[Daily variations of the level of neural secretions in Owenia fusiformis. Persistance of a daily rhythm in cultured tissues].

A quantitative study of elementary granules in neuron axons of the nervous chain of Owenia fusiformis (Annelid polychaete) shows that daily variations of the number of secretory granules occur in unamputated animals and in ventral tissue cultures. These variations are correlated with the thythm of the cell cycle.