PLATE II. THE CURRANT AND PINE RUST. 



Cronartium ribicola. 



1, Uredo and teleutospore stages on leaf of black currant; 2, Uredo- 

 spores, a, and telutospores, I), cemented together to form an erect, 

 hairlike structure (X50); 3, Uredospore, (X300) ; 4, Four teluto- 

 spores, two of which are germinating, and one of the germ-tubes has 

 produced four sporidia or secondary spores (X300) ; 5, Aecidia on bark 

 of white pine; 6, Aecidiospores (X300). (After Massee.) 



