134 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The average weight of the Battle Creek specimens could not be determined, 
owing to the selection of the larger males for spawning, but it was certainly less 
than that given in the Jelly Ferry record. 
It will thus be seen that throughout the fall season of 1900 there was a greater 
proportion of female salmon taken by fishermen in Suisun Bay and the lower river. 
On the other hand, the small males, being too small to be taken in the regulation net 
of the market fishermen, were greatly predominant in the headwaters. The evidence 
here given does not indicate that more of one sex is produced than of the other. 
This point should be considered in making laws governing salmon fishing. The 
small males are not desirable for propagation, either natural or artificial, and on 
account of their great number they are a nuisance at the Government fisheries. 
They are simply so much valuable food wasted. The present law prohibits the use 
of nets that would catch them, and it should be amended. As there are no small 
females, the small-mesh net would not affect the supply of breeding females. A 
law prohibiting the taking of small fishes is of value only when the small fishes are 
growing fishes. But the small salmon that come in from the ocean are not growing 
fishes. None of the salmon ever return to salt water. Their sole value lies in adding 
so many pounds to the market supply or in reproducing their kind on the spawning- 
beds. A large fish is worth more on the markets than a small fish; but so are large 
cattle worth more on the market than small cattle, yet a stock- raiser would never 
think of selling his fine cattle and keeping only the runts to breed from. It would 
be better for the salmon as a species, and therefore better for the salmon industry, 
if the present minimum net-mesh were made the maximum. A small-meshed net 
does not catch so many large fishes, which would allow the larger individuals to 
reach the spawning-grounds. The salmon will certainly deteriorate in size if the 
medium and larger sizes are taken for the markets and only the smaller with a few 
of the medium allowed to breed. 
NATURAL PROPAGATION. 
Spawning habits . — Salmon in spawning usually take a position at the upper end 
of a riffle where the current is strong and where there are gravel and cobblestones 
among which the eggs may lodge. After selecting the place the female extrudes a 
few eggs and then moves away. The male immediately takes her exact position, or 
perhaps a point one or two feet downstream from it, and extrudes a small quantity 
of milt. In about five minutes the process is repeated, the female always taking the 
position first occupied. This they continue day and night for over a week, usually 
nearly two weeks. I have observed salmon spawning at night, but have never been 
able to watch one pair until spawning was completed. Branded salmon No. 91, pre- 
viously referred to, was only eight days in spawning, although some eggs had been 
extruded before it was taken. Two weeks is the spawning time usually assigned by 
persons living in the vicinity of salmon streams, which is probably about right. 
On account of the difficulty in seeing eggs under water, it has been impossible 
to determine the rate at which ova are deposited. The motions of the fish show just 
when ova are being extruded, but observation at a distance of 5 feet, with the aid 
of a field glass, has failed to disclose the eggs. 
The female at irregular intervals turns over on her side and digs her tail into 
the gravel. If the gravel is fine there is often a considerable hillock thrown up, 
leaving a hole 6 or 8 inches deep and 2 feet across. This digging is probably not 
