that it was a wasp, and the remainder thought it to be a hornet. A very reduced figure of the insect is shown in the illustration, and will give a good idea of its general form. In size it is exceedingly variable, some specimens being twice as large as others.

The Sirex is a terrible destroyer of fir-wood, in some cases riddling a tree so completely with its tunnels that the timber is rendered useless. In a little fir-plantation about two miles from my house, there are a number of dead and dying trees, and almost every tree shows the ravages of this destructive insect. The absence of external holes is no proof that the Sirex has not attacked the tree, for they are only the doors through which the insect has escaped from the tree into the world.

The mode in which the Sirex carries on its operations is simple enough.

With the long and powerful ovipositor the mother insect introduces her eggs into the tree, and there leaves them to be hatched. As soon as it has burst from the eggs the young grub begins to burrow into the tree, and to traverse it in all directions, feeding upon the substance of the wood, and drilling holes.

of a tolerably regular form. Towards the end of its larval existence it works its way to the exterior of the trunk, and there awaits its final change, so that when it assumes its perfect form it has only to push itself out of the hole, and so finds itself in the wide world. The insects may often be seen on the trunks of the trees, clinging to the bark close to the hole out of which they have emerged. Sawyers frequently destroy the grubs while they are cutting trees into planks, but as many of the larvæ escape the saw, they remain in the boards, and afterwards emerge in houses, to the great consternation of the inmates. Should such a circumstance occur in the house of any reader of this book, he may at once infer that the wood from which the insect escaped was not properly seasoned. I have known the Sirex to be so numerous that it has fairly driven the inhabitants out of their rooms, for it has a very ferocious appearance, and, on account of its long ovipositor, is always thought to be armed with a venomous sting of peculiar potency.

Two species of Sirex inhabit this country. In general appearance they are very similar to each other, but the species just mentioned is nearly twice the size of its relative. They inhabit similar localities, and I have now before me a piece of a fir tree in which are the holes of both species. These insects are not only interesting in their habits, but they furnish many beautiful objects for the microscopist.

IN the accompanying illustration, we have three excellent examples of wood-boring insects. In the centre of the drawing is seen a portion of a tunnel, which is completely hollowed out, and divided into cells. This is the dwelling which is constructed by the splendid South African CARPENTER BEE (Xylocopa Capensis), a wood-borer of great power. She sets about her work in a curiously systematic manner, each action being exactly calculated, nothing left to chance, and all useless labour saved.

When the insect has fixed upon a piece of wood which suits her purpose, usually the trunk or branch of a dead tree, an old post, or a piece of wooden railing, she bores a circular hole about an inch and a half in length, and large enough to permit her to pass. Suddenly, she turns at an angle, and drives her tunnel parallel to the grain of the wood, and makes a burrow of several

inches in length. None of the chips and fragments are wasted, but are carried aside and carefully stored up in some secure place, sheltered from the action of the wind.

The tunnel having now been completed, the industrious insect seeks rest in change of employment, and sets off in search of honey and pollen. With these materials she makes a little heap at the bottom of the tunnel, and deposits an egg upon the food which she has so carefully stored.

Having now shown her powers as a burrower and a purveyor, she exhibits her skill as a builder, and proceeds to construct, above the inclosed egg, a ceiling, which shall be also the floor of another cell. For this purpose, she goes off to her store of chips, and fixes them in a ring above the heap of pollen, cementing them together with a glutinous substance, which is probably secreted by herself. A second ring is then placed inside the first, and in this manner the insect proceeds until she has made a nearly flat ceiling of concentric rings. This ceiling bears some resemblance to the operculum of the conimon water snail. The reader will probably remember, that the ceilings constructed by the ant are made on similar principles. The thickness of each ceiling is about equal to that of a penny.

The number of cells is extremely variable, but on the average each tunnel contains seven or eight, and the insect certainly makes more than one tunnel. As each tunnel generally exceeds a foot in length, and the diameter is large enough to admit the passage of the wide-bodied insect who makes it, the amount of labour performed by the bee is truly wonderful. The jaws are the only boring instruments used, and though they are strong and sharp, they scarcely seem to be adequate to the work for which they are destined.

In the illustration, the upper part of one of these tunnels is shown, and in the two uppermost cells the egg has not been hatched. In the lower cells the young larva is given, in order to show the attitude in which it passes its early life. When all is completed the entrance is closed, with a barrier formed of the same substance and in the same manner as the ceilings.

As far as is yet known, no member of the genus Xylocopa is indigenous to this country.

Among the insect nests in the British Museum is a fine example of the burrow made by a Brazilian member of this