80 THE DESTRUCTIVE AGENTS OF FORESTS. 



damage is done by saprophytic forms which find an entrance to 

 the valuable heartwood. Nearly all of the destructive fungi of 

 this class belong to the group known as pore fungi, most of 

 which send out from the tree trunks the familiar sporophores, 

 variously known in West Virginia as ''brackets", "toadstools", 

 * Spunks", gnat-woods ", or "puddicks". Heartwood of affect- 

 ed trees is rendered worthless by all the fungi of this class. The 

 diseased wood becomes dry or wet, powdery or fibrous, light or 

 dark-colored, according to the species of the attacking fungus. 

 One of the most familiar examples under this head is the locust 

 fungus {Pyropolyporus rohiniae Murr.) which enters the wood 

 of the tree through broken limbs or through the tunnels of the lo- 

 cust borer. Another, the false-tinder fungus {Fomes igniaritis 

 Gill.) is an enemy of many broad-leaved trees including beech, 

 maples, yellow birch, walnuts, oaks, hickories, and willows. The 

 sulphur polyporus {Polyporus sulphureus (Bull.) Fr.) is found 

 on oaks, chestnut, locust, walnuts, and many other deciduous 

 trees. Others are the soft-rot fungus {Polyporus oltusus Berk.) 

 found growing in wood of oaks ; and the heart-rot fungus {Fomes 

 nigricans Fr.) of birches, vdllows, and aspens. Many others, de- 

 scribed in various publications relating to this subject, may be 

 found in the forests and woodlots of the State. 



Fungi That Injure Dead Wood. 



No estimate can be made of the immense damage to fallen 

 trees and manufactured timbers caused by various species of 

 saprophytic fungi. It has been pointed out that decay from these 

 causes under favorable circumstances is rapid and certain, and 

 that in order to preserve wood it is necessary at once to insure it 

 against attack by seasoning or chemical treatment. According 

 to some writers, the most widely distributed and most destructive 

 of the wood-rotting fungi is the comparatively small and vari- 

 colored species {Polysiictus versicolor (L.) Fr.) found growing 

 singly or more often in dense masses on almost every kind of 

 hardwood. A more conspicuous example of this class is the com- 

 mon sap-rotting fungus {Elfvingia megaloma (Lev.) Fr.), the 

 large sporophores of which are seen growing on logs in damp 



