BEE-spoke-data/bees-v0 huggingface dataset:
I have repeated all my observations in hives of this shape and the results were exactly the same as in the thinnest hives. I thus believe that I have obviated all the objections that might be made upon the supposed inconveniences of my flat hives. Besides, I have no regret of having repeated all my work; by going over the same observations several times, I am much more certain of having avoided error, and I have found in these hives (which I will call book or leaf hives) several advantages which make them very useful in the economic treatment of bees. I will detail them afterwards, if you permit me.
I come now, Sir, to the particular object of this letter, the foundation of the queen-bee.2
I will first examine, in a few words, the different opinions of naturalists on the peculiar problem which this foundation presents; I will mention to you the most remarkable observations which their conjectures caused me to make, and will then describe the new experiments through which I believe that I have solved the problem.
Swammerdam, who had observed bees with constant assidulty, and had never been able to see a real mating of a drone with a queen, was satisfied that mating was unnecessary for the foundation of the eggs; but as he noticed that the drones exhaled, at certain times, a very strong odor, he imagined that this odor was an emanation of the _aura seminalis_, or the aura seminalis itself, which penetrating the body of the female, operated foundation. He became confirmed in this conjecture, when he dissected the organs of generation of the males; he was so struck with the disproportion which they present, compared with the organs of the female, that he did not believe that copulation was possible; his opinion upon the influence of the odor of the drones had the advantage that it explained very plausibly their prodigious multiplication. There are often 1,500 to 2,000 of them in a hive, and, according to Swammerdam, it was necessary that they be there in great numbers, that the emanation proceeding from them be sufficiently intense or energetic to effect fecundation.
2 I do not dare insist that my readers, in order to better comprehend what I have to say, should read the memories of Mr. de R\(cute{
m e}\)aumur upon bees and those of the Lusattian Society, but I urge them to study the extract that Mr. Bonnet has given of them in his work, tome X of the octavo edition, and tome V of the quarto edition. They will find in it a short and clear summary of all that naturalists had hitherto discovered on those bees.
Mr. de Reaumur has already refuted this hypothesis by just and conclusive reasoning; but he has not made the sole experiment which could verify or overturn it in a decisive manner. It was necessary to confine all the drones of a hive in a box perforated with very minute holes, which would allow the passage of the odor, without permitting the passage of the organs of generation; place this box in a well peopled hive, but entirely deprived of males of either large or small size, and observe the result. It is evident that, after having thus disposed matters, if the queen had laid fertilized eggs, Swammerdam's hypothesis would have acquired much probability, and on the contrary, it would have been entirely overthrown, if the queen had not laid any eggs or only sterile ones. We made this experiment as I have just indicated it, and the queen remained barren. It is therefore certain that the odor of the drones is insufficient to impregnate her.
Mr. de Reaumur had a different opinion: he believed that the fecundity of the queen-bee was the result of actual mating; he enclosed a few drones with a virgin queen, in a glass sand-box; he saw her make many advances to the males, but, as he could not see any connection sufficiently intimate to call it a mating, he made no decision, leaving the question open. We have repeated the experiment after him, we enclosed, at different times, virgin queens, with drones of all ages, we made the experiment in all seasons; we saw the advances made by the queen: we have even at times thought that we detected between them a sort of union, but so short and imperfect that it was not likely that it had operated fecundation. However, as we did not wish to neglect anything, we confined to her hive the queen which had been approached by the male and observed her for several days. She was imprisoned for more than a month, she did not lay a single egg during that time, therefore she had remained sterile. Those momentary junctions do not operate fecundation.
In the _Contemplation de la Nature_, part XI, chapter XXVII, you have reported the observations of an English naturalist, Mr. de Braw. They appeared made with accuracy and seemed, at last, to clear the mystery of the fecundation of the queen-bee.3 This observer, favored by chance, one day perceived, at the bottom of some cells containing eggs, a whitish liquid, of spermatic appearance, distinct at least from the jelly which the workers usually gather around the newly hatched worms. Curious to learn its origin, and conjecturing that it was drops of the prolific masculine liquid, he undertook to watch in one of these hives the actions of the drones, so as to detect them at the time when they would be sprinkling the eggs. He asserts that he saw several of them insinuating the posterior part of their body in the cells, depositing the liquid there. After repeating this observation several times he undertook a long series of experiments: he confined a number of workers with a queen and a few drones in a glass bell; he supplied them with pieces of comb containing honey but no brood and he saw this queen lay eggs which the drones afterwards sprinkled and from which worms hatched. On the other hand, when he failed to enclose drones within the prison with the queen, she did not lay, or laid only sterile eggs. He did not hesitate to give, as a demonstrated fact, that the males of bees fecundate the eggs of the queen in the manner of fishes and frogs, that is to say, externally after they have been laid.
This explanation appeared specious; the experiments upon which it was based appeared well made, and it especially accounted for the prodigious number of males which are found in hives. However there remained a very strong objection which the author had overlooked. Larvae are born when there are no longer any drones. From September till April the hives are, usually, deprived of drones and notwithstanding their absence, the eggs which the queen lays in that interval are not sterile: thus they have no need, to be fertile, of the influence of the drone's sperm. Should we suppose that it is needed at a certain time of the year and that in other seasons it becomes useless?
To discover the truth amid these apparently contradictory facts, I resolved to repeat the experiments of Mr. de Braw and to take greater precautions than he had taken himself. First, I sought, within the cells which contained eggs, to see the liquid of which he speaks, and which he mistook for drops of sperm; we found, Burnens and I, several cells containing an appearance of liquid, and I must acknowledge that, during the first days, after making this observation, we had no doubt of the reality of this discovery: but we recognized the illusion afterwards, caused by the reflection of the rays of light; for we could see traces of this liquid only when the sun was sending its rays to the bottom of the cells. That bottom is usually lined with debris of different cocoons of the worms which have successively hatched in it. Those cocoons are sufficiently bright and when strongly lighted there results an illumination, which is quite deceiving. We became convinced of this when we examined the matter more closely. We detached the cells which presented this peculiarity, we cut them up in different ways and saw very clearly that there was not the least trace of liquid in them.
Although this observation inspired us with a sort of distrust of Mr. de Braw's discovery, we repeated his other experiments with the greatest care. On the 6th of August 1787, we immersed a hive and examined all the bees while they were in the bath. We made sure that there was not a single drone in it, either of the large or of the small size. We examined also all the combs and we made sure that there were neither nymph nor larvae of males in them. When all the bees were dry we placed them all back with the queen in their hive; and transported this hive into my cabinet. As we wished them to enjoy full liberty, we did not close them up; they went into the fields and made their usual harvest; but, as it was necessary that, during the entire time of the experiment, there should be no drones among them, we adapted a glass tube to the entrance, the dimensions of which were such that two bees only could pass at once, and we watched this tube attentively during the four or five days that the experiment lasted. Had a drone appeared, we would have recognized him instantly and removed him so that the result of the experiment be not disturbed. We can affirm that not one was seen. However, the queen laid, from the first day (6th of August), 14 eggs in worker cells and all the worms hatched on the 10th of the same month.
This experiment is decisive. Since the eggs were fertile that the queen laid in a hive containing no drones, and where no drones could possibly have been introduced, it is very certain that they do not need to be sprinkled with the sperm of the drones in order to hatch.
It appears to me that no reasonable objection can be brought against this inference. However, as I have accustomed myself, in all my experiments, to seek the most trifiling difficulties which might be raised against their results, I thought that Mr. de Braw's partisans would say that the bees, deprived of their drones, might seek those living in other hives, remove the fertilizing liquid from them, and bring it to their own home to deposit it upon the eggs.
It was easy to appreciate the value of this suspicion. It was only necessary to repeat the previous experiment, confining the bees in their hive so closely that not one of them could escape. You know, sir, that the bees may live for three or four months in confinement in their hive, otherwise well provisioned with honey and wax, and in which small openings have been left for the passage of air. I made this experiment on the 10th of August; I had made sure, by means of immersion, that there was not a single drone among them; they were kept prisoners, in the closest manner, for four days, and at the end of that time I found forty worms newly hatched, on their bed of jelly. I went to the length of immersing this hive again to make sure that no male had escaped my search; we examined all the bees separately and we can assure that there was not a single one which did not show us her sting. This result, coinciding with the first experiment, demonstrated that the eggs of the queen-bee are not fecundated externally.
In order to conclude the confutation of Mr. de Braw's opinion, I need only to indicate that which led him into error. In his different observations he used queen-bees with which he was not acquainted from their birth. When he saw the eggs hatch which were laid by a queen confined with males, he determined that they had been sprinkled with the prolific liquid; but to have a just conclusion, he should have ascertained that this female had never mated, and this he neglected. The fact is, that, without knowing it, he had employed in this experiment a queen which had dammerce with a male. Had he used a virgin queen and enclosed her with drones within his glass bells, at the moment of her emerging from the royal cell, he would have had an entirely different result. For even amidst this sergalio of males, she never would have laid, as I will prove in the sequel of this letter.
The Lusatian observers, and Mr. Hattorf in particular, thought that the queen was fertile, of herself, without the concourse of the males.* I will recall here the experiment upon which this opinion was founded.
Mr. Hattorf took a queen of whose virginity there could not be any doubt; he confined her to a hive from which he excluded all the males of the large or small size and a few days after he found in it eggs and worms. He asserts that, in the course of this experiment, no drones were introduced
4 See in Schirach's history of bees a memoir of Mr. Hattorf, entitled: Physical researches upon this question: Does the queen-bee require fecundation by drones?
within this hive, and, since in spite of their absence the queen laid eggs from which worms hatched, he concluded that she is fertile by herself.
Reflecting on this experiment, I did not find it sufficiently exact. I knew that drones pass easily from one hive to another and that Mr. Hattorf had taken no precautions to prevent any of them from being introduced within his hive; indeed he says that no males came, but he does not say by what means he made sure of this fact: even though he might have made sure that no drones of the large size had entered, it might have been possible that one of the small size had entered, escaping his vigilance, and had fecund-dated the queen. To clear up this doubt, I resolved to repeat the experiment of this observer, as he described it, without greater care or precautions.
I placed a virgin queen within a hive from which I removed all the drones, and left entire freedom to the bees: a few days after, I visited this hive and found newly hatched worms in it. Here then was the same result as Mr. Hattorf had obtained; but to draw similar consequences, it was necessary to make sure that no males had been introduced. It was necessary to immerse the bees and examine them separately. We performed this operation and after careful search we found four small males. It results from this, that to render an experiment decisive on this question, it is not only necessary to remove all the drones, but one must also, by some sure method, prevent any from being introduced, which the German observer had neglected to do.
I prepared to repair this omission. I placed a virgin queen in a hive from which I carefully removed all the males, and to be physically certain that none would come, I adapted to the entrance of the hive a glass tube of such dimensions that the worker bees could easily pass through, but which was too small for even a drone of the small size. Matters remained thus for thirty days; the workers, going and coming, did their usual work, but the queen remained sterile; at the end of the thirty days, her belly was as slender as at the time of her birth. I repeated this experiment several times and the result was the same.
Therefore, since a queen remains sterile which is rigorously separated from all commerce with the males, it is evident that she is not fertile by herself. So the opinion of Mr. Hattorf is ill-founded.
Hitherto, when seeking to verify or destroy the conjectures of all the previous observers by new experiments, I had acquired the knowledge of new facts; but these facts were apparently so contradictory that they rendered the solution of the problem still more difficult. While working upon Mr. de Braw's hypothesis, if I confined a queen within a hive from which I had excluded all the drones; she did not fall in fertility. On the contrary, if, while examining the opinion of Mr. Hattorf, I placed in the same conditions a queen of whose virignity I was positively certain, she remained sterile.
Embarrassed by so many difficulties, I was on the point of abandoning this subject of researches, when at last, in reflecting more attentively upon it, I thought that these apparent contradictions were due to my bringing together experiments made on virgin queens and others executed upon females which I had not observed from their birth, and which had perhaps been fecundated unknown to me. Impressed with this idea, I undertookto follow a new plan of observation, not on queens taken haphazard from my hives, but on positively virgin females, whose history was known to me from the moment of their leaving the cell.
I had a great number of hives: I removed all the reigning females and substituted for each of them a queen taken at the moment of her birth; I then divided those hives into two classes. From those of the first class I removed all the males of both large and small sizes, and adapted to the entrances a glass tube so narrow that no drone could enter, but large enough for the free ingress and egress of the workers. In the hives of the second class, I left all the drones that were there and even introduced new ones, and to prevent them from escaping, I placed on these hives, as with the first, a glass tube too narrow for the passage of the drones.
I followed with great care, for over a month, this experiment made on a large scale, and was very much surprised, at the end of that time, to see my queens equally sterile.
It is therefore absolutely certain that queens remain unfertile, even amidst a sergalio of drones, when one confines them to the hive. This result led me to suspect that the females cannot be decundated in the interior of their hives, and that they must go out in order to receive the approaches of the males. It was easy to ascertain this by a direct experiment. As this is important, I shall relate in detail that which we made, my secretary and I, on the 29th of June, 1788.
We knew that, during the fine season, the drones usually emerge from their hives at the warmest hour of the day. It was therefore natural to conclude that, if the queens are also compelled to emerge in order to be decundated, they would be induced to select the hour of the drones' flight.
We therefore stationed ourselves in front of a hive whose unfertile queen was five days old. It was 11 o'clock in the forenoon: the sun had been shining from its rising, the air was very warm; the drones began to fly from several hives, we then enlarged the entrance of that selected for observation; then fixed our attention upon that entrance and the bees that issued from it. We first saw a few males appear, which took flight as soon as released. Soon afterwards, the young queen appeared at the entrance of the hive; she did not fly at once. We saw her promenading on the stand of the hive for a few instants, brushing her belly with her posterior legs: neither the bees nor the males that emerged from the hive appeared to bestow any attention upon her: at last the young queen took flight. When a few feet from the hive, she turned and approached as if to examine the point from which she had left; (it seemed that she judged this precaution necessary to recognize it on her return) she then flew away, describing horizontal circles twelve or fifteen feet above the earth. We then contracted the entrance of the hive, so that she might not re-enter unobserved, and we placed ourselves in the center of the circles which she was describing in her flight, to be better able to follow her and witness all her actions. But she did not remain long in a situation so favorable for observation; soon she took speedy flight and arose out of sight: we returned immediately to our place in front of the hive, and in seven minutes we saw the young queen return and alight at the entrance of this hive from which she had emergedonly once. We took her in our hands to examine her and having found no signs of decundation upon her we allowed her to re-enter the hive. She remained inside nearly a quarter of an hour, when she appeared again; after having brushed herself as before, she took flight, turned to examine the hive, and rose so high that we lost sight of her. This second absence was much longer than the first, it was only after twenty-seven minutes that we saw her return and alight on the board. We found her then in a very different state from that in which she was after her first excursion: the posterior part of her body was filled with a whitish substance, thick and hard, the interior edges of her vulva were covered with it; the vulva itself was partly open and we could readily see that its interior was filled with the same substance. This substance very much resembled the liquid contained in the seminal vesicles of the males, completely similar to it in color and consistency; but we needed a stronger proof than this resemblance, to make sure that the white liquid with which she was impregnated, was really the feecundating liquid of the drones; it was necessary that it should operate decundation. We then allowed this queen to enter the hive and confined her there. Two days later we opened the hive and saw the proof that she was fertile. Her belly was perceptibly enlarged and she had already laid nearly a hundred eggs in worker cells.
To confirm this discovery, we made several other experiments, with the same success. I will transcribe this one from my journal: The second of July, the weather being very fine, the males came out in numbers. We set at liberty a queen which had never lived with drones (for her hive had always been entirely deprived of them.) She was eleven days old and positively not fertile; we soon saw her leave the hive, turn to examine it, and rise out of sight: she returned after a few minutes, without any exterior signs of decundation; she flew again for the second time, at the end of a quarter hour, but with so rapid a flight that we were able to follow her for only an instant; this new absence lasted thirty minutes. The last ring of her abdomen was open and the vulva was filled with the whitish matter already mentioned. We replaced her in her home, from which we continued to exclude all males. We examined her two days later and found her fertile.
These observations at length taught us why Mr. Hattorf had obtained results so different from ours. He had fertile queens, in hives which were deprived of drones, and he had concluded that their intercourse was not necessary for decundation, but he had not deprived his queens from the liberty of flight and they had taken advantage of this to join the drones.
* It will be shown in the following letter that what we took for drops of coagulated sperm was really the male organs, which the mating fixes into the body of the female. We owe this discovery to a circumstance that I will here relate. In order to shorten this work, perhaps I should have omitted all the accounts I give of my first observations on the decundation of the queen-bee, and pass directly to the experiments which prove that she brings home with her the genital organs of the male; but in observations of this kind, which are both new and delicate, it is so easy to be deceived, that I believe I serve my readers by exposing candidly the errors which I committed. It is an additional proof, added to so many others, of the necessity for an observer, to repeat his experiments thousands of times, to obtain the certainty of seeing facts in their true light.
We, on the contrary, had surrounded our queens with a great number of males, and they had remained sterile, because the precautions which we had taken for confining the males to the hhves had also prevented the queens from departing and seeking _outside_ the foundation which they could not obtain within.
We repeated these experiments upon queens aged twenty, twenty-five, thirty, thirty-five days. All became fertile after a single impregnation. However, we have observed some essential peculiarities in the fecundity of those queens which were fecundated after the twentieth day of their life; but we defer speaking of it until we can offer to naturalists some observations sufficiently positive and sufficiently numerous to better merit their attention.