THALLOPHYTA 343 
CLASS FUNGI 
The fungi are saprophytic or parasitic plants which are related 
to the alge but which do not possess chlorophyll. They are fre- 
quently colorless, but may have various colors and may even be 
green, although their 
color is never due to 
chlorophyll. The plant 
body consists of a sys- 
tem of threads (hyphe) 
which are single rows of 
cells. A mass of hyphe 
is known as a mycelium. 
The mycelium may be . 
either a loose, cobwebby | 
structure, as in molds 
(Fig. 359); relatively 
hard and firm, as in 
mushrooms (Fig. 381); 
or even woody, as in 
- the bracket fungi (Figs. 
382, 383). In no case, 
however, do fungi pro- 
duce true tissues, as the 
plant body of even the 
woody forms is made 
up of interlacing hy- 
phe, and the hyphe 
are always single rows 
of cells. 

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c) 
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Fig. 355. Sexual reproduction in Nemalion, 
a red alga 
In the first drawing, the long branch at the left 
bears numerous antheridia, whereas the one at 
the right terminates with a special kind of odgo- 
nium known as a carpogonium. Two male cells 
from the antheridia are in contact with the pro- 
jection from the carpogonium. A male cell will 
fuse with the projection from the carpogonium, 
and its contents will pass into the carpogonium. 
The second and third drawings represent stages 
in formation of spores from the carpogonium. 
(Redrawn after Bonnet and Thuret) 
Reproduction in the fungi is by means of spores, which may 
be formed either asexually or as a result of sexual fusion. 
Many plants besides the fungi lack chlorophyll and live as 
saprophytes or parasites. Among these are the bacteria. The 
fungi can easily be distinguished from the bacteria by their larger 
size and more complex structure. Like the alge, and unlike the 
