FUNGI AND FUNGOUS DISEASES OF PLANTS 235 
undergrowth one may find large numbers of these saprophytic 
plants growing upon decaying organic matter. By breaking 
open an old log or branch of wood (fig. 183) upon which 
fungi are growing, or by upturning rich soil, one often finds the 
extensively interwoven, mold-like saprophytic growth. This 
internal growth gathers nourish- 
ing material for the whole depend- 
ent plant, and at the same time 
helps to bring about the decay of 
the material upon which it lives. 
221. The alge-fungi. There are 
many different groups of fungi, 
and they are often so unlike that 
it is at first hard for the student 
to regard them as belonging to 
the same larger group, the fungi. 
In the case of some of the molds, 
if the thread-like fibers of which 
they are composed were to pos- 
sess chlorophyll, they would ap- 
pear quite similar to some of the 
alge. Because of this structural 
resemblance one group of fungiis ye. 183, A section through a 
called the algee-fungi (Phycomy- dead branch of a cottonwood tree 
cetes, meaning : alge-fungi as Note the white patches of internal 
that. is, fungi that are more like mycelium and the external spore- 
5 producing bodies of the fungus, a 
alge than are other fungi. Most Polyporus 
of the saprophytic molds and a 
good many destructive parasites belong to the algae-fungi. 
A few types will show their nature, how they live, and how 
they affect the things upon which they live. 
222. Bread mold. If a piece of slightly moistened bread is 
placed in a glass jar or in a covered dish for a few days, an abun- 
dant supply of mold soon appears upon it. Several kinds of 
molds may develop at the same time under such conditions, 
but the common bread mold, or black mold, is the one which 
