152 TIMBEES AND THEIR USES 



cracks and warps. Later a dry stage, the dry- 

 rot stage is reached when the wood crumbles 

 up into a fine brown-coloured powder, and should 

 moisture be present the whole turns into a soft 

 cheese-like mass. Properly seasoned timber 

 which is kept reasonably dry is little hable to 

 attack by dry rot, in fact the fungus cannot 

 grow in dry air. This disease is doubly to be 

 feared because it may spread either by means 

 of its mycelium or by its spores. The latter may 

 be carried from diseased to healthy timber in a 

 number of difierent ways. The spores are small 

 and light and they are easily carried on air 

 currents ; insects and rodents may transport 

 them about their bodies, they may even be carried 

 on woodworking tools or on the hands and clothes 

 of workmen. 



Of the other enemies of timber we have no 

 space to speak, some of them, such as the Coral 

 spot disease, frequently so conspicuous on pea 

 sticks in the shape of bright red pustules, only 

 attack dead and decaying wood. In any investi- 

 gation of fungoid growth on wood it is essential 

 to discern as a preliminary whether the presence 

 of the fungus is due to the decay of the wood or 

 whether the decay is due to the presence of the 

 fungus. A distinction with a difference and an 

 important difference. 



