SEXUAL SELECTION 413 



about during the afternoon. On the otter hand, in many 

 genera, as Mr. Stainton informs me, the males have the 

 hind- wings whiter than those of the female— of which fact 

 Agrotis exclamationis offers a good instance. In the Ghost 

 Moth {Hepialus humuli) the difference is more strongly- 

 marked; the males heing white, and the females yellow 

 with darker markings." It is probable that in these cases 

 the males are thus rendered more conspicuous, and more 

 easily seen by the females while flying about in the dusk. 



From the several foregoing facta it is impossible to admit 

 that the brilliant colors of butterflies, and of some few 

 moths, have commonly been acquired for the sake of pro- 

 tection. We have seen that their colors and elegant patterns 

 are arranged and exhibited as if for display. Hence I am 

 led to believe that the females prefer or are most excited 

 by the more brilliant males; for on any other supposition 

 the males would, as far as we can see, be ornamented to 

 no purpose. We know that ants and certain Lamellicorn 

 beetles are capable of feeling an attachment for each other, 

 and that ants recognize their fellows after an interval of 

 several months. Hence there is no abstract improbability 

 in the Lepidoptera, which probably stand nearly or quite 

 as high in the scale as these insects, having sufficient mental 

 capacity to admire bright colors. They certainly discover 

 flowers by color. The Humming-bird Sphinx may often be 

 seen to swoop down from a distance on a bunch of flowers 

 in the midst of green foliage; and I have been assured, by 

 two persons abroad, that these moths repeatedly visit flowers 

 painted on the walls of a room, and vainly endeavor to 

 insert their proboscis into them. Fritz Muller informs 

 me that several kinds of butterflies in South Brazil show 

 an unmistakable preference for certain colors over others: 



" It is remarkable that in the Shetland Islands the male of this moth, instead 

 ot differing widely from the female, frequently resembles her closely in color (see 

 Mr. MacLaohlan, "Transact. Ent. Soc," vol. ii., 1866, p. 459). Mr. G. Eraser 

 suggests ("Nature," April, 1871, p. 489) that at the season of the year whea 

 the ghost moth appears in these northern islands, the whiteness of the males 

 would not he needed to render them visible to the females in the twilight night. 



