I have frequently testified my admiration of M. de Reaumur's observations on bees. I feel a sensible pleasure in acknowledging that if I have made any progress in the art of observation, I am indebted for it to profound study of the works of this naturalist. In general his authority has such weight, that I can scarcely trust my own experiments when the results are different from his. Likewise, on finding myself in opposition to the historian of bees , I repeat my experiments. I vary the mode of conducting them; I examine with the utmost caution all the circumstances that might mislead me, and never are my labours interrupted before acquiring the moral certainty of avoiding error. With the aid of these precautions, I have discovered the justice of M. de Reaumur's suggestions, and I have a thousand times seen, if certain experiments seemed to combat them, it was from incorrectness of execution. Yet I must except some facts where my results have constantly been different from his. Those respecting the reception of a stranger queen substituted for the natural one, are of the number.

If, after removing the natural queen, a stranger is immediately substituted, the usurper is ill received. I never could succeed in making them adopt her, but by allowing an interval of twenty or twenty-four hours to elapse. Then they seemed to have forgot their own queen; and respectfully received any female put in her place. M. de Reaumur, on the contrary, asserts, that should the original queen be removed, and another presented, this new one will be perfectly well received from the beginning. As evidence of this assertion, he gives the detail of an experiment which must be read in his work, for I shall here give only an extract of it L . He induced four or five hundred bees to leave their native hive and enter a glass box, containing a small piece of comb towards the top. At first they were in great agitation; and, to pacify or console them, he presented a new queen. From this moment, the tumult ceased, and the stranger queen was received with all respect.

I do not dispute the truth of this experiment; but, in my opinion, it does not warrant the conclusion that M. de Reaumur deduces from it. His apparatus removed the bees too much from their natural condition, to allow him to judge of their instinct and dispositions. In other situations, he has himself observed, that these animals, reduced to small numbers, lost their industry and activity, and feebly continued their ordinary labours. Thus their instinct is affected by every operation that too much diminishes their number. To render such an experiment truly conclusive, it must be made in a populous hive; and on removing the native queen, a stranger must immediately be substituted in her place. Had this been done, I am fully persuaded, that M. de Reaumur would have seen the bees imprison the usurper, confine her at least twelve or fifteen hours among them, and frequently suffocate her: nor would he have witnessed any favourable reception before an interval of twenty-four hours after removal of the original queen. No variation has occurred in my experiments regarding this fact. Their number, and the attention bestowed on them, make me presume they merit your confidence.

M. de Reaumur, in another passage of the same Memoir, affirms, that bees, which have a queen they are satisfied with, are nevertheless disposed to give the best possible reception to any female that seeks refuge among them . In the preceding letter, I have related my experiments on this head: their success has been very different from that of M. de Reaumur's. I have proved that the workers never employ their stings against the queen; but this cannot be called the welcome reception of a stranger. They retain her within their ranks, and seem to allow her liberty only when she prepares to combat the reigning queen. This observation cannot be made except in the thinnest hives. Those used by M. de Reaumur had always two parallel combs at least, which must have prevented him from observing some very important circumstances that influence the conduct of workers when supplied with several females. The first circles formed around a stranger queen he has taken for caresses; and, from the little that this queen could advance between the combs, it must have been impossible for him to observe that the circles, which always continued contracting, ended in restraint of the females there inclosed. Had he used thinner hives, he would have discovered that what he supposed indication of a favourable reception was the prelude of actual imprisonment.

I feel reluctant to assert that M. de Reaumur was deceived. Yet I cannot admit that, on certain occasions, bees tolerate a plurality of females in their hives. The experiment on which this affirmation rests will not be considered decisive. In the month of December, he introduced a stranger queen into a glass hive, in his cabinet, and confined her there. The bees had no opportunity of going out. This stranger was well received; her presence awakened the workers from their lethargic state, into which they did not relapse; she excited no carnage; the number of dead bees on the board of the hive did not sensibly increase; and no dead queens were found.

Before concluding any thing favourable to the plurality of queens, it was necessary to ascertain whether the native queen was living when the new one was introduced into the hive: however the author neglected this; and it is very probable the hive had lost its queen, since the bees were languid, and the presence of a stranger restored their activity.

I trust, Sir, that you will pardon this slight criticism. Far from industriously seeking faults in our celebrated Reaumur, I derive the greatest pleasure when my observations coincide with his, and still more, when my experiments justify his conjectures. But I think it proper to point out those cases where the imperfections of his hives have led him into error, and to explain from what causes I have not seen certain facts in the same manner he did. I feel particular anxiety to merit your confidence, and I am aware that the greatest exertions are necessary, when I have to combat the historian of bees. I confide in your judgment; and pray you to be assured of my respect.

PREGNY , 30. August 1791.