Chap. VI.
ORIGIN OF SPECIES.
265
to its former shape when brought by natural redistribution into contact with it.[1]
- ↑ If this explanation of the derivation of Heliconius Thelxiope be true, the origination by natural process of a host of now distinct allied species of this genus, as well as, in fact, all other genera containing numerous closely related species, will have to be admitted. A species allied to H. Thelxiope, namely, H. Vesta, seems to have been derived also from H. Melpomene, for amongst the numerous varieties already mentioned are many examples intermediate between the two. There is this difference, however, between H. Thelxiope and H. Vesta: the former is confined in its range to the Amazons valley, whilst H. Vesta extends beyond this region over Guiana and the central valleys of the Andes; it seems, therefore, to have acquired a power of adaptation to a much wider diversity of local conditions. Insects seem to be well adapted to furnish data in illustration of this interesting but difficult subject. This arises chiefly from the ease with which ample suites of specimens can be obtained for comparison from many points in the areas of distribution, both of species and varieties. It is scarcely necessary to add that the conclusions thus arrived at will apply to all organic beings.
