Pyrrol-that construct which flaunts its chemical versatility through having achieved the distinction of being the dominant sub-unit in the characteristic coloring matters of both the animal and plant king doms-is a fascinating entity. The determined skeptic will be well ad vised to keep his distance from this book, for only the most obdurate could fail to be captivated by the enormous wealth of detail collected, correlated, and presented here in eminently readable form. It seems certain that this work will be the indispensable hand maiden of all who would essay to embellish the lovely garden of pyrrol chemistry for a generation, and I will hazard the surmise that it will stimulate many to join that group. Inevitably, the appearance of this volume invites comparison with the great monograph on pyrrol chemistry given to the chemical com munity forty years ago by Hans Fischer and Hans Orth. That invaluable earlier work had a unique character; one cannot resist the temptation to express the opinion that that character was Hans Fischer, whose love for pyrrol and the superb array of substances related to it was his life. The book which he and Orth produced was essentially a detailed ac count of the ways in which pyrrols can be made-a practical and highly useful description of the state of synthetic art in 1934 in the special field to which Fischer himself had made such enormous contributions.