BUTTERFLIES AND MOTHS. 313 



belong to groups which generally fly about during the afternoon. 

 On the other 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 bumuli) the difference is more strongly 

 marked; the males being 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 whilst flying about in the dusk. 



Prom the several foregoing facts it is impossible to admit that 

 the brilliant colors of butterflies, and of some few moths, have 

 commonly been acquired for the sake of protection. We have 

 seen that their colors and elegant patterns are arranged and ex- 

 hibited 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 im- 

 probability in the Lepidoptera, which probably stand nearly or 

 quite as high in the scale as these insects, having suflicient 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 Miiller informs me that several kinds of butterflies 



toria, Hypogymn dispur, Dasychira pudibunda, and Cycnia mendica. 

 In this latter species tiie difference in color between the two sexes is 

 strongly marked; and Mr. Wallace informs me that we here have, 

 as he believes, an instance of protective mimicry confined to one sex, 

 as will hereafter be more fully explained. The white female of the 

 Cycnia resembles the very common Spilosoma menthrasti, both sexes 

 of which are white; and Mr. Stainton observed that this latter moth 

 was rejected with utter disgust by a whole brood of young turkeys, 

 which were fond of eating other moths; so that if the Cycnia was 

 commonly mistaken by British birds for the Spilosoma, it would 

 escape being devoured, and Its white deceptive color would thus be 

 highly beneficial. 



21 It is remarkable, that in the Shetland Islands the male of this 

 moth, instead of differing widely from the female, frequently re- 

 sembles her closely in color (see Mr. MacLachlan, 'Transact. Ent. Soc' 

 vol. ii. 1866, p. 459). Mr. G. Fraser suggests ('Nature,' April 1871, p. 

 489) that at the season of the year when the ghost-moth appears in 

 these northern islands, the whiteness of the males would not be needed 

 to render them visible to the females in the twilight night. 



