ABSTRACT
Unicellular algae (zooxanthellae) occur in certain Actiniaria. The first important experimental work on the nature of the association was that of Brandt (1883 a, b), who starved anemones in Light and in darkness. From the results of these experi-ments he concluded that the animals obtained nutriment from the zooxanthellae when deprived of animal food. Later work by Boschma (1926) on Cribina xantho-grammica supports Brandt’s view. Brandt was unable to observe the digestion of the zooxanthellae and assumed that food material was passed in soluble form from algae to animal. By studying the mesenterial filaments of C. xanthogrammica Boschma brought forward evidence in favour of the view that zooxanthellae are actually digested by the anemone. In his opinion such actinians live partly on animal matter and partly on the zooxanthellae. During starvation they depend chiefly on the algae.
