14 JANUARY 1922, Page 25

A Textbook of Geology. By Amadeus W. Grabau. (Harrap. 2

vols. 64s. net.)—Professor Grabau's substantial treatise is well written and very fully illustrated, with special reference to America. The first volume deals with general geology, begin- ning with the rocks, which are treated in detail. The second volume is devoted to historical geology. There is a good deal to be said for the author's departure from the usual method of studying the subject.