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Show 236 INSECTA. are frequently concealed or considerably re?uced. The or· gans of generation are situated a~ the po~ter10r extremity and issue through the anus. The luh and Ltbellulre alone consti. tute exceptions. The last annuli of the abdomen, in several fe. males, form a retractile or always projecting ovipositor-oviscapte of Marcel de Serres-more or less complicated, which act as an auger. A sting is substituted for it in many of the female Hymenoptera. The fecundating organ of the male is almost always provided with hooks or a forceps(l). The sexes usually copulate but once, and this junction in certain genera is even sufficient for the fecundation of several successive generations. The male places himself on the back of his mate, and remains there for some time. The latter soon lays her eggs(2), and deposits them in the way best adapted for their preservation, and in such a manner that the moment the larvre make their appearance, suitable aliment is always within their reach. Frequently she collects provisions for them. This maternal solicitude often excites our surprise, and more particu· larly unveils the instinct of Insects. In the numerous societies of several of these animals, such as the Ant, Termes, Wasp, Bee, &c., those individuals which form the greater portionof the community, and by whose labour and vigilance thewhole community are maintained, have been considered as being of neither sex. They have also been designated by the terms of labourers and mules. It is now known, however, that they are females, whose sexual organs or ovaries have not been fully developed, and that if an amelioration of their diet per· (1) The generating organs of the male consist of an apparatus for the elabora· tion of the semen, and of the parts proper to copulation. The preparatory ap. paratus is composed of testes, vasa deferentia, and vesicula: seminales. The copu· Jating instrument is a penis provided with an armature consisting of surrounding parts, of various forms, acting like pincers or forceps, with which the male seizes the posterior extremity of the body of the female. The sexual apparatus of the latter is composed of an ovdry, the receptacle or calyx fonned by its base and the oviduct. For more minute details, see the memoirs of M. Dufour, Ann. des Sc. Nat., and the Dissertation of llegetschweiler, Zurich, 1820. (2) M. Audouin supposes, that in a great number of Insects, the ova are fecun· dated, as they descend, in a sac situated near the aims; but this idea requires to be ~onfirmed hy experiment, and one of those naturalists who have most closely studied the anatomy oftht!Se animals, M. Dufour, is of a different opinion. INSECTA. 237 feet those organs at a particular epoch while they are young, they become fruitful. The ova are sometimes hatched in the abdomen qf the mother; she is then vivipa'rous. The number of generations in 8 year depends on the duration of each of them. Most commonly there is but one or two. A species, all things being equal, is so much the more common, as one generation succeeds more rapidly to another, and as the female is more pro-lific. A female Papilio or Butterfly, post coitum, lays her eggs, from which are hatched, not Butterflies, but animals with an elongated body, divided into rings, and a head furnished with jaws and several small eyes, having very short feet, six of which are anterior, scaly, and pointed, the rest varying in number and membranous, being attached to the posterior annuli. These animals, called caterpillars, live in this state for a certain period, and repeatedly change their skin. An epoch, however, arrives, when from this skin of a caterpillar issues a totally different being, of an oblong form and without distinct limbs, which soon ceases to move and remains a long time apparently desiccated and dead under the name of a chrysalis. By close examination we may discover on the external surface of this chrysalis, lineaments which represent all the parts of the Butterfly, but under proportions differing from those they are one day to possess. After a longer or shorter period, the skin of the chrysalis splits, and the Butterfly, humid and soft, with flabby short wings, issues from it-a few moments, however, and it is dry, the wings enlarge and become firm, and the perfect animal is ready for flight. It has six long legs, antenn: e, a spiral proboscis, and compound eyes-in a word, it has no resemblance whatever to the caterpillar, from which it has originated, for it is ascertained that these various changes are nothing more than the successive development of parts contained one within the other. This is what is styled the metamorphosis of Insects. In their first condition they are called larvre, in their second |