PRINCIPAL GROUPS OF PLANTS. 



A mass of cells after numer- 

 ous divisions, all surrounded 

 by a mucilaginous envelope. 



GLOEOCAPSA. 



Single cell just after 

 division. The two 

 daughter cells re- 

 tained in a gelatinous 

 mass. Diameter 

 about 4 microns. 



A single colony. 

 Diameter of colonies varying Single cell showing 



from 40 to 290 microns. spiral chromatophore. 



Length, 14 to 18 mi- 



UROGLENA * 



Heterocyst which divides the 

 filament into smaller filament*. 



Thick-walled resting cellt. 



Filamentous colonies coiled 

 within the masses of jelly 



Spherical gelatinous masses 

 as found floating in /ponds. 

 About twice natural size. 



Part of a single filament 

 Diameter, 4 to 12 microns. 



u 



OSCILLATORIA 



Diameter of filaments, 



5 to 50 microns. 



Decaying cell 

 unctioning as a heterocyst. 



Filaments, about 10 to 60 

 in diameter. 



LYNGBYA 



FIG. 6. Forms of Cyanophyceae or Blue-Green Algae. Adapted from Engler and 

 Prantl and Somewhat modified by Lobeck. 



