scent-scales

The scent-scales are never thus transmitted, probably for the same reason that the decorative colours of many birds are often not transmitted to the females: because with these they would be exposed to too great elimination by enemies.

Evolution in Modern Thought Gustav Schwalbe 1880

This is the case in the males; the females have no _special_ scent-scales recognisable as such by their form, but they must, nevertheless, give off an extremely delicate fragrance, although our imperfect organ of smell cannot perceive it, for the males become aware of the presence of a female, even at night, from a long distance off, and gather round her.

Evolution in Modern Thought Gustav Schwalbe 1880

But from the sporadic distribution of scent-scales in Lepidoptera, and from their occurrence or absence in nearly related species, we may conclude that fragrance is a relatively _modern_ acquirement, more recent than brilliant colouring.

Evolution in Modern Thought Gustav Schwalbe 1880

We may therefore conclude, that both sexes have long given forth a very delicate perfume, which announced their presence to others of the same species, and that in many species (_not in all_) these small beginnings become, in the males, particularly strong scent-scales of characteristic form (lute, brush, or lyre-shaped).

Evolution in Modern Thought Gustav Schwalbe 1880

The ethereal oil to which this fragrance is due is secreted by the skin-cells, usually of the wing, as I showed soon after the discovery of the _scent-scales_.

Evolution in Modern Thought Gustav Schwalbe 1880

Vanessa, have no scent-scales, while these are often markedly developed in grey nocturnal Lepidoptera.

Evolution in Modern Thought Gustav Schwalbe 1880