A Pheophytin‐like Pigment in Dark‐Adapted <i>Euglena gracilis</i>

Abstract

SYNOPSIS. The pigments of Euglena gracilis var. bacillaris change when cultures of light‐grown organisms are placed in the dark; the alterations in spectrum indicate the formation of a pheophytin‐like substance from chlorophyll. This pheophytin‐like compound is not an artifact of extraction and separation of the pigments; the spectral changes occur in the intact cells. The “dark” pigment is not yet definitely characterized. Formation of this material on dark adaptation seems dependent on the nutritional history of the cells.