44 MICROSCOPIC FUNGI. 



The result of these investigations shows that the 

 bean-rust {Uromyces appendiculatus) , besides sper- 

 mogones^ possesses four sorts of reproductive or- 

 ganSj which all serve to propagate the species, but 

 that one alone of them produces it in a form always 

 identical, whilst the others present well-marked 

 alternations of generation. Hence it is concluded 

 that there are, 



I. Spores which produce in germinating the pro- 

 mycelium, and 



II. Sporidia. — These give place to a mycelium, 

 which bears afterwards — 



m. j^cidium. — Particular organs which engen- 

 der stylospores, and which produce — 



IV. TJredo, the second form of the stylospores, 

 and later, spores (No. I.), which are always asso- 

 ciated with TJredo in the same pustule. The spores 

 and stylospores of TJredo come also upon the old 

 mycelium, which has previously produced jEcidium: 

 The Uredo stylospores always produce TJredo^ and 

 'true spores. 



