448 



damaged by it. So it is better to use 2% Bordeaux mix- 

 ture, which gave good results. When a small number of 

 trees is badly attacked, it may be of great advantage to 

 collect the witliered leaves hanging from the branches 

 and those lying under the tree, and to burn them. 



Generally the damage caused by the disease is only of 

 small importance, and spray ing will not be necessary in 

 the majority of cases; I should advise it for plots of 

 trees, badly attacked, which seem to be a centre of in- 

 fection in the midst of the cultivation. 



The damage done in Surinam coffee is greatei , the trees 

 often lose so many leaves that they become almost bare. 



SUMMAEY. 



The silverthread disease attacks Coffea arabica as well 

 as G. liberica. 



It forms rhizomorphous strands, which grow acropetalous, 

 and at the nodes of the branches, they spread ôver the 

 under side of the leaves. 



The hyphae clog the stomata; no sooner are the guard 

 cells killed, then they also penetrate the leaf. Brown spots 

 arise on the leaves; finally thèse wither completely and 

 hang from the top of the branches by the mycel strands. 



•The fungus does not show any fructification; the my- 

 célium has some typical characteristics. 



Artificial inoculation gave positive results. 



It is not identical with Pellicularia Koleroga, nor with 

 candeJillo, the same disease exists in Porto-Kico. 



Spraying with Bordeaux Mixture is a good means of 

 combating it. 



