Antiseptic treatment, such as creosoting, is the best prevention.
[Footnote 41: Falck, Richard: Die Meruliusfauele des Bauholzes, Hausschwammforschungen, 6.Heft., Jena, 1912.] [Footnote 42: Mez, Carl: Der Hausschwamm.

Dresden, 1908, p.

63.] All fungi require moisture and air[43] for their growth.
Deprived of either of these the fungus dies or ceases to develop.

Just what degree of moisture in wood is necessary for the "dry-rot" fungus has not been determined, but it is evidently considerably above that of thoroughly air-dry timber, probably more than 15 per cent moisture.

Hence the importance of free circulation of air about all timbers in a building.
[Footnote 43: A culture of fungus placed in a glass jar and the air pumped out ceases to grow, but will start again as soon as oxygen is admitted.] Warmth is also conducive to the growth of fungi, the most favorable temperature being about 90 deg.F.They cannot grow in extreme cold, although no degree of cold such as occurs naturally will kill them.