236 
PLANT STUDIES 
upon the return of favorable conditions. These may be 
regarded as resting cells. So notable is the fact of repro- 
duction by fission that Cyanophyceae are often separated 
from the other groups of Algae and spoken of as " Fission 
Algae," which put in technical form becomes Schizophyceae. 
In this particular, and in several others mentioned above, 
they resemble the "Fission Fungi" (Schizomycetes), com- 
monly called "bacteria," so closely that they are often 
associated with them in a common group called "Fis- 
sion plants" (Schizophytes), distinct from the ordinary 
Algae and Fungi. 
2. CHLOROPHYCE^; (Green Alg&). 
163. Pleurococcus. This may be taken as a type of one- 
celled Green Algae. It is most commonly found in masses 
covering damp tree-trunks, etc., and looking like a green 
stain. These fine- 
ly granular green 
masses are found 
to be made up 
of multitudes of 
spherical cells re- 
sembling those of 
Glceocapsa, except 
that there is no 
blue with the chlo- 
rophyll, and the 
cells are not im- 
bedded in such 
jelly-like masses. 
The cells may be 
solitary, or may 
cling together in 
colonies of various sizes (Fig. 204). Like Glceocapsa, a cell 
divides and forms two new cells, the only reproduction 
FIG. 204. Pleurococcus, a one-celled green alga : A, show- 
ing the adult form with its nucleus ; B, C, D, E, 
various stages of division (fission) in producing new 
cells ; F, colonies of cells which have remained in 
contact. C ALDWELL. 
