INTRODUCTION 



In 1909 a biological laboraton'- Avas established by the State of 

 North Dakota, Tinder the auspices of the State I^'nivcrsity, on the 

 shore of Devils Lake. Since that time the writer, acting at first as 

 assistant and later as director, has been engaged in studying the 

 life of the lake, and this report is the result of such studies. His 

 thanks are due principally to the former director, Dr. INI. A. Bran- 

 non, now Chancellor of the University of Montana, to whose initiative 

 the laboratory owed its establishment, for his encouragement and 

 friendly assistance during the first five years of this work. He has 

 also received much valuable assistance from his present colleagues, 

 Professors H. E. Simpson, G. A. Abbott and Karl Fussier and 

 E. D. Coon, and from Drs. F. H. Heath, C. E. King and Messrs. 

 Robert Hulberd, Eric G. Moberg and R. H. Johnstone, formerly of 

 the University of North Dakota. Professor Simpson's valuable 

 work on the Physiography of Devils Lake (1912) is the basis of 

 that part of the present report descriptive of the history of Devils 

 Lake. Drs. Heath and King have furnished the major part of the 

 chemical data. Mr. Moberg, as my former assistant, has aided in 

 the collection of material and has made most of the plancton counts, 

 while the other gentlemen have kindly assisted me in various ways. 



Several specialists have aided in the identification of organ- 

 isms, without which assistance the work could not have been carried 

 on. Messrs. C. F. Rousselet and David Bryce have identified the 

 rotifers, Professors C. J. Needham and R. Mattheson and Messrs. 

 C. R. Plunlcett and C. K. Sibley the insects. President E. A. Birge 

 and Professors Chancey Juday, A. Willey and C. Dwight Marsh 

 the Crustacea, Dr. N. A. Cobb, the nematodes. Dr. Karl Viets and 

 Professors R. H. Wolcott and Ruth Marshall, the mites, and Drs. 

 Geo. T. ]\Ioore and Nellie Carter, the algae. Professor C. H. Edmond- 

 son has spent several weeks at the station in 1914 and 1917, working 

 on the Protozoa, and has worked over several collections sent him at 

 other times. Professor C. J. Elmore has identified the diatoms, in part 

 from collections sent to him, and in part from material collected 

 by himself during a visit to the lake in 1915. To all of these gentle- 

 men the writer's thanks are due for their invaluable aid. Professor 

 Jacob Reighard and President E. A. Birge have given very helpful 

 advice regarding methods and apparatus, the former loaning the 

 proof of a chapter in Ward and Whipple's "Fresh Water Biology" 

 which deals with these subjects. 



The charts accompanying the paper are the work of Mr. Wilfred 

 P. Lowe. 



The first two years were spent chiefly in collection of apparatus, 

 development of methods and in a general preliminary survey of the 

 lake. Since that time collections, both qualitative and quantitative, 



