PI#ATE 3 
Puccinia graminis tritici form III on Kanred (A-C) and Mindum (D) 
A. —Kanred. Seven-day infection. Group of “runners” of the fungus growing 
along the inner surface of the epidermis through a substomatal chamber. X 730. 
B. —Kanred. Seven-day infection. Portion of young uredinium and mesophyll 
tissue below it. Spore bearing layer a lifting epidermis b. Cell contents of central 
mycelium drained into uredinium. X 333. 
C. —Kanred. Fifteen-day infection. Strip through a longitudinal section of the 
leaf at the center of an old uredinium. Epidermis is gone and many spores liberated. 
Mycelium practically empty. X 333. 
D. —Mindum. Four-day infection. Young infection. Appressorium d and sub¬ 
stomatal vesicle below it, c, empty. First host cell attacked by the fungus / dead 
and shriveled. Second attack begun at g. Several cells plasmolyzed. X 333. 
