79 



was that with the exception of the Helminthosporium, these fungi were 

 very rarely present, and then only a single colony or part of a mixed colony 

 on occasional plates. Alternaria occurred with remarkable rarity; only 

 two or three colonies among several thousand. Fusarium was found in 

 only a few colonies and so mixed that it was isolated with difficulty. Ep- 

 icoccum occurred in two colonies; Phyllosticta also in two colonies (two 

 species) . 



A Helminthosporium, however, appeared in every plate and from 

 nearly every bit of tissue used, no matter how great the care in securing the 

 inoculum. On many plates this Helminthosporium (which throughout 

 this article I designate as H. No. 1) appeared in pure culture Thus it 

 may be said that the Helminthosporium was universally present in the 

 plates; that it was the only organism that was present with any constancy; 

 and that all other fungi were obviously strays.* Though conidia were 

 never found in great numbers on plants brought in direct from infested 

 fields, when the plants were placed in moist chamber for two or three 

 days conidia developed in abundance. This was also the case with portions 

 of wheat stems which had been placed in bichloride of mercury for ten 

 minutes and then placed in moist chamber for several days. In passing 

 it may be remarked that although great numbers of nematodes and amebae 

 appeared in the plates there is no reason to believe that they had any relation 

 to the disease under discussion or to any diseased condition. 



GROWTH OF THE CAUSAL FUNGUS ON VARIOUS MEDIA 



Since the characters exhibited by various Helminthosporiums when 

 growing in artificial culture have been considered as of importance as a 

 means of distinguishing one species, variety, race, or strain from another, 

 many media were employed in the present study. This was done in part for 

 the purpose of comparing the growth characters of the Helminthosporium 

 with characters reported by others in connection with other forms; in part 

 with the hope that some of the media tested might give emphasis to cer- 

 tain characters and thus serve to differentiate between species or strains 

 of the forms under observation. 



The following notes are, in the main, statements of the characters 

 presented by the foot-rot Helminthosporium (H. No. 1), though for the 

 purpose of comparison notes are added regarding the growth of several 



*A letter from Professor Hoffer written in May, 1919, tells me of a similar result from platings of wheat 

 foot-rot from Indiana, and similar reports reach me from several other sources. 



