THIS monograph on a subject of outstanding in1terest will commend itself under its sectional title to a wide circle of workers as an important and timely critical survey. The author's treatment of the matter, however, is much more comprehensive than might be inferred from the title, for it embraces the full perspective, and the work is consequently a contribution to natural history, and, beyond the phenomenal aspects of plant life, to general philosophy. The scope of the monograph, in fact, is first to set out the very considerable chemistry of lignin resulting from the investigations of some three hundred workers whose researches are critically reviewed in the text, and then to re-examine the scientific material thus accumulated, critically selected and co-ordinated by the author, in relation to the several sections of the science of botany, systematic (classification), physiology, structure and histology, to modern conceptions of the ultimate structure of the forms of matter, to the scientific technology of industry, and thus implicitly to the philosophy of the hurhan story, intimately interrelated as it is with that of plant life and evolution. Die Chemie des Lignins. Von Dr. Walter Fuchs. Pp. xi + 327. (Berlin: Julius Springer, 1926.) 18 gold marks.