much more easily procured than queen-bees, and what we cannot display in one specimen we may find in another, with leisure and patience. Glands, tubes, and membranes, in their elementary forms, are of such universal occurrence, and are structures of such plasticity of development, that organs composed of these materials admit of great variety of form, and occur-are improvised-almost anywhere. Such are the simple appendages to the oviduct which we have just been tracing. They are mere appendages to what is itself merely the duct of another organ. The materials of which they are made are not peculiar to the parts, for they are found everywhere; it is their plasticity that is peculiar, their power of adaptation to all the minutiae of local requirements. This very power tells us not to expect to find identity of form here in the two sexes respectively; and least of all in parts where the correspondence is essentially one not of uniformity but of reciprocity. In the ovaries however we see, at once, that we are dealing with a more important structure, and the analogy to the testes of the male is complete, both in internal structure and in external conformation and relations. Just, in fact, as in the higher animals. As we follow the uterus, or, in accordance with these views of its functions, the oviduct backwards, we observe that it divides into two horns. These are again each subdivided into six egg Fig. 10.-Uterus, N tubes, which are called, collectively, the ovaries of either side, and are filled with eggs in different stages of development. The eggs which lie nearest the uterine end of the tubes are much more advanced than those farther in. As we follow the tubes inwards the eggs are found to be smaller, harder, and of a whiter colour. Hunter* counted fifty eggs, though with some difficulty, in one of the twelve egg-tubes of a hornet. I have never counted more than seventy eggs, rudimentary or well-developed, in the entire ovaries of a wasp; rarely more than half that number. While the ovaries of the female honey-bee contain more than ten times as many. My observations were mostly made on wasps taken in the early summer, and of course this number did not represent all the wasps which were to be developed in the course of the season, but only so many eggs or germs as were sufficiently advanced at that time to be visible. Still, making all allowances, the fertility of wasps is really much inferior to that of the honey-bee. Not only are the eggs fewer, but the egg-tubes are much fewer. And the difference is apparent at whatever period the examination of the ovaries be made, whether they have been taken from the queen-mother of a thriving swarm in July, or from the strong-minded female who has to be servantof-all-work to the infant swarm in May or June. The organs, which have been just traced in the perfect female, may be found in a more or less imperfect form in nearly all the workers, which are, in fact, * 'Posthumous Works,' by Owen. Vol. I, p. 80. See Swammerdam. Bybel des Natuure.' Tab. XIX, Fig. 3. Folio Ed.; also Rymer Jones. 'Animal Kingdom,' Fig. 127, p. 283. imperfect females. We owe the discovery of the female sex of the workers of the honey-bee to Mademoiselle Jurine.* Not to anticipate here what there will be occasion to discuss fully at a later period, I would only add that the rudimentary female organs are usually much less perfectly developed, and found, accordingly, with much greater difficulty in the worker-bee than in the worker-wasp. To the general reader the part of these organs that has the greatest interest is unquestionably the sting. In the higher animals, with the exception of many birds and some beasts of prey, the male is most commonly the more powerful of the two sexes, and wears the offensive armour. But in insects, as in spiders, this order is generally reversed; and, with the care of the young, which devolves on the female, is given the means of protecting them. Aristotlet has a singular remark that, "insects with four wings are distinguished by their greater size or a caudal sting. The Diptera are either such as are small, or have a sting in their head." In both these classes alike it is the female which carries the weapon; not only in the Hymenoptera, where the sting consists of a portion of the male organs in a transformed state, but in the Diptera, where the biting instrument is common to both sexes. Fleas know no such distinction, and the male seems to bite worse than the * I have no more direct authority at hand to refer to for this statement than the note in Van Der Hoeven's' Handbook,' Vol. I, p. 271, with references to Huber, 'Nouv. Observ. sur les Abeilles.' Aristotle's History of Animals,' transl. by Cresswell, p. 8, Book I. chap. V, § 5. female; besides, from his smaller size, and from his never being encumbered with the internal burden of a family, being much harder to catch. But it is the female mosquito and the female horse-fly only which bite. To procure a sting and all its appendages for examination, the best way is, as before, to press the abdomen of a recent specimen till the sting, and the muscular bulb to which it is attached, protude. Now, grasp the sting at its root with a pair of forceps, and draw it gently out, still keeping up the pressure. By this means we may secure the sting, the bulbous mass which moves it, and the poison bag, all together. As with regard to the ovaries, it is best to secure as many specimens of stings, and of as large a size, as we can, and set them aside in glycerine against a leisure afternoon. They will need, however, very little dissection. Under a low power of the microscope, brightly illuminated on a black back-ground, the chief anatomical characters will be readily made out. And first of the sting itself. This consists of two very fine triangular bristles, presenting on the outer side a sharp edge finely serrated at the point, and on the inner side a flat channelled surface, where they lie in juxta-position, along the middle line, like two bayonets laid together. These are the barbs. The scabbard, in which they slide, is a flat horny piece of considerable strength which most people, without a microscope, would take for the sting. It is connected at its inner end with the muscular bulb, and has its edges turned over to form guides for the barbs. It is nearly straight in the workers, but strongly curved in the females, and tapers towards its free end. The curved form of the scabbard gives the barbs a certain amount of elasticity, without which such delicate instruments could scarcely be driven into any hard substance, while the fact of its tapering keeps the barbs close together at their points. Within the body, where they no longer need the protection of the scabbard, the barbs leave the groove and, still diverging from each other, bend round either side of the muscular bulb till they end by being articulated at right angles to a strong horny limb or lever, which gives attachment to powerful muscles. By a rapid alternate movement of these levers the barbs are driven into the wound, the teeth of one barb acting as a fulcrum for the other. The two channelled surfaces on the inner side of the barbs are pressed firmly against each other, so as to form a closed tube between them, down which, with all the force the muscular walls of the poison bag can exert, the venom is injected quite to the bottom of the wound. The poison bag, which is readily recognizable as a hard roundish white body, is a strong hollow muscle made in four segments, like a foot-ball, the fibres. of each segment meeting those of the adjoining ones at an acute angle. At one end of this bag, two long glands may be observed, which secrete the poison. From the opposite end issues a long, strong duct, which conveys the poison from the interior of the bag |