40 
BULLETIN OF THE BUBEAU OF FISHERIES 
fish in their fourth year with ocean nuclei, fourth year with stream nuclei, and fifth 
year with stream nuclei, are taken. 
Table 6. — Percentages of females of different age groups and different degrees of maturity taken in 
the ocean at different times during the season ' 
Date 
Ocean nuclei in — 
Stream nuclei in — 
Second 
year 
Third year 
Fourth year 
Fifth 
year 
Si.xth 
year 
Third 
year 
Fourth year 
Fifth year 
Sixth 
year 
I. 
I. 
M. 
I. 
M. 
M. 
M. 
I. 
I. 
M. 
I. 
M. 
M. 
May 8 to 10 
11. 5 
60.6 
29. 0 
43. 7 
47. 0 
33.3 
6. 5 
1. 2 
7. 5 
6.3 
10 9 
20. 5 
0. 6 
12. 2 
10.9 
1. 2 
5. 6 
1.8 
5.6 
1.2 
May 18, 1920.. ._ 
13. 1 
18. 7 
1.5 
6. 5 
May 24 
25.0 
26.4 
33.3 
19. 3 
42.8 
14. 1 
3. 1 
2. 1 
4.9 
16. 7 
6.3 
16. 2 
22. 2 
12.9 
14.3 
7. 1 
7. 1 
1.0 
1.9 
16.7 
June 4 
1.5 
5.9 
1. 5 
June 10.. 
11. 1 
32. 3 
28.6 
22. 2 
50.0 
66. 4 
18. 6 
June 21 
6. 5 
3.2 
16. 1 
14.3 
7. 1 
2. 0 
6.3 
2. 9 
3. 2 
June 25 
July 2.... 
26.3 
13. 2 
6.3 
3.9 
58. 3 
5. 1 
3. 1 
9. 5 
20.6 
1. 0 
11. 1 
18.4 
4.2 
18. 6 
3. 0 
1.0 
1. 0 
3.0 
1. 0 
July 28 
1.0 
Aug. 13 _ 
3. 2 
1.0 
Aug. 13 to 17 
26.5 
1.0 
Sept. 18 and 19 
8.3 
' The initials I. and M. stand for immature and mature, respectively. 
PERCENTAGES OF IMMATURE FISH AT DIFFERENT TIMES 
The composition of the various collections as regards mature and immature 
fish is best sho^vn in Tables 7 and 8, which give the percentages of mature 
and immature fish found in each collection taken inside and outside, respectively. 
In Table 8 is also given the estimated percentage of fish that would not mature for 
two or more 3"ears. This has been derived by assuming that in any one collection 
the 2-year fish with either ocean or stream nuclei would, the next year, show a 
similar percentage of mature and immature fish as did the 3-year fish with the same 
type of nucleus at the time the collection was made. As has been mentioned above, 
this assumption is not necessarily justified, but it is believed that the general results 
of the application of such an assumption will approximate more closely the true 
state of affairs than could otherwise be reached. 
Table 7. — Percentage of mature and immature females taken inside the river at different times during 
the season 
Date 
Percentage 
Date 
Percentage 
Imma- 
ture 
Mature 
Imma- 
ture 
Mature 
May 10 
100 
100 
100 
95 
100 
100 
100 
100 
100 
100 
Julys.... 
2 
25 
98 
75 
100 
100 
100 
100 
100 
100 
May 13 
July?..- - 
May 16 _ 
July 16.. _ 
May 17 and 18 
5 
July 28 
May 27.. 
Aug. 5.. 
May 30 and 31 
June 10 
Aug. 6... 
Aug. 22 _ 
June 16 
Sept. 12 
June 16 and 17 . 
June 24 and 25 
