FIG. 46. Pucciniagraminis, an heteroecious fungus producing different 

 kinds of spores on different hosts, and on the same host at different 

 periods, i, leaves of wheat plant with pustules of uredospores ; 2, a 

 pustule or group of uredospores more highly mag. ; 3, uredospores in 

 various stages of development ; 4, uredospores germinating ; 5, portion 

 of a wheat stem showing pustules of teleutospores ; 6, teleutospores in 

 various stages of development ; 7, teleutospores germinating ; 8, a bar- 

 berry leaf bearing groups of the aecidium or ' cluster-cup' form of fruit ; 

 9, section of an aecidium containing spores in chains ; 10, two aecidia seen 

 from above; n, sporules from a spermogonium. Figs i, 5, and 8, nat. 

 size ; remainder mag. 



