Transmission of symbiotic algae to eggs of green hydra.

Evidence from light and electron microscopy shows that symbiotic algae occur in a large percentage of fertilized eggs of two strains of green hydra. Transmission of algae to eggs may occur by insertion of algae-laden endodermal cell processes across the mesogloea into the ooplasm of the ectodermally-derived egg when oocyte maturation is well under way. This transmission mechanism is contrasted with mechanisms postulated for other strains of green hydra.