ALASKA SALMON INVESTIGATIONS IN 1900. 
345 
Of these fish 7,270 males and 15,579 females, or a total of 22,849, were trans- 
ferred to the ripening-ponds during the season, as follows: 
Month. 
Males. 
Females. 
Total. 
June 
1,931 . 
3,974 
5, 905 
July 
2, 296 
5, 574 
7, 870 
August 
2, 225 
3, 658 
5, 883 
September 
818 
2,373 
3,191 
Total 
7,270 
15, 579 
22, 849 
No report of the egg-take for the season has been received, but 5,524 females 
were spawned in all. Applying the usual Karluk hatchery factor of 3,000 per average 
fish, the take would appear to have been 16,582,000 eggs. Allowing, however, for 
“other shrinkage in various ways,” and judging from the hatchery capacity, 
15,000,000 eggs would appear to be a fair estimate. 
According to a report from the hatchery, under date of November 3, 1900, all 
the June eggs and part of the July eggs had hatched out, producing an excellent lot 
of healthy fry. It was found (1900) that the earlier eggs and the September eggs 
were the best, while a portion of those taken during the middle of the season were 
of indifferent quality. 
The following temperatures of the water in the hatching-troughs are recorded: 
Month. 
High. 
Low. 
M can . 
Remarks. 
Max. 
Mean. 
Min. 
Mean. 
o 
o 
O 
O 
O 
Mav, 1900 
48 
43 
36 
38.7 
40.9 
June, 1900 
57 
49.3 
39 
41 7 
45. 5 
57° June 28. 
July, 1900 
57 
51 
43 
45 
48 
57° July 9. 
August, 1900 
56 
50.2 
42 
46.3 
48.2 
September, 1900. . 
48 
46.1 
39 
43.1 
44.6 
October, 1900 
46 
41 
34 
40 
40.5 
November, 1900. . 
39 
36.6 
34 
36.1 
36.3 
December, 1900.. 
38 
35.3 
33 
34.7 
35 
33° Dec. 22 and 31. 
January, 1901 
36 
34.4 
34 
34.3 
34.3 
The eggs of the redtish readily admit of forcing, but to what extent is not 
known. Judging from the fact that “freaks” or malformations and prematures 
occur anywhere from 20 to 80 days, 90 days would seem the limit of safety, but at 
what temperature the limit is reached is not yet known. At Karluk fall-run eggs 
have been successfully forced to hatch in 165 days, or say 45 days sooner than would 
have been the case under natural conditions. To do this the temperature during the 
last 42 to 45 days — that is, after the one hundred and twentieth day — was artificially 
raised to 46° and 48°, or 10° to 12° higher than otherwise would have obtained. It 
has been observed that during warm misty or rainy weather eggs which are nearly 
ready to hatch will be hastened by several days. 
After a basket of eggs has been placed in a trough at the Karluk hatchery it 
receives the most tender care. For the first two or three days the basket is not 
touched, but remains “buried” under the canvas tarpaulin; it is then handled once a day 
for the next four or five days by the superintendent himself, who merely floats the eggs 
once, very gently, and picks off the dead eggs and “empties” showing on top; after 
