248 THE DESCENT OF MAN. 



rufocinerea. It is well known that it 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 in confinement. 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 pock- 

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

 the house with him." 



Mr. Doubleday has called my attention to M. Staudinger's"^ list 

 of Lepidoptera, which gives the prices of the males and females 

 of 300 species or well-marked varieties of butterflies (Rhopalo- 

 cera). 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 propoi-- 

 tion. About 2000 species or varieties of moths (Heterocera) are 

 catalogued, those with wingless females being here excluded on 

 account of the difference in habits between the two sexes: of 

 these 2000 species, 141 differ in price according 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 butter- 

 flies in this priced list, Mr. Doubleday thinks (and no man in 

 England has had more experience), that there is nothing in the 

 habits of these species which can account for the difference in 

 the prices of the two sexes, and that it can be accounted for only 

 by an excess in the number of the males. But I am bound to 

 add that Dr. Staudinger informs me, that he is himself of a dif- 

 ferent opinion. He thinks that the less active habits of the fe- 

 males and the earlier emergence of the males will account for 

 his collectors securing a larger number of males than of females, 

 and consequently for the lower prices of the former. With respect 

 to specimens reared from the caterpillar-state. Dr. Staudinger 

 believes, as previously stated, that a greater number of females 

 than of males die whilst confined in the cocoons. He adds that 

 with certain species one sex seems to preponderate over the other 

 during certain years. 



Of direct observations on the sexes of Lepidoptera reared 



'^ Blancharcl, 'Metamorphoses, Moeurs des Insectes,' 1868, pp. 225-226. 

 •^ 'Lepidopteren-Doubletten Liste,' Berlin, No. x. 1866. 



