Went. — Notes on Sugar-cane Diseases . 585 
gumming \ and I do so because I have several times read the 
assertion that I should have found the Australian gumming- 
disease, as described by Cobb 1 2 , in Java. Now, only a few 
months ago I observed some phenomena here which might be 
identical with the Queensland disease, ascribed by Cobb to 
the influence of parasitic Bacteria. But the gummy red- 
coloured vascular bundles found in all diseases of the cane 
have nothing to do with this, and are not due to any action 
of Bacteria. 
If we turn now to the microscopic examination of the 
disease, it will be seen that the cells in the diseased spots 
are filled with the mycelium of a fungus. The hyphae contain 
a great many small oil-drops, soluble in alcohol and ether. 
Frequently in older blotches the fungus can no longer be found 
in the centre of the diseased spots, but here the oil-drops very 
generally have persisted, so that the direction of the former 
hyphae is still manifest. It is very easy to cultivate this 
fungus by bringing sections of diseased canes into a damp 
place. In from twelve to twenty-four hours a beautiful 
mycelium grows out of the diseased spots ; this mycelium is 
at first almost white, but afterwards its colour becomes greyish 
or smoky, perhaps between Nos. 2 and 39 of Saccardo 3 : 
if the hyphae are moistened, the colour changes and be- 
comes light olive-green (No. 39, Saccardo). The mycelium 
is again characterized by its oil-drops. After a few days’ 
growth chlamydospores are formed, sometimes in the middle 
of a filament (Fig. 3), but mostly at the end of a hypha 
(Figs. 1, 2). They contain large oil-drops and have a some- 
what irregular form ; their cell-wall is coloured dark olive- 
green. 
In making cultures of the fungus on nutrient solutions 
or agar-agar, these chlamydospores are produced in great 
1 Went, De Serehziekte : Mededeelingen van het Proefstation West Java. Archief 
voor de Javasuikerindustrie, I, 1893 ; Bot. Centralbl. 59, 1894. 
2 N. A. Cobb, Plant Diseases and their Remedies ; Diseases of the Sugar-cane. 
Department of Agriculture, N. S. W. Sydney, 1893. 
3 P. A. Saccardo, Chromotaxia sen Nomenclator Colorum. Ed. altera, 1894. 
