On account of rather serious losses in stored wood and wood pulp, the authors made a study of the causes of decay in wood and wood pulp and conditions which favor it, complete with mill tests, and laboratory investigations. To combat deterioration during storage, careful attention must be given to the elimination of sources of infection, and the chemicals best adapted for this are identified, and an application scheme outlined. The authors investigate fungi that inhabit pulp, which do more damage than molds, and cause certain chemical actions on ground-wood pulp. It is undoubtedly the most extensive discussion that has yet been published on this subject; the authors and the Forest Products Laboratory deserve sincere thanks.