44 MICROSCOPIC PTJNGI. 





The result of these investigations shows that the 

 bean-rust (TJromyces appendiculatus) , besides sper- 

 mogones, possesses four sorts of reproductive or- 

 gans, 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 — 



III. j^Ecidium. — Particular organs which engen- 

 der stylospores, and which produce — 



IV. TJredo, the second form of the stylospores, 

 and later, spores (Xo. 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 TJredo stylospores always produce TJredo, and 

 true spures, 



