This is, I believe, the most important single contribution in the field of Hymenomycetes for years. The author was attracted to the group commonly known as Clavariaceae as early as 1925 when in England; he continued his studies when working on the staff at the Singapore Botanic Gardens and after his return to England. He got the conviction that before science could undertake a wholesale revision of the present classification of Hymenomycetes, the larger constituent groups should be worked over, one at a time, and ‘their particular kind of fruit-body described in terms of hyphal properties’, and that to omit the tropical element would mean certain failure. Thus, the aims of this admirable volume become clear: a large number of species of “Clavariaceae“ are described in an exemplary manner as to their hyphal structure after the living state, and about all that is known about the group and its species was compiled so that the often quite inadequate tropical library has to a large extent become superfluous. This is one of the rare occasions on which we find that an author’s field knowledge of a group is based rather on tropical than on European or North American materials The author combines with an exceptional tropical field experience, the insight of an agile mind and a great artistic skill for drawing. It might be regretted that he neglected the many and scattered poor specimens in the European and American herbaria that served as a basis for the already described species, but it is fair to point out that, as stated, this side was not his primary object and that it is unreasonable to ask for everything. The result is an imposing book that will serve as an absolutely indispensable guide for every future student of the group. We hope that it will be extensively used by collectors in the tropics, who now can pay attention to a group about which they can instruct themselves at their own will and according to their needs..