pletely filled. These cells, however, are never used as honey-pots by Wasps, as they are by Bees; for Wasps make no honey, and the cells are wholly appropriated to the rearing of their young. Like other Hymenopterous Insects, the grubs are placed with their heads downwards; and the openings of the cells are also downwards; while their united bottoms form a nearly uniform level, upon which the inhabitants of the nest may walk.

"When the foundress Wasp has completed a certain number of cells, and deposited eggs in them, she soon intermits her building operations, in order to procure food for the young grubs, which now require all her care. In a few weeks these become perfect Wasps, and lend their assistance in the extension of the edifice; enlarging the original coping of the foundress by side walls, and forming another platform of cells, suspended to the first by columns, as that had been suspended to the ceiling.

"In this manner several platforms of combs are constructed, the outer walls being extended at the same time; and, by the end of the summer, there are generally from twelve to fifteen platforms of cells. Each contains about 1060 cells-forty-nine being contained in an inch and a half square, and, of course, making the enormous number of about 16,000 cells in one colony. Réaumur, upon these data, calculates that one vespiary may produce every year more than 30,000 Wasps, reckoning only 10,000 cells, and each serving successively for the cradle of three generations. But, although the whole structure is built at the expense of so much labour and ingenuity, it has scarcely been finished before the winter sets in, when it becomes nearly useless, and serves only for the abode of a

few benumbed females, who abandon it on the approach of spring, and never return; for Wasps never make use of the same nest for more than one season." "" *

Some Hymenopterous Insects excavate cells, for the habitation of their young, out of solid timber. The large and beautiful Violet Bee (Xylocopa violacea) of Spain, for example, bores a cylindrical hole into a post to the depth of fifteen inches, the first inch being horizontal, and the rest perpendicularly upwards. The sawdust which accumulates from the action of her jaws, she stores up in a little heap, for future use. Having completed her tunnel, she lays an egg at the furthest extremity, gluing it to the wood. She then collects the farina of flowers, and, making it into a paste with honey, covers with it the new-laid egg, and fills a space of the tunnel of about an inch in length.

Now the store of sawdust comes into request. Grain by grain she carries it in, and, with her glutinous saliva, cements it in the form of a ring to the tunnel wall, immediately under the food she has treasured up. When this has hardened, she carries in more grains, and cements them in a narrower ring to the former, proceeding thus till the whole space is occupied, and a transverse partition is formed of cemented sawdust, which completely seals up the egg and food in a closed chamber, and forms a floor for the attachment of a second egg. This she provides for and seals up also, and so proceeds till she has divided the tunnel into ten or twelve cells, each occupied by an egg, and sufficient food to meet the wants of the grub until its arrival at the winged state.

*"Insect Architecture," 75.

It is evident that, since the earliest-laid egg will be hatched first, and will soonest come to maturity, it will want its liberty before its younger brethren are ready for theirs. But it is imprisoned at the very end of the tunnel; how, then, can it be freed, without destroying all the other cells in its course? This emergency is provided for. A back-door is prepared, in the shape of a gallery, leading sideways from the furthest cell to the surface of the post; this the young Bee has the instinct to avail itself of; the rest following in succession, each breaking through its own floor, and then finding a clear passage.

There is a Bee somewhat resembling the Hive-bee, but rather stouter (Megachile centuncularis), common in summer in our gardens, which lines the tunnels that she bores in firm earth with portions of the leaves of rose-beeches. These she cuts into the required patterns with inimitable rapidity and accuracy, and forms them into thimble-like cells within the tunnel, fitting the end of one into the mouth of another, and storing each cell with an egg, and the needful store of food.

But the workmanship of this species is excelled by that of another, the Poppy Bee (Osmia papaveris). Her hole resembles in form a Florence flask, but is no more than one-third so large. The walls are made very smooth, and thus prepared for her most exquisite tapestry.

The material used for this purpose, "is supplied by the petals of the scarlet field-poppy, from which she successively cuts off small pieces of an oval shape, seizes them between her legs, and conveys them to the nest. She begins her work at the bottom, which she overlays with three or four leaves in thickness, and the sides have never

less than two. When she finds that the piece she has brought is too large to fit the place intended, she cuts off what is superfluous, and carries away the shreds. By cutting the fresh petal of a poppy with a pair of scissors, we may perceive the difficulty of keeping the piece free from wrinkles and shrivelling; but the Bee knows how to spread the pieces which she uses as smooth as glass.

"When she has in this manner hung the little chamber all round with this splendid scarlet tapestry, of which she is not sparing, but extends it even beyond the entrance, she then fills it with the pollen of flowers mixed with honey, to the height of about half an inch. In this magazine of provisions for her future progeny she lays an egg, and over it folds down the tapestry of poppy-petals from above. The upper part is then filled with earth."*

Many other examples might be given of the wonderful instinct of Insects manifested in the construction of dwellings, as those of the Mud-wasps (Pelopaus) of America, the Termites of tropical Africa, and the Ants of all countries. For these, however, we must refer our readers to works specially devoted to the economy of Insects.

*Ins. Arch." 55.

M

CHAPTER XIX.

INSECTA (Insects).

Continued.

THIS Class of minute animals is so immense, that it would be impossible within our limits to give a hundredth part of what is on record concerning them, even if we omitted all technical details, and confined ourselves to that which is popularly interesting. The study of the whole Class is felt to be far too large for one human life to embrace with any degree of completeness, and hence we hear of men eminent as coleopterists, lepidopterists, hymenopterists, &c., from their having devoted themselves to some one or other of the subordinate groups of this vast assemblage. We shall just give a bird's-eye view of these subdivisions, indicating here and there some of the more prominent points of interest for which each is distinguished.

Chief among them stands, by universal consent, the order of Beetles, principally because they are the most "perfect" of Insects. By this term "perfect" as applied to struc ture, which has sometimes stumbled uninitiated students, we do not, however, mean to imply that a House-fly or a Bug is not as perfectly adapted for its mode of life as a Beetle, nor that it is in the least degree less worthy of an