5 i8 



Dry Rot. 



contact with deadening material should first be painted over 

 with methylated spirit containing corrosive sublimate in solution 

 — six ounces to one gallon. The spirit evaporates, leaving a 

 coating of corrosive sublimate on the boards, which completely 

 destroys any mycelium coming in contact with it. 



It has been proved that the spores of dry rot can only 

 germinate in moisture containing some alkali in solution, hence 

 coal-dust, cinders, or any kind of humus should never be used 

 for deadening or packing. 



The fruit of the dry rot fungus presents the appearance of 

 irregularly shaped, flattened or undulating patches of variable 

 size, adhering by their entire under surface to the substance 

 on which they are growing. When mature the central portion 

 of the patch is covered with an irregular network formed by 

 slightly raised anastomosing ribs, and is of a rich brown colour? 

 due to the enormous quantity of spores, which are deposited 

 on surrounding objects under the form of snuff-coloured 

 powder. These spores are diffused by currents of air, rats, 

 mice, insects, &c. 



The margin of the fruiting patch is surrounded by a snow- 

 white fringe of mycelium, which spreads in every direction 

 over surrounding objects, creeping up walls and passing through 

 crevices, the advancing mycelium being supplied with food and 

 moisture from the parent plant growing on wood. This food 

 is conducted through cord-like strands which form behind the 

 thin advancing margin of mycelium. 



Owing to this supply of food from a central source, the 

 mycelium can extend over stones and other substances not 

 containing food, and thus spread from the basement to the 

 top of a house. Each time the migrating mycelium comes in 

 contact with wood, the latter is attacked, and a new centre 

 of food-supply is established from which strands spread in 

 search of other sources of food. The mycelium often forms 

 felt-like sheets of large size that can readily be removed intact. 

 These sheets are at first white, but soon change to a pale grey 

 colour, a character by which dry rot can be readily distinguished 

 from another wood-destroying fungus, Polyporus fopientarius* 

 even in the absence of fruit, the felted mycelium of the latter 

 remaining permanently white. 



