.312 THE PRINCIPLES OF Part II. 



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. Trim en 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 endeavoured 

 to gain admittance. M. "Verreaux, in Australia, having placed 

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

 lowed by a crowd of males, so that about 200 entered the house 

 with him. 63 



Mr. Doubleday has called my attention to Dr. Standi nger's 64 list 

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

 300 species or well-marked varieties of (Ehopalocera) butterflies. 

 The prices for both sexes of the very common species are of 

 course the same ; but with 114 of the rarer species they differ ; the 

 males being in all cases, excepting one, the cheapest. On an ave- 

 rage 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 2000 species or varieties of moths (Heterocera) 

 are catalogued, those with wingless females being here excluded on 

 account of the difference in habits of the two sexes : of these 2000 

 species, 141 differ in price according to sex, the males of 130 being 

 cheaper, and the males 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 

 priced 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 excess in the numbers of 

 the males. But I am bound to add that Dr. Staudinger himself, as 

 he informs me, is of a different opinion. He thinks that the less 

 active habits of the females 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 under confinement 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 either 



63 Blanchard, ' Metamorphoses, Mceurs des Insectes,' 1868, p. 225-226, 

 H4 ' Lepidopteren-Doubblettren Liste,' Berlin, No. x. 1866, 



