POLYPORACEAE 179 



of the cell-walls to swell into a gelatinous mass without 

 being changed into cellulose before they are completely 

 dissolved. 



Hartig, Die Zersetztmgscrscheinungen des Holzes, p. 97, 

 pi. xii. 



POLYPORACEAE 



( Tramdes pin /, Frie s. ) 



Very hard, forming an irregular, thick, projecting mass, 

 often almost triangular in section; pileus dark brown, 

 concentrically grooved, rough, margin strigose; flesh rusty; 

 tubes long, stratified, rusty; smell pleasant; two to four 

 inches across. Hartig, who has given a very elaborate 

 account of the effect produced by this parasite on the 

 wood, states that the sporophores sometimes live for fifty 

 years. The fungus is a wound-parasite, attacking various 

 coniferous trees, and as a rule does not develop on trees 

 under fifty years of age, as up to that period wounds are 

 quickly protected by turpentine, whereas later in life 

 turpentine in the heart-wood is scanty, and thus the 

 wounds caused by broken branches are not so quickly 

 protected against floating spores. 



Sporophores are only produced after a luxurious 

 formation of mycelium is present in the living tissues. 

 Diseased wood assumes a reddish-brown colour, after- 

 wards white blotches, and finally holes appear here and 

 there. 



The fungus is very abundant in the pine woods of 

 North Germany, less so in the spruce woods of South 

 Germany. It is everywhere rare in Britain. 



