Summary The net effect of the action of the wood-destroying fungi, Lentinus lepideus, Poria vaillantii and Lenzites sepiaria on white Scots pine and white fir woods is a depletion in the cellulose composition of the wood, together with a concomitant increase in the relative content of lignin. 2. After seven months of decay by Lentinus lepideus there is approximately a two-fold increase in the yield of alcohol-extractable lignin from the decayed wood in ...