402 
SEXUAL SELECTION. 
Part II. 
to colour there is no difficulty, as any number of highly 
variable Lepidoptera could be named. One good in- 
stance will suffice. Mr. Bates shewed me a whole series 
of specimens of Pajpilio sesostris and childrens ; in the 
latter the males varied much in the extent of the beau- 
tifully enamelled green patch on the fore-wings, and 
in the size of the white mark, as w r ell as of the splendid 
crimson stripe on the hind-wings ; so that there was 
a great contrast between the most and least gaudy 
males. The male of Papilio sesostris , though a beautiful 
insect, is much less so than P. cliildrense. It likewise 
varies a little in the size of the green patch on the fore- 
wings, and in the occasional appearance of a small 
crimson stripe on the hind-wings, borrowed, as it would 
seem, from its own female ; for the females of this and 
of many other species in the iEneas group possess this 
crimson stripe. Hence between the brightest specimens 
of P. sesostris and the least bright of P. childrens , there 
was but a small interval ; and it was evident that as far 
as mere variability is concerned, there would be no 
difficulty in permanently increasing by means of selec- 
tion the beauty of either species. The variability is 
here almost confined to the male sex ; but Mr. Wallace 
and Mr. Bates have shewm 18 that the females of some 
other species are extremely variable, the males being 
nearly constant. As I have before mentioned the Ghost 
Moth (. Hejoialus humuli ) as one of the best instances in 
Britain of a difference in colour between the sexes of 
moths, it may be worth adding 19 that in the Shetland 
18 Wallace on the Papilionidae of the Malayan Region, in i Transact. 
Linn. Soc.’ vol. xxv. 1865, p. 8, 36. A striking case of a rare variety, 
strictly intermediate between two other well-marked female varieties, 
is given by Mr. Wallace. See also Mr. Bates, in 4 Proc. Entomolog. 
Soc.’ Nov. 19th, 1866, p. xl. 
19 Mr. R. MacLachlan, ‘ Transact. Ent. Soc.’ vol. ii. part 6th, 3rd 
series, 1866, p. 459. 
