HEMIBASIDIOMYCETES 337 



bridging forms, etc. The following arrangement of the 

 species in the genus Puccinia, taken from Saccardo, illus- 

 trates the gradual elimination or dropping out of the 

 various spore-forms. 



Puccinia 



Sect. A. Eu-Puccinia. Spermogonia, aecidia, uredo- 

 spores and teleutospores produced on a living host ; 

 teleutospores germinating after a period of rest (not on a 

 living matrix). 



I. Auto-Puccinia. Spermogonia, aecidia, uredo - 



and teleutospores produced on the same 

 matrix. 

 Ex. Puccinia galii, on various species of Galium. 



II. Hetero-Puccinia. Secondary spores germinating 



and giving origin to aecidia on a different 

 species of host - plant to that on which the 

 teleutospores were produced. 



Ex. Puccinia graminis, aecidia on Barberry, remainder 

 on wheat. 



Sect. B. Brachypuccinia. Spermogonia, uredo- and 

 teleutospores produced on the same matrix; aecidia 

 absent. 



Ex. Puccinia suaveolens, on thistle (Ctrsium). 



Sect. C. Hemipuccinia. Uredo- and teleutospores pro- 

 duced on the same matrix ; spermogonia and aecidia 

 absent. 



Ex. Puccinia polygon^ on various species of Polygonum. 



Sect. D. Pucciniopsis. Spermogonia, aecidia and teleu- 

 tospores produced on the same matrix; uredospores 

 absent (or rarely a few mixed with the teleutospores). 



