CARBON DIOXIDE-INDUCED DELAY OF CELLULAR DEVELOPMENT IN TWO CHLORELLA SPECIES(1).

Two species of Chlorella, C. fusca and C. vannielii, manifest delay in cell development in synchronous cultures when gassed with air enriched with 1.5% vol. C02 or higher. This effect is greater if the final developmental steps proceed in the light rather than in the dark. Despite this, as much as 5% vol. CO2 does not decrease the production of dry matter in continuous light. It is not unlikely that this action of CO2 is restricted to cases in which nitrate serves as the only N source.