PLATE 97- 



A. — Pollen grains of Marquis wheat. 



B. — Fi Marquis XKubanka (C I 2094), showing sterile grains. 



C. — Pollen grains of Kubanka (C I 2094). 



D. — Stems of Kubanka (C I 2094) grown under rust-epidemic conditions. Note 

 absence of rust infection. 



E. — Fi Kubanka (C I 2094) X Marquis, showing normal uredinia. 



F. — Marquis, the susceptible parent. 



H. — Fj emmer (Minnesota 1 165) X Marquis, showing no normal uredinia. 



I. — Minnesota 11 65, the resistant emmer parent. Note that in the durum-common 

 cross the Fj generation is susceptible while in the emmer-common cross the Fi gener- 

 ation is resistant. 



