HABITS OF YELLOW PERCH. 309 
Poms eda gait: inte heel: REF cia” iis ater Aiahar Oe? PES, 
do 
Fig. 2s. 
20 Sialis Larva 
Fig. 26. / 
Cladocera 
ME Fig. 27. 
Fics. 25 to 27.—Percentage by volume of three constituents of perch food which increased in amount in the winter. -0-0-0-, 
Lake Mendota, 1915; ------ , Lake Mendota, 1916; ...--- , Lake Wingra, 1916-17; , average. 
