48 CURIOSITIES OF ENTOMOLOGY. 



retire, glide right and left in face of each other, wheel round 

 to a considerable distance, again approach, and so on ; then a 

 third joins in, then a fourth, and others until a large party is 

 assembled. They never touch ; but when too many are con- 

 gregated a general flutter ensues, and they all fly off to fall 

 in again by pairs soon afterwards. 



Wherever large numbers of these Heliconidse are found, 

 they are always accompanied by species which mimic them in 

 size, form, colour, and marking, so closely that it is often im- 

 possible to distinguish one species from the other when they 

 are on the wing, as the imitators fly in the same part of the 

 forest, and usually accompany the species they imitate. To 

 so wonderful a degree does this imitation extend, that in cases 

 where there is a local variety of a species of this family, the 

 butterfly imitating that particular species changes so as to 

 follow the varieties of its model. 



It may be asked, if two butterflies, of totally distinct 

 groups, and different structures, so closely resemble one 

 another, how can it be known which is the imitator and 

 which the imitated ? But the apparently puzzling question is 

 easily answered. The imitated preserve the form and like- 

 ness peculiar to the family to which they belong; but the 

 imitators are of a different aspect to their nearest allies. 

 Thus when a clear- winged moth is found, bearing a close > 

 resemblance to any species of bee, it may be reasonably in- 

 ferred that the moth, having departed from the usual aspect 

 of its group, has imitated the bee, which remains like its 

 congeners or fellows, and not that the bee has imitated the 

 moth which differs from its species. For example, we are 

 justified in assuming that the different species of Leptalis, 

 shown in our plate (Figs. 2, 3, and 4), are the imitators, 

 because they have departed from the proper normal form of 

 the genus Leptalis which is shown in Fig. 1, representing 

 L. Nehemia ; and that the Heliconidas there shown belonging 

 to the genera Ithomia and Methona are the imitated, because 

 they resemble their nearest allies. Hence we regard Leptalis 

 T/ieonoe, var. Leuconoe (Fig. 2), as imitating Ithomia Ilerdi.na 

 (Fig. 2a) ; Leptalis Orise (Fig. 3) as imitating Methona Psidii 



