Influence of Culture Conditions on the Length of the Lag Period of Chlorophyll Synthesis in Preilluminated Dark-grown Euglena.

Two parameters of the potentiation process, the lengths of preillumination and of the subsequent dark phase have been determined for Euglena cells which had been grown in the dark under two different culture conditions. In both cases a maximum potentiation response is obtained after a preillumination period of about 2 hours. The minimum length of the dark period necessary for maximum potentiation changes from 1 hour for cells which contain, at the moment of illumination, a high paramylum content, to 6 hours for cells which have a low paramylum content.