502 MR. H. W. BATES ON THE LEP1DOPTERA 
strict reference to the geographical relations of their varieties. Many closet naturalists, 
who receive disconnectedly the different varieties in any group, treat them all as inde- 
pendent species : hy such a proceeding, it is no wonder that they have faith in the 
absolute distinctness and immutability of species. 
The sexes in the Heliconida 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 Buna) 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 applied 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 Heh- 
conida?. In the genus Pavonia, 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 Heliconidce 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 Heliconida ; 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 
o 
their true nature and orig 
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 : — Papilio, Pieris, Euterpe, and Leptalxs (fam. Papilionidce), Protogonius (Nym- 
phalidce), Ithomeis {Erycinidai), Castnia (Castniadce), Dioptis, Pericopis, Hyelosia, and 
other genera (Bombycida Moths)*. I conclude that the Heliconidce 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 accompanvin 
imitation 
