64 



Amphispores of the Grass and Sedge Rusts. 



J. C. Arthur. 



( Abstract. ) 



The paper described and illustrated tb..' nredospores and amphispores 

 of five species of I'mrinia from central L'nited States, and one species 

 of Uromi/ces fiom Northern India, all occurring upon various kinds of 

 grasses; they were P. rexans Farl., P. Tripsaci D. & H., P. Stipce Arth., 

 P. tosta Arth., P. CriJiitandri E. & B., and U. KotthocUicc Arth. It also 

 described and illustrated the amphispores, the uredospores not being 

 known, of three species of PucclnUi from the United States occurring upon 

 different species of Carcx; they were P. Caricis-strictir Diet., P. atrofiisca 

 (D. <fc T.) Holw.. and P. Garrettii Arth. These are all the species of rusts 

 so far known to possess amphispores. This kind of spore is the resting 

 or winter form of the uredospore. They are not uredospores. however, 

 accurately speaking, because they show distinct structural differences, 

 often very great, and are correspondingly moditied physiologically. 



