PROTOBASIDIOMYCETES 



Rumex spp. (sorrels) 

 Coffea arabica (coffee) 

 Chrysanthemum spp. 

 Polygonum spp. 

 Allium Cepa (onion) 



393 



Uromyces Rumicis (Schum.) Wint 

 Hemileia vastatrix Berk. & Br. , 

 Puccinia Chrysanthemi Roze. 

 Puccinia Polygoni Pers. . 

 Puccinia Allii De C. 



Microuredo (Stage III) 



Uromyces Solidaginis (Somm.)Niessl. Solidago spp. (goldenrod) 



Puccinia Ribis De C Ribes spp. (currant, gooseberry) 



Puccinia fusca Relhan. . . . Anemone nemorosa, etc. 



Leptouredo (Stage III) 



Puccinia malvacearum Mont. 

 Puccinia Xanthii Schw. . . 



Althaea rosea (hollyhock), etc. 

 Xanthium spp. (cocklebur) 



(Stages O, III) 

 Uromyces tepperianus Sacc. . . . 



(Stages O, I) 



ALcidium elatinum Alb. & Schw. . 

 jEcidium Grossularice Schum. 

 Peridermium Engelmannii Thum. 



(Stage II) 



Uredo Fici Cact. ... . . 



Uredo Gossypii Sager. 



Acacia spp. 



Abies spp. (firs) 



Ribes spp. (currant, gooseberry) 



Pinus Engelmannii 



Ficus carica (fig) 



Gossypium hirsutum (cotton), etc. 



During the past few years considerable activity has been mani- 

 fest in the study of the cytology and possible fertilization processes 

 in the Uredinales. It had been known since the studies of Sappin- 

 Trouffy and Dangeard that the binucleate condition of the teleuto- 

 spore and of the mycelium preceding it leads finally to a fusion of 

 these two nuclei preceding the development of the promycelium. 

 The recent studies have been directed primarily toward a knowl- 

 edge of the origin of this binucleate condition. Blackman in some 

 extensive studies of a caeoma stage, in particular, demonstrated what 

 he believed to be a fusion phenomenon in the following manner : 

 During the early development of this stage numerous gametic 

 branches arise. These come in contact in pairs, the older and 



