722 
Journal of Agricultural Research 
Vol. XXIV, No. 8 
mentally by applying large quantities of conidia of Helminthosporium 
sativum to the foliage of com seedlings and incubating in a damp chamber 
for several days. The parasite has not been found on other hosts. It 
is undoubtedly distinct from H. penicillosum, a saprophyte described 
from Argentina by Speggazini {137) on the decaying culms of P. pla- 
tensis and of an unidentified species of Andropogon. The measurements 
given for the sporophores of the South American fungus, 150 to 600 by 
10 to 15 as well as for the diameter of the spores, 10 to 12 indicate a 
great difference in the dimensions of the two forms. Nor does the 
parasite on P. hoscianum bear any close resemblance to H. mayaguezense 
described by Miles (gi) as occurring on the culms and leaves of P. con- 
jugatum in Porto Rico, for the measurements of the conidiophores and 
conidia, 300 to 500 by 18 to 22 /i and 135 to 155 by 35 to 45 /i, respectively, 
point toward an order of. dimensions not approa^ed by the fungus under 
consideration. Furthermore, the spores of the Porto Rican fungus, in 
spite of their relatively large size, are described as being only 3 to 4 
septate; and are figured as having the septa associated with constric¬ 
tions, a condition altogether absent from those of the Florida form. As 
the latter appears not to have been described, the specific name micropus 
is suggested to signalize the characteristic modification of the basal end 
of its spores. 
DIAGNOSIS 
Helminthosporium micropuSy n. sp. 
* Attacking the leaf blades of young plants of a species of Paspalum, provisionally 
identified as Paspalum hoscianum Flugge, killing me foliar tissues in elongated regions 
usually varying in length from 5 to 30 mm., the affected parts having first a scalded 
appearance and later becoming dry and shriveled. On the foliage of older plants, 
affected regions more restrictea in extent, elliptical usually with brownish margins; 
bringing alSjut death of leaf by more gradual progressive withering. 
Conidiophores appearing on portions of withered leaves previously involved in 
lesions; emerging singly or in groups of 2 or 3, from stomata or between epidermal cells; 
dark brown; 4 to 6 ju in diameter; septate at intervals of 5 to 40 n; producing first spore 
65 to 140 Mfrom base; successive spores produced at intervals of 5 to 15 marked by 
pronoimced geniculations. 
Spores subhyaline to light fuliginous; straight or more typically somewhat ctu^ed; 
of nearly uniform diameter between end segments or slightly tapering from middle; 
longer ones usually of cylindrical type, shorter one more nearly elliptical. Apex 
usually rounded off by hemispherical or hemiellipsoidal contour; basal segment ap¬ 
proximately obconical, tapering uniformly to a width of 2 to 3 /n, then produced as a 
very short prolongation terminating in hilum. Peripheral wall moderately thin, but 
visibly double-contoured except in small circular spot at apex and about basal modifi¬ 
cation immediately adjacent to hilum, where it becomes very thin and appears single- 
contoured. Germinating by two polar germ tubes, one being proliferated from each 
of the thin-walled regions. Measuring 10 to 18 by 28 to 92 m; 3 to 9 septate, the septa 
not marked by constrictions. 
Habitat.— Collected near Wauchula, Fla., April 18,1921, and May 2,1921. 
HELMINTHOSPORIUM ROSTRATUM, N. SP. 
In an effort to collect material of a fungus reported by Ellis and Ever¬ 
hart {36) on Eragrostis major Host, in Delaware, more than three decades 
ago and described by them as Helminthosporium hadotrichoides, the writer 
took occasion to examine specimens of stink grass gathered in the vi¬ 
cinity of Washington, D. C., at various times in September and October, 
1921. As the grass matiures relatively early, it was represented exclu¬ 
sively during these months by entirely dry mature plants—a fact that 
could hardly be supposed to facilitate search for a parasite such as the 
fungus described by Ellis and Everhart presumably represents. At any 
