DIURNAL MOVEMENTS OF THE EYE PIGMENTS OF ANCHISTIOIDES

Abstract

1. The distal pigment cells and the reflecting pigment in the eyes of Anchistioides, a crustacean, continue their characteristic movements under constant external conditions. 2. The movements of the distal pigment cells continued for fifteen days in animals kept in constant darkness and in constant illumination. Movements, normal in extent, occurred in constant darkness while in constant illumination the movements were greatly suppressed. 3. The persistence of this diurnal rhythm indicates that an internal cyclical mechanism is responsible, in part, for pigment movements in crustacean eyes. 4. The possibility of the blood gland or X-organ being concerned in the diurnal rhythm in retinal pigment movement is considered.