304 THE PRINCIPLES OF [Part II. 



being here excluded on account of the difference in habits of the 

 two sexes : of these 2,000 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 ac- 

 counted 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 from eggs or caterpillars, I have received only the few fol- 

 lowing cases : 



Males. Females. 



The Rev. J. Hellins, 05 of Exeter, reared, during 18G8, imagos of 73 



species, which consisted of 153 137 



Mr. Albert Jones, of Eltham, reared, during 1868, imagos of 9 species, 



which consisted of 159 120 



During 1869 he reared imagos from 4 species, consisting of 114 112 



Mr. Buckler, of EmsworuY, Hants, during 1869, reared imagos from 



74 species, consisting of 180 169 



Dr. "Wallace, of Colchester, reared from one brood of Bombyx 



cynthia 52 48 



Dr. Wallace raised, from cocoons of Bombyx Pernyi sent from 



China, during 1869 224 123 



Dr. Wallace raised, during 1868 and 1869, from two lots of cocoons 



of Bombyx yama-mai 52 46 



Total 934 761 



So that in these eight lots of cocoons and eggs, males were 

 produced in excess. Taken together, the proportion of males is 



65 This naturalist has been so kind as to send me some results from 

 former years, in which the females seemed to preponderate ; but so many 

 of the figures were estimates, that I found it impossible to tabulate them 



