STONEWORTS 333 
Green Algae because they are green, while others regard them as 
so different from any of the Algae as to put them in a separate 
class. They grow in fresh and brackish waters and often form 
dense masses of vegetation covering large areas. They grow 
Fie. 287. — Chara fragilis. A, part of a plant, showing nodes, internodes, 
and the two kinds of branches (natural size); B, part of a plant, showing a 
node bearing sex organs, the odgonium enclosed in its jacket being at o and 
the antheridium with its shield-shaped wall cells shown at a (X 25); C, wall 
cell of the antheridium, showing the stalk-like projection at the end of which 
are borne the filaments in the cells of which the sperms are produced (X 
about 50); at the left of C, two cells of a filament in which the sperms are 
formed, and a single sperm below. Redrawn from Sachs and Thuret. 
attached to the bottom and are often so incrusted with calcium 
carbonate that they are rough and brittle as the name Stoneworts 
suggests. 
The plant body has a much branched stem-like axis quite 
distinctly differentiated into nodes and internodes (Fig. 287). 
