Statocyst lacking Cilia in the Coelenterate Corymorpha palma

Abstract

STATOCYSTS are sensory organs which detect the direction of gravitational force, and usually consist of a vesicle which contains a nodule (statolith) resting on a bed of sensory hairs (generally cilia). Changes in orientation cause the statolith to roll onto and stimulate new groups of hairs which pass information to the nervous system. This pattern is true of most coelenterate statocysts₁. I wish to describe a coelenterate statocyst in which cilia and nerves are absent, the statolith resting directly on the wall of its vesicle.