CARPOSPORE^. 143 



stage was formerly called the genus Uredo (Fig. 258). The 



uredo-spores germinate quickly, and from their mycelium 

 other uredo-spores are produced, and this process may con- 

 tinue a great length of time. Finally, from the same 

 mycelium, are produced (Fig. 259) thick-walled, brown 

 or black spores, called teleutospores (Gr. teleuta, end), 

 which may be one-celled (as in Uromyces and Melamp- 

 sora), two-celled (as in Pucoinia, Fig. 259 ; and Podisoma, 



x340. 



259 



Fig. 258. Rust on Wheat {Puccinia grajninis) ; section through the leaf, showing 

 the uredo-spores (wr), highly magnified. Fig. 259. Rust on Corn {Puccinia sorghi); 

 section through the leaf, showing teleutospores, highly magnified. 



