4. PLANKTON OF WINNEBAGO AND GREEN LAKES. 



kosh, we had the use of a sail boat for longer trips. Through 

 the courtesy of Mr. M. W. Feck and Mr. D. Jack of Fond du 

 Lac, we were provided with transportation in their gasoline 

 yacht for an extended trip through Lakes Buttes des Morts, 

 Winneeonne, and Foygan. Acknowledgment should be ren- 

 dered, too, for unnumbered services rendered by Mr. D. O. 

 Fernandez of Oshkosh. 



The location proved to be particularly convenient, as Stony 

 Beach is reached by an electric line from Oshkosh and yet is 

 so far removed from the city that under ordinary conditions it 

 is not probable that this part of the lake is contaminated by the 

 city sewage. 



Systematic work on Lake Winnebago was commenced the 

 fifth of July, 1899. During July and August, with the excep- 

 tion of a few days spent on other lakes, daily plankton collec- 

 tions were made at at least two locations. For these daily col- 

 lections a station was selected about a mile from the shore on the 

 muddy bottom common to all the deeper parts of the lake, and 

 another nearer shore on the rocky bottom. This was with a 

 two-fold object, first to have two stations some distance apart 

 in order to get an average of plankton, and second to ! determine 

 whether there was any decided difference in the plankton over 

 the mud and over the rocky bottom, for the fishermen think 

 that some fish have a decided preference for the stony bottom. 

 Some days a considerable number of collections was made, the 

 locations being widely distributed over the lake. During the 

 summer the collections extended over a distance of some twelve 

 or fourteen miles on the west shore of the lake; many were 

 made in the central region of the lake, and some on the east 

 shore. 



A number of collections, for comparison, were made on other 

 lakes synchronously with those on Lake Winnebago, my assist- 

 ant remaining on that lake while I did the work at other loca- 

 tions. After the month of August the collections were kept 

 up at intervals of about two weeks, the collections being made 

 ordinarily at the two regular summer stations off Stony BeacL 



