134 
BULLETIN OF THE BUREAU OF FISHERIES 
(herring in their fifth summer) taken during 1930, a consecutive series of 8 periods 
shows no consistent changes in length during the first 5 periods (from June 21 up to 
and including Aug. 10). There is an abrupt increase in length, however, between 
the fifth and sixth periods, the fish of the last three periods averaging about a half 
centimeter greater in body length. Such a sudden increase in length can scarcely be 
ascribed to growth but is probably due to an influx of new schools of herring onto the 
fishing grounds. 
That such a sudden change in body length is not due to growth is supported by 
the Noyes Island data, in wnich both the 4- and 5-year-olds taken toward the end of 
July were considerably smaller than those taken during the last of June, the largest 
difference, that between the 5-year-olds, being 6 millimeters. 
Table 8. — Body lengths in various localities for 1929 and 1930 by 10-day periods 
Locality 
Age 
Date 
Number 
of speci- 
mens 
Median 
Qi 
Qz 
1929 
4 
June 11-20 
226 
199. 2 
193 7 
204 6 
4 
June 1-10 
212 
193 5 
188 0 
198 7 
Do 
4 
June 1 1—20_ 
190 
194. 5 
189. 7 
200 1 
Do 
4 
June 21-30 
68 
198 7 
193 8 
204 5 
4 
do 
226 
199 6 
195 1 
204 6 
Do . - 
4 
July 1-10 
131 
200 9 
196 6 
206 O 
Do 
4 
July 11-20 
51 
203. 4 
199 3 
207 6 
Do 
4 
July 21-31 
39 
202 4 
198 3 
206 1 
4 
May 31 
85 
191 7 
185 1 
198 3 
4 
June 1-10 
60 
194 5 
187 7 
202 0 
4 
June 11-20 
87 
190 4 
185 1 
197 1 
4 
do 
38 
194 2 
187 4 
198 0 
4 
do 
147 
203 4 
199 2 
208 5 
4 
June 1-10 
74 
186 9 
183 7 
191 0 
4 
June 8-12 
95 
185 9 
178 8 
190 9 
4 
July 1-10 
59 
200 0 
195 8 
204 9 
Do . 
4 
July 11-20. 
65 
201 2 
196 3 
205 1 
Do 
4 
July 21-31 
37 
201 6 
198 1 
208 ' 9 
4 
do 
57 
201 8 
192 8 
205 3 
4 
do 
44 
184. 5 
175 5 
189 5 
4 
....do 
36 
187.5 
179.5 
191.0 
1930 
4 
July 21-31 
65 
204. 6 
198 1 
208 9 
Do 
4 
Sept. 1-10 
132 
206. 4 
201 5 
211 5 
4 
June 21-30 
34 
194 8 
191 1 
200 0 
4 
July 11-20 
47 
198 4 
194 3 
208 1 
4 
July 1-10 
37 
197. 8 
194 8 
204 4 
Do - 
4 
July 21-31 - 
28 
196.0 
191 5 
202 0 
4 
June 21-30 
121 
192.8 
188 3 
197 2 
"Do 
4 
July 1 1-20 
53 
187. 6 
181 3 
190 7 
Do 
4 
July 21-31 
34 
188. 5 
181. 3 
190 4 
Todd 
4 
June 1-10 
160 
176. 0 
169 5 
181 9 
June 21-30 
80 
210. 8 
204 2 
214 8 
Do 
5 
July 1-10 
98 
213. 0 
206. 8 
217 4 
Do - 
5 
July 11-20 
157 
212. 1 
207. 4 
218 0 
Do 
5 
July 21-31 
284 
211. 5 
206 1 
218 1 
Do 
5 
Aug. 1-10 
46 
212.9 
208 8 
217 3 
Do 
5 
Aug. 21-31. 
67 
219. 1 
213. 2 
223 0 
Do 
5 
Sept. 1-10. 
334 
216.0 
210. 7 
222 ’0 
Do 
5 
Sept. 11-20 
38 
216. 5 
207 3 
222 7 
5 
June 11-20 
70 
211.8 
206 1 
214 8 
Do 
5 
June 21-30 
145 
209.9 
200 1 
214 7 
Do 
5 
Aug. 21-31 
43 
213. 3 
209 8 
219 6 
5 
July 11-20 
63 
207. 1 
201 7 
210 8 
5 
do 
68 
215. 2 
209. 5 
218 8 
Do 
5 
July 21-31 
188 
214. 7 
209.3 
220 4 
Do 
5 
Aug. 11-20 
48 
212.5 
204.8 
217 2 
5 
June 21-30. 
38 
212. 2 
209 5 
218 9 
Do 
5 
July 1-10... 
119 
209. 1 
203 9 
212 8 
Do 
5 
July 11-20 
162 
211. 1 
205. 3 
215 5 
Do 
6 
July 21-31 
51 
213.0 
208. 4 
217 3 
5 
June 21-30 _ . 
134 
204.5 
199. 6 
210 8 
Do 
5 
July 11-20 
39 
197. 1 
193.9 
201 8 
5 
July 1-10 
29 
214.0 
209.8 
217 8 
5 
do... 
195 
213.6 
208.0 
218.8 
Q2—Q\ 
10.9 
10.7 
10.4 
10.7 
9.5 
9.4 
8.3 
7.8 
13.2 
14.3 
12.0 
10.6 
9.3 
7.3 
12.1 
9. 1 
8.8 
10.8 
12.5 
14.0 
11.5 
10.8 
10.0 
8.9 
13.8 
9.6 
10.5 
8.9 
9.4 
9. 1 
12.4 
10.6 
10.6 
10.6 
12.0 
8.5 
9.8 
11.3 
15.4 
8.7 
14.6 
9.8 
9.1 
9.3 
11.1 
12.4 
9.4 
8.9 
10.2 
8.9 
11.2 
7.9 
8.0 
10.8 
Because of these large variations in the size of herring of the same age taken from 
the same locality, it was adjudged unwise to attempt any careful statistical com- 
