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SOME DISEASES OF CEREALS CAUSED BY 
SCLEROSPORA GRAMINICOLA. 
BY 
E. J. BUTLER, 
Imperial Mycologist. 
A CURIOUS disease of Pennisetum typhoideum (bajra) occurs 
sporadically in most provinces of India where this cereal is grown. 
It is not usually of sufficient intensity to attract much notice ; 
but at times, particularly in low-lying ill-drained land, it 
develops into epidemics of varying severity. Its chief interest 
is, however, at present pathological, for it is one of a small 
number of diseases, caused by parasites, which produce deep 
alterations in the reproductive paris of plants, resulting in great 
modification in the floral organs and entire or partial sterility. 
The general appearance of diseased ears is represented in plate 
I. The spicate inflorescence, from which this species obtains its 
name of the bulrush millet, is transformed wholly or in part into 
a loose green head, composed for the most part of small twisted 
leaves. Every stage can be found between ears in which the 
_ greater part ripens its grain normally, only a small proportion 
showing the characteristic deformity, and ears entirely affected 
and absolutely sterile. 
To understand the changes in the inflorescence to which this 
mappearance is due, it is necessary, in the first place, to have a clear 
Sxidea of the structure of the normal inflorescence. The bajra ear 
‘is composed of crowded spikelets arranged around a woolly, un- 
— branched axis, the whole ear being up to a foot long, by one, or one 
> 1 
