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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 
by visible openings in their walls, so that the Connected 
protoplasm is continuous from cell to cell. ie 
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 (phycocyanin), so that the plants appear 
red or purple, instead of green, although in fact they 
are green; but lit 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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