AS early as 1861 it had become apparent to certain leading German botanists that the limits of their science had been so far extended as to make it impossible for one writer to treat the whole subject with such uniformity and thoroughness as is required in the composition of a standard text-book, including the substance of the facts well ascertained up to the date of its issue. Accordingly Hofmeister, with the assistance of others, and especially of Sachs and De Bary, planned a joint “Handbook of Physiological Botany,” and though, owing to the difficulties which are always liable to attend joint authorship, the parts written by the several contributors were issued at various dates from 1865 to 1877; and though some of the parts included in the original scheme never appeared at all, those published are together the result of the most considerable attempt hitherto made to issue a comprehensive and standard Text-book of Physiological Botany. During the twenty years which have followed the adoption of this plan by Hofmeister and his colleagues unprecedented advance has been made in the science, and it is thus still more necessary than before that the task of authorship of a comprehensive handbook should be divided. The “Handbook of Botany,” which is in course of issue by Prof. Schenk, and of which two volumes are already complete, is a second attempt, some-what similar in idea to that of Hofmeister, though differing from it in many points. The staff of authors is larger, and since the space allotted to the several authors is less, greater uniformity in date of issue has been attained; there is, however, in Schenk's “Handbook” no prearranged and well-balanced plan of the ground to be covered, or at least the first two volumes give no clue to any such plan. Each article appears to be independent of its neighbours, and must be regarded as a separate essay on a definitely circumscribed, and in some cases a very limited, branch of the science. Since this is the case, it is clear that the “Handbook” cannot be used by beginners as a text-book of the science; it is suited rather to specialists, and others who may desire special information on the subjects which are treated. To these the book will be of the greatest use and interest, since the articles are written by well-known men, who have made the subjects of their essays their special study. Handbuch der Botanik. I. and II. Herausgegeben von Dr. A. Schenk. (Breslau: Verlag von Eduard Trewendt, 1879–1882.)