262 Transactions British Mycological Society. 



experience of the disease and its treatment, that the disease 

 can be effectively controlled in this way. Silver-leaf and similar 

 troubles are sometimes looked upon as "Acts of God " for which 

 there is no treatment, or else alarm is raised and some nostrum 

 is requested in a hurry which will cause recovery in trees that 

 are already doomed and dying. The cry has been raised that 

 the cultivation of the valuable ' Victoria' plum will be wiped out 

 by the spread of silver-leaf disease. Nothing of the kind — that 

 is, if the measures advocated in this paper are effectively pursued. 

 Where plantations of ' Victoria ' plums have been killed by this 

 disease, there has always been terrible neglect, but one hopes 

 that such gardens will soon cease to exist in all the important 

 fruit-growing districts of the country. 



A DRAIN-BLOCKING FUNGUS. 



By A. Lorrain Smith, F.L.S. 



In September 1919, material was submitted to me that had 

 been taken out of a sewer in the City of London 30 feet below 

 ground, and under the vaults of a bank previously the site of 

 Crosbie Hall. The whole mass weighed about | cwt. and had 

 completely closed the drain-pipe. The substance was sodden 

 with water and of a uniform brownish-yellow, but there was 

 no difficulty in recognising its fungus nature and that it was a 

 Fomes. As the fungus dried, layers of white pileus and long 

 cinnamon-coloured tubes became visible. The specimen was 

 exhibited a few days later to the members of the Mycological 

 Society at their annual meeting at Baslow, and Mr Carleton Rea 

 unhesitatingly pronounced it to be Fomes ulmarius, a fungus 

 which has always been considered to grow on elms. 



There is at the present date no living elm in the neighbourhood 

 of Crosbie Square. Search was made, while tunnelling to remove 

 the obstruction, for any material on which the fungus could have 

 originated ; the gap in the pipes was found by which the fungus 

 had penetrated into the pipe; and near to this lay a piece of 

 timber of coniferous wood. The wood was fairly rotten and the 

 cells occupied by mycelium, but there was no sufficient evidence 

 that the fungus had any connection with this wood. Mr Rea 

 tells me that elm roots travel long distances and he has had 

 experience of drains being blocked by the roots of an elm tree 



