SOME PLANKTON STUDIES IN THE GREAT LAKES. 129 



marketable whitefisb. Sboukl we not pursue our object more intelligently by first 

 determining tbe characteristics of the materials with which we have to work ? It was 

 with this object in view that the Michigan Fish Commission, in the summer of 1893, 

 established a scientific laboratory on Lake St. Clair. This lake is readily accessible 

 from the Detroit hatchery at the season when whitefisb are planted. Whitefisb are 

 caught in certain parts of the lake in considerable numbers in the spawning season, 

 so that it is probable that spawning-grounds of this fish are found along the west 

 shore of the lake near its outlet. In establishing a laboratory on the lake the Michigan 

 Fish Commission hoped, therefore, to accomplish two things: 



(1) To study carefully, and in the broadest possible way, the life of the lake. 

 After examining the physical characteristics of the lake, such as the color, transparency, 

 and chemi try of the water, such a study should include a determination of the kinds 

 of animal , and plants in the lake. Every species should be sought out, carefully 

 described and figured, and a specimen of it preserved. Then the habits of each 

 species should be known, its habitat, its food, its enemies, and its parasites. The 

 numbers of animals and plants of each species in a given volume of water should be 

 determined, and the variations in these numbers in different parts of the lake and at 

 different seasons of the year. Such a collection of data would form a complete picture 

 of the biology of the lake. 



(2) It was hoped that young whitefisb might be captured in the lake by suitably 

 arranged nets and that it might thus be possible to determine the food habits of the 

 young fish and the other conditions under which they are found in nature. 



Should both these objects be accomplished we should be in a position to determine 

 where in the Great Lakes are to be found the conditions favorable to the whitefisb fry. 



The materials collected have not been all worked up at this time, so that it is 

 possible to give only a brief survey of the plan of work together with some of the 

 more immediate results. 



The laboratory was located at New Baltimore, near the head of Anchor Bay, 

 which is the northeastern portion of Lake St. Clair. Here the second story of a large 

 warehouse, situated on a dock, was transformed, by the use of temporary sheathing, into 

 a commodious laboratory room about 20 by 40 feet. There were four large and very 

 rigid laboratory tables, designed especially for their portability and intended each for 

 two workers. The vacant places on the walls were filled with temporary shelves, and 

 two large work tables were provided for general purposes. At one of the windows 

 was placed a table arranged to hold a dozen small aquaria, to which running water 

 was supplied from a tank outside the building. On the wharf without was erected a 

 temporary shed which sheltered three large aquaria supplied with water from a special 

 tank. In these aquaria the largest fish of the lakes could be kept under observation. 



The laboratory was supplied with a sail and row boat. For more extended trips 

 and for use with the heavier collecting apparatus there was a small steamer, the Ben 

 Ilur, of Detroit, a boat of about 10 tons burden, and with a very roomy cabin. She 

 was found to serve every purpose admirably. 



A considerable collection of pertinent literature as well as microscopes and the 

 other usual laboratory apparatus were loaned by the University of Michigan. A 

 liberal supply of the usual glassware and reagents and of the minor apparatus was 

 provided by the fish commission. The collecting apparatus included the usual hand 



F. C B. 1893—0. 



