CHAPTER XII 



PHYLUM VI. RHODOPHYCEAE 



THE RED ALGAE 



315. The Red Algae are almost wholly marine plants, 

 in structure ranging from small, simple, cellular, attached 

 filaments to stout, massive, rooted plants which may- 

 attain considerable dimensions (half a meter or more). 

 The smaller plants are often diffusely and beautifully 

 branched into quite intricate patterns, rising from a 

 short basal stem which is rooted below, while in the 

 larger forms there may be a thick, rooted stem 

 which bears one or more flat leaves above. 



316. The cell walls of the Red Algae are 

 more or less gelatinous in nature and swell 

 greatly in fresh water, even dissolving. The 



cells usually are connected with one another 



• •11- ■ 1 • ^'°- 89- 



by visible openings in their walls, so that the Connected 



protoplasm is continuous from cell to cell. 



317. The cells contain chloroplasts, but their green 

 color is masked by the presence of a red or purple 

 coloring matter (phycoerythrin) and sometimes a blue 

 coloring matter (phj^cocyanin), so that the plants appear 

 red or purple, instead of green, although in fact they 

 are green; but it must not be overlooked that a few 

 species are parasitic, and therefore devoid of coloring 

 matter! 



318. The Red Algae are propagated by non-ciliated, 

 naked cells which are separated from the plant, either 



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