CHAPTER VII 
FUNGI 
76. General characters.—The Fungi do not contain 
chlorophyll, and this fact forms the sharpest contrast be- 
tween them and the Algw. The presence of chlorophyll 
enables the Algze to be independent of any other organism, 
since they can manufacture their food out of carbon dioxide 
and water (§ 14). The absence of chlorophyll compels 
the Fungi to be dependent upon other organisms for their 
food. This food is obtained in two general ways: either 
(1) directly from living plants and animals, or (2) from 
organic waste products or dead bodies. In case a living 
body is attacked, the attacking fungus is called a parasite; 
and the plant or animal attacked, the host. In case the food 
is obtained in the other way, the fungus is called a sapro- 
phyte. For example, the rust that attacks wheat is a 
parasite, and the wheat is the host; while the mold which 
often develops on stale bread is a saprophyte. 
In case parasites attack valuable plants or animals they 
may be very harmful, giving rise to destructive diseases. 
The United States Government has expended a great deal 
of money in studying such Fungi, trying to discover some 
method of destroying them or of preventing their attacks. 
There is an interesting selective power exhibited by many 
parasites, that restrict themselves to certain plants and 
animals, or even to certain organs. Many, however, are 
more general in their attacks; and some can live as para- 
sites or saprophytes as occasion demands. It must not be 
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