52 



Mycologia 



Ariz., H, S. Coe, Ames, Iowa, H. M. Jennison, Crawfordsville, 

 Ind., S. Kusano, Tokio, Japan, E. F. Smith, Hannaford, N. D., 



E. M. Wilcox, Lincoln, Neb., J. J. Wolf, Durham, N. C, and 



F. Vasku, Oberlin, Ohio, Seeds and living plants were also sent 

 by a number of botanists to provide host plants of native species 

 required in the work. To all these and to others who aided in 

 the work of the year grateful acknowledgment is due and is 

 hereby extended. The investigations were carried out under the 

 auspices of the Indiana Experiment Station, and financed from 

 the Adams fund. 



During the present season 193 collections of material with 

 resting spores and 37 collections with active spores were em- 

 ployed, from which 691 drop cultures were made to test the 

 germinating condition of the spores. Out of the 193 collections 

 with resting spores 156 failed to germinate, leaving 37 collections 

 available for experimental tests. Altogether about 235 sowings 

 were made and 32 infections obtained. All but three sowings 

 were made on plants growing in pots in the greenhouse. The 

 most important conclusions derived from a study of the results 

 are given in the following paragraphs. 



Negative Results. — It has been customary in these reports 

 to record sowings with germinating spores when no infections 

 were obtained, to serve as a guide in selecting hosts for future 

 attempts. This year only a few instances will be given, as all 

 sowings made after the heated term began, May 8, are deemed too 

 uncertain to be of value. 



I. PucciNiA TOSTA Arth., on Sporobolus asperifolius (Nees & 

 Meyen) Thurb., collected at Denver Colo., by Mr. E. Bethel, 

 was sown April 19, on Atnplex confertifolia and Malvastrum 

 coccineum, with no infection. The day following a collection 

 with same data from Delta, Colo., was sown on Aesciilus glabra 

 and Xanthoxylum americanum, and again. May 10, on ten other 

 hosts, with no infection. 



The resemblance of this rust and of its host to that of Puc- 

 cinia subnitens Diet., on Distichlis spicata, is very marked, as seen 

 in the field. The two species grow under the same conditions, 

 often intermixed, and might be expected to have the same aecial 



