The study of phylogeny has suggested fourteen classes arranged in the following sequence: (1) Bacteria; (2) Cyanophyceae (Blue-green algae); (3) Flagellatae; (4) Myxomycetes (Slime-fungi); (5) Pendineae; (6) Conjugatae; (7) Diatomaceae (Diatoms); (8) Fleteroconteae; (9) Chlorophyceae (Green Algae); (10) Characeae (Stoneworts); (II) Rhodophyceae (Red Algae); (12) Eumycetes (Fungi);
In some cases both the nucleus and the chromatophores may be carried along in the rotating stream, but in others, such as T.Titeila, the chloroplasts may remain motionless iii a non-motile layer of the cytoplasm in direct contact with the cell wall.i Desmids, Diatoms and Oscillaria show creeping movements probably due to the secretion of slime by the cells; the swarmspores and plasmodium of the Myxomycetes exhibit amoehoid movements; and the motile spores of Fungi and Algae, the spermatozoids of mosses, ferns, &c., move by means of delicate prolongations, cilia or flagella cf the protoplast.
Vol ut-in occurs in the cytoplasm of various Fungi, Bacteria, Cyanophyceae, diatoms, &c., in the form of minute granules which have a characteristic reaction towards methylene blue (Meyer).
+h,r, 1)s~,~s-s Diatoms and Desmids, according to recent researches, the thickenings on the outer walls of the cells are due to the passage of protoplasm from the interior of the cell to the outside, through pores which are found perforating the wall on all sides.
Filamentous diatoms may be mounted like ordinary seaweeds, and, as well as all parasitic algae, should whenever possible be allowed to remain attached to a portion of the alga on which they grow, some species being almost always found found parasitical on particular plants.