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Show 312 TIJE PHTNCirLES OF PART II. Mr. Doubleday believes that be 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. V errcaux, in Australia, having place~1 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.63 Mr. Doubleday has called my attention to Dr. Staudinger's 64 list of Lepidoptera, which gives the prices of the males and females of 300 species or well-marked varieties of (Hhopalocera) butterflies. 'l'he 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 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 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 sexe~, 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. Staudincrer himself as he informs me, is of a different opinion. He thinks"' that the icss. 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 Blan?hard, 'Metamorphoses, Mreu rs des Insectes,' 1868, p. 225-226 .. <VI 'Le.pidopteren-Doubblettren Liste,' Berlin, No. x. 1866. CIIAP. VIII. SEXUAL SELECTI ON'. 313- from eggs or caterpillars, I have received only the few following cases:- The Rev. J. Hell ins 65 of Exeter reared, during 1868, imagos of 73 species, which consisted of • . • . Mr. Albert Jones of Eltham reared, during 1868, imagos of 9 species, which consisted of . . . . . . During 1869 he reared imagos from 4 species, consist-ing of • . • • . • . • . • • . • . . • . . Mr. ~uckler of Emsworth, Hants, during 1869, reared 1magos from 7 4 species, consisting of . . . • . . Dr. Wallace of Colchester reared from one brood of Bombyx cynthia . • • • • • • . • . . . . . Dr. Wallace raised, from cocoons ofBombyx Pernyi sent from China, during 1869 . . . . . . . . Dr. Wallace raised, during 1868 and 1869, from two lots of cocoons of Bombyx yama-mai • . . . Total .. Males. Females. 153 137 159 126 11-l 112' 180 1G9 52 4S 224 123 52 46 934 7Gl So that in these eight lots of cocoons and eggs, males were produced in excess. 'l'aken together the proportion of males is as 122·7 to 100 females. But the numbers an' hardly large enough to be trustworthy. On the whole, from the above various sources of evidence all pointin2; to the same direction, I infer that with mo$t speci;s of Lepidop~era, the males in the imago state generally exceed the females m number, whatever the proportions may be at their first emergence from the egg. With reference to the other Orders of insects, I have been able to collect very little reliable information. With the starr-beetle (Lucamts cervus) "the males appear to be much more n~erous "than the females;" but when, as Cornelius remarked durin"' 1867 an unusual number of these beetles appeared in one part ~f Ger~ many, the females appeared to exceed the males as six so one. With one of the Elateridru, the males are said to be much more numerous than the females, and "two or three are often found "united with one female ,66 so that here polyandry seems to prevail. 65 This naturalist has been so kind as to sr.nd me some results from former 1ears, in which. the females seemed to preponderate ; but so many of J6 he ~.gures ,were estimate~, that_! found it impossible to tabulate them: Gunther s 'Record of Zoolog1cal Literature,' 1867, p. 260. On the excess of female Lucanus, ibid. p. 250. On the males of Lucanus in EnO'~ a~d, West~vood, 'Modern Class. of Insects,' \OJ. i. p. 187. On the Siagoniun~, Ibid. p. 17 -· |