BEE-spoke-data/bees-v0 huggingface dataset:
On the 19th we released a virgin queen four days old. She flew twice, the second absence, longer than the first, lasted thirty-six minutes; she returned with the signs of levendation. We wanted to secure in their entirety the parts which the drone had left in her vulva; for this purpose it was necessary to prevent her from breaking them by drawing them out with her claws: after having killed her as promptly as we could, we cut open her last rings to uncover the vulva; but in depriving her of life we had not deprived her of motion; there was so much of this in these parts that the lenticular body dropped out spontaneously, and the part which we were interested in was broken as it had been the previous time; we were thus compelled to repeat the test: I will give only the results of this.
In several instances, when we separated the lenticular body from the orifice of the vagina, against which it was pressed, we found with it a white body which adhered to it by one of its extremities; the other being engaged in the excretory canal of the eggs.
This body appeared cylindrical at its end near the lentil; it became enlarged farther along, then shrunk and again enlarged more than at first; it thus formed a sort of acorn, after which it terminated in a sharp point.
These details were not perceptible with the naked eye, a magnifying glass was needed to perceive them.
The shape of this body and its position seemed to indicate that it was the special male organ, of which the lenticular body was only an appendix; but the last queen that we had under our control destroyed this conjecture.
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On the 20th, we liberated two virgin queens: the first one had already taken flight the previous days, but had not been fecundated; we seized her upon her return; her vulva was open and the lentil of the drone appeared between its lips: we wanted to prevent her from getting rid of it, but she removed it with her legs so quickly that we could not forestall her, and we allowed her to re-enter the hive.
The second queen liberated flew twice; her first absence was as short as usual: the second lasted about a half hour; she returned fecundated, and we caught her at her arrival. We opened her promptly after having killed her. We found the lenticular body placed as in all the queens observed before: its pinecrs penetrated to the base of the vulva; the dull points which terminate them appeared to be implanted under the exeretory canal of the eggs; they pressed between them some parts which their infinitely small size did not permit us to distinguish: the resistance which they offered, in trying to loosen them, convinced us that these hooks serve to bring the end of the lentil against the orifice of the vagina and to hold it there. Through this precaution, of which we see examples in other insects, as the drone and the queen cannot pull apart until the requirements of nature are accomplished, the success of their union is assured.
Before disturbing these parts, we placed them under the lens of the microscope: we then saw a peculiarity which had escaped our observation: when drawing back the lenticular body, there emerged from the vagina a small body (figure 2 v), adhering to the posterior end of the lentil and located under the scaly plates. It drew back of itself within the lentil, like the horns of a snail. This part is very short, white and apparently cylindrical: there was, under the plates, a little of the seminal fluid half clotted at the bottom of the vulva. Looking farther in the vagina, we did not find any other hard substances: we pressed out much sperm: it was almost liquid, but soon elotted and became a shapeless whithish mass. This careful observation put an end to our doubts and convinced us that what we had mistaken for the characteristic organ of the drone was the semen itself which had clotted in the interior of the vagina and assumed the shape of the latter.
Thus, the only hard part that the male had introduced within the vagina of the female was this short cylindrical point which had withdrawn into the lentil when we had drawn it out. Its action and situation prove that it is there that we must seek the escape of the seminal liquid, if it is possible to find it open at any other time than during the mating.
We sought this new part in the drones and found it in the first one dissected; by pressing the seminal vesicles s s, figure 1, from above, we forced the white liquid with which they were filled to flow and run down into the root of the penis r, and into the lenticular body l, l, which was then considerably enlarged. We prevented this liquid from flowing back, and forced it forward by a renewed pressure. However, the liquid did not flow out when we pressed the lentil, but we saw, at its posterior end and under the scaly plates, a small white body, short, cylindrical and with the same appearance as that which we had found in the vagina of the queen. When we ceased to press the lentil, this part re-entered it, but reappeared every time that we pressed it.
I ask you, Sir, when you read this letter, to glance at the figure which Mr. de Reaumur has published of the sexual organs of the drones, and which I caused to be copied (Plate II); the descriptions that accompany it appear quite correct, and give a proper idea of the position of these parts. Upon examination of these figures one easily conceives the appearance which they present within the vulva of the female, when they are implanted in it after mating.
The details which I have exposed, help to fix the idea of the reader and sufficiently indicate the shape and position of the organ which I discovered and which must be considered as the penis of the male bee, of which the lentil must be only an appendix.
I have no doubt that the drones perish when they lose their sexual organs after mating. While reflecting one day upon the discovery which is the subject of this letter and upon the impossibility of witnessing a mating which takes place in the air, it seemed to us that one could add another proof to those that we had, if one could find the male which had fecundated one of our queens and catch him on his return; but we could hope for this only in case he did not die suddenly after mating, and if he had time to return to the hive.
Burnens thought that it would be easy to distinguish such a male from those that die without having mated and without having suffered any mutilation. So he condemned himself to examine, one after another, all the drones that he would find dead near the hives during the swarming season.
After long and useless researches, he found a few that had died in front of the hives and were evidently mutilated, for they had lost those of the genital parts that remain within the body of the queens. The root of the penis had protruded out of their body after mating, a piece of this canal ten or twelve lines long was hanging at the extremity of their belly and had dried there. None of the parts which pressure may force out showed itself in that case.
These observations, made with greatest care, confirmed the conjecture which I had already stated, that is: that no other part than the penis and its appendages extrudes from the body of the male during mating. They proved also that the males perish after having lost their sexual parts, and that their death is not as prompt as one might have expected.
By coming back to die at the front of the hive, they bring back, as the queen does, the evidence of their union and of a long unknown fact.
But for what reason has nature required from the drone so great a sacrifice? It is a mystery which I will not attempt to penetrate. I do not know of any similar fact in the history of animals; but as there are two kinds of insects whose mating can only take place in the air, the ephemerids and the ants, it would be very interesting to learn whether their males also
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lose their sexual organs in those circumstances, and whether, while making love upon the wing, like drones, the enjoyment of it is also for them a harbinger of death?
Accept the assurance of my respect, &c.
May 29th.
N. B. I have not observed the matings of ephemerids, but Mr. Degers who has witnessed them, does not speak of the males as being mutlated. So remarkable a circumstance could not have escaped him.
As to the ants, their drones lose so small a part of their sexual organs, that they are able to recundate several females in succession, and I have made sure of this through repeated observations.
_Continuation of the same subject. Observations on queen-bees whose recundation is delayed._
Pregny, August 21, 1791.
Sir, I wrote you in my first letter that when the young queens were not permitted to mate until the twenty-fifth or thirtieth day after their birth, the result of this feecundation presented some very interesting pecu-
liarittes. I did not then give you the detail of these, because, at the time when I had the honor of writing you my experiments upon this subject had not been sufficiently multiplied. I have repeated them so many times since, and their results have been so uniform, that I am not afraid of announcing to you, as a positive discovery, the singular effect that retarded foundation produces upon the ovaries of the queen. When a queen is mated within the first fifteen days of her life, she becomes able to lay worker or drone eggs; but if her feecundation is delayed up to the twenty-second day, her ovaries become vicitated so that she will be unable to lay worker eggs; she will lay only male eggs.
I was occupied with researches relative to the formation of swarms, when I had, for the first time, occasion to observe a queen that laid only drone eggs. It was in June, 1787. I had found out that, when a colony is ready to swarm, the time of issue is always preceded by a very lively agitation, which first affects the queen, is then communicated to the workers, and excites among them so great a tumult that they abandon their labors and issue in disorder through all the entrances of the hive. I then knew well the cause of the queen's agitation (I will describe it in the history of swarms); but I was still ignorant how this delirium is communicated to the workers and this difficulty interrupted my work. To solve it, I thought of seeking, by direct experiments, whether when the queen was greatly agitated, even at other times than that of swarming, her agitation would be communicated similarly to the workers. I enclosed a queen in a hive, at the time of her birth, and prevented her issuing, by contracting the entrances in such a manner that they would be too narrow for her. I had no doubt that she would make great efforts to escape, whenever she would feel the imperious desire of joining the males, and that this impossibility
### New observations upon bees.
might throw her into a kind of delirium. Burnens had the patience of observing this captive queen for thirty-five days. Every morning, towards 11 o'clock, when the sunshine invited the males to issue from the hives, he saw her traverse every corner of her habitation seeking an issue: but as she found none, her useless efforts threw her each time into an extraordinary agitation, the symptoms of which I shall describe elsewhere, and by which all the common bees were affected.
During the course of this long imprisonment, the queen did not go out a single time, she could not then be feecundated. On the thirty-sixth day, I at last set her at liberty; she quickly took advantage of it and soon returned with the most evident marks of feecundation. Satisfied with the success of this experiment for the particular object I had proposed, I was far from hoping that she would supply me also with the knowledge of a remarkable fact. How great was my surprise, when I found that this female, which began to lay, as usual, forty-six hours after mating, did not lay worker eggs, but only drone eggs, and that she continued, afterwards, to lay only this kind of eggs!
At first, I exhausted myself in conjectures upon this singular fact; but the more I reflected on it, the more did it seem inexplicable. At last, by attentively meditating on the circumstances of this experiment, it appeared to me that there were two points which I should try to weigh separately. On the one hand, this queen had suffered from long imprisonment; on the other hand, her fecundation had been extremely retarded. You know, sir, that queen-bees usually have commerce with a male on the fifth or sixth day after their birth, and this one had not mated until the thirty-sixth day. I do not put great weight upon the supposition that this imprisonment had been the cause of this result. In natural conditions queen-bees fly out only to seek the males, a few days after birth: during the remainder of their life, excepting for the departure of swarms, they remain voluntary prisoners: it was therefore unlikely that captivity should have produced the result which I was trying to elucidate. However, as one must neglect nothing in so new a subject, I desired to ascertain whether it was the length of confinement or retarded fecundation which brought about the singularity which I had observed in the laying of this queen.
But this was not an easy task. To discover whether captivity, and not retarded fecundation, had vitiated the ovaries of the queen, it would have been necessary to allow a queen to mate, while retaining her a pris-oner; this could not be done since queen-bees never mate inside of the hive. For the same reason it was impossible to delay her mating without keeping her a prisoner. I was long embarrassed by this difficulty: at last I devised an apparatus which was not exactly what I wanted, but which filled the purpose fairly.
I took a queen, at the end of her metamorphosis; I placed her within a well supplied hive, stocked with a sufficient number of workers and males. I contracted the entrance, so that it would be too narrow for the queen, but wide enough to give the workers free passage. At the same time, I made another opening for the passage of the queen and adapted to it a glass tube communicating with a large glass box measuring eight feet on each face. The queen could at all times come to this box, fly about and sport, breath
## Chapter THIRD LETTER.
ing a better air than within the hive, in which nevertheless she could not be decundated; for, although the males could also fly within this enclosure, the space was too limited for any mating between them. You know, sir, that the experiences which I have related to you show that the mating takes place only high in the air. I therefore found in this apparatus the advantage of retarding decundation, while the queen had sufficient liberty that her condition of life was not too remote from the natural state. I followed this experiment for fifteen days. The captive female emerged from her hive every morning, when the weather was nice; she sported in her glass prison, and flew about with ease and much motion. She did not lay during this time, for she had no connection with a male. At last, on the sixteenth day, I set her at liberty: she flew from the hive, rose into the air and came back with all the signs of decundation. Two days afterwards she began laying: her first eggs were worker eggs and from that time on, she laid as much as the most fertile queens.
It thence follows, first, that captivity does not alter the organs of queen-bees.
Second. That when decundation takes place within the first sixteen days after their birth, they lay eggs of both sorts.
This first experiment was important; it rendered my task more simple, by pointing out to me clearly the method to be pursued; it absolutely precluded the supposed influence of captivity and left nothing to seek but the effects of a longer delayed decundation.
For this purpose, I repeated the previous experiment; but instead of giving her liberty to the virgin on the sixteenth day, I detained her until the twenty-first day; she flew then, rose in the air, was decundated and returned to her home. Forty-six hours afterwards, she began to lay, but it was male eggs, and although very prolific, she never laid any other kind. During the remainder of the year 1787, and the two following years, I occupied myself with experiments on retarded decundation and constantly had the same results. It is therefore true that, when the mating of queen-bees is delayed beyond the twentieth day, there is but a semi-recundation, if one may thus call it: for instead of laying both worker eggs and male eggs, those queens lay male eggs only.
I do not aspire to the honor of explaining this strange fact. When the continuation of my observations on bees made known to me the fact that there are sometimes queens that lay only drone eggs, I sought for the proximate cause of this singularity, and ascertained that it was due to retarded decundation. The proof that I acquired is demonstrative, for I can always prevent queens from laying worker eggs by delaying their decundation until the twenty-second or twenty-third day. But what is the remote cause of this fact, or in other words, why does retarded decundation prevent queens from laying worker eggs? It is a problem upon which analogy throws no light; in all the physiological history of animals I do not know of any observation bearing the least similarity to it.
This problem appears still more difficult, when we know how things happen in natural circumstances, that is, when decundation has not been delayed. The queen then lays worker eggs 46 hours after mating and continues, for the space of 11 months, to lay almost only these. It is usually only at the end of these 11 months that she begins a considerable and uninterrupted laying of eggs of drones.' When, on the contrary, feecundation is retarded beyond the 20th day, the queen begins to lay drone eggs from the 46th hour, in considerable numbers, and never lays any others during her entire life. Since she lays only worker eggs, during the first 11 months in a natural condition, it is clear that the worker eggs and the drone eggs are not indiscriminately mixed in her oviducts: doubtless they occupy a situation corresponding to the laws that regulate her laying: those of workers are first, those of drones are behind them; it appears that the queen cannot lay drone eggs until she has discharged all the worker eggs that occupy first place in her oviducts. Why then is this order inverted by retarded impregnation? How does it happen that all the worker eggs that the queen should have laid, if fecundated in time, are withered and disappear, without obstructing the passage of the drone eggs, which occupy only second place in the ovaries?
This is not all: I ascertained that a single mating is sufficient to fertilize all the eggs that a queen will lay in the course of two years at least: I have even reason to believe that this single act of fecundation is sufficient for the fertilization of all the eggs that she will lay during her life, but I have full evidence only for the two years. This fact, which is already very remarkable in itself, renders the influence of retarded fecundation still more difficult to conceive. Since a single mating is sufficient, it is clear that the masculine liquid acts from the first moment upon the eggs that the queen is to lay for two years. According to your principles, sir, it gives them that degree of _animation_ which afterwards determines their successive development; after having received this first impulse of life, they grow, ripen, so to speak, progressively, until the day when they will be laid: and as the laws of laying are invariable, as the eggs laid during the first 11 months are always eggs of workers, it is clear that those eggs, whlch are to appear first, are also the first to mature; thus in the natural state, the space of 11 months is necessary for the male eggs to acquire the growth which they must have at the time they are laid. This consequence which seems to me direct, renders the problem insoluble in my eyes. How can the male eggs which must grow slowly during 11 months, acquire at once their full development in the space of 48 hours, when fecundation has been retarded beyond 21 days, and by the effect of this delay alone? Observe, I beg you, that the supposition of the successive growing of eggs is not gratuitous: it is upon the principles of sound physics: besides, to be convinced that it is well founded, it is only necessary to glance at the figure given by Swammerdam of the ovaries of the queen: we see there that the eggs in that part of the oviduct contiguous to the vulva of the queen, are much farther advanced, larger than those contained in the part more remote of the same oviduct. The difficulty which I mention remains therefore in full force. It is an abyss wherein I am lost.
The only known fact which seems to have a semblance of connection with those just mentioned is the state in which some vegetable seeds are found, which, although outwardly in good preservation, lose the faculty of germinating, through age; it might be, similarly, that the eggs of workers retain for only a short time the property of being decundated by the seminal liquid, and that, after this period, which might be fifteen or eighteen days, they may be so disorganized as to be no longer susceptible of being animated by this liquid. I realize, sir, that this comparison is very imperfect; and besides that it explains nothing; it does not even put us in the way of making any new experiments; I will add but one reflection.
Up to this time, no effects had ever been observed of retarded fecundation upon the females of animals, excepting its rendering them absolutely sterile. The queen-bees offer us the first example of a female upon which this delay still leaves the faculty of engendering males. As no fact is unique in nature, it is very probable that we should find the same peculiarity in some other animals. So it would be a very curious object of research to observe insects under this new point of view. I say insects, for I do not conceive that anything similar would be found in other species of animals. It would even be necessary to begin these experiments upon the insects most analogous to bees, such as wasps, woolly bumblebees, mason bees, all kinds of flies, etc. Some experiments might afterwards be made upon butterflies; finding perhaps some animal upon which retarded fecundation would produce the same effect as upon bees. If this animal were of a greater size than the bees, dissection would be easier, and we could discern what happens to the eggs, whose retarded fecundation prevents their development. At least we might hope that some fortunate circumstance would lead us to the solution of the problem.8
I now return to the reeital of my experiments.
In May 1789, I took two queens at the time when they were going through their last metamorphosis; I placed one of them in a leaf hive, well stocked with honey and wax, and sufficiently peopled with workers and males. The other was placed in a similar hive from which all the drones had been removed. I arranged the entrances of these hives for the freedom of the worker bees, but too narrow for the passage of females and drones. I kept those queens prisoners for 30 days. After that time, I liberated them. They departed eagerly and came back decundated. In the beginning of July, I examined the two hives and found much brood: but this consisted entirely in worms and nymphs of males; there was not a single nymph, not a single worm, of a worker. Both queens laid without interruption until autumn, and uniformly eggs of drones. Their laying ended during the first fortnight of November, as did that of the queens of my other colonies. I was very desirous of ascertaining what would become of them in the ensuing spring; whether they would resume their laying, whether a new fecundation would be necessary, and, in case they should lay, of what sort their eggs would be; but as their hives were already much weakened