28 
BULLETIN OF THE BUREAU OF FISHERIES 
Table 3. — Chinook salmon taken by troll in Monterey Bay, Calif., June 19 to 21, 1918 
Females in third year, and which migrated as fry (scales with ocean nuclei), tabulated to show correlation between size of fish 
and size of eggs 
0. 07. 
. U* 
. 13. 
. 15. 
. 17. 
. 19. 
. 21. 
. 23. 
. 25 
.33* 
.35. 
.37. 
.39. 
.41. 
.43. 
.45. 
.49* 
Centimeter length (mid-value of class) 
ggs (mid-value of class) 
57 
59 
61 
63 
65 
67 
69 
71 
73 
75 
77 
79 
81 
83 
85 
87 
89 
r. 
1 
•.. 
1 
1 
1 
2 

1 
2 
1 
3 
1 
1 
1 
.... 
3 
.... 
2 
.... 
2 
1 
)... 
1 
1 
1 
1 
2 

1 

1 
!*• 
1 
1 
1 
1 
1 
7 
1 
) 
1 
1 
1 
1 
1 

1 
1 

.... 
)• 
1 
Total 
1 
1 
2 
2 
9 
4 
5 
2 
8 
6 
3 
5 
3 
Group 1 
1 
1 
2 
2 
9 
4 
4 
1 
6 
4 
1 
1 
Group 2. . . .. 
1 
1 
2 
2 
2 
4 
3 
Total 
Group 1 (36 indi- 
viduals). 
Group 2 (15 indi- 
viduals) . 
These examples indicate clearly that within a single category (that is, among 
females of a similar degree of matm"ity and of the same age group) the size of the 
eggs is dependent to a considerable extent upon the size of the fish. The regression 
coefficients have been calculated for the two groups for which the coefficients of 
correlation were determined. From these it was found that in the first group 
(mature fish taken ofi^ the Columbia River in August) the logarithm of the diameter 
of the eggs was, on the average, increased by 0.005850 for each increase of 1 cm. 
in the length of the fish. In the second group (immature fish taken at Monterey 
in June) an increase of 1 cm. in the length of the fish was accompanied, on the 
average, by an increase of 0.005535 in the logarithm of the diameter of the eggs. 
It may readily be seen, however, from an examination of Tables 2 and 3, that 
the groups distinguished as mature and immature are sharply and widely separated 
on the basis of egg sizes but overlap almost completely in so far as length is con- 
cerned. Within each group there is the distinct tendency for the larger fish to have 
larger eggs, but this is quite inadequate to account for the greater difference observed 
between the mature and immature groups. These can only be explained as the 
residt of the difi^erential growth of the eggs during the last year. 
FISH TAKEN IN THE COLUMBIA RIVER AND IN THE OCEAN OFF THE 
MOUTH OF THE RIVER 
In discussing the various features of the life history, which will be treated in 
this paper, the data on the fish from the Columbia River, from near Fort Bragg 
and Point Reyes on the northern coast of California, and from Monterey Bay wiU 
be handled separately. Each age group will also be given separate consideration. 
The oldest fish will be treated first, since the results of their study will aid in inter- 
preting the data from the younger age groups. 
