ROOT-ROT OF CONIFERS 183 



very thin, white felt of mycelium between the bark and the 

 wood, hyphae from which attack the wood. The contents 

 of the living cells change to a brown colour, and finally 



rA-§\ 



V 



,0'^" 



■•ri-r-:::-S 



/'^Wltllilf"-"-'*'^-'"^ ''^'lifl' 



-X 





Fig. 41. — Fomes afinoszis. i, portion of fungus, half 

 nat. size; 2, section of same, showing the stratified 

 tubes in three layers, nat. size ; 3, portion of hymeniuni 

 showing the tubes and their openings or pores, slightly 

 mag. 



almost disappear; the wood next assumes a pale, yellowish- 

 brown colour witli scattered white patches, each having 

 a black spot in the centre. Finally the cell-walls are 



