234 



PLANT DISEASES 



F'S- 59' — Cronartium ribicolum, i, uredoand teleulo- 

 spore stages on leaf of black currant ; 2, uredospores, 

 a, and teleutospores, 6, cemented together to form an 

 erect, hairlike structure, x 50 ; 3, uredospore, X300; 

 4, four teleutospores, two of which are germinating, and 

 one of the germ-tubes has produced four promycelium 

 or secondary spores, x 300 ; 5, aecidia on bark of Wey- 

 mouth pine ; 6, aecidiospores, X300. 



Rostrup, Bot, Centralb. xliii. p. 353. 



Prillieux, il/(T/(Z£/. des Plantes Agric.^ vol. i. p. 275. 



