Anyone who has watched the flight of the bee must have been struck by its sheer facility and freedom no less than by its speed. It is quite evident that the bee is not only an accomplished aërial navigator, but that she sustains and propels herself through the air with very little effort. Obviously her equipment for flight must be a thoroughly efficient one, and yet at first glance it is not quite clear how she manages so well. The student of the flight-problem, taking his ideas and conception of first principles from the flight of birds, is accustomed to believe that there are at least two vital indispensable elements in the process—a pair of wings or combination of aëroplane and propellers that will sustain as well as drive, and some sort of steering-apparatus like the bird’s tail. Yet, as far as a first general inspection carries us, the bee appears to have no rudder-mechanism at all, but to depend on her four wings for every purpose. The wings of the bird have a variable action. They can be used together or separately, and are as capable of eccentric adjustment, both in themselves and in relation to one another, as a pair of human arms. But the bee’s wings have none of this adaptability. They have but the one motion, up and down; and they work symmetrically, each wing keeping time with its fellow. Yet the bee steers herself perfectly well in a hundred different evolutions, accomplishing all that the bird attains with his more complicated apparatus for flight. The whole problem is bound up with another problem; and the two, difficult of solution apart, easily resolve one another when taken in conjunction. Insects are so called because their bodies are in two parts, entirely divided except for an extremely slender connecting joint. We are so accustomed to accept this arrangement as a common fact in nature that we seldom stop to consider its real significance. It is not easy to see how such a construction can be anything else than a drawback to any living creature. But in the hive-bee the whole arrangement seems to amount to what must be called an ideal inconvenience, seeing that her honey-sac and complicated organs for producing the larval food are in her abdomen, with no way to them but through this fine joint. Clearly there is some weighty reason for it, out-balancing all other considerations, or it would not exist; and when we come to study it in connection with the honey-bee’s peculiar system of flight, we soon arrive at the true solution.