CHAPTER X. 



FUNGI Continued. 

 CLASS Basidiomycetes. 



THE Basidiomycetes include the largest and most highly 

 developed of the fungi, among which are many familiar forms, 

 such as the mushrooms, toadstools, puff-balls, etc. Besides 

 these large and familiar forms, there are other simpler and 

 smaller ones that, according to the latest investigations, are 

 probably related to them, though formerly regarded as con- 

 stituting a distinct group. The most generally known of these 

 lower Basidiomycetes are the so-called rusts. The larger Ba- 

 sidiomycetes are for the most part saprophytes, living in decay- 

 ing vegetable matter, but a few are true parasites upon trees 

 and others of the flowering plants. 



All of the group are characterized by the production of 

 spores at the top of special cells known as basidia, 1 the number 

 produced upon a single basidium varying from a single one to 

 several. 



Of the lower Basidiomycetes, the rusts (Uredinece) offer com- 

 mon and easily procurable forms for study. They are exclu- 

 sively parasitic in their habits, growing within the tissues of 

 the higher land plants, which they often injure seriously. 

 They receive their popular name from the reddish color of the 

 masses of spores that, when ripe, burst through the epidermis 

 of the host plant. Like many other fungi, the rusts have several 

 kinds of spores, which are often produced on different hosts ; 

 thus one kind of wheat rust lives during part of its life within 



1 Sing, basidium. 



77 



