700 
Journal of Agricultural Research 
Vol. XXIV, No. 8 
produced by the parasite on any host, and, indeed, unlike any injury 
produced under conditions obtaining in nature by any congeneric form 
with the exception of H. micropuSy seems altogether improbable. The 
results obtained by exposing experimental plants to the rigorous treat¬ 
ment incident to the application of relatively large quantities of inoculum 
and incubation in a saturated atmosphere during long periods, should at 
all events be interpreted with caution. And the necessity of caution 
would seem especially evident in dealing with a fungus, more or less 
promiscuous in its parasitism, the experimental host range of which 
would tend to be out of all proportion to its actual range in nature. 
The occurence of Helminthosporium sativum on com has brought about 
a measure of confusion regarding the indentity of H. turcicum. It is 
interesting to note that in Peck's account (roy) of H. inconspicuum, the 
spores of this fungus are described as “nearly black, septate up to 8 to 
9 times;" and figured as decidedly dark, curved cylindrical, with rounded 
ends, attached to sporophores emerging singly from the substratum. 
In all details of habit and morphology the correspondence with H, 
sativum is much closer than with H. turcicum) and it appears probable 
that although Peck observed the corn disease correctly, he inadvertently 
based his account of the fungus not on the well characterized parasite, 
but on the adventitious form. Specimens deposited in the herbarium of 
the Office of Pathological Collections of old com leaves from various 
localities in the United States, labeled “ Helminthosporium inconspicuumy*^ 
on examination, were found to bear dark olivaceous spores with non- 
protuding hila, not dissimilar from those of H, sativumy although their 
collapsed condition precluded the possibility of reliable identification. 
OCCURR^NC^ OR FUNGUS ON GRASSES OTHER THAN CEREAUS 
Bolley (i5) reported the occurrence of a species of Helminthosporium 
on quack grass collected in North Dakota and Wisconsin. As the 
fructifications developing on this host were held responsible in certain 
instances for the infection of wheat plants in the field, it is apparent 
that he regarded the species as identical to the parasite causing root rot 
and brown spot. In any case, the writer found H. sativum quite com¬ 
monly present on quack grass in the northern tier of Middle Western 
States, being associated with a leaf-spot disease, affecting the foliage of 
plants of'all ages. (PI. i8, H.) The discolored leaf areas, although 
quite numerous, are decidedly smaller than those characteristic of spot 
blotch of barley, occurring usually in the form of linear streaks, dark 
chocolate brown in color, 0.3 to 0.4 mm. in width and 0.5 to 3 mm. in 
length. During the season of 1919 the writer collected in the vicinity 
of Madison, Wis., diseased green leaves as early as May 6, and as late as 
October 24. The injury to the host appeared to be greater than that 
resulting from the parasitism of H. tritici-repentisy although neither of 
the two congeneric parasites could be said to have been especially de¬ 
structive. In the region about New York City, during the season of 
1920, the leaf spot due to H, sativum was, however, relatively rare, being 
considerably less abundant than the blight due to H. tritici-repentis. 
A fungus quite similar to the parasite causing “late blight" of barley 
was reported by Pammel, King, and Bakke (104) as occurring on Festuca 
elatior L. (^Festuca pratensis Hud.) in Iowa. Examination of material 
deposited in the herbarium of the Office of Pathological Collections only 
confirms the opinion of these authors concerning the similarity of the 
lesions to those characteristic of spotblotch of barley, and the very 
