Evidence for the Presence of a ‘Factor’ in Elysia Viridis Which Stimulates Photosynthate Release From Its Symbiotic Chloroplasts

SUMMARY Tissues of Elysia viridis contain a ‘factor’ which stimulates release of fixed 14C from isolated Codium chloroplasts and also from the symbiotic algae of Anemonia sulcata. This ‘factor’ appears to be thermolabile, non‐particulate, and only occurs in effective amounts in the chloroplast‐containing tissues of the animal. So far, attempts to mimic the action of Elysia homogenates by varying the pH of the medium, or by adding Codium homogenates, fructose 1,6 di‐phosphatase or‘2C‐glucose to it, have failed.