Here, yet again, there confronts us an enigma of the hive; and in this case one of the most unfathomable. We know that the virgin queen is not sterile; but the eggs that she lays will produce only males. It is not till after the impregnation of the nuptial flight that she can produce workers or drones at will. The nuptial flight places her permanently in possession, till death, of the spermatozoa torn from her unfortunate lover. These spermatozoa, whose number Dr. Leuckart estimates at twenty-five millions, are preserved alive in a special gland known as the spermatheca, that is situate under the ovaries, at the entrance to the common oviduct. It is imagined that the narrow aperture of the smaller cells, and the manner in which the form of this aperture compels the queen to bend forward, exercise a certain pressure upon the spermatheca, in consequence of which the spermatozoa spring forth and fecundate the egg as it passes. In the large cells this pressure would not take place, and the spermatheca would therefore not open. Others, again, believe that the queen has perfect control over the muscles that open and close the spermatheca on the vagina; and these muscles are certainly very numerous, complex, and powerful. For myself, I incline to the second of these hypotheses, though I do not for a moment pretend to decide which is the more correct; for indeed, the further we go and the more closely we study, the more plainly is it brought home to us that we merely are waifs shipwrecked on the ocean of nature; and ever and anon, from a sudden wave that shall be more transparent than others, there leaps forth a fact that in an instant confounds all we imagined we knew. But the reason of my preferring the second theory is that, for one thing, the experiments of a Bordeaux bee-keeper, M. Drory, have shown that in cases where all the large cells have been removed from the hive, the mother will not hesitate, when the moment for laying male eggs has come, to deposit these in workers' cells; and that, inversely, she will lay workers' eggs in cells provided for males, if she have no others at her disposal. And, further, we learn from the interesting observations of M. Fabre on the Osmiae, which are wild and olitary bees of the Gastrilegidae family, that not only does the Osmia know in advance the sex of the egg she will lay, but that this sex is "optional for the mother, who decides it in accordance with the space of which she disposes; this space being often governed by chance and not to be modified; and she will deposit a male egg here and a female there." I shall not enter into the details of the great French entomologist's experiments, for they are exceedingly minute, and would take us too far. But whichever be the hypothesis we prefer to accept, either will serve to explain the queen's inclination to lay her eggs in workers' cells, without it being necessary to credit her with the least concern for the future.