SPKING RUST AND MILDEW. 



139 



is the Uredo produces simple oval yellow spores ; whilst 

 the Puccinia produces dark brown or blackish spores, each 

 of the latter having a joint or septum across its narrowest 

 diameter. 



A section through a Puccinia 

 sorus is shown, enlarged 200 diam- 

 eters, at Fig. 68 ; the Puccinia 

 spores are pushing in the same 

 manner as the Uredo through the 

 ruptured epidermis of the wheat 

 leaf. The dark elongated bodies at 

 A A are said to be paraphyses pos- 

 sibly in this case undeveloped 



X-5 



FIG. 66. Fragment of Wheat stem 

 invaded \tyPucdnia Rubigo-rcra, 

 D.C. Enlarged o diameters. 



-X-25 



FIG. 07. Pustules or Sori of Pc- 

 ciniaRubigo-vera, D.C. Enlarged 

 25 diameters. 



Puccinia spores. The compound spores of Pwcinia 

 Rubigo-vera, D.C., act as resting -spores, for although 



