356 BULLETIN OF THE BUREAU OF FISHERIES. 
TABLE 20.—Loss AND GAIN IN’ PERCH FED DIFFERENT Foops From AUG. 19 TO SEPT. 18, 1916. 
Aug. 19 Sept. 18. Per cent gain. Per cent loss. 
Number 
Average Average 
Food. of perch Volume Volume 
feat’ ‘Average | volume | Average | volume Weight || (cabic | Weight |) (cubic 
roe (cubic eons (cubic (grams). || centi- {-(grams). | centi- 
grams).| centi- grams).| centi- : ‘ 
meters). meters). meters). meters). 
Liver and flour. & J... i5..)..5-..). a3 2-104 2.40 2.50% 2. 
Hyalella.......... Ns 3 1.856 1.76 2.2 2. 
Entomostraca. . 3 2-683 2-91 3-874 3 
Earthworms.... 3 1.856 1.68 2-726 2. 
Insects, adult... 3 2-152 2-07 1.643 Ty 
Chironomid larve 3 2-099 2.00 2.836 2. 
VCE Hoag eee 8 3 1-944 I-91 2-380 2. 
Normal. . 2 3-232 3:20 3-850 tS 
SUSCV esi discnisndevinan chasderae b3 1-205 1-26 -86r 
@1 died Sept. 6 on account of fouling of water. bx died Sept. x1. 
TABLE 21.—COMPARISON OF Foops EATEN BY ADULT PERCH IN LAKE WINGRA AND IN LAKE MENDOTA, 
SHOWN By MonrTHs. 
[The figures are percentages by volume and + means a trace; 350 perch were examined in Lake Wingra from March, 1016, 
to February, 1917. In Mendota, 499 were examined in rors and 188 in r916. To obtain averages given for Lake Mendota 
the figures for r9r5 were multiplied by 3 and averaged with those for 1916.) 
LAKE WINGRA. 
a . . g . P 2 3 
oe & 8 a g 5 
B/E] 8] § Fi el leah fal a t|2i3/% 
Month. | 2 | = nile bs 3 g a 3 3 5 Bee | hes ce aliaas e 
a B11 8392 a | @ 4 S 3 s 8 | 2 a6 
aye (ieee ee ee et ae ye ie | gy 
ot = a a Oo = 
AOL: i WR AO PLP OO a 8 
January..-| 41.5 3:0 
February -| 35-3 i 
March.....] 8.7 
April, = ia iL 
Maw 3b s<lucesct 
June. 10 
July......-] 10-3 
August....] 41.9 
September.] 7.4 
October... .} 17.7 
November.| 16.0 
December.|..:... 
Average.| 15.4 9.6 | 10-4 1-6 ga@i.S.4 °3 [22-7 +2 +4| 10.8 +3 x +4 - Ph Bl ed ol Gene 
6 o.8 II.7 
-2 myn a 15-2 
me) 3-1 10.3 
-6 6.8 14-2 
“5 7-0 |. 2-1 
74 8.9 |. reg 
. <7 2.6 4:9 
abe Sa 3-61) BrP [x)| Moco) f X90] Seale aened 2-2 
2. 5 XB wT | ek WOeS F) 4sO8)  eGilsse tei 5-1 
~ -6 ey RE bee 3:5 
November.} 1.5 | 10.0 3-9) fe XS[i ds...) AGRO | Beth! baw fhe 9-7 
December. =4 | 16.8 ‘8: ] +83} } 3 | sags) | 9.8) ).2..b. (5. .pee 5-5 
Average-| 1.7 | 27-8 533 “9 “5 0 Bees 4 3+4 4 +3.|33-0] 1-7 1-9 +s 2-2 7-6| 9-0 4 
