HISTORICAL DEVELOPMENT OF THE CONCEPT 17 



the habitat. However, it has concerned itself very little with the 

 nature of the community, its composition in terms of dominants and 

 influents, the processes involved in development, and the distinction 

 between climax and serai communities. It uses an adjective nomen- 

 clature which allows a wide latitude in the concepts concerned. 



Within the scope of the present book, it is impossible to deal ade- 

 quately with the investigations in this field, a subject, moreover, that 

 is covered in encyclopedic manner by Naumann and Thienemann in 

 the contributions mentioned below. In consequence, the treatment 

 will be limited chiefly to basic concepts and units, and the relations 

 of limnology to the larger theme of bio-ecology, especially as a mat- 

 ter of synthesis (cf. Chapter 7). 



Thienemann (1913-1935). In discussing the progress of limnology, 

 Naumann (1932:13) considers the first major step to have been taken 

 by Thienemann (1913-14), in basing lake types upon oxygen content 

 and the consequent composition of the bottom fauna. This has re- 

 mained a chief interest through a long series of papers, but these have 

 been accompanied by a number of publications dealing with basic 

 concepts and methods of classification in the field of "biocenotics" or 

 bio-ecology. In this connection, the author has emphasized the causal 

 relation between habitat and community, the reaction of the latter 

 upon the former, and the organic unity of the lake as complex organ- 

 ism, all in close accord with the early elaboration of these principles 

 in ecology in 1901 (cf. Clements, 1904, 1905). A general understand- 

 ing of Thienemann's contributions to the organization of the field is 

 most readily obtained from his papers in Abderhalden's "Handbuch," 

 from "Die Binnengewasser INIitteleuropas" (1925), and "Die Sauer- 

 stoff im eutrophen und oligotrophen See" (1928). 



Naumann (1918-1932). Naumann's earlier researches dealt mainly 

 with pliytoplankton, with more or less special reference to the biology 

 of production, but since 1922 they have been concerned primarily 

 with the broad organization of the field. Regional limnology has 

 occupied the chief place in this program, but physical factors, reac- 

 tions, and methods have also received much attention, and this has 

 involved also the consideration of concepts and terms. Fortunately 

 for both investigator and student, the author's threescore of papers 

 are epitomized in three recent publications. INIethods are discussed 

 in comprehensive fashion in Abderhalden's "Handbuch" (1925), and 

 guiding principles in "Grundziige der regionalen Liranologie" (1932), 

 while his "Limnologische Tcrminologie" (1931) is a combined lexicon 

 and encyclopedia of the subject. 



Regional limnology, or fresh-water ecology, is considered from the 

 various angles, viz., habitat factors, types of water bodies, plankton, 

 littoral and profundal in regional correlation, types of lakes and their 

 natural succession, modifications in the biology of production, and the 

 relation to applied limnology. The treatment of limnological terminol- 

 ogy is a compendium of the present knowledge in the field, detailed 

 but concise, and arranged in alphabetical order to permit ready refer- 

 ence to the host of terms peculiar to the field or borrowed from related 

 subjects. 



