SEXUAL SELECTION 333 



known tliat 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 

 tlie 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 in con- 

 finement. In the Isle of Wight Mr. Trimen exposed a box 

 in which a female of the Lasiocampa had been confined 

 on the previous day, and five males soon endeavored to 

 gain admittance. In Australia, M. Verreaux, having placed 

 the female of a small Bombyx in a box in his pocket, was 

 followed by a crowd of males, so that about 200 entered 

 the house with him." 



Mr. Doubleday has called my attention to M. Stau- 

 dinger's*'' list of Lepidoptera, which gives the prices of the 

 males and females of 800 species of well-marked varieties 

 of butterflies (Ehopalocera). The prices for both sexes of 

 the very common species are of course the same; but in 114 

 of the rarer species they differ; the males being in all cases, 

 excepting one, the cheaper. 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 the same proportion. About 

 2,000 species or varieties of moths (Heterocera) are cata- 

 logued, those with wingless females being here excluded 

 on account of the difference in habits between the two 

 sexes: of these 2,000 species, 141 differ in price accord- 

 ing to sex, the males of 130 being cheaper, and those of 

 only 11 being dearer, than the females. The average price 

 of the males of the 130 species, to that of the females, is 

 as 100 to 143. With respect to the butterflies in this price 

 list, Mr. Doubleday thinks (and no man in England has had 

 more experience) that there is nothing in the habits of the 

 species which can account for the difference in the prices of 

 the two sexes, and that it can be accounted for only by an 



81 Blanchard, "Metamorphoses, Maeurs des Insectes," 1868, pp. 225-226. 

 ^^ "Lepidopteren-DouWetteu Lists," Berlin, No. x., 1866. 



