Why have insects without jaws long tubular tongues?
Because they derive their nourishment chiefly from liquids, which they get from animal or vegetable substances by means of this spiral or tubular tongue, or a soft proboscis with a broad opening, admitting of extension and retraction ; or a horny pointed tube, containing sharp bristly bodies internally. In many species of the butterfly, this proboscis, when not in use, is coiled up like a watch-spring.