HABITS OF YELLOW PERCH. 305 
By) 2 Fig. 6. Fish 
fig. 7. x 
id Fig, 6. Ls 
2s Chironomid ches 
Pupae ‘i. . et 
20 j : 
15 
4a 
5 
o 
5 Fig, , 
a Corethra Pupae ss 
a 
/ is ne 
0 os _ . 
Fics. 6 To 9.—Percentage by volume of four constituents of perch food which increased markedly in the summer. -o-0-0-, Lake 
Mendota, rors; - - - - - - , Lake Mendota, 1916; ......, Lake Wingra, 1916-17; , average. 
