232 TIMBER AND SOME OF ITS DISEASES [chap. 



seen a number of small cup-like fungus fiuctifications 

 (Fig. 35, b), each of which is white or grey on the 

 outside, and lined with orange-yellow. These are 

 the fruit-bodies of a discomycetous fungus called 

 Pezi::.a Wtllkommzz (Htg.), and which has at various 

 times, and by vaiious observers, received at least 

 four other names, which we may neglect 



In the spring or early summer, the leaves of 

 the tree are found to turn yellow and wither on 

 several of the twigs or branches, and a flow of 

 resin is seen at the dead patch of cortex. If the 

 case is a bad one, the whole branch or young tree 

 above the diseased place may die and dry up. At 

 the margins of the patch, the edges of the sounder 

 cortex appear to be raised. 



As the disease progresses in succeeding years, 

 the merely flattened dead patch becomes a sunken 

 blistered hole from which resin flows : this sinking 

 in of the destroyed tissues is due to the up-growth 

 of the margins of the patch, and it is noticed that 

 the up-growing margin recedes further and further 

 from the centre of the patch. If this goes on, the 

 patch at length extends all round the stem or 

 branch, and the death of all that lies above is 

 then soon brought about, for since the young wood 

 and cambium beneath the dead cortex are also 



