_The Abdomen_ is, then, the only remaining portion of the insect which we have now to notice. It has no legs attached to it, and contains the intestines, and other portions of the insect's internal anatomy. It is formed of a varying number of rings, which are easily distinguishable in the wasp and many other insects, and these rings are connected together by delicate folds of membrane, fitting sometimes into each other like the tubes of a telescope; in other instances fastened together, like so many hoops, by their edges. In consequence of this mode of structure it is often very movable, and may even be bent into a half curve, in various directions, at the pleasure of the insect. The common earwig is particularly gifted with this movableness of its abdomen; and so are many insects which carry weapons of offence or defence in their tails. These organs, or appendages, are deserving of a brief notice, although it is probable that the structure of some of them is already familiar to most readers.
[Illustration: _A Bee's Sting magnified._ _a_, represents the pair of darts; _d_, a single dart; _b_, the poison-bag; and _c_, the sheath.]
The sting of the bee is, perhaps, as formidable a weapon as any of those attached to the abdomen in insects; under the microscope the structure of this apparatus appears in all its beauty. It is found to consist of a sort of sheath, or scabbard, which is composed of two pieces, and is of extreme fineness, as will be readily made visible by placing a fine sewing needle by its side, when the latter will more resemble a bar of iron from the smith's forge, or a kitchen poker, than anything else; while the former will, under the strongest magnifying power, exhibit a smoothness, elegance, and polish, of the most beautiful description. When the bee thrusts forth its sting, it is the sheath which we generally see, and not the more delicate apparatus which is enclosed within it. Inside this scabbard is a pair of most fine darts, which are even more delicate than the human hair, and are therefore invisible to the eye, unassisted by a good lens. These darts are notched like very fine saws at the end, the teeth being so directed as to oppose the retraction of the instrument if it is thrust into the human skin; the sting being therefore left in the wound, and the wounded person having the comfort of knowing--if we should call it a comfort--that the insect will surely die speedily, in consequence of its attack upon him. An exquisite adaptation of fine muscles is attached to this weapon, by which it is forcibly driven home. The venom which produces the pain and inflammation is contained in a small muscular bag in connexion with the sting; and when the latter is thrust out, the poison is also forced out and flows into the wound. The sting of the scorpion is a less complicated, but more dangerous weapon, though not often fatal. The earwig, though unprovided with a sting, carries a most awful-looking forceps in its tail, which it can put in action with great force on occasion of danger; and since it can twist its abdomen about with great facility, it is a contrivance of which a tender finger may well be afraid.
