species in their natural position, and although valueless for an herbarium, they are not only very ornamental, but useful, if space can be devoted to them. Leaf parasites, whether on living or dead leaves, may be dried in the usual way for drying plants, between folds of bibulous paper under pressure. It may be sometimes necessary with dead leaves to throw them in water, in order that they may be flattened without breaking, and then dry them in the same manner as green leaves. All species produced on a hard matrix, as wood, bark, etc., should have as much as possible of the matrix pared away, so that the specimens may lie flat in the herbarium. This is often facilitated in corticolous species by removing the bark and drying it under pressure. The dusty _Gasteromycetes_ are troublesome, especially the minute species, and if mounted openly on paper are soon spoiled. A good plan is to provide small square or round cardboard boxes, of not more than a quarter of an inch in depth, and to glue the specimen to the bottom at once, allowing it to dry in that position before replacing the cover. The same method should be adopted for many of the moulds, such as _Polyactis_, etc., which, under any circumstances, are difficult to preserve. In collecting moulds, we have found it an excellent plan to go out provided with small wooden boxes, corked at top and bottom, such as entomologists use, and some common pins. When a delicate mould is collected on a decayed Agaric, or any other matrix, after clearing away with a penknife all unnecessary portions of the matrix, the specimen may be pinned down to the cork in one of these boxes. Another method, and one advisable also for the _Myxogastres_, is to carry two or three pill-boxes, in which, after being wrapped in tissue paper, the specimen may be placed.