502 MR. H, W. BATES ON THE LEPIDOPTERA 



strict reference to the geographical relations of their varieties. Many closet natviralists, 

 who receive disconnectedly the different varieties in any group, treat them aU as inde- 

 pendent species: by such a proceeding, it is no wonder that they have faith in the 

 absolute distinctness and immutability of species. 



The sexes in the Hellconidce very rarely differ in colours. Secondary sexual characters 

 of another description occur, however, very generally in the Danaoid group. The 

 males, in all the genera but two {Lycorea and Ituna) of this section, are furnished with a 

 pencil or fringe of long hairs near the costal edge of the hind wings on the upper sur- 

 face. It sometimes arises from the bottom of a shallow horny cup situated between the 

 costal and subcostal nervures ; the hairs are long, soft, and adpressed. I was unable to 

 discover any use in this structure ; it seemed not to be under the control of the insect. 

 There is no movement in flight, or position in repose, peculiar to the male sex, which 

 might require an instrument to hold the wings together — a function which the position of 

 the hairs, in the place where the fore wing overlaps the hind wing, suggests to the mind. 

 I believe the appendage must be considered as an outgrowth of the male organization, 

 which is not in this case appHed to any especial purpose : it may be taken to be of the 

 same nature as the pencil of hairs on the breast of the male Turkey. Growths of one 

 kind or other, on the surface of the wings, peculiar to the male sex, are frequent in 

 Butterflies : in Danais the males have a small horny excrescence on the disk of the 

 hind wings, which, considering the near relationship proved to exist between the two 

 groups, I take to be homologically the same as the pencil of hairs in the Danaoid Seli- 

 conidce. In the genus Favonia, belonging to the family Brassolidce, the males in some 

 species have a fringe of hairs near the abdominal border ; in others, a long pencil of the 

 same on the disk ; and, again, in others, instead of these appendages, a thickened plate 

 on the inner margin of the hind wings. 



The most interesting part of the natural history of the HeliconidcB is the mimetic 

 analogies of which a great many of the species are the objects. Mimetic analogies, it is 

 scarcely necessary to observe, are resemblances in external appearance, shape, and colours 

 between members of widely distinct families : an idea of what is meant may be formed 

 by supposing a Pigeon to exist with the general figure and plumage of a Hawk. Most 

 modern authors who have written on the group have mentioned the striking instances 

 of this kind of resemblances exhibited with reference to the SeliconidcB ; but no attempt 

 has been made to describe them fully, nor to explain them. I will give a short account 

 of the leading facts, and then mention some circumstances which seem to throw light 

 on their true nature and origin. 



A large number of the species are accompanied in the districts they inhabit by other 

 species which counterfeit them in the way described. The imitators belong to the following 

 groups : — JBapilio, Fieris, Euterpe, and Leptalis (fam. Fapilionida;), Protogonius {Nym- 

 phalidce), Ithomeis {JErycinidcB), Castnia (Castniadce), Dioptis, Fericopis, Hyelosia, and 

 other genera {BombycklcB Moths)*. I conclude that the ILeliconidcB are the objects 

 imitated, because they all have the same family facies, whilst the analogous species are 

 dissimilar to their nearest allies— perverted, as it were, to produce the resemblance, from 



* The accompanying Table, in which a number of the most striking of these are arranged in parallel columns, will 

 2;ive some idea of the extent to which this system of imitation prevails. 



