SUMATRA AND OTnEE JAVA SOETS. 79 



infected. During a certain period, however, the mycelium ap- 

 pears not to do much injury to the trees, until periodically, at 

 different places and different seasons, under the influences of cir- 

 cumstances entirely unknown, it begins to fructify abundantly. 

 The spores produce innumerable new filaments, which, by their 

 rapid growth, require abundant nourishment, which they draw 

 from the shrub. The consequence is that the leaves, the young 

 berries, and the extremities of the stems wither and finally die. 

 The tree usually produces fresh shoots, but the disease immedi- 

 ately renews its attacks ; the young leaves again die. The second 

 attack is very dangerous, and few plants, without a long enough 

 respite, survive the third. The general public do not believe in 

 the attack except wllen the spores are visible, but the presence of 

 the fungus can be recognized at other times also, and with the 

 naked eye. It may then be noticed on the leaves in almost trans- 

 parent spots, which are caused by the destruction of the cellular 

 tissues of the leaves, on which the filaments of the mycelium feed. 

 Naturally, the tree then feels the influence of the parasite, but 

 not to such an extent as to reduce perceptibly the yield. The case 

 is very different when the spores appear. 



" One consolatory fact, which has been more and more con- 

 firmed, is that by high cultivation the trees can offer more resist- 

 ance to the disease. At first it was asserted that manuring favored 

 the progress of the disease, but this has not been proved, and 

 a, frlori it would be difiicult to admit it. There is no remedy 

 known for this disease, and one cannot be discovered. The pre- 

 servatives will be to uproot and burn the infected trees, and to 

 prohibit the introduction of coffee from places where, the disease 

 exists. But after all, high cultivation is the best preservative. In 

 what manner and at what period the disease appeared in Sumatra, 

 or indeed whether it was introduced, it is impossible to say, and 

 probably sooner or later it will make its appearance in Java also. 

 Some of the natives asserted that long ago they noticed it in Su- 

 matra, but very rarely, and especially when a very long drought 

 succeeded to constant and superabundant rains. Hitherto it seems 

 to have restricted itself to the Pandangsche Bovenlanden resi- 

 dency, and the Ayer Bangles district. In that residency it has now 

 been recognized in the districts of the Limapoeloe Kotas, Pang- 



