This result induced me to suspect that the females could not be fecundated in the interior of the hive, and that it was necessary for them to leave it for receiving the approaches of the male. To ascertain the fact was easy, by a direct experiment; and as the point is important, I shall relate in detail what was done by my secretary and myself on the 29. June 1788. Aware, that in summer the males usually leave the hive at the warmest time of the day, it was natural for me to conclude that if the queens were also obliged to go out for impregnation, instinct would induce them to do so at the same time as the males. At eleven in the forenoon, we placed ourselves opposite a hive containing an unimpregnated queen five days old. The sun had shone from his rising; the air was very warm; and the males began to leave the hives. We then enlarged the entrance of that which we wished to observe, and paid great attention to the bees that entered and departed. The males appeared, and immediately took flight. Soon afterwards, the young queen appeared at the entrance; at first she did not fly, but brushed her belly with her hind legs, and traversed the board a little; neither workers nor males paid any attention to her. At last, she took flight. When several feet from the hive, she returned, and approached it as if to examine the place of her departure, perhaps judging this precaution necessary to recognize it; she then flew away, describing horizontal circles twelve or fifteen feet above the earth. We contracted the entrance of the hive that she might not return unobserved, and placed ourselves in the centre of the circles described in her flight, the more easily to follow her and observe all her motions. But she did not remain long in a situation favourable for us, and rapidly rose out of sight. We resumed our place before the hive; and in seven minutes, the young queen returned to the entrance of a habitation which she had left for the first time. Having found no external appearance of fecundation, we allowed her to enter. In a quarter of an hour she re-appeared; and, after brushing herself as before, took flight. Then returning to examine the hive, she rose so high that we soon lost sight of her. Her second absence was much longer than the first; twenty-seven minutes elapsed before she came back. We then found her in a state very different from that in which she was after her first excursion. The sexual organs were distended by a white substance, thick and hard, very much resembling the fluid in the vessels of the male, completely similar to it indeed in colour and consistence{E}. But more evidence than mere resemblance was requisite to establish that the female had returned with the prolific fluid of the males. We allowed this queen to enter the hive, and confined her there. In two days, we found her belly swoln; and she had already laid near an hundred eggs in the worker's cells.