CH. X] BLUE-GREEN ALG^ 399 



CLASSES OF ALG.E CLASSES OF FUNGI 



CLASS!. CYANOPHYCE^J: CLASS 2. SCHIZOMYCETES : 



BLUE-GREEN ALG^E. BACTERIA. 



CLASS 3. FLAGELLATA : CLASS 4. MYXOMYCETES : 



FLAGELLATES. SLIME MOLDS. 



CLASS 5. CHLOROPHYCE^E : CLASS 6. PHYCOMYCETES: 



GREEN ALG^B. ALGAL FUNGI. 

 CLASS 7. PH^EOPHYCE^E : 



BROWN ALG.E. 



CLASS 8. RHODOPHYCE^ : CLASS 9. ASCOMYCETES : 



RED ALG^J. SAC FUNGI. 



CLASS 10. BASIDIOMYCETES 

 BASIDIA FUNGI. 



CLASS 1. CYANOPHYCE.E : THE BLUE-GREEN 

 (Myxophycese, Schizophyceae : the Fission Algae) 



These are the simplest of all known plants which form their 

 own food. They show to the eye as the dark bluish-green 

 scums, felts, slimy layers, or gelatinous lumps which occur 

 in sluggish streams, on damp shaded rocks or earth, on logs 

 of old wharves, or wherever organic matter is present in 

 solution. The masses are colonies of microscopic individuals 

 held together by a copious gelatinous secretion from their 

 walls. Some 1200 species are known, very widely distrib- 

 uted over the earth, some living in the water, either attached 

 or floating, some on the land, and some indifferently in 

 either. 



Typical forms are pictured in Fig. 276. Glceocapsa lives 

 on wet rocks. It consists of a single round simple cell, which 

 reproduces only by division (page 299), though the gela- 

 tinous walls of the resultant cells keep them together for 

 a time in loose aggregations. Oscillatoria lives submerged 

 in shallow waters, especially such as contain organic matter. 

 Its cells are coin-shaped, and divide in their own planes; 

 and since they remain attached, they form cylindrical 

 filaments. Although a filament is thus only an aggregation 

 of similar cells, it yet acts physiologically as a unit, for it 

 executes oscillatory movements (whence the name) which 

 effect a limited locomotion. Nostoc grows both in water 



