The Fine Structure of Prochloron

This is the authors' abstract. We don't add key points for this paper.

SUMMARY The fine structure is described of Prochloron, a unicellular prokaryotic alga which contains both chlorophyll a and chlorophyll b. The cell wall resembles that of a blue‐green alga. The thylakoids and cytoplasm together occupy a wide peripheral band. However, the thylakoids are present not as single lamellae, as in blue‐green algae, but in pairs or, sometimes, in thicker stacks. Both thylakoids and cytoplasm are absent from a large central zone which is generally electron‐transparent, but may contain electron‐dense granules and fibrils. The function of the central zone is not known.