Holt, Stanley C. (Dartmouth Medical School, Hanover, N.H.), S. F. Conti, and R. C. Fuller. Photosynthetic apparatus in the green bacterium Chloro-pseudomonas ethylicum. J. Bacteriol. 91:311–323. 1966.—When cells of Chloro-pseudomonas ethylicum were broken by ballistic disruption and examined by electron microscopy, vesicles 1,300 to 1,500 A long and 300 to 500 A wide were found to rim the periphery of the cell. Examination of these vesicles obtained by disruption with a French pressure cell and purified by density gradient centrifugation revealed inter-connections between the vesicles. During sonic and Mickle disruption of the cells, chlorophyll was released at a lower rate than soluble cytoplasmic components, but faster than the membrane-bound enzyme succinic dehydrogenase. Unlike the situation that exists in the purple photosynthetic bacteria, it appears that the chlorophyll in the green bacteria is contained as part of a structure which may be differentiated both structurally and functionally from the bacterial cytoplasmic membrane.