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12 Journal of Mycology [Vol.12 



J. J. Davis, Racine, Wis. ; E. Bartholomew, Rockport, Kansas ; 

 H. H. Whetzel and H. S. Jackson, Ithaca, N. Y. ; C. L. Shear 

 and P. L. Ricker, Washington, D. C. ; Wm. J. Home, Santiago 

 de las Vegas, Cuba ; Jos. J. Wolfe, Durham, N. C. ; Lewis Kauf- 

 man, Morrison, Iowa; R. D. Echlin, Washington, Iowa; R. E. 

 Buchanan, Ames, Iowa ; H. L. Bolley, Fargo, N. D. ; and H. L. 

 Shantz, Lincoln, Neb. ; to whom my warmest thanks are ex- 

 tended. I am also much indebted to Messrs. Bethel and Garrett 

 for rooted wild plants on which to make sowings, and to Dr. 

 Davis for field observations and the suggestion which led to 

 successful sowings of Puccinia Eleocharidis. 



During the present season 85 collections of material with 

 resting spores and 15 collections with active spores were em- 

 ployed, from which 484 drop cultures and 13 Petri dish cultures 

 were made to test the germinating condition of the spores, these 

 being made almost wholly from the resting spores. Out of the 

 85 collections with resting spores 32 could not be made to germ- 

 inate, although every condition seemed favorable, and were there- 

 fore useless. There were in all 194 sowings of spores made, rep- 

 resenting 45 species of rusts, and for this purpose 100 species 

 of hosts were utilized, which were grown temporarily in pots in 

 the greenhouse. 



A few cultures were made with heteroecious species for 

 which no clue to the alternate host had been obtained, and with 

 one exception the results were negative. These negative trials 

 are here recorded to serve for reference. 



1. Puccinia on Carex Pennsylvanica, sent by Rev. J. M. 

 Bates from Red Cloud, Neb., was sown on Urtica gracilis with 

 no infection. Similar material in former seasons has been tried 

 on twenty-one other species of hosts with negative results. 3 



2. Puccinia emaculata Schw. on Panicum capillare L. 

 from Lafayette, Ind., was sown on Ambrosia art emisiae folia, 

 Rudbeckia triloba, R. laciniata and Steironema ciliatum, with no 

 infection. This very common and distinctive rust was sown in 

 former seasons on fourteen other species of hosts with negative 

 results. 4 



3. Puccinia tosta Arth., on Sporobolus asperifolius, sent 

 from Denver, Colo., by Mr. E. Bethel, was sown on Napaea 

 dioica Symphoricarpos racemosus, Xanthoxylum Americanum, 

 Aesculus glabra and Viola papilionacea, with no infection. Sow- 

 ings of what is taken to be the same species of rust, but on 



8 See Jour. Mvcol. 10: 10. 1904; and 11: 51. 1905. 

 4 See Jour. Mycol. 8:52. 1902; Bot. Gaz. 35: 12. 1903; and Jour. 

 Mycol. 10 : 10. 1904. 



