Abstract
Chloroplasts from Codium vermilara, isolated by relatively crude methods, are able to fix CO(2) at rates comparable to the rates of intact plants. Sections in thalli of Codium vermilara show that the chloroplasts are surrounded by a thin layer of cytoplasm. This surrounding layer of cytoplasm, is retained also in isolated chloroplasts, and presumably preserves the intactness of the chloroplast envelope.