250 



THE PROTECTION OF WOODLANDS. 



so that this measure is only advisable where they can be collected and 

 burned before they ripen and scatter their spores. 



The White-rot fungus, Forties igniarius, is one of the commonest wound- 

 parasites on broad - leaved trees, and chiefly Oak and Willows. When 

 infected, wood turns brown, then yellowish-white, and the spongy sporo- 

 phores form a cap or bracket up to 10 or 12 in. broad. At first yellowish- 

 Fig. 68. 



Young Scots Pine killed by Agaricus melleus. 



a. Branching subterraneous rhizomorphs thrown out from the mycelium under the 



living bark, 



b. Abortive sporophores produced at extremity of a rhizomorph. 



c. Normal sporophores produced at extremity of a rhizomorph. 



d. Sporophores produced in a cluster from the bark at base of stem of the dead Pine. 



brown and felty, they afterwards turn blackish-brown and smooth with 

 concentric ridges, the openings of the spore-tubes being cinnamon-brown. 

 Its spongy sporophore was formerly (as well as F. fomentarius) used as 

 tinder (hence igniarius) in the days of flint and steel. Forties fomentarius 

 is a wound-parasite on Beech chiefly, also Oak and Elm, where its broad 

 leathery mycelium, penetrating the wood radially, also produces " white- 

 rot." It forms large, hoof-shaped, russet- brown or greyish sporophores, 



