PLATE i8 



A. — Puccinia graminis tritici from Hordeum jubatum, originally from Moorhead, 

 Minn., but with subsequent history of Rj — B4 — Rj — Wj — B5 — Rj: Small uredinia 

 and sharp flecks on rye. 



B, C. — Piiccinia graminis tritici on wheat. Normal development of uredinia pro- 

 duced by inoculating with urediniospores of the following life history: B. P. graminis 

 tritici (St. Paul, Minn.) B31 — Agropyron tenerum^ — A. repens, — Wj — A. repens^. 

 C. P. graminis tritici{St. Paul, Minn.) B31 — Agropyron tenerum^ — A. repens^ — ^Wi — A. 

 tenerum^. 



