Chap. YIIL] SEXUAL SELECTION. 303 



and consume more food and moisture ; and thus they would be 

 exposed during a longer time to danger from ichneumons, birds, 

 etc., and in times of scarcity would perish in greater numbers. 

 Hence it appears quite possible that, in a state of nature, fewer 

 female Lepidoptera may reach maturity than males ; and for our 

 special object we are concerned with the numbers at maturity, 

 when the sexes are ready to propagate their kind. 



The manner in which the males of certain moths congregate 

 in extraordinary numbers round a single female, apparently indi- 

 cates a great excess of males, though this fact may perhaps be 

 accounted for by the earlier emergence of the males from their 

 cocoons. Mr. Stainton informs me that from twelve to twenty 

 males may often be seen congregated round a female ElacMsta 

 rufocinerea. It is well known that if a virgin Lasiocampa quercus 

 or Saturnia carpini be exposed in a cage, vast numbers of males 

 collect round her, and if confined in a room will even come down 

 the chimney to her. Mr. Doubleday believes that he has seen 

 from fifty to a hundred males of both these species attracted in 

 the course of a single day by a female under confinement. Mr. 

 Trimen exposed in the Isle of Wight a box in which a female of 

 the Lasiocampa had been confined on the previous day, and five 

 males soon endeavored to gain admittance. M. Verreaux, in 

 Australia, having placed the female of a small Bombyx in a box 

 in his pocket, was followed by a crowd of males, so that about 

 two hundred entered the house with him. 68 



Mr. Doubleday has called my attention to Dr. Staudinger's 64 

 list of Lepidoptera, which gives the prices of the* males and 

 females of 300 species or well-marked varieties of (Rhopalocera) 

 butterflies. The prices for both sexes of the very common species 

 are of course the same; but with 114 of 'the rarer species they 

 diner ; the males being in all cases, excepting one, the cheapest. 

 On an average of the prices of the 113 species, the price of the 

 male to that of the female is as 100 to 149 ; and this apparently 

 indicates that inversely the males exceed the females in number 

 in the same proportion. About 2,000 species or varieties of 

 moths (Ileterocera) are catalogued, those with wingless females 



63 Blanchard, 'Metamorphoses, Moeurs des Insectes,' 1868, pp. 225, 226, 



64 ' Lepidopteren-Doubblettren Liste,' Berlin, No. x. 1866. 



