Oct. 15,1925 Leaf spot of Maize Caused by OpTiiobolus heterostrophus 725 
preted as incipient perithecia, and by conidial apparatus either being 
absent, or, if present, not infrequently represented by proliferous 
atypical structures in which sporophoric elements and spores are 
poorly differentiated. 
The maize parasite, like Helminthosporium sativum P. B. and K., 
H. sacchari and H. oryzae —to mention only a few of the more im¬ 
portant species—represents a type of Helminthosporium with mostly 
elliptical, curved conidia, germinating by the production of two germ 
tubes, both from small, thin-walled regions, one at the apex and the 
other immediately adjacent to and surrounding the basal scar. In 
artificial culture, sporulation is usually abundant and not markedly 
abnormal, although the conidia may be shorter and less regularly 
curved than those produced under natural conditions. There can be 
little doubt that the species adhering to this type, including many 
parasites of higher plants and very probably a considerable number of 
small-spored forms often referred to the conidial genus Brachysporium, 
are closely related with one another, and that the latter, when con¬ 
nected with ascigerous stages, be found not without similarity to 
OpTiiobolus TieterostropTius . It is apparent that a proper taxonomic 
disposition of the general run of species of Helminthosporium with 
bipolar germination is contingent on the discovery of the perfect con¬ 
dition of additional forms, from the morphology of which the common 
characters may be deduced for incorporation in the definition of a 
suitable genus, or, if possible, for appropriate revision of a genus 
already established. 
SUMMARY 
A foliar disease has been found to occur on maize in Florida and 
on maize and teosinte in the Philippines, which is characterized by 
cinnamon-buff lesions which are considerably smaller and much 
more numerous than those of leaf blight, and are also distinguished 
by being usually confined to a single intervascular region. 
The disease is associated with a fungus which, in its conidial con¬ 
dition, differs from Helminthosporium turcicum in the smaller diameter 
of its conidiophores, as well as in the smaller diameter, more abundant 
septation, and greater curvature of its elliptical conidia, which, more¬ 
over, have an internal basal scar rather tnan a protruding modifica¬ 
tion. 
The fungus produces discrete, subglobose perithecia with a well 
defined beak, and bearing asci containing typically four multiseptate, 
fuliginous, filamentous spores, each coiled in a heterostrophic helix of 
approximately four turns. It is described tentatively as Ophiobolus 
heterostrophus, n. sp., though not obviously closely related to several 
well-known species of Ophiobolus parasitic on grasses. 
The morphological difference between this ascigerous stage and 
Pyrenophora or Pleospora lends support to the view that the species 
of Hehninthosporium with straight subcylindrical conidia germinat¬ 
ing laterally from end and intermediate segments constitute a natural 
group distinct from the group of species producing curved elliptical 
conidia germinating by two polar germ tubes. 
The leafspot disease is probably widely distributed in tropical and 
subtropical maize-growing regions, having evidently been confused 
with leaf blight, which occurs in the same territory. It appears not 
improbable that one type of tassel mold will prove to be identical 
with the foliar parasite, in spite of the greater length of its conidia. 
