Light–dark Adaptation, and ‘Glow’, in Abnormal Moth Eyes without Pigment

Abstract

THE role of pigment migration in light–dark adaptation of the eyes of nocturnal moths has long interested investigators^1,2. Efforts have been made to find out what part pigment migration plays in the behavioural changes associated with light–dark adaptation³, and in the phenomenon called ‘glow’⁴. Recently, it has been reported that adaptation in nocturnal moths occurs in two stages, the first of which is not accompanied by pigment migration⁵. The discovery that variations can occur in the light-threshold of a dark-adapted compound eye with practically no change in the glow area⁶ is further evidence of the independence of adaptation and pigment position.