236 INSECTA. 



are frequently concealed or considerably reduced. The or- 

 gans of generation are situated at the posterior extremity and 

 issue through the anus. The Iuli and Libellulae alone consti- 

 tute exceptions. The last annuli of the abdomen, in several fe- 

 males, form a retractile or always projecting ovipositor ovis- 

 capte 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 suc- 

 cessive 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 

 larvss 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 portion of 

 the community, and by whose labour and vigilance the whole 

 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- 

 lating 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 ovary, the receptacle or calyx formed by its base and the 

 oviduct. For more minute details, see the memoirs of M. Dufour, Ann. des Sc. 

 Nat., and the Dissertation of Hegetschweiler, 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 anus; but this idea requires to be 

 confirmed by experiment, and one of those naturalists who have most closely 

 studied the anatomy of these animals, M. Dufour, is of a different opinion. 



