ALASKA SALMON INVESTIGATIONS IN 1900. 
343 
The first eggs were taken June 27 from a few fish, but were not basketed; the 
milt curdled when it came in contact with the eggs, and it was not thought impregna- 
tion would take place. Spawning was again carried on June 30, when the milt once 
more curdled upon contact with the eggs, and none of the latter were basketed. 
July 3 the first eggs were placed in the troughs, although the same condition of milt 
was met with. This curdling tendency continued in a diminishing degree for about a 
week longer, when it ceased; strange to say it did not affect the vitality of the sperm 
as far as could be judged. Spawning was carried on about every other day in July, 
the run slacking up toward the latter part of the month; in August eggs were taken 
three times up to the 10th, from which time until the 28th none were taken. With 
the beginning of the fall run work went on once more every other day until the end 
of September; during October spawn was taken on an average of about once a week, 
and the last stripping of 10 fish was done November 3. On the last-mentioned date 
about 40 adult salmon, still unripe, were released from the reservoir and turned into 
the river. 
The period of incubation varies with the temperature of the water, of course, but 
it is also believed to be of less duration with eggs taken from the spring run than is 
the case with those of the later or fall run. That is, the eggs of the spring run of 
redfish seem to have a more vigorous vitality, hatching more rapidly under similar 
thermal conditions; but this is still a matter of opinion and must remain so until the 
collection of sufficient data from which to draw careful conclusions. 
From the meager figures at hand for the 1899-1900 season the following table 
has been prepared: 
Eggs taken in 1899. 
Eyed. 
Hatching period. 
Hatch- 
ing 
range. 
Prema- 
ture 
births. 
First. 
Last. 
Mean. 
Julv 3 
30 
74 
109 
92 
35 
23 
July 13 
40 
125 
109 
132 
121 
23 
July 31 
93 
185 
139 
92 
62 
Aug. 3 
90 
127 
202 
165 
83 
75 
Aug. 28 
65 
126 
199 
163 
73 
74 
Sept. 7 
64 
161 
206 
184 
62 
158 
214 
186 
56 
75 
154 
218 
1S6 
Sept. 20 
81 
162 
223 
193 
61 
89 
207 
237 
222 
30 
Oct. 14 
110 
199 
230 
215 
31 
Oet. 21... 
125 
186 
Summary. 
35 
91 
122 
107 
31 
July 31-Aug. 10 ... 
110 
193 
151 
83 
69 
152 
212 
182 
60 
Sept. 30-Oct. 27 
108 
197 
233 
215 
36 
Remarks 
Delicate period, 
Sept. 1-Oct. 15. 
Delicate period, 
Oct. 20- ? 
Spring- run. 
Fall run. 
Eggs taken in 1899. 
Spring run 
Fall run . . 
Season 
Eyed. 
Hatching period. 
First. 
100 
174 
137 
Last. 
158 
222 
190 
129 
198 
163 
Hatch- 
ing 
range. 
58 
48 
53 
Note.— I n the above table a day of 24 hours is the unit. 
