Mar. as, 1914 
Imperfect Fungi from Wheat , Oats , and Barley 
485 
which gathers more or less in masses; and //. avenae, a mycelium more 
nearly resembling H . gramineum , but less smooth and with more of a 
tendency to mass together. The developmental history and morphology 
of the mycelium and conidia in culture was very similar for the three 
species, but when the conidia were measured in large numbers those of 
H. teres were slightly longer than those of H. gramineum and those of H. 
avenae slightly larger than those of H. teres . 
In a series of inoculation experiments Helminthosporium teres from 
barley transferred to barley, but not to oats, rye, or wheat; H . grami¬ 
neum to barley, but not to oats; and H . avenae to oats, very slightly to 
barley, and not to rye. 
Until Ravn made these intensive studies of the three Helminthospo- 
riums they had been confused in the literature as to identity. The strain 
of H . gramineum discussed in this paper corresponds in cultural and 
morphological characteristics to the descriptions by Ravn. 
Pammel, King, and Bakke (19) report a number of species of Helmin¬ 
thosporium on cereals in Iowa, among them H . gramineum . They cite 
inoculation tests to show that infection occurred when barley seedlings 
were inoculated with spores of this fungus and when the soil in which 
seedlings grew was inoculated. Beckwith (5) reports the isolation of 
undetermined species of Helminthosporium from old wheat soils, roots, 
and stems of wheat in North Dakota, but no inoculation experiments 
are mentioned. A comprehensive bibliography of the literature on 
Helminthosporiums up to 1900 is given by Ravn (20). 
The literature relating to Fusariums on grains is also very extensive. 
Chester (10) reports that F. culmorum is the cause of the disease known 
as scab of wheat and shows that many shrunken wheat kernels con¬ 
tain a fungous mycelium. Detmers (11) shows that the disease known 
as wheat scab in Europe and caused by F . culmorum has become preva¬ 
lent in America. Selby (30) ascribes wheat scab in Ohio to the fungus 
F. roseum Link, and believes the conidial form of Gibberella saubinetti to 
be its conidial stage. Some field inoculations with Fusarium attempted 
by him were unsuccessful. 
The first investigator to show with any degree of certainty that Fusa¬ 
rium infection can be carried with the seed is Rostrup (25, 26, 27, 28). 
Ritzema Bos (24), Westerdijk (35), Volkart (34), Appel (1,2), and Selby 
and Manns (31) came to similar conclusions. Sorauer (32, 33) was the 
first to prove that infection could be carried with the seed. He main¬ 
tains, however, that infection in this manner is of small consequence 
as compared with infection through the soil. 
Selby and Manns (31), in their studies on the form Gibberella, con¬ 
clude that this fungus attacks rye, oats, barley, and spelt. Inoculations 
on wheat with pure cultures of Gibberella saubinetti (Mont.) Sacc. from 
perithecia on wheat reduced germination to the extent of 17.1 and 32.4 
per cent, respectively. Similar results on both wheat and oats were 
obtained by them with Fusarium roseum from wheat and clover. 
