Preliminary observations on scales and their mode of origin in Chrysochromulina polylepis sp.nov.

A species of Chrysochromulina is described which habitually produces four different types of scale on one and the same cell. Scales are more opaque to electrons than in other recorded species of the genus and it has consequently been possible to trace something of their mode of production. They develop within vesicles inside the body and are subsequently deposited on the cell surface. The vesicles responsible are in a compact group beside the Golgi body and below the flagellar bases. Scale-production is at a maximum in the afternoon and greatly reduced or discontinued at night. A marked diurnal rhythm also affects other cell components, mitotic phases being abundant at 4.30 a.m. Some changes occurring in the Golgi body are described and discussed in a preliminary way.