74 



MR. H. W. BATES ON THE INSECT FAUNA 



moved than one hundred to two hundred miles. Such species, how- 

 ever, have often the character of local varieties, some of them 

 indeed showing the connecting links. From facts observed, it 

 would seem that the excessive multiplication together with the 

 distinctness of the species were owing to their great susceptibility 

 of modification, combined with the habit in pairing of selecting 

 none but their exact counterparts, and probably other causes tend- 

 ing to eliminate the intermediate gradations. The species are 

 mostly extremely numerous in individuals, and show every sign 

 of flourishing existence, although they are of feeble structure, and 

 fly slowly in exposed situations frequented by swarms of insec- 

 tivorous animals. They are gregarious in habits, the individuals 

 of the same species and clusters of closely allied species being 

 found in company restricted to limited spots in the forest. They 

 are often seen in pairs or small parties, apparently engaged in a 

 kind of dance. The large handsome species are so numerous in 

 some places that they form part of the physiognomy of the localities. 

 The only secondary sexual characters are tufts of hairs on the fore 

 margin of the hind wing in the males of most of the Acrseoid 

 group. These appear to be of no particular utility, but are 

 apparently analogous to the pencil of hairs on the breast of the 

 male turkey. The allied group, Danaince, afford a similar fea- 

 ture, the males having a horny excrescence on the disk of the hind 

 wing, which is evidently homologous with the structure above de- 

 scribed. The most interesting part of the natural history of the 

 Helic onince is the mimetic analogies of which they seem to be th e 

 objects. This involves questions of the highest scientific interest. 

 Many of the species are mimicked by members of widely distant 

 groups, e.g. JPapilio and Leptalis (Papilionidce) , Ithomeis (JEry- 

 cinidce), Castnia (Castniadce), Dioptis, JPericopis, Hyelosia, &c. 

 (Bombycidce moths). It is fair to conclude that they are the 

 objects imitated, because they :tll have the same family facies, 

 whilst the analogous species are dissimilar to their nearest allies 

 perverted, as it were, from the normal facies of their genera or 

 families. The mimicking species are found in company with the 

 Heliconince; and it often happens, where these latter art; modified 

 into local varieties, species or local varieties of the former in an 

 analogous dress also occur with them. A parallel series of imita- 

 tions occurs in flu; old-world tropics, where it is the represen- 

 tatives of the Tfeliconincc that are the o bjects imita ted/ Tho 

 instance of this kind of analogy most familiar to European ento- 

 tnologistf is that of t he species of TrochMum (a genua of moths), 



