OK GENERATION. 325 



Donovan, may be one species. In all these instances the male is darker 

 coloured and more brightly marked, whereas the markings of the female 

 are dirty and confused. In the extensive genus of blues (LycoziKB) the 

 upper side of the males are almost all of a beautiful sky-blue, and the 

 females brown ; or the former are bright yellow-brown and the latter 

 of a dark brown. In the large Bombyces, in the genus Attacus, for 

 example, the markings of the male are much more decided, brighter, 

 and distinct, whereas the colour and markings of the fe males are con- 

 fluent. The same is the case in the Geometers. In the other orders 

 we find a similar relation, particularly in the above mentioned Coccus, 

 in which the small males have frequently beautiful markings upon their 

 wings, whereas the females are uniformly brown-grey, or at least 

 always darker. In all these sexual differences insects are paralleled by 

 the birds. We here also in general find larger females, but the males 

 are invariably more beautifully marked, have longer wings, longer 

 crests, and spurs, which are wanting in the female. This, conse- 

 quently, still further confirms the analogies of both classes pointed out 



above. 



207- 



The act which precedes impregnation, arid consists in the sexual 

 union, is called copulation (cojmla). We shall consider it in the order 

 of its time, place, duration, and particular relations. 



As insects are preeminently animals of light, consequently the most im- 

 portant occupation of their lives (namely, copulation,) takes place in the 

 light, that is, by day. This we find confirmed in all true diurnal insects. 

 The butterflies copulate about noon, in the brightest sunshine. When 

 the female has placed itself upon a flower or a leaf the male flies to her 

 and flutters around her in a caressing manner ; if agreeable to his caresses 

 she indicates it by a gentle pulsation of her wings, and raising her 

 abdomen upwards the male flies down, and copulation ensues. The com- 

 mon domestic fly copulates constantly in windows in the sun, the male 

 ascending the body of the female, and instantly quitting it each flies off, 

 resuming its preceding business. Bees, which live solitarily and in pairs, 

 are frequently found copulating upon flowers which the female has visited 

 in her industrious and laborious pursuit, and even without any cessation 

 of her labours, and just as speedily as each accomplishes its amorous 

 desires does their love cease; they then avoid each other as before, and 

 the female continues, but perhaps more zealously, her preceding occu- 



