288 MANUAL OF ZOOLOGY. 



tremity of the abdomen mostly furnished with an ovipositor 

 (terebra or acnleus], consisting chiefly of three elongated pro- 

 cesses, of which two serve as a sheath for the third. Besides 

 the compound eyes, there are usually three ocelli placed on 

 the top of the head. The antennae are generally filiform or 

 setaceous. The metamorphosis is complete, but the various 

 parts of the pupa are visible through the delicate enclosing mem- 

 brane. The larvae are sometimes provided with feet, and live 

 on vegetable food (as in the Tenthredinidce, fig. 1 16); but they are 

 mostly footless, without a distinct head, and fed by the adult. 



The Hymenoptera form a very extensive order, comprising 

 the Bees, Wasps, Ants, Ichneumons, Saw-flies (fig. Ti6), &c. 

 The ovipositor, which is very generally present in the females 

 of this order, is sometimes a boring organ (terebra), or in other 

 cases a " sting " (aculeus}. 



Amongst the Hymenoptera we find social communities, in 

 many respects resembling those of the Termites, of which a 

 description has already been given. The societies of Bees 

 and Ants are well known, and merit a short description. 



The social Bees, of which the common Honey-bee (Apis 

 mellifica) is so familiar an example, form organised communities, 

 consisting of three classes of individuals the males, females, 

 and neuters. As a rule, each community consists of a single 

 female " the queen " and of the neuters, or " workers." The 

 impregnation of the female is effected by the production of 

 males, or " drones," during the summer. After impregnation 

 has been effected, the aiunes, us being then useless, are de- 

 stroyed by the workers. The eggs produced by the fecundated 

 queen are mostly intended to give origin to neuters, to which 

 end they are placed in the ordinary cells. The ova which are 

 to give origin to females the " queens " of future colonies 

 are placed in cells of a peculiar construction, and the larvae 

 are fed by the workers with a special food. The ova which 

 are to produce males are likewise placed in cells, which are 

 slightly larger than those allotted to the workers. It is 

 asserted, however, that this is not the sole or true cause of the 

 production of the males ; but that the ova which are intended 

 to produce drones are not fertilised by the female with the 

 semen which she has stored up in her spermatheca, and are 

 therefore produced by a process of Parthenogenesis. That 

 the males are produced parthenogenically in some, at any 

 rate, of the Hymenoptera, appears to have been placed beyond 

 a reasonable doubt by the researches by Von Siebold. (See 

 Introduction.) 



In the Humble-bees (Bombid(z\ and in the Wasps ( Vespidcz), 



