Abstract
Some of the phenomena associated with the growth and photosynthetic capabilities of ac-21 in comparison with the wild type strain are described. It is concluded that ac-21 is a genetic alteration at a locus which controls the process of photosynthetic phosphorylation, this ability being lost. This results in either a genetic uncoupling of photosynthetic phosphorylation or a dis -ruption of electron transfer below the level of release of molecular oxygen.