The books which have been consulted in the preparation of this work are, "British Fungi," by Rev. John Stevenson; "British Fungus-Flora," by George Massee; "Mushrooms and their Uses," and "Boleti of the United States," by Professor Charles H. Peck, State Botanist of New York; "Moulds, Mildew and Mushrooms," by Professor L. M. Underwood; and a pamphlet by Mr. C. G. Lloyd, entitled "The Volvae of the United States." No attempt has been made to do more than to put in popular language the statements of experienced botanists, and so to arrange the matter as to aid beginners in their work.