PRESSURE-INDUCED COLOR MUTATION OF EUGLENA GRACILIS.

Photosynthetic cultures of Euglena gracilis Z which were illuminated during growth were more resistant to the lethal effect of high hydrostatic pressures than nonphotosynthetic cultures grown in the dark. A high percentage of mutants permanently lacking chlorophyll and with altered carotenoids was obtained after subjecting cultures to high pressure. A minimum pressure of 500 atmospheres was critical for color mutation and morphological change. The highest effective pressure used was 1000 atmospheres.