This proceeding was attended with the most ample success. We soon found eggs in the hive; their number increased daily; and their worms were all drones. But a long interval elapsed before we could take the bees that laid them. At length, by means of assiduity and perseverance, we perceived one introducing the posterior part into a cell; we opened the hive, and caught the bee: We saw the egg it had deposited, and by the colour of the thorax, and privation of the right antenna, instantly recognised that it was one of the six that had passed to the vermicular state in the vicinity of the royal cells. I could no longer doubt the truth of my conjecture; at the same time, I know not whether the truth will appear as rigorous to you, Sir, as it does to myself. But I reason in the following manner: If it is certain that fertile workers are always produced in the vicinity of royal cells, it is no less true, that in itself, the vicinity is indifferent; for the size and figure of these cells can produce no effect on the worms in those surrounding them; there must be something more; we know that a particular aliment is conveyed to the royal cells; we also know, that this aliment has a very powerful effect on the ovaries; that it alone can unfold the germ. Thus, we must necessarily suppose the worms in the adjacent cells have had a portion of the same food. This is what they gain, therefore, by vicinity to the royal cells. The bees, in their course thither, will pass in numbers over them, stop and drop some portion of the jelly destined for the royal larvae. This reasoning, I presume, is consistent with the principles of sound logic. I have repeated the experiment now described so often, and weighed all the concomitant circumstances with so much care, that whenever I please, I can produce fertile workers in my hives. The method is simple. I remove the queen from a hive; and very soon the bees labour to replace her, by enlarging several cells, containing the brood of workers, and supplying the included worms with the royal jelly. Portions of this aliment also fall on the young larvae deposited in the adjacent cells, and it unfolds the ovaries to a certain degree. Fertile workers are constantly produced in hives where the bees labour to replace their queen; but we very rarely find them, because they are attacked and destroyed by the young queens reared in the royal cells. Therefore, to save them, all their enemies must be removed, and the larvae of the royal cells taken away before undergoing their last metamorphoses. Then the fertile workers, being without rivals at the time of their origin, will be well received, and, by taking the precaution to mark them, it will be seen, in a few days, that they produce the eggs of males. Thus, the whole secret of this proceeding consists in removing the royal cells at the proper time; that is, after being sealed, and previous to the young queens leaving them{K}.