206 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



According to our present state of knowledge, it is useless to try 

 to retain trees already attacked by the fungus ; they are incurable 

 and only deteriorate. However, their removal takes time, and in 

 the meantime measures should, Dr Moeller advocates, be taken 

 without delay to render them innocuous as hosts for the further 

 spreading of the disease. The only conceivable method is the 

 removal of the sporophore brackets, painting the wounds caused 

 with Ermisch's caterpillar glue, known in the trade as Schwammtod 

 (fungus death), or some similar substance, to prevent the 

 reformation of sporophores. 



The Prussian Government is taking most energetic and 

 systematic measures in this respect, having spent nearly ;i^20,ooo 

 thereon during the four years 1905-8. It is expected that by the 

 end of 191 2, or very soon after, the whole of the 332 forest 

 divisions reported as affected in 1904 will be declared free; 

 with few exceptions all attacked trees will have been felled, and, 

 barring oversights, sporophore brackets will have ceased to exist. 

 It has been argued that, with the milliards of spores a single 

 bracket is able to produce, these oversights suffice for the spread 

 of the fungus over a whole forest area. There is nothing to be 

 said against the milHards of spores, for Dr Moeller himself 

 ascertained that one sporophore of about 15 sq. inches emitted 

 150 million spores in one hour, and repeats this emission for 

 months. The danger of infection is, in spite of these terrible 

 figures, Hmited and reduced in the exact ratio that infection 

 centres are destroyed and diminished. 



A periodical inspection of all pine forests over sixty years of 

 age, at intervals of not over five years, and a careful search for 

 infected trees has been directed. Such trees will be conspicuously 

 marked for immediate removal. 



With these energetic measures, it is hoped to make Trametes 

 pint before long a rare fungus in State forests, and the feasibility 

 of interference in the management of private forests, in the same 

 direction, is already under consideration. 



Explanation of Plates. 



The pictures on the plates are true photographic representa- 

 tions of the trees they depict. They were, in the first instance, 

 re-photographed to a convenient size on Velox paper. The mam 

 lines of these photos were carefully followed by experienced 



