirtieth of May and fifteenth of June. On the sixteenth, a sixth swarm cast, which I shall give you no account of, as it shewed nothing new.
Unfortunately we lost this, which was a very strong swarm; the bees flew out of sight, and could never be found. The hive was now very thinly inhabited. Only the few bees that had not participated in the general agitation remained, and those that returned from the fields after the swarm had departed. The cells were, therefore, slenderly guarded; the queens escaped from them, and engaged in several combats, until the throne remained with the most successful.
Notwithstanding the victories of this queen, she was treated with great indifference from the sixteenth to the nineteenth, that is, the three days that she preserved her virginity. At length, having gone to seek the males, she returned with all the external signs of fecundation, and was henceforth received with every mark of respect; she laid her first eggs forty-six hours after fecundation.
Behold, Sir, a simple and faithful account of my observations on the formation of swarms. That the narrative might be the more connected, I have avoided interrupting it by the detail of several particular experiments which I made at the same time for elucidating various obscure points of their history. These shall be the subject of future letters. For, although I have said so much, I hope still to interest you.
Pregny, 6. September 1791.
P. S.—In revising this letter, I find I have neglected taking notice of an objection that may embarrass my readers, and which ought to be answered.
After the first five swarms had thrown, I had always returned the bees to the hive: it is not surprising, therefore, that it was continually so sufficiently stocked that each colony was numerous. But things are otherwise in the natural state: the bees composing a swarm do not return to the hive; and it will undoubtedly be asked, What resource enables a common hive to swarm three or four times without being too much weakened?
I cannot lessen the difficulty. I have observed that the agitation, which precedes the swarming, is often so considerable, that most of the bees quit the hive, and in that case we cannot well comprehend how, in three or four days afterwards, it can be in a state to send out another colony equally strong.
But remark, in the first place, that the queen leaves a prodigious quantity of workers' brood, which soon transforms to bees; and in this way the population sometimes becomes almost as great after swarming as before it.
Thus the hive is perfectly capable of affording a second colony without being too much weakened. The third and fourth swarm weaken it more sensibly; but the inhabitants always remain in sufficient numbers to preserve the course of their labours uninterrupted; and the losses are soon repaired by the great fecundity of the queen, as she lays above an hundred eggs a day.
If, in some cases, the agitation of swarming is so great, that all the bees participate in it, and leave the hive, the desertion lasts but for a moment. The hive throws only during the finest part of the day, and it is then that the bees are ranging through the country. Those that are out, therefore, cannot share in the agitation; when returned to the hive, they quietly resume their labours; and their number is not small, for, when the weather is fine, at least a third of the bees are employed in the fields at once.
Even in the most embarrassing case, namely, where the whole bees desert the hive, it does not follow, that all those endeavouring to depart become members of the new colony. When this agitation or delirium seizes them, the whole rush forward and accumulate towards the entrance of the hive, and are heated in such a manner that they perspire copiously. Those near the bottom, and supporting the weight of all the rest, seem drenched in perspiration; their wings grow moist; they are incapable of flight; and even when able to escape, they advance no farther than the board of the hive, and soon return.
Those that have lately left their cells remain behind the swarm, still feeble, they could not support themselves in flight. Here then are also many recruits to people what we should have thought a deserted habitation.
To preserve greater regularity in continuing the history of swarms, I think it proper to recapitulate in a few words the principal points of the preceding letter, and to expatiate on each, concerning the result of new experiments, respecting which I have still been silent.
In the first place. If at the return of spring, we examine a hive well peopled, and governed by a fertile queen, we shall see her lay a prodigious number of male eggs in the course of May, and the workers will chuse that moment for constructing several royal cells of the kind described by M. de Reaumur. Such is the result of several long continued observations, among which there has not been the slightest variation, and I cannot hesitate in announcing it as demonstrated. However, I should here add the necessary explanation. It is necessary that the queen, before commencing her great laying of the eggs of males, be eleven months old; when young she lays only those of workers. A queen, hatched in spring, will perhaps lay fifty or sixty eggs of drones in whole, but before beginning her great laying of them, which should be two thousand in a month, she must have completed her eleventh month in age. In the course of our experiments, which more or less disturbed the natural state of things, it often happened that the queen did not attain this age until October, and immediately began laying male eggs. The workers, as if induced by some emanation from the eggs, also adopted this time for building the royal cells. No swarm resulted thence, it is true, because in autumn all the necessary circumstances are absolutely wanting, but it is not less evident, that there is a secret relation between the production of the eggs of males, and the construction of royal cells.
This laying commonly continues thirty days. The bees on the twentieth or twenty-first lay the foundation of several royal cells. Sometimes they build sixteen or twenty; we have even had twenty-seven. When the cells are three or four lines high, the queen lays those eggs from which her own species will come, but not the whole in one day. That the hive may throw several swarms, it is essential that the young females conducting them be not all produced at the same time. One may affirm, that the queen anticipates the fact, for she takes care to allow at least the interval of a day between every egg deposited in the cells. It is proved by the bees knowing to close the cells the moment the worms are ready to metamorphose to nymphs. Now, as they close all the royal cells at different periods, it is evident the included worms are not all of an equal age.
The queen's belly is very turgid before she begins laying the eggs of drones; but it sensibly decreases as she advances, and when terminated is very small. Thus she finds herself in a condition to undertake a journey which circumstances may prolong; thus this condition was necessary; and as every thing is harmonious in the laws of nature, the origin of the males corresponds with that of the females, which they are to fecundate.
Secondly. When the larvæ hatched from the eggs laid by the queen, in the royal cells, are ready to transform to nymphs, this queen leaves the swarm conducting a swarm along with her; and the first swarm that proceeds from the hive is uniformly conducted by the old queen.M I think I can divine the reason of it.
That there may never be a plurality of females in a hive, nature has inspired queens with a natural horror against each other; they never meet without endeavouring to fight, and to accomplish their mutual destruction. Thus, the chance of combat is equal between them, and fortune will decide to which the empire shall pertain. But if one combatant is older than the rest, she is stronger, and the advantage will be with her. She will destroy her rivals successively as produced. Thus, if the old queen did not leave the hive, when the young ones undergo their last metamorphosis, it could produce no more swarms, and the species would perish. Therefore, to preserve the species, it is necessary that the old queen conduct the first swarm. But what is the secret means employed by nature to induce her departure? I am ignorant of it.
In this country it is very rare, though not without example, for the swarm, led forth by the old queen, in three weeks to produce a new colony, which is also conducted by the same old queen; and that may happen thus. Nature has not willed that the queen shall quit the first hive before her production of male eggs is finished. It is necessary for her to be freed of them, that she may become lighter. Besides, if her first occupation, on entering a new dwelling, was laying more male eggs, still she might perish either from age or accident before depositing those of workers. The bees in that case would have no means of replacing her, and the colony would go to ruin.
All these things have been with infinite wisdom foreseen. The first operation of the bees of a swarm is to construct the cells of workers. They labour at them with great ardour, and as the ovaries of the queen have been disposed with admirable foresight, the first eggs she has to lay in her new abode are those of workers. Commonly her laying continues ten or eleven days; and at this time portions of comb containing large cells are fabricated. It may be affirmed, that the bees know their queen will also lay the eggs of drones; she actually does begin to deposit some, though in much smaller number than at first; enough however to encourage the bees to construct royal cells. Now, if in these circumstances the weather is favourable, it is not impossible that a second colony may be formed, and that the queen may depart at the head of it within three weeks of conducting the first swarm. But I repeat, the fact is rare in our climate. Let me now return to the hives from which the queen has led the first colony.
Thirdly. After the old queen has conducted the first swarm from the hive, the remaining bees take particular care of the royal cells, and prevent the young queens successively hatched from leaving them, unless at an interval of several days between each.
In the preceding letter, I have given you the detail and proof of this fact, and I shall here add some reflexions. During the period of swarming, the conduct or instinct of bees seems to receive a particular modification. At all other times, when they have lost their queen, they appropriate workers worms to replace her; they prolong and enlarge the cells of these worms; they supply them with aliment more abundantly, and of a more pungent taste; and by this alteration, the worms that would have changed to common bees are transformed to queens. We have seen twenty-seven cells of this kind constructed at once; but when finished the bees no longer endeavour to preserve the young females from the attacks of their enemies. One may perhaps leave her cell, and attack all the other royal cells successively, which she will tear open to destroy her rivals, without the workers taking any part in their defence. Should several queens be hatched at once, they will pursue each other, and fight until the throne remain with her that is victorious. Far from opposing such duels, the other bees rather seem to excite the combatants.
Things are quite reversed during the period of swarming. The royal cells then constructed are of a different figure from the former. They resemble stalactites, and in the beginning are like the cup of an acorn. The bees assiduously guard the cells when the young queens are ready for their last metamorphosis. At length the female hatched from the first egg laid by the old queen leaves her cell; the workers at first treat her with indifference. But she, immediately yielding to the instinct which urges her to destroy her rivals, seeks the cells where they are enclosed; yet no sooner does she approach than the bees bite, pull, and drive her away, so that she is forced to remove; but the royal cells being numerous, scarce can she find a place of rest. Incessantly harassed with the desire of attacking the other queens, and incessantly repelled, she becomes agitated, and hastily traverses the different groupes of workers, to which she communicates her agitation. At this moment numbers of bees rush towards the aperture of the hive, and, with the young queen at their head, depart to seek another habitation.
After the departure of the colony, the remaining workers set another queen at liberty, and treat her with equal indifference as the first. They drive her from the royal cells; being perpetually harrassed, she becomes agitated; departs, and carries a new swarm along with her. In a populous hive this scene is repeated three or four times during spring. As the number of bees is so much reduced, that they are no longer capable of preserving a strict watch over the royal cells, several females then leave their confinement at once; they seek each other, fight, and the queen at last victorious reigns peaceably over the republic.
The longest intervals we have observed between the departure of each natural swarm have been from seven to nine days. This is the time that usually elapses after the first colony is led out by the old queen, until the next swarm is conducted by the first young queen set at liberty. The interval between the second and third is still shorter; and the fourth sometimes departs the day after the third. In hives left to themselves, fifteen or eighteen days are usually sufficient for the throwing of the four swarms, if the weather continues favourable, as I shall explain.
A swarm is never seen except in a fine day, or, to speak more correctly, at a time of the day when the sun shines, and the air is calm. Sometimes we have observed all the precursors of swarming, disorder and agitation, but a cloud passed before the sun, and tranquillity was restored; the bees thought no more of swarming. An hour afterwards, the sun having again appeared, the tumult was renewed; it rapidly augmented; and the swarm departed.
Bees generally seem much alarmed at the prospect of bad weather. While ranging in the fields the passage of a cloud before the hive induces them precipitately to return. I am induced to think they are disquieted by the sudden diminution of light. For if the sky is uniformly obscured, and there is no alteration in clearness or in the clouds dispelling, they proceed to the fields for their ordinary collections, and the first drops of a soft rain does not make them return with much precipitation.
I am persuaded that the necessity of a fine day for swarming is one reason that has induced nature to admit of bees protracting the captivity of their young queens in the royal cells. I will not deny that they sometimes seem to use this right in an arbitrary manner. However the confinement of the queens is always longer when bad weather lasts several days together. Here the final object cannot be mistaken. If the young females were at liberty to leave their cradles during these bad days, there would be a plurality of queens in the hive, consequently combats; and victims would fall. Bad weather might continue so long, that all the queens might at once have undergone their last metamorphosis, or attained their liberty. One victorious over the whole would enjoy the throne, and the hive, which should naturally produce several swarms, could give only one. Thus the multiplication of the species would have been left to the chance of rain, or fine weather, instead of which it is rendered independent of either, by the wise dispositions of nature. By allowing only a single female to escape at once, the formation of swarms is secured. This explanation appears so simple, that it is superfluous to insist farther on it.
But I should mention another important circumstance resulting from the captivity of queens; which is, that they are in a condition to fly, when the bees have given them liberty, and by this means are capable of profiting by the first moment of sunshine to depart at the head of a colony.
You well know, Sir, that all drones and workers are not in a condition to fly for a day or two after leaving their cells. Then they are of a whitish colour, weak, and their organs infirm. At least, twenty-four or thirty hours must elapse before the acquisition of perfect strength, and the development of all their faculties. It would be the same with the females was not their confinement protracted after the period of transformation; but we see them appear, strong, full grown, brown, and in a better condition for flying than at any other period. I have elsewhere observed, that constraint is used to retain the queens in captivity. The bees solder the covering to the sides of the cell by a cordon of wax. As I have also explained how they are fed, it need not be repeated here.
It is likewise a very remarkable fact, that queens are set at liberty earlier or later according to their age. Immediately when the royal cells were sealed, we marked them all with numbers, and we chose this period because it indicated the age of the queens exactly. The oldest was first liberated, then the one immediately younger, and so on with the rest. None of the younger queens were set at liberty before the older ones.
I have a thousand times asked myself how the bees could so accurately distinguish the age of their captives. Undoubtedly I should do better to answer this question by a simple avowal of my ignorance. At the same time, I must be permitted to state a conjecture. You will admit, that I have not, as some authors, abused the right of giving myself up to hypothesis; may not the humming or sound emitted by the young queens in their cells, be one of the methods employed by nature to instruct the bees in the age of their queens? It is certain that the female, whose cell is first sealed, is also the first to emit this sound. That in the next emits it sooner than the rest, and so on with those immediately subsequent. As their captivity may continue six days, it is possible that the bees in this space of time may forget which has emitted it first; but it is also possible, that the queens diversify the sounds, encreasing the loudness as they become older, and that the bees can distinguish these variations. We have even ourselves been able to distinguish differences in the sound, either with relation to the succession of notes, or their intensity; and probably there are gradations still more imperceptible that escape our organs, but may be sensible to those of the workers.
What gives weight to this conjecture is, that the queens brought up by M. Schirach's method, are perfectly mute; neither do the workers form any guard around their cells, nor do they retain them in captivity a moment beyond the period of transformation, and, when they have undergone it, they are allowed to combat until one has become victorious over all the rest. Why? Because the object is only to replace the last queen. Now, provided that among the worms reared as queens, only one succeeds, the fate of the others is uninteresting to the bees, whereas, during the period of swarming, it is necessary to preserve a succession of queens, for conducting the different colonies; and to ensure the safety of the queens, it is necessary to avert the consequences of the mutual horror by which they are animated against each other. Behold the evident cause of all the precautions that bees, instructed by nature, take during the period of swarming; behold an explanation of the captivity of females; and that the duration of their captivity might be ascertained by the age of the young queens, it was requisite for them to have some method of communicating to the workers when they should be liberated. This method consists in the sound emitted, and the variation they are able to give it.
In spite of all my researches, I have never been able to discover the situation of the organ which produces the sound. But I have instituted a new course of experiments on the subject, which are still unfinished.
Another problem still remains for solution. Why are the queens reared, according to M. Schirach's method, mute, whilst those bred in the time of swarming have the faculty of emitting a certain sound? What is the physical cause of this difference? At first I thought it might be ascribed to the period of life, when the worms that are to become queens receive the royal food. While hives swarm, the royal worms receive the food adapted for queens, from the moment of leaving the egg; those on the contrary, destined for queens, according to M. Schirach's method, receive it only the second or third day of their existence. It appears to me that this circumstance may have an influence on the different parts of organisation, and particularly on the organ of voice. Experiment has not confirmed this conjecture. I constructed glass cells in perfect imitation of royal cells, that the metamorphosis of the worms into nymphs, and of the nymphs to queens, might be visible. These experiments are related in a preceding letter. Into one of these artificial cells we introduced the nymph of a worm, reared according to M. Schirach's method, twenty-four hours before it could naturally undergo its last metamorphosis; and we replaced the glass cell in the hive, that the nymph might have the necessary degree of heat. Next day, we had the satisfaction of seeing it divest itself of the spoil, and assume its ultimate figure. This queen was prevented from escaping from her prison; but we had contrived an aperture for her thrusting out her trunk, and that the bees might feed her. I expected that she would have been completely mute; but it was otherwise; for she emitted sounds similar to those already described, therefore my conjecture was erroneous.
I next conceived that the queen being restrained in her motions, and in her desire for liberty, was induced to emit certain sounds. All queens, in this new point of view, are equally capable of emitting the sound, but to induce them to it, they must be in a confined situation. In the natural state, the queens that come from workers are not a single instant in restraint; and, if they do not emit the sound, it is because nothing impels them to it. On the other hand, those produced at the time of swarming are induced to do so by the captivity in which they are kept. For my own part, I give little weight to this conjecture; and though I state it here, it is less with a view to claim merit than to put others on a plan of discovering something more probable.
I do not ascribe to myself the credit of having discovered the humming of the queen bee. Old authors speak of it. M. de Reaumur cites a Latin work published 1671, Monarchia Femina, by Charles Butler. He gives a very brief abstract of this naturalist's observations, who we easily see has exaggerated or rather disguised the truth, by mixing it with the most absurd fancies; but it is not the less evident that Butler has heard this peculiar humming of queens, and that he did not confound it with the confused humming sometimes heard in hives.
Fourthly. The young queens conducting swarms from their native hive are still in a virgin state. The day after, being settled in their new abode, they generally depart in quest of the males; and this is usually the fifth day of their existence as queens; for two or three pass in captivity, one in their native hive, and a fifth in their new dwelling. Those queens that come from the worm of a worker, also pass five days in the hive before going in quest of males. So long as in a state of virginity, both are treated with indifference by the bees; but after returning with the external marks of fecundation, they are received by their subjects with the most distinguished respect. However, forty-six hours elapse after fecundation before they begin to lay. The old queen, which leads the first swarm in spring, requires no farther commerce with the males, for preservation of her fecundity. A single copulation is sufficient to impregnate all the eggs she will lay for at least two years.