The fact that he lives for some days in the hive with the queen, before her nuptial flight, apparently unaware of her presence, would seem to indicate some special “trigger” for the release of the sexual instincts. But it must be remembered that he does not attain to maturity until after his first flight, and this it is, probably, which arouses the mate-hunger. More than this, however, it is probable that coitus is possible only when on the wing, when the air-sacs become inflated, and exert pressure on the genital organs. How he recognizes the queen when on her wild flight heavenwards is unknown: possibly by scent, but more probably by the very different vibrative note of her wings, that of the male being much stronger and deeper. His continued return to the hive is a proof of his failure to justify his existence, for no drone ever experienced Love’s embrace and lived to tell the tale: hence, when the time comes, he is slain without compunction. These differences between the fully-developed male and female present nothing very striking; but how are the singular peculiarities of structure and instinct in the “workers” to be accounted for? They are present in neither queen nor drone, yet by them they are transmitted to their offspring from one generation to another! It is true that every worker, for a time, is a potential queen, and every queen, but for the grace of Chance, might have been a worker. All depends on the food. It is remarkable, but apparently the fact, that a more generous diet, or, rather, a more stimulating diet, should so profoundly modify the organism, but, it is to be noted, this sleight-of-hand is only successfully practised on a larva during its first three days of existence. Thus the royal bee jelly stimulates the growth of the sexual organs and inhibits the development of the structures peculiar to the worker—the basket, and pollen-hairs, and so on. These structures are not made by the food; they are simply nourished or inhibited, as the case may be. Nevertheless, one cannot help being mystified by the fact that the mere difference in the quality of the food, or, rather, in the chemical constituents thereof, should cause the inhibition, or, rather, the suppression, of relatively complex structures like the corbiculum and the reduction of the number of the facets of the eye. To say that the structures inhibited, in the case of the queen, are just those which will be of no service when in her royal state, is by no means to explain the mystery. And what is true of the physical side is no less true of the psychical, for with this change of diet the behaviour of the insect, throughout its whole life, is most profoundly changed. If the pollen-basket is wanting, no less so are the instinctive actions associated with its use; if the genital organs are atrophied, so also are the instinctive acts associated therewith. This nexus between instinct and structure is not to be lost sight of.