Ever since the days of Jonathan Otley and of Sedgwick the Lake District has attracted much attention from geologists, largely on account of the variety and difficulty of the problems that it presents. As is well known, Dr. Marr has devoted a very large part of his life to the study of these problems, and the present volume contains an admirable summary of the results obtained by his predecessors, by his contemporaries, and by himself in this field. Although comparatively small when measured in square miles, there is, perhaps, no other well-defined area where so much variety of topography and of geological Structure is to be found, or where the connection between geology and scenery is so clearly marked. On this latter feature the author rightly lays much stress, pointing out that each formation gives rise to its own particular type of scenery, easily distinguishable even in the distant view.