312 
THE PRINCIPLES OF 
Part B- 
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 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.® 
Mr. Doubleday has called my attention to Dr. Staudinger’s 84 list 
of Lepidoptera, which gives the prices of the males and females of 
300 species or well-marked varieties of (Rkopaloeera) butterflies. 
Ihe prices lor both sexes of the very common species are of 
course the same ; hut with 114 of the rarer species they differ ; th 8 
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 140; and this apparently indicates chat 
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 ot only 11 being dearer than the females. 
The average price ot 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. Staudingcr himself, as 
he informs me, is of a different opinion. He thinks that the less 
active habits of the lemales and the earlier emergence of the males 
will account for his collectors securing a larger number of males than 
ot females, and consequently for the lower prices of the former. 
With respect to specimens reared from the caterpillar- state, Dr- 
Staudingcr 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. 
Oi direct observations on tko sexes of Lepidoptera, roared either 
Blanchard, ‘ Metamorphoses, Moeurs des Insectes,’ 1868, p. 225-226. 
‘ Lcpidopteren-Doubblettren Liste,’ Berlin, No. x. I860. 
