PACIFIC HERRING 
251 
This method of comparison does not bring out the significance of differences as 
clearly from a mathematical standpoint as will the comparison of eight principal 
localities given in Table 7. (These eight localities are marked in fig. 14 by circles.) 
Here the averages for each locality are compared with those for the other localities, 
and their differences considered in relation to the probable errors of these differences, 
calculating the probable errors upon the assumption that the samples adequately 
represent the populations from which taken. 
Table 7. — Comparisons of the means of the vertebral counts of some distant localities 
[Asterisk shows differences that are not significant] 
Localities compared 
San Diego Bay and South British 
Columbia 
San Diego Bay and Stephens Passage. 
San Diego Bay and Tebenkof Bay. . 
San Diego Bay and Shuyak Strait — 
San Diego Bay and Shumagin Islands. 
San Diego Bay and Unalaska 
San Diego Bay and Golovin Bay 
South British Columbia and Stephens 
Passage 
South British Columbia and Teben- 
kof Bay 
South British Columbia and Shuyak 
Strait 
South British Columbia and Shu- 
magin Islands 
South British Columbia and Una- 
laska 
Differ- 
ence 
between 
means 
Proba- 
ble error 
of dif- 
fere nee 
Differ- 
ence 
divided 
by 
proba- 
ble error 
of dif- 
ference 
Localities compared 
Differ- 
ence 
between 
means 
Proba- 
ble error 
of dif- 
ference 
Differ- 
ence 
divided 
by 
proba- 
ble error 
of dif- 
ference 
South British Columbia and Golo- 
1. 10 
0. 025 
44.0 
vin Bay.. ... .... 
1.01 
0. 039 
25.9 
1.28 
.029 
44. 1 
Stephens Passage and Tebenkof Bay. 
.32 
. 025 
12.7 
2. 00 
.029 
69.0 
Stephens Passage and Shuyak Strait. 
.36 
.028 
12.9 
2.04 
.032 
63.8 
Stephens Passage and Shumagin 
3. 99 
.037 
107.6 
Islands 
2.31 
.034 
67.9 
2. 54 
.039 
65.2 
Stephens Passage and Unalaska. 
.86 
.036 
23.9 
2. 11 
.044 
48.0 
Stephens Passage and Golovin Bay.. 
.43 
.042 
10.2 
Tebenkof Bay and Shuyak Strait 
.04 
.028 
* 1.4 
.58 
.020 
29.0 
Tebenkof Bav and Shumagin Islands. 
1.99 
.034 
58.3 
Tebenkof Bay and Unalaska. 
.54 
.037 
14.6 
.90 
.020 
45.0 
Tebenkof Bay and Golovin Bay 
. 11 
.042 
* 2.6 
Shuyak Strait and Shumagin Islands. 
1.95 
.036 
54. 2 
.94 
.024 
39.2 
Shuyak Strait and Unalaska 
.50 
.039 
12.8 
Shuyak Strait and Golovin Bay 
.07 
.044 
* 1.8 
2.89 
.031 
93. 2 
Shumagin Islands and Unalaska. . 
l. 45 
.043 
33.7 
Shumagin Islands and Golovin Bay— 
1.88 
.048 
39.2 
1.44 
.033 
43.6 
Unalaska and Golovin Bay 
.43 
.050 
8.6 
It will be observed that this method indicates that local stocks of herrings, 
which are not shown to be obviously different by the visual comparison used in 
Figure 14, are actually sharply distinct from a mathematical viewpoint. Thus 
the difference between the herring of Tebenkof Bay and of Stephens Passage is sig- 
nificant, the difference between the means being 0.32 ±0.025 or 12.8 times the 
probable error. 
COMPARISON OF STOCKS OF ADJACENT LOCALITIES 
This method of comparison may be applied also to closely adjacent localities 
within the same region. Thus Tables 13, 14, and 15 give comparisons of the means 
of the vertebral counts for southeastern Alaska (localities 7-13 of Table 6), Prince 
William Sound (localities 14-21), and Cook Inlet-Kodiak district (localities 22-27). 
Tables 8, 9, 10, 11, and 12 present the frequency distributions of vertebral counts 
upon which these comparisons are made, each minor locality being given separately 
and contributing to the totals for the general regions as listed in Table 6. 
