Abstract: THE part of “Die Binnengewsser” before us deals exclusively with lake bottoms. It is a large and interesting subject and very thoroughly handled from all aspects. The study of fresh waters as undertaken at the present day is a comparatively recent branch of science, and there has arisen, with its growth, a number of new terms, mostly introduced by the Swedish school at the Limnological Laboratory, Aneboda, of which Dr. Naumann is director. This laboratory is a model for all such fresh-water research. Most of these terms have come to stay, although many of them have no English equivalent. Good definitions are given throughout the work. The chapters deal with the development and origin of the various bottoms, their layers and zoning, principles and methods of sampling, with descriptions of apparatus; the botany and zoology of the layers, including bacteria; and the organic and inorganic deposits. All these are carefully classified and described. Bodenkunde is the study of the origin, qualities, and changes of the bottoms. In it, geology, zoology, and botany are all involved, besides physics and chemistry. It is an extremely important part of the larger and wider study of fresh waters in general. This volume is indispensable to all those engaged in such researches, and is one of the most interesting of the series. It is illustrated by photographs, maps, and text figures which are good and well selected.