Fungi are best sought with a stereoscopic binocular microscope, when their full beauty will be seen, but a hand lens or simple magnifier, although less convenient, is sufficient for all but the smallest forms. The larger ascomycetes and most of the basidiomycetes are readily seen with the unaided eye, but the binocular microscope is still very useful for observing the gross features of the veil of the basidiomycetes. Perithecia, apothecia and similar structures can be removed with fine needles or forceps quite cleanly for mounting, initially in water, on slides. Subsequent irrigation with iodine solution will allow any reaction of ascus wall, tip or pore to be observed, and mounting in diluted Indian ink can enhance the visibility of appendages, caudae and sheaths which occur on some spores. Spore discharge in the ascomycetes often occurs from mature asci when material is mounted in water, so mature spores can immediately be seen. Many of the coprophilous toadstools (agarics), because of their small size and/or rapidly deliquescent nature, often do not give spore prints in the normal way, but mature spores can usually be found on the stipe or in natural spore prints formed on the absorbent material on which the dung is supported. For accurate identification the ability to measure the size of spores and other structures will be necessary. Basic microscopical technique and mycological knowledge is assumed. Common species are well described and illustrated in popular books, and references are given to specialist works to allow descriptions of less common species to be found. It will be necessary to refer to these for critical taxa. Although this edition contains about one half more species than the 1982 edition, there are still many species to be described and new records and observations to be made, especially in the Ascomycotina.