DISEASES CAUSED BY WOUND FUNGI. 29 



successful unless in the smaller vessels. We are informed by Gleditsch that in Fran- 

 conia he has seen these beaten pieces of Boletus which resembled the softest leather 

 curiously sewed together and made into garments. 



The false-tinder fungus has been well known in Europe for about 

 two hundred years. Its synonymy is given below: 



Boletus igniarius, Linnaeus, C., Species Plantarum, p. 1176. 1753. 

 Polyporus igniarius, Fries, E., Syst. Mycol., vol. 1, p. 375. 1821. 

 Fomes igniarius, Gillet, C. C., Champ. France, vol. 1, p. 687, pi. 156. 1878. 

 Phellinus igniarius, Quelet, L., Enchir. Fung., p. 172. 1886. 



Mucronoporus igniarius, Ellis, J. B., and Everhart, B. M., Jour. Mycol., vol. 5, 

 p. 91. 1889. 



Pyropolyporus igniarius, Murrill, W. A., Jour. Mycol., vol. 9, p. 101. 1903. 



The name Fomes igniarius has been accepted and is in general use, 

 while the three later generic- names are not so \vell known or so gen- 

 erally accepted. It seems best to use the more common and better 

 known name in the present account of this fungus. 



The' false-tinder fungus (Fomes igniarius) is one of the most con- 

 spicuous of the so-called punks, or shelf fungi, which grow upon living 

 trees. It varies much in shape, size, and color, depending upon its 

 age and upon the species of tree upon which it grows. It is commonly 

 more or less hoof shaped, measuring about as much in thickness as in 

 width. Its size varies from 1 or 2 inches to 12 inches or more in width. 

 The upper surface is smooth in the younger forms and becomes 

 concentrically marked as the fungus grows older. It is characterized 

 by a very hard external layer, which is at first brown, gradually 

 becoming black, and in the older forms is considerably roughened 

 and cracked. The cracks, how r ever, rarely penetrate far into the 

 mass of the sporophore. The sporophores are very woody and of a 

 rusty brown color on the inside. The pores are formed in layers, one 

 below the other, and the sporophores apparently may grow to a 

 great age. The writers have found them with 50 layers. Atkinson 

 (4) reports one with 80 layers. The average number is from 15 to 30 

 layers, presumably indicating an age of approximately the same 

 number of years. The lower surface is gray to red-brown in color, 

 varying according to the season. The edge is yellowish brown when 

 first formed, and very much lighter in color than the top. To\vard 

 the end of the season the newly formed portion weathers considerably 

 above and has a rusty appearance. Although there is considerable 

 variation in the form of the sporophore, its general characteristics arje 

 so decided that it is rarely confounded with any of the other wound 

 fungi. 



SPREAD OF THE DISEASE. 



The white heart-rot, as has been stated, is caused by the growth 

 and development in the wood of the trees of the mycelium of Fomes 



149 



