DRY ROT 
3 i 
woods around Haslemere, where there was not a trace of it 
ten years ago. 
Fig. 7. Polyponis betulinus. —Though usually associated 
with dead birches, on which its large sporophores form very 
artistic objects, this species also attacks living trees, its 
presence being indicated by the brown discoloration of the 
wood. It is an annual; the mycelium is probably perennial 
in the wood. 
Additional parasites figured on our plates are: 
Stercum hirsutum (Plate I.), which attacks various living 
trees, and is said to be the cause of “fly ” wood and “yellow 
and white piped ” wood. 
Fomes fomentarius (Plate XXXIII.) attacks beech and oak, 
and is said by Hartig to be the cause of the “ white rot.” 
Polyponis sulphureus (Plate XXXIII.) attacks oak, larch, 
poplar, willow, yew, etc. 
Polyponis squamosiis (Plate XXXIII.) infests many of our 
native trees, notably the elm. 
Hirneola auricula-juda , the “Jew’s ear” (Plate XXVI.), 
attacks living elder. 
Merulius lacrymans, the “ dry rot ” (Plate XXXII.), is one 
of the most destructive of parasites. Too often does the 
purchaser of a newly-built house make its acquaintance, the 
first indication of its unwelcome presence usually being a 
streak or film of reddish-brown “ dust ” coming from a crack 
in the floor, often within an ill-ventilated cupboard. The 
“dust” is its spores, myriads of them. If the floor is not 
quickly taken up by the owner, it will soon be eaten up by 
the fungus. Rotting wood should be removed, and what 
appears to be sound should be carefully disinfected with 
creosote. The presence of the mycelium of the fungus in 
wood is easily known by the “red stripe,” and it is regrettable 
that builders constantly use such wood for building pur¬ 
poses without thoroughly disinfecting it. 
Fistulina hepatica (Plate XV.).—The “ beefsteak ” grows 
