78 SUPPLEMENT ON 



hymenoptera, principally in ants, wasps, bees, and in some 

 neuroptera or hemiptera, as the termites and pucerons. It 

 is seldom that insects of one and the same species live in 

 pairs, or in a state of monogamy. The necessity of fecun- 

 dation alone brings them together for a very short time ; 

 shortly after this function is performed the male perishes, 

 but the female survives until after the eggs have been laid. 

 It would seem that the early age of the insect is employed 

 in the elaboration of those juices alone, which are to serve 

 for the work of generation : for as soon as these animals have 

 assumed their final form, and have obtained the faculty of 

 giving or receiving the fluid which transmits life, they 

 couple, lay, and die. The males are in general smaller than 

 the females, they are more elegantly formed, more brilliant 

 and better coloured. The forms of the antennae, of the 

 wings, and especially of the extremity of the abdomen, where 

 the sexual organs and the instruments destined to place the 

 eggs in situations most favourable to their development, 

 often exhibit notable differences. 



Thus the males of ants, of the cochineal insects, of puce- 

 rons, and of some herbivorous coleoptera, are exceedingly 

 small if compared with the females. The antennae of bom- 

 byces, of rhipiptera, and others, are much more developed in 

 the males. The wings of some male insects have scarcely 

 any relations with those of the females. Some females are 

 even altogether without wings. 



In the majority of insects, the sexual organs are placed at 

 the extremity of the abdomen. They most usually cause an 

 external projection in the males, and sometimes in the 

 females. In some species however, the female organs are 

 differently disposed from those of the male. 



The noises produced by some insects are manifestations of 

 the desire of reproduction, and guides of one sex to the other. 

 The phosphoric emissions of others during the obscurity of 



