Returning to bees of the solitary kind, “the operations of the wood-piercers,” says Bingley, “merit our careful attention.” They shall have it for a moment, but space is against them. However, the female of the species, _Xylocopa violacea_, which for some reason is disliked by householders, bores in the springtime, by the aid of her strong mandibles alone, neat little circular tunnels in such objects as garden-seats, gates, front doors, arbours, window-shutters, rustic tables, and the like. At first, it is stated, she “bores perpendicularly, but when she has advanced about half an inch she changes her direction, and then proceeds nearly parallel with its sides for twelve or fifteen inches. If the wood of the seat, door, table, etc., be sufficiently thick, she sometimes forms three or four of these long holes in its interior, a labour which for a single insect seems prodigious, and in the execution of it some weeks are sometimes employed. On the ground, for about a foot from the place in which one of these bees is working, little heaps of timber-dust are to be seen. These heaps daily increase in size, and the particles that compose them are almost as large as those produced by a hand-saw.”[88] When the tunnels are finished, the mother bee divides them into some dozen little rooms about an inch deep, making the divisions of wood-dust, which she cements together by aid of a glutinous secretion with which she is furnished. Before each cell is closed it is filled with a paste composed of the farina of flowers, mixed with honey (it makes one envy the grub), and an egg is deposited in it. As each cell takes some time to make and provision, it is obvious that the egg in the lower one will hatch a little sooner than the one above it, and so on right up to the top. If, therefore, any one of the larvæ “were to force its way upwards, which it could easily do, it would not only disturb, but would infallibly destroy all those lodged in the superior cells.”[88] Here, however, natural selection (called Providence in Bingley’s time) steps in, and “has wisely prevented this devastation, for the head of the nymph (chrysalis), and consequently of the emerging bee, is always placed in a downward direction.”[88] Of course, therefore, the insect moves forward in the direction towards which it looks at birth—its new birth, that is to say; and, moreover—this is the really astonishing thing—“the mother digs a hole at the bottom of the long tube, which makes a communication between the undermost cell and the open air. By this contrivance, as all the bees instinctively endeavour to cut their way downward, they find an easy and convenient passage, for they have only to pierce the floor of their cells in order to make their escape, and this they do with their teeth very readily.” As regards this communicating passage, however, it is presumably a mere continuation of the tunnel, and was probably once occupied with cells, like the upper portion. Why the lower end of the