SOME CHARACTERISTICS OF RECENT WORK ON 

 THE BIOLOGY OF FRESH WATERS. 



By PROF. REIGHARD. 



I had intended to prepare a paper reviewing what had been 

 accomphshed in the scientific study of the biology of our fresh 

 waters, but an attempt to carry out this purpose soon showed me 

 that a paper so- prepared would include much matter that does not 

 especially appertain to fisheries. I shall, therefore, not attempt 

 to carry out the original plan of giving a summary of results, but 

 shall point out merely two lines along which advances have been 

 made, and shall then indicate the bearing which some of this work 

 has upon practical problems. 



Perhaps the most striking feature of recent scientific work on 

 our fresh waters has been its rapid extension within the past few 

 years. Before 1890 scientific men, zoologists particularly, had 

 given attention to the sea, almost to the exclusion of the fresh 

 waters. The sea contains representatives of more animal groups 

 than the fresh water, and it contains also a large number of forms 

 generally considered to be primitive. To the sea, then, zoologists 

 have generally turned for the solution of their scientific problems. 

 Within ten years, however, a reaction has ipade itself felt in the. 

 direction of the study of fresh water animals. Interest in this 

 study finally led to the establishment by Zacharias at Plon, in 

 North Germany, of a laboratory devoted exclusively to the study 

 of the fresh waters. This laboratory, which has been subsidized 

 by the German Government, was the first of its kind. Like most 

 of the similar laboratories which have been since established, it 

 is a purely scientific institution, whose object is to afiford facilities 

 for the solution of the problems of fresh water biology. Its 

 founder. Dr. Zacharias, hoped that its investigations would furnish 

 data for the solution of many of the practical problems of the 

 fisheries, and he did not hesitate to hold forth this hope wlien 

 asking for financial support. Its realization can only be a matter 

 of time. In this connection it cj^rnot be too forcibly pointed out 

 that science cannot afford to serve. Her best results are obtained 

 when sh© is left quite free to grow a^ her own gait and in her own 

 way, and these results cannot be other than of value to the useful 

 arts It is a mistake to require that a scientific institution should 



