328 PHYSIOLOGY. 



wholly ceases, and the male is carried along by the female as if lifeless ; 

 thus, in many of the Chrysomelina, the male contracts all its limbs, 

 whereas the female endeavours to escape. Or both move at the same 

 time, as among the Diptera, which fly about thus occupied, and also 

 the swimming water-beetles ; or, lastly, the male alone moves, as in 

 Methoca (Tengyra) and Myrmosa, the females of which are apterous. 



In their contiguous position, which we frequently observe in those 

 Cicadaria, which are furnished with spiny processes upon their backs, 

 and, consequently, cannot sit upon each other, all motion either entirely 

 ceases, or else both sexes move at the same time ; at least, I have fre- 

 quently detected this in some of our native Cicadaria, for example, the 

 species of the genera Jassiis and Aphrophora. 



The contiguous position is found chiefly in the crepuscular and 

 nocturnal Lepidoptera. In these, generally, all motion ceases ; both 

 constantly remain in repose ; or else the female alone moves, drawing 

 the male with it, as in the cockchafer. 



With respect to the duration of the act, we can say but little that 

 applies generally. From what precedes, it will have been seen, that in 

 some, for example, the butterflies, it quickly transpires. The same is 

 the case in the Hymenoptera, viz. in the bees. Others remain for 

 some hours in this situation, others again several days, as the 

 cockchafer. These, cohsequently, do not repeat the connexion, one 

 union being sufficient for impregnation : others, as the domestic fly, 

 appear to copulate several times successively : it is also probable that 

 the queen bee has intercourse with several males. Perhaps, also, the 

 intercourse may be repeated in such insects in which it rapidly trans- 

 pires, but many genera, for example, Ephemera, may make an exception 

 to this rule. 



Peculiar organs adapted to facilitate the duration of the connexion, 

 are found in many insects. The Carabodea, according to Leon Dufour, 

 have hooks at the penis, by which they retain the female, and the 

 distended tarsi with their sucking cups in the male water-beetles, 

 are also subservient to this purpose. In others, namely, Panorpa, 

 Laphria, Asilus, Dolichopus, Tipula, the penis lies between fangs, 

 which retain the pointed apex of the female's abdomen ; in the males 

 of many Meloe and wasps, the male antennae are hooked ; in the male 

 Crabros, the anterior tibiae are distended into lateral lobes, by means 

 of which they cling to the thorax of the females ; in the Lepidoptera, the 

 sexual organs of both sexes have hooks, which retain each other during 



