Swammerdam, who studied bees with unremitting attention, and who never could see a real copulation between a drone and a queen, was satisfied that copulation was unnecessary for fecundation of the eggs: but having remarked that, at certain times, the drones exhaled a very strong odour, he thought this odour was an emanation of the _aura seminalis_, or the _aura seminalis_ itself, which operated fecundation by penetrating the body of the female. His conjecture was confirmed on dissecting the male organs of generation; for he was so much struck with the disproportion between them and those of the female, that he did not believe copulation possible. His opinion, concerning the influence of the odour, had this farther advantage, that it afforded a good reason for the prodigious number of the males. There are frequently fifteen hundred or two thousand in a hive; and, according to Swammerdam, it is necessary they should be numerous, that the emanation proceeding from them may have an intensity or energy sufficient to effect impregnation. Though M. de Reaumur has refuted this hypothesis by just and conclusive reasoning, he has failed to make the sole experiment that could support or overturn it. This was to confine all the drones of a hive in a tin case, perforated with minute holes, which might allow the emanation of the odour to escape, but prevent the organs of generation from passing through. Then, this case should have been placed in a hive well inhabited, but completely deprived of males, both of large and small size, and the consequence attended to. It is evident, had the queen laid eggs after matters were thus disposed, that Swammerdam's hypothesis would have acquired probability; and on the contrary it would have been confuted had she produced no eggs, or only sterile ones. However the experiment has been made by us, and the queen remained barren; therefore, it is undoubted, that the emanation of the odour of the males does not impregnate bees. M. de Reaumur was of a different opinion. He thought that the queen's fecundation followed actual copulation. He confined several drones in a glass vessel along with a virgin queen: he saw the female make many advances to the males; but, unable to observe any union so intimate that it could be denominated copulation, he leaves the question undecided. We have repeated this experiment: we have frequently confined virgin queens with drones of all ages: we have done so at every season, and witnessed all their advances and solicitations to the males: we have even believed we saw a kind of union between them, but so short and imperfect that it was unlikely to effect impregnation. Yet, to neglect nothing, we confined the virgin queen, that had suffered the approaches of the male, to her hive. During a month that her imprisonment continued, she did not lay a single egg; therefore, these momentary junctions do not accomplish fecundation.