28 DISEASES OF DECIDUOUS FOREST TREES. 



rence of this fungus in them. The recent statement of Schuman and 

 Lauterbach (92) that it occurs the world over can scarcely be doubted. 



The amount of destruction caused by this fungus in the North 

 American forests is beyond computation, because of both the wide 

 occurrence of the fungus and the large number of host species upon 

 which it grows. The loss caused thereby differs considerably with 

 the locality and the host species. The greatest losses are brought 

 about in more or less definitely limited localities. There are districts 

 which are very badly affected with this disease, and others which are 

 comparatively free therefrom, which may be considered a good 

 augury from the standpoint of prevention. 



Where this fungus occurs extensively almost the entire stand of 

 certain species is frequently found so badly injured with the white 

 heart-rot as to be practically worthless. In a certain area of decidu- 

 ous forests in the Adirondacks in the State of New York, where the 

 timber was comparatively a mature stand, actual counts showed 

 that from 90 to 95 per cent of the otherwise merchantable trees of 

 beech were rendered valueless from the attacks of this fungus. The 

 same is true to a certain degree in the regions where the aspen is 

 grown extensively for pulp wood. In the New England States, 

 Colorado, and New Mexico it is almost impossible to find healthy 

 groves of aspen which have attained any age, because of the extreme 

 destruction brought about by the false-tinder fungus. In the mature 

 beech stands of Texas and Louisiana, where the trees are 1 50 years 

 old or more, a very large percentage are wholly decayed in the interior 

 by this fungus. (PL II, fig. 1.) The same is true of many of the 

 tracts of the Appalachian deciduous forests. It may be stated that 

 the amount of damage caused by the white heart-rot is very great; 

 and its wide distribution, together with the almost universal suscepti- 

 bility of deciduous trees thereto, make it the worst enemy of these 

 species, especially during the period when they are approaching 

 maturity. 



DESCRIPTION OF THE FUNGUS. 



The fungus Fomes igniarius has been known for a great many years 

 and has been made the subject of a large number of descriptions, as a 

 result of which a very extensive bibliography has developed, which is 

 too bulky to be here included. It is probably one of the oldest fungi 

 known, as ft attracted attention in the early days because of its size 

 and uses. Lightfoot (47) in 1777 made the following statement: 



An excellent touchwood is made from this fungus, by first paring off the outer rind, 

 then boiling the remainder in lye, and afterwards drying and pounding with a hammer, 

 or else pounding and boiling it up with saltpeter. The same fungus beaten into soft 

 square pieces is well known to surgeons by the name of Agaric, and has been much 

 celebrated for stopping the bleeding of arteries; it has not, however, proved altogether 



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