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An investigation of Douglas fir, Pseudotsuga taxifolia (Poir.) Britton, in coastal British Columbia has shown that decay losses in old-growth stands are low, amounting to 2.6 and 7.3% of the gross volume of living and combined living and dead trees respectively. Twenty-five decay-producing fungi were isolated from living trees and 29 from dead trees. The most important of these were Fomes pini (Thore) Lloyd, Polyporus schweinitzii Fries, and Fomes pinicola (Sw.) Cke. Certain irregularities in the occurrence of decay-producing fungi and the amounts of decay associated with them were traced to the influences of site, tree age or size, latitude, and stand history. Root infections were the most frequent but branch-stub infections caused the greatest average amount of decay. An examination of tree abnormalities showed that a select group of them, sporophores and swollen knots of Fomes pini in particular, are useful indicators of hidden decay. A separate analysis of dead trees has shown that they occasion ally form a high proportion of Douglas fir stands and that much of the wood in such trees is sound.

Studies of sexuality in Fomes pinicola (Sw.) Cooke based on material from 43 new sources, combined with results already published (1929) have led to the following conclusions: (i) Collections from North America may be divided into two groups, a large Group A, and a small Group B. Monosporous mycelia of any culture in Group A are compatible (mutually fertile) with those of every other member of the group; similarly monosporous mycelia of any member of Group B are compatible with other monosporous mycelia of Group B; but monosporous mycelia of Group A are almost completely incompatible (sterile) when paired with those of Group B. (ii) Collections of European and Japanese origin form a third Group C. These are almost completely compatible with Group A and only partially incompatible with Group B. (iii) In Group B are several isolates of the so-called Populus or hardwood form of F. pinicola which has been designated at times as a separate species F. marginatus. The remainder are, however, the typical coniferous or "red-belt" form.

The nature, causes, and rate of pathological deterioration of jack, red, and white pine killed by fire in the Mississagi region of Ontario in 1948 were studied to determine the practicability and probable duration of profitable salvage operations in such stands. Blue and brown sapwood stains appeared in all species 1 year after the fire, and became extensive during the succeeding 3 years. Sap rot was first noted 2 years after the fire; 5 years after the fire most of the sapwood was affected, and in some cases this rot extended into the heartwood. Three fungi, Peniophora gigantea (Fries) Massee, Polyporus anceps Peck, and Polyporus abietinus Dicks. ex Fries, were isolated consistently from white sap rots, while Fomes pinicola (Sw.) Cooke and Fomes subroseus (Weir) Overh. were recovered from many of the brown sap rots. The increase in the volume of heart rot encountered during the course of the study, chiefly associated with Fomes pini (Thore) Lloyd, was much greater than that observed in living pine over a similar period, and for this reason the excess was considered as a form of deterioration. The average rate of radial penetration of visible deterioration was significantly faster in trees with widely spaced annual rings in the outer portion of the bole than in slow-growing trees. Variations in the severity of burn in individual trees or stands apparently had little effect on the rate of pathological deterioration.

The petroleum ether extract of Fomes pinicola, upon chromatography on an alumina column, yielded ergosterol and a crystalline compound which was identified as eburicoic acid by means of IR and NMR spectroscopy. Ultraviolet spectrum analysis indicated that eburicoic acid was contaminated with trace impurities of dehydroeburicoic acid.

A macromolecular hypotensive substance in water extract of Fomes pinicola was purified by sequential fractionation on columns of Sephadex G-75, DEAE-cellulose, Sephadex G-150, Hydroxyapatite and Sepharose CL-4B gels. On the basis of its chemical properties and component analysis, it was considered to be a glycoprotein containing a large proportion of carbohydrate.