Went. — Notes on Sugar-cane Diseases. 587 
The fungus will be sufficiently recognizable I am sure if I give 
some measurements : hairs, 100-200 x 4 yot ; conidia, 25 x 5 ju ; 
basidia, (about) 20 x 8 /x (but the size of the basidia is very 
variable). 
Every cane diseased by red smut contained the mycelium 
of Colletotrichum falcatum , and as during the last four years 
I have examined a very large number of diseased canes, it 
seemed very probable that this fungus might be the cause of 
the disease; But this had to be proved. With this object 
I made incisions in sound canes and inoculated them with 
mycelium from pure cultures of Colletotrichum falcatum ; the 
wound was shut off from the air by a little tinfoil. After 
ten days some of the canes treated in this manner were cut 
longitudinally ; it could be very distinctly seen that round 
the wound the cane had become diseased by red smut. After 
twenty days the whole joint was diseased, showing the charac- 
teristic red spots with white blotches, and under the micro- 
scope the cells were seen to be filled with the mycelium of 
Colletotrichum falcatum. Incisions made in sound canes, with- 
out inoculating with the fungus, did not produce the disease ; 
only the dead cells round the wound became coloured red, as 
is always the case when a cell of the sugar-cane dies. 
We may conclude therefore that Colletotrichum falcatum is 
the cause of red smut. But it is only a wound-parasite ; 
sound canes, which have not been damaged, cannot be 
attacked by the fungus, with the exception of very young 
parts of the stem. This is practically of no importance, as 
these parts are protected by the surrounding sheaths of 
the leaves. 
The attack of the fungus may cause serious damage, owing 
to the deterioration of the canes and the diminution of the 
sugar. At the Tjomal estate, where the disease was first 
detected in 1892, at the beginning of the grinding season 
samples are taken from all the various cane-fields and cut 
longitudinally ; all the canes of those fields which prove to be 
attacked in any serious degree by red smut are reaped and 
crushed before the others, because the disease spreads very 
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