CHAPTER XXV 

 THE FUNGI 



304, Definition ; Occurrence. — The fungi are parasitic 

 or saprophytic spore-plants. They constitute a series of 

 the division Thallophyta. The difference between algse 

 and fungi is one of mode of life, not of structure or of 

 reproductive methods ; and it cannot be said that fungi as 

 a wliole are either higher or lower in the scheme of classi- 

 fication than algae. 



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 : ^ 



Class 7. Bacteria, Schizomycetes. 



" 8. Yeast fungi, Saccharomycetes. 



" 9. Algal fungi, Phycomyceies. 



" 10. Sac fungi, Ascomycetes. 



" 11. ^usidia tangi, 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. 

 239 



