CHAPTER XXV 
THE FUNGI 
304. Definition; Occurrence. — The fungi are parasitic . 
or saprophytic spore-plants. They eonstitute a series of 
the division Thallophyta. The difference between alge 
and fungi is one of mode of life, not of structure or of 
reproductive methods; and it cannot be said that fungi as 
a whole are either higher or lower in the scheme of classi- 
fication than alge. 
Fungi occur in all situations where they can find organic 
food on which to live. Some are terrestrial, others aquatic ; 
some can support life in a variety of situations, others are 
confined to the interior or exterior of the body of a single 
kind of host. 
305. Classes of Fungi. — In treating the fungi they will 
here be grouped under five classes as follows :! 
Crass 7. Bacteria, Schizomycetes. 
ie 8. Yeast fungi, Saccharomycetes. 
“ 9. Algal fungi, Phycomycetes. 
« 10. Sac fungi, Ascomycetes. 
« 11. Basidia fungi, Basidiomycetes. 
The classification of this great group of spore-plants 
is based partly on the modes of reproduction, partly on 
other considerations, and is as yet far from being definitely 
settled. The life history of many is only partially known. 
1 See p. 210. 
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