Some Observations on the Fertilization and the Early Development of Phoronis australis

1. In Phoronis australis, the eggs liberated out of the body cavity into the sea water have the capacity to develop without further artificial insemination. 2. At the stage of maturation divisions, the egg has bundles of cilium-like protrusions near the polar bodies. These protrusions are constantly flickering and probably form a ring around the bodies. 3. Cleavages proceed rather regularly, and in the 4th day, the egg develops into an Actinotrocha with four pairs of tentacles which corresponds to the oldest one found attached to the lophophore