16 SOME DISEASES OF CEREALS, 
Oospore 40-60#. d.; hybernating spore with smooth 
contour, with oogonial wall not or little thicker than 
that of the oospore, pale yellow. Scl. macrospora. 
As an asexual stage has only been found in Sel. graminicola, 
Traverso bases his classification on the sexual stage alone. It 
is in this stage only, that the majority of students of the genus 
have seen their species, 
Sclerospora graminicola (Sacc.) Schroet. has been recorded up 
to the present only on species of Setaria, chiefly S. viridis, but also 
S. italica, S. glauca and 8, verticillata, in Italy, France, Germany, 
Austria, Russia, the United States and Japan, The influence oi 
the parasite is very similar to that above described, virescence of 
the ears and distortion and shredding of the leaves being common, 
An excellent illustration of the disease of 8. italica (‘* Awa ’’) 
in Japan is given in Arata Ideta’s Lehrbuch der Pflanzenkrank- 
heiten in Japan (1903) with a description in Japanese. In this, 
the prolification of the spikelets and shredding and torsion of the 
leaves is well shown, and the fungus is clearly figured. It will be 
remembered that this is one of the cereals mentioned above, as 
being subject to Sclerospora disease in India. Similar effects on 
the other host plants have been referred to by several authors. 
Sclerospora macrospora Sacc., under which Traverso, ap- 
parently with good reason, includes Scl. Kriegeriana Magn. 
(1895) occurs on a number of grasses, having been found in 
Australia on Alopecurus sp.; in Germany on Phalaris arundinacea ; 
in France on oats ; and in Italy in recent years, on wheat, maize, 
oats, Avena fatua, Agropyrum repens, Glyceria maritima (?), 
Phalaris coerulescens (?), Ph. arundinacea (?), Ph. canariensis, 
Lolium perenne, Agrostis alba(?), Holeus mollis (?) and Phragmitis 
communis. Its conidial stage has not been discovered. The 
Italian species, which was, after critical study, referred to this 
species by Traverso, was first considered by Peglion (1900 and 
1901), who had chiefly investigated it in the field, to be Sel. 
graminicola. In the neighbourhood of Rome in 1899 a rather 
severe outbreak occurred in wheat, due chiefly, according to 
Peglion, to flooding of the fields by the Tiber in that year. The 
