194 



CRYPTOGAMS 



to uninfected plants ; (2) two-celled teleutospores, charac- 

 teristic of the latter part of the season, thick-walled, and 

 fitted to survive the winter. While still 

 remaining on the dead stalks of the grain 

 in the following spring, the teleutospores 

 germinate. Each cell puts out a short 

 filament (Fig. 322) ; and on the sides of 

 these filaments small spores called spo- 

 ridia are formed. Finally, by these spo- 

 ridia the Barberry leaves are infected, 

 and the life cycle is brought to the point 

 at which this description was begun. 



458. Puccinia graminis is one of many 

 Fungi adapted to different hosts at dif- 

 ferent periods of their life history, and 

 failing to develop if the proper hosts are 

 not met with at the particular stages 

 when they are required. The sporidia 

 of this Rust germinate only on Barberry; 

 while the cluster-cup spores and uredospores of the same 

 Fungus refuse to develop except on certain grasses 

 (Wheat, Oats, Rye, etc.). 



322. Germination of 

 the teleuto- 

 spore (t) ; s, 

 s, the spo- 

 ridia. 

 -DE BARY. 



Basidiomycetes 



459. The Basidiomycetes include the Toadstools and 

 Puffballs and their relatives. The mycelia usually live 

 saprophytically in soil, leaf mold, decaying wood, etc. 1 

 The fructifications which arise may be simple layers of 

 tissue, coating the surface of the substratum, as in the 

 whitish or brownish incrusting growths found everywhere 

 on the under sides of rotting sticks ; but in the majority 

 of cases they are stalked structures. 



In the common Toadstool (Fig. 323) the stalk (stipes, s) 

 supports a cap (pileus,p) from which depend radial gills (la- 

 meUce, I). Upon the surfaces of these gills the sporiferous 



1 Some Basidiomycetes are parasitic ; for example, the Fungus which 

 causes on Azalea and allied plants the growths known as "May Apples." 



