This booklet is a very consice edition of the same author’s large work “Die Vegetation der Erde in oko-physiologischer Betrachtung”, which comprised 1234 pp., 642 figs, and 168 tables in all. The author realized that only a widely travelled worker could be regarded as capable of writing such a book with a sufficient basis of personal observations, and shows in the introduction that he belongs to this privileged category. Two recent trips, to the U.S. and Venezuela, even enabled him to revise and supplement, by his own observations, the paragraphs devoted to these areas.