PACIFIC HERRING 
267 
Using this measure of variability it is found that in only six cases is the difference 
between the means of two samples greater than the 0.35 maximum variability found 
between samples from the same locality. Dogfish Bay is found to differ significantly 
from Shuyak Strait, Unalaska, southeastern Alaska, and Puget Sound. It differs 
from Halibut Cove by 0.35, which, being exactly the same amount as the maximum 
variability found between samples from the same locality, can not be considered as a 
valid racial difference. Puget Sound differs significantly from Prince William Sound. 
Prince William Sound differs from Shuyak Strait by 0.46 ±0.058, or 7.9 probable 
errors, which is somewhat in excess of the variability found within one locality. 
To conclude, the anal-ray count does not show any general change associated 
with distance as is the case with the vertebral count. Differences between distant 
localities are shown in a few cases. Taking into consideration the variability within 
one locality, it suggests that Shuyak Strait is independent of either Dogfish Bay or 
Prince William Sound. 
HEAD LENGTHS 
The length of the head increases with the growth of the fish but does not increase 
as rapidly as the length of the body. For this reason only head lengths of fish of 
approximately the same body length are strictly comparable. This being the case 
the head lengths have been expressed as percentages of the body length. (Table 25.) 
Table 25. — Average -per cent head is of body length at each centimeter 
Length in millimeters 
Puget Sound 
Craig 
Stephens 
Passage 
Southeastern 
Alaska, total 
Elrington 
Passage, 1925 
Elrington 
Passage, 1926 
Elrington 
Passage, 1927 
Num- 
Aver- 
Num- 
Aver- 
Num- 
Aver- 
Num- 
Aver- 
Num- 
Aver- 
Num- 
Aver- 
Num- 
Aver- 
ber 
age 
ber 
age 
ber 
age 
ber 
age 
ber 
age 
ber 
age 
ber 
age 
60-69 
70-79 
80-89 
90-99 
100-109 
1 
25.7 
1 
110-119 
5 
26. 1 
5 
26. 1 
1 
24.6 
120-129 
21 
25.3 
21 
25.3 
130-139 
22 
25.3 
22 
25.3 
6 
24 6 
140-149 
20 
24. 6 
20 
24.6 
8 
23 9 
150-159 
25 
23.9 
25 
23.9 
3 
23 3 
160-169 
1 
24.1 
3 
24.4 
65 
23.7 
68 
23.7 
1 
23! 2 
170-179 
7 
23.8 
23 
23.8 
129 
23.6 
152 
23.6 
5 
23.0 
8 
22 6 
180-189 
29 
23.3 
60 
23.7 
205 
23. 5 
265 
23.5 
13 
22.6 
4 
22.2 
17 
22.3 
190-199 
34 
23.0 
68 
23.4 
204 
23.4 
272 
23.4 
11 
21.9 
5 
22. 1 
22 
22. 1 
200-209.. 
24 
22.7 
54 
23.2 
118 
23.3 
172 
23.2 
21 
21.8 
12 
21.8 
9 
21.7 
210-219 
4 
22.9 
43 
23.0 
61 
23. 1 
104 
23.0 
28 
21.5 
24 
21.3 
6 
21.5 
220-229 
1 
22.7 
31 
22.8 
64 
22.8 
95 
22.8 
31 
21.5 
35 
21.3 
16 
21.6 
230-239 
15 
22.8 
24 
22.8 
39 
22. 8 
24 
21. 1 
25 
21 0 
22 
21 2 
240-249... 
1 
22.6 
2 
23.0 
3 
22.8 
13 
21.4 
11 
21 0 
18 
250-259 
15 
21. 3 
3 
21 8 
2 
260-269 
j 
21 
21.3 
2 
21 1 
4 
21 4 
270-279 
7 
20.5 
3 
21.3 
3 
21.8 
280-289 
i ■ 
1 
21.3 
290-299.. 
300-309 
1 
19. 7 
310-319 
. 
i 
