RECENT FRESHWATER INVESTIGATIONS 303 



SUMMARY OF PROGRESS. 



Among the general works treating of freshwater subjects 

 the lmmologic monograph of Forel easily deserves the foremost 

 place, both by virtue of the breadth of its scope and by reason 

 of the completeness and precision of its treatment. Planned to 

 cover the entire field for a single lake, Geneva in Switzerland, 

 the work is worthy of the magnificent sheet of water with 

 which it deals. It is truly monographic and an indispensable 

 aid to every limnologic enterprise. Thus far but two volumnes 

 have appeared, the first of which (Forel, 92) falls really just 

 without the time limits of this review, yet for completeness 

 cal Is for mention here. It first deals with the apparatus employed 

 and the plan of the entire work, and then covers the sections 

 on I Geography, II Hydrography, depth, shore, bottom, III 

 Geology, IV Climatology, V Hydrology, sources, outflow, 

 level. The second volume (Forel, 95) handles sections YI 

 Hydraulics, current, movements, seiches, waves, YII Thermics, 

 VIII Optics, transparancy, color, mirages, IX Acoustics, X 

 Chemics, density, odor and value as drinking water. 



The American student possesses in Russell (95) a valuable 

 discussion of the geologic and physiographic features of North 

 American lakes and lake systems. Lampert (98) has given a 

 semi-popular yet thorough and accurate presentation of life in 

 fresh-water. The larger part of the work is devoted to a sys- 

 tematic and biologic description of the genera which occur in 

 the German waters, but there are also important chapters on 

 the history of freshwater investigation and on general limno- 

 logic questions. Apstein has published (96) a convenient and 

 valuable work on the freshwater plankton which presents the ex- 

 tensive investigations of the author on Holstein lakes in compar- 

 ison with the results achieved by other workers elsewhere. The 

 details of the work are referred to under special topics later in 

 this article. Klunziger (97) s lias given an admirable review of 

 the methods and results of plankton work, with special refer- 

 ence to the problems of fish culture, and Field (98a) has pre- 

 sented a concise study of the same question. 



