Many are epiphytic on other algae, more especially the larger Phaeophyceae and Rhodophyceae.

In the case of marine algae, the hosts are chiefly the larger Phaeophyceae and Rhodophyceae.

Most algae, particularly Phaeophyceae and Rhodophyceae, spend the whole of the life-cycle immersed in water.

PHAEOPHYCEAE.-ThePhaeophyceae are distinguished by the possession of a brown colouring matter, phycophaein, in addition to chlorophyll.

A census of Phaeophyceae is given below:-

A similar uncertainty exists with reference to certain groups of Phaeophyceae, and the matter will thus arise again.

The intercalated growing region of Phaeophyceae.

The only case among Phaeophyceae which has been considered to point to the existence of such a phenomenon is Cutleria.

PHAEOPHYCEAE, or Brown Algae.

Among Phaeophyceae it is well known that the oospore of Fucaceae germinates directly into the sexual plant, and there is thus only one generation.