344 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
It would appear from the above that the eggs eye very much faster with the 
spring run, and that the hatching range covers a much longer period. It is also 
apparent that in considering the hatching of redfish at Karluk the two runs must 
be treated separately — the runs are so marked and the prevailing conditions so 
radically different. For example, eye-spots have appeared in 30 days in spring-run 
eggs, and have with fall-run eggs been as long as 138 days before being visible. 
With the early run eye-spots are looked for between 35 and 40 days, the interval 
advancing with the season; with fall eggs the eye-spots are not expected until more 
than two months have passed, the time again increasing with the advancement of 
the season. The “tender stage” is a variable quantity, difficult to calculate; it is 
carefully looked for within about three weeks from the stripping, but may not occur 
for as many months. Its duration is also variable, anywhere from one to five or six 
weeks, depending upon the temperature, and it is thought, other conditions not yet 
known. This season, 1900, no tender condition had made its appearance up to 
August 8. 
The period of incubation ranged in 1899 from 74 days to 237 days, and there is 
a maximum record for some prior season of 244 days. The early run in 1899, under 
natural conditions of temperature, hatched in an average of 129 days, whereas the 
fall run required 198 days. Seven months is supposed to be the period of incubation 
under natural conditions, with the temperature at a mean minimum during the cold- 
est months of between 33° and 35° F., and this seems to be a fairly correct approxi- 
mation, judging from the record of the October eggs of 1899 and the following 
temperature record: 
Temperatures in hatching troughs, winter 1899-1900. 
Month. 
Mean 
maximum. 
Mean 
minimum. 
Mean. 
o 
o 
o 
October, 1899 
42 
40 
41 
November, 1899 
40 
38 
39 
December, 1899 
+3/ 
36 
-37 
January, 1900 
-37 
+ 35 
36 
February, 1900 
37 
35 
36 
March, 1900 
38 
36 
37 
April, 1900 
39 
36 
+37 
In 1900 the seining crew delivered into the river corrals 79,753 adult salmon. 
Of this number 13,123 escaped from time to time through the water gate when 
opened to admit live-cars, and through breaks in the corral fences during the time the 
corrals were in use. 114 days; there were also lost 7,334 stock-fish at a time when the 
fencing of one of the corrals blew down. The proportion of males to females 
among these 20,457 fish which escaped alive is, of course, unknown. The remaining 
59,296 comprised 33,523 males and 25,773 females, which are accounted for as follows: 
Males. 
Females. 
Total. 
14, 324 
19, 199 
19,498 
6,275 
33, 822 
25, 474 
33, 523 
25, 773 
59, 296 
