DISEASES 



261 



they will invariably be found to be covered with white slime 

 and the thread-like filaments of the fungus. Wherever such 

 roots are they should be thoroughly searched out and no 

 fragments allowed to remain in the soil as a source of infection. 

 Even if financial considerations do not permit a manager to 

 remove all dead timber, roots and stumps, there must be no 

 half measures about the entire removal of the roots of these 

 hardwood trees. Undoubtedly the proper course to pursue 

 is to remove all roots and decaying timber, but counsels of 

 perfection, however excellent, are not always followed. 



FIG. 72. View on an Estate in Siantar, Sumatra, showing Trenches made to 

 Isolate Trees suspected of Fomes. 



The apparent connection between the attacks of white ants 

 and Fomes has been frequently commented upon. That there 

 is some connection is not to be doubted, but the exact nature 

 of the connection has not yet been made clear. One point in 

 dispute is : which attacks the roots of the Hevea first the pest 

 or the disease. The two seem to act as allies in their attacks 

 on the tree community. 



It might seem not improbable that spores of the fungus are 

 transported to the roots of the Heveas by the white ants in the 

 same way perhaps as bees and other insects carry away on their 

 heads and shoulders pollen from one plant to another. It is 



