junei7, i9i8 A Third Biologic Form of Puccinia graminis on Wheat 653 



Diagram i. — Results of inoculations with 

 urediaiospores of the new biologic form of 

 Puccinia graminis Pers.' 



Stejnrust from — C 5 

 volunteer wheat , 

 Stillwater.Okla., 

 October 18, 1917. 



-^6 



Wi -,-Cg - 



-W^W \ -w| 



-Bi 



1 Although in some cases, owing to a limited amount of 

 inoculum, the percentage of infection was small, in all 

 cases large, normal uredinia were developed. 



Date of last infection experiment April 22, igiS. 



-Ba| 



— Ba 5 762i^ — Ba 



■762^3 — Rotq 



-Ma| 



-762; 



-Majg — 'R6^ 

 1 



-Ma|| 



■'66i 



-66^ 



-Ba| 



— 762fn ~— Ba/7,-762 



Ba?n -&S\k 



-'66s 



-Mas 



- 66jg 



""10 

 -Ro/g 



-W 



10 



-762. 



