

THE RED ROT OF CONIFERS 15 



Clearly the fungus is capable of destroying the wood and makes 

 it unfit for manufacturing purposes. The advisability of cutting and 

 marketing trees affected by the disease as soon as the presence of the 

 fungus is noted, is evident. In this way only can the timber be used 

 at all. It should be noted that the strength of the sticks cut from dis- 

 ease-free wood corresponds closely to that of standard seasoned 

 pine. This tree, as a whole, however, was affected so seriously with 

 disease that at least 50 percent of it would have fallen into a $10 grade, 

 and 25 percent of it was utterly useless. 



VIII. METHOD BY WHICH THE FUNGUS SPREADS THROUGH A FOREST 



Root infection. According to Khan (6) an examination of vari- 

 ous specimens of the roots of coniferous trees in an East Indian for- 

 est infected with Trametes Pini showed that there is a strong possibility 

 that the disease may spread by the passing of the mycelium from the 

 roots of diseased to those of healthy trees. Even more striking is 

 Runnebaum's (4) statement based on the inspection of 70 infected 

 trees, to the effect that 50 of them had been infected from the roots. 

 A careful examination of the roots and trunks of these 50 trees, on 

 the side on which the fruiting bodies occurred, showed mycelium up 

 to a point only half a meter higher than the level of the ground. The 

 infection in the other 20 trees evidently had occurred in a branch 

 wound, because the rot was confined to the parts above ground. While 

 this channel of infection may be open to some cases, the chances of the 

 fungus penetrating the cambium and sap-wood of an uninjured root 

 seem rather slight. In any case the fungus can be spread thus but 

 slowly. The writer is of the opinion that root infection does not take 

 place to any great extent in this locality, certainly very few of the 

 specimens seen in Vermont were diseased below the ground. It may 

 be that the fungus has been confused with its closely allied form, 

 Trametes radiciperda, which produces much the same condition of de- 

 cay in the wood but is spread solely by underground methods, its fruit- 

 ing bodies forming below the surface. Tubeuf (3) has made clear the 

 distinction between Trametes Pini and Trametes radiciperda, although 

 the two species produce much the same condition in the wood. 



Fruiting bodies or sporophores. The fungus follows in general the 

 habits of other wood fungi and spreads through a forest mainly by 

 the production of spores in a fruiting body, or sporophore. That these 

 sporophores are very plentiful on the diseased trees in German forests 



