592 Went. — Notes on Sugar-cane Diseases. 
on to the cut surface of cuttings of the sugar-cane. After two 
or three days the cuttings exhibit all the symptoms of the 
disease. The same may be seen by infecting half- or full- 
grown cane with the conidia of the fungus through holes 
previously made. The conidia cannot infect canes through 
the sound epidermis of the stem, with the exception of the 
very young white parts of it, which however are naturally 
protected by the surrounding leaf-sheaths. From these facts 
it follows that the means of preventing the disease are very 
simple. They consist in protecting from the air the cut 
surfaces of cuttings. This is done here by means of tar, 
previously rendered more liquid by the addition of a little 
arrack. On estates where this method is employed the 
disease has ceased to show itself. 
The physiological properties of Thielaviopsis are very 
interesting. It is quite easy to cultivate the fungus on all 
sorts of nutrient solutions, on potatoes, bananas, &c. It is 
a saprophyte, which attacks all sorts of materials containing 
sugar, such as different fruits, mangoes, pineapples, bananas, 
& c. It spreads so easily that it is very difficult to get rid 
of the fungus where it once exists. In most of these cultures 
the agreeable odour can be detected. What is the substance 
possessing this flavour produced by the fungus ? In order 
to determine this, I made a culture of Thielaviopsis in 
ii litre of a sterilized solution, containing 1 5°/ o of saccha- 
rose, i°/ o of peptone, and a little K 3 P 0 4 and MgS 0 4 . 
After a week the liquor was distilled, and in this distillate 
the presence of ethyl acetate (and perhaps of very small 
quantities of other esters) and of ethylic alcohol could be 
proved. I further made a solution of i°/ o peptone in water 
with very little K 3 P 0 4 , MgS 0 4 and CaCl 2 . I divided this 
solution into seven flasks, and added to them separately the 
following substances : No. i, nothing ; No. 2, cellulose ; 
No. 3, starch; No. 4, io°/ 0 dextrine; No. 5, J0°/ o glucose; 
No. 6, io°/ o saccharose ; No. 7, 5°/ o ethylic alcohol. After 
having sterilized I inoculated with the conidia of Thielavi- 
opsis . In flasks Nos. 1, 2 and 3 the fungus developed pretty 
