Much that baffles one in the history of the Hive-bee becomes clear in the light of the facts revealed by the life-story of the Bumble-bee. In the first place it will be remembered her first eggs produced only workers, which appeared at a time when her energies were severely strained, and their food allowance was no more than barely sufficient to sustain life. The females which appeared later produced fertile eggs, having been more abundantly fed by their infertile elder sisters. The number of fertile females which appear at this stage of the colony seems again to be regulated by the abundance of food, which varies in amount with fine, or cold, weather. Even among the worker broods fertile females may appear. They owe their fertility apparently to good luck, which afforded them the opportunity of securing more food than their sisters. The birth of young from females about whose virginity there can be no question is certainly remarkable, but it would seem that this parthenogenetic state is one of limited endurance, for towards the end of summer males appear, and these mating with some of the later-born females, lead again to the appearance of a queen, who, being fertilized, alone survives the winter to carry on the race with the succeeding summer. Thus, then, the mysterious existence of the workers among the Hive-bees, displaying structural peculiarities and instincts so different from those of the queen-mother, is explained. For the queen, in this case, is evidently the product of a more intensified, more perfected, social system, relieved, from the first, of the labours of building and the care of her offspring, duties which the queen Bumble-bee has at first to perform for herself, because all her children die at the end of the summer. Among Hive-bees fertile workers also occasionally occur; they are probably bees which in their larval state received a more than usually abundant supply of food, or food approximating to the “bee jelly” which produces young queens. The difference, then, between the individuals of a colony of Hive-bees and one of Bumble-bees lies in the greater abundance of fertile workers and in the fact that the queen of the Hive-bees is relieved of all work from the first, and so is enabled to devote her whole energies to the duties of reproduction. She is the descendant of a race of queens which in earlier times, like the Bumble-bee queen, had to perform the duties now relegated to her daughters, who inherit not only her house-building and child-nurturing instincts, but also her potentiality for child-bearing, though this potentiality is commonly inhibited by the starvation of the reproductive activities. Selection secures survival of this state of affairs by the elimination of any tendency to lose any of these qualities on the part of the queen. The workers of the Hive-bee, in short, have not evolved their peculiarities of structure and instinct by some mysterious process of natural selection