Bacterial Photosynthesis**This article is not intended as a complete review of the photosynthetic bacteria. It will deal primarily with the relationship of photochemical reactions of extracts to the photosynthetic activity of the intact bacterial cells. A more complete discussion, including the culture and metabolism of photosynthetic bacteria, may be found in H. Gest and M. D. Kamen, Chapter IV, Volume 5 of “Handbuch der Pflanzenphysiologie” (1958). The reader is also referred to S. R. Elsden, Chapter 1 of Volume III of “The Bacteria,” for a discussion of carbon dioxide fixation, and to M. D. Kamen and J. W. Newton, Chapter 8 of Volume II of “The Bacteria” for a detailed discussion of the cytochromes in electron transport systems of photosynthetic bacteria.