220 
BULLETIN OF THE BUREAU OF FISHERIES 
satisfactory means for the calculation of growth during the various years of the 
individual’s existence. The formida used in the calculation of growth was: 
T —D — 
J^n- U n Dt 
where 
X T = length of fish at time of capture; 
D t = total diameter of scale; 
X n = length of fish at end of n th year of life; 
Z> n — diameter of scale within the n th annulus. 
Tables 3 to 7 present the data for the calculated growth in length for the ciscoes 
of Trout, Muskellunge, Silver, and Clear Lakes. Since no difference in the growth of 
the two sexes was apparent in the fish of the first three lakes the data for these lakes 
as presented represent a combination of males and females. In the data for the Clear 
Lake cisco the sexes are treated separately. 
Table 3. — Calculated growth of Trout Lake ciscoes to the end of each year of life for the different year 
classes at each age; sexes combined 
[Groups marked with asterisks unreliable because of selective action of gear] 
Year class 
Year of 
capture 
Age 
Num- 
ber of 
speci- 
mens 
Length 
in 
milli- 
meters 
Year of life 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
1919 
1931 
XII 
i 
226 
80 
104 
117 
130 
148 
169 
180 
190 
199 
211 
218 
224 
1920 
1931 
XI 
2 
205 
75 
103 
119 
130 
142 
152 
162 
172 
180 
198 
204 
1922 
1931 
IX 
2 
200 
83 
112 
127 
140 
154 
168 
ISO 
190 
198 
1923-.. 
1931 
VIII 
5 
192 
87 
115 
134 
145 
156 
169 
179 
190 
1924 
f 1928 
IV 
17 
147 
85 
120 
133 
143 
\ 1931 
VII 
4 
175 
80 
113 
128 
141 
153 
162 
174 
( 1928 
III 
61 
143 
84 
123 
137 
1925 
•J 1930 
V 
9 
167 
82 
116 
135 
148 
160 
l 1931 
VI 
12 
165 
79 
116 
132 
145 
156 
164 
f 1928 
II 
102 
134 
82 
117 
1926 
\ 1930 
IV 
99 
156 
82 
118 
137 
147 
l 1931 
V 
79 
156 
81 
118 
135 
145 
154 
( 1928 
*1 
2 
128 
97 
1927 
l 1930 
III 
347 
149 
79 
117 
139 
l 1931 
IV 
269 
148 
78 
115 
135 
146 
1928 
/ 1930 
*11 
36 
140 
91 
127 
t 1931 
III 
173 
142 
84 
120 
137 
1929 
1931 
•II 
61 
136 
87 
127 
1930 
/ 1930 
0 
17 
66 
\ 1931 
•I 
2 
128 
106 
Table 4. — Calculated growth of Muskellunge Lake ciscoes to the end of each year of life for the different 
year classes at each age; sexes combined 
[Groups marked with asterisks unreliable because of selective action of gear] 
Year class 
Year of 
capture 
Age 
Number 
of 
speci- 
mens 
Length 
in 
milli- 
meters 
Year of life 
1 
2 
3 
4 
1925 
1928 
III 
10 
172 
105 
142 
162 
1926 
1928 
II 
252 
160 
99 
147 
( 1928 
•I 
19 
137 
97 
1927... 
| 1930 
III 
14 
166 
85 
132 
157 
1 1931 
IV 
2 
176 
90 
143 
161 
174 
1928 
/ 1930 
II 
214 
162 
95 
143 
\ 1931 
III 
347 
166 
96 
145 
163 
1929 
/ 1930 
*1 
17 
148 
103 
\ 1931 
II 
258 
149 
98 
138 
1930 
1931 
*1 
9 
136 
96 
