254 
PLANT STUDIES 
The other group, represented by Fucus (Fig. 221), pro- 
duces no asexual spores, but is heterogamous. A single 
oogonium usually forms eight eggs (Fig. 221, A), which are 
discharged and float freely in the water (Fig. 221, E). The 
antheridia (Fig. 221, (7) produce numerous minute laterally 
biciliate sperms, which are discharged (Fig. 221, 6r), swim 
in great numbers about the large eggs (Fig. 221, F, H), 
and finally one fuses with an egg, and an oospore is formed. 
As the sperms swarm very actively about the egg and im- 
pinge against it they often set it rotating. Both antheridia 
and oogonia are formed in cavities of the thallus. 
4. KHODOPHYCE^; (Red Algce) 
172. General characters. On account of their red colora- 
tion these forms are often called Floridece. They are mostly 
marine forms, and are 
anchored by holdfasts 
M 7'^ff ofvariouskinds - They 
5g?i?C 
belong to the deepest 
waters in which Algae 
gr W ' and [t is P robable 
that the red coloring 
matter which character- 
izes them is associated 
with the depth at which 
they live. The Eed 
Algae are also a high- 
ly specialized line, and 
will be mentioned very 
briefly. 
173. The plant body. 
-The Eed Algas, in 
general, are more deli- 
cate than the Brown 
Algae, or kelps, their graceful forms, delicate texture, and 
brightly tinted bodies (shades of red, violet, dark purple, 
FIG. 222. A red alga (Gigartlrta}, showing 
branching habit, and "fruit bodies." 
After SCHENCK. 
