122 
A NOTE ON INDIAN WHEAT-RUStS. 
position of its pustules. In place of being circumscribed areas these 
consisted of linear streaks, sometimes several inches in length, along 
the culms and along the outside of the leaf-sheaths. Whether this 
rust affects the glumes cannot be said, for it was only found on one 
plant, and as it happened that plant had every head destroyed by 
usttlago^ The plant, strange to say, was apparently quite vigorous ; 
this, coupled with the general appearance of the rusted spots, led to 
the belief at the moment of gathering, that it was but an extreme 
example of the ** Mozufferpur Rust*' in which the pustules had be- 
come confluent. But when minutely examined it was found that it 
has nothing whatever to do with the MozuflFerpur Rust it differs 
entirely as regards uredospores and has no teleutospores. The 
uredospores are also extremely different both from those of the 
‘'^Shibpur Rust ” and of those the ** Ferozepur Rust.” From the latter it 
differsTnoreover in having no teleutospores at all ; from both it differs 
in having uredospores with an unusually large number of germ-pores. 
Whether it be capable of affecting barley is as yet unknown. It is, 
however, clear that there is a fifth rust — the fourth occurring on wheat 
in the plains of India — the life-history of which requires further investi- 
gation before the subject of rust on wheat in India is fully under- 
stood. 
Any consideration of the question of the relationship of the geo- 
graphical distribution of Launea asplenifolia to the wheat-growing 
area is almost premature, in view of the fact that the connection 
betw^een the Puccinia which this Launea carries and one of the rusts 
on wheat, has- not been definitely demonstrated. 
It is well knowm, for example, that in years when rust attacks 
wheat in the Central Provinces, its ravages are excessive. Yet in the 
Central Provinces no examples of Launea asplenifolia were obtained. 
Too much stress should not be laid upon this point for several 
reasons. It is, to begin with, a matter capable of experimental de- 
monstration whether this connection exists or not. If it be proved 
that it does exist, the observations made during the present season 
need not give rise to any great difficulty. There is no reason why 
a rust, under suitable conditions may not, after having once started 
from a focus of infection in the shape of a diseased Launea patch, 
travel by direct infection in a very brief period from one end of a 
province to another. But it does not follow because it was not 
found in the Central Provinces that Launea asplenifolta does not 
occur there. It is a species that, though always plentiful where it 
occurs, has an exceedingly “ local” distribution, and it is conceivable 
that it may exist and yet have been overlooked. Again though 
