PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1921. 27 
dam to permit the passage of fish it was never effective. The matter 
of providing a suitable fishway was taken up with the California 
Fish and Game Commission, and at the close of the year the case was 
pending in the courts. 
There was a very large run of fall chinooks in the Sacramento 
River, and while Rae early fall was marked by low-water stages it 
was estimated on November 15 that there were enough fish impounded 
at the Battle Creek substation to yield not less than 15,000,000 eggs. 
At Mill Creek the run was even larger, and the egg collections for 
that substation were estimated at not less than 30,000,000. Beginning 
November 20 several days of heavy rains occurred, bringing about 
flood conditions of unusual severity. Many miles of territory, in- 
cluding railroads and highways, were under water. The retaining 
racks at all points were destroyed and spawning operations abruptly 
brought to a close. 
At the Battle Creek substation 2,450,000 eggs were taken, of which 
504,000 were transferred to Baird for incubation and 20,000 shipped. 
to central station, Washington, D. C., for exhibition. The remainder 
were hatched successfully, and 1,781 000 fingerling fish were planted 
in Battle Creek. At the Mill Creek substation 5,460,000 eges were 
secured, of which 1,000,000 were shipped to Baird and 3,000,000 to 
the State hatchery at Sisson. From the remainder 1,347,400 finger- 
ling fish were produced at the station. 
INVESTIGATIONS AND EXPERIMENTS, 
FERTILIZATION OF SALMON EGGS IN NATURAL SPAWNING. 
At many points on the Pacific coast certain species of salmon, 
notably the humpback and chum, spawn at or near the mouths of 
streams in tidewater. A rather general belief has existed that the 
results of such natural spawning were negative, and in order to ob- 
tain information on the subject the field superintendent in charge of 
the Pacific coast stations and the superintendent of the Baker Lake 
(Wash.) station were detailed to investigate these conditions in 
Puget Sound. The report of their findings | follows: 
In conformity with instructions relative to securing information on the per- 
centage of fertilization of salmon eggs in natural spawning, with special refer- 
ence to the eggs deposited in places over which the tide ebbs and flows, an 
investigation was made of Walcott Slough, at Brinnon, Wash., on March 5, 
1920. 
Walcott Slough runs through extensive tide flats, which at flood tide are 
completely covered with salt water. During ebb tide a good flow of fresh 
water, estimated at about 3,000 gallons per minute, passes through the slough, 
its-source beimg spring seepage at the slough head. The fish—chum salmon 
with a few silver salmon—enter this slough to spawn, the entire slough bottom 
being composed of gravel suitable for the purpose. The bureau has a rack and 
trap installed at a favorable point in the slough, about 500 yards from salt 
water, where fish are captured for propagation. Below the rack some natural 
spawning occurs, and this occupied our attention. Several nests were in- 
vestigated, all but two of which contained eggs. These two might possibly 
have been made last year, though they had the appearance of being used quite 
recently. Eight nests were examined, beginning with No. 1 (see table, p. 28) 
just below the trap, about 500 yards from salt water at low tide, and ending 
with No. 8, about 200 yards from the same water stage. During flood-tide 
periods salt water covered the nests from three to six and three-fourths hours 
to a depth of 13 to 53 feet. This will vary somewhat with higher or lower 
runs of tide. 
The condition and character of the bottom wherever nests were found would 
indicate that the fish chose points where spring seepage occurs through 
