BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Olema, and Hatchery creeks. The fry were strong and healthy, and were turned 
into the streams in the best of condition. The young salmon were watched day 
after day, and systematic observations were made of their movements, habits, 
enemies, and rate of growth. The work was first begun by the United States Fish 
Commission and carried on until the middle of May. After a break here of three 
weeks the California State Commission carried it to completion. 
In the winter of 1897-98 eggs were again shipped from Battle Creek to Bear 
Valley. This time t he number was increased to 2,000,000, necessitating the plant- 
ing of the alevins as soon as they began to hatch. All were planted before the 
yolk-sac was absorbed. This, when taken in connection with the previous year’s 
work, gave an opportunity to study the comparative effectiveness of planting alevins 
and fry. The alevins were transported from the hatchery to the planting-grounds 
in 20-gallon cans. It was possible to carry 40,000 alevins in such a can for two hours 
at a temperature of 40° without loss, though 20,000 or 30,000 to the can was the usual 
number carried. They were carried by wagon or rail as the ease required. A 
wagon was found to be preferable, the jolting being an advantage, as the splashing 
in the cans kept the water well aerated. If the road was smooth or if carried by 
rail, the water had to be aerated frequently, and it was necessary to put fewer in the 
can. Although alevins appear to be very delicate, they stand transportation much 
better than fry, and a much larger number can be safely carried in each can. 
Paper-mill Creek and its tributaries, where the young salmon were planted, were 
never visited by the quinnat salmon. This was one reason that they were selected 
for the experiment, as any young of that species that we might find would be known 
to have been. planted there. The streams are rich in aquatic insect life, affording an 
abundance of food for the salmon fry. Trout and sculpins ( Cottus ) are the only 
predaceous fishes. The streams do not flow directly into the ocean but through 
several miles of brackish tidewater into Tomales Bay, and the transition from fresh 
to salt water is very gradual, removing the danger of the fry being rushed too quickly 
from river to ocean water. It was thought that if the fry could thrive in these 
streams and pass successfully into salt water it would be of advantage to utilize 
coast hatcheries and plant in the smaller streams, where the young salmon would 
not be subjected to their supposed enemies during the long journey from the Upper 
Sacramento to the sea. The thing feared in the experiment was that the streams 
would prove too short and that the young salmon would arrive at salt water before they 
were ready to conform to the conditions of life they would have to encounter there. 
Observations indicate that fry can be as safely planted in Paper-mill Creek and 
its tributaries as in the Sacramento River, and they reach the ocean six weeks earlier. 
If it is true, as the experiments made at the Clackamas hatchery in Oregon indicate, 
that most of the salmon return to fresh water to spawn after being in the ocean two 
years, a difference of one or two months in the time of reaching the ocean is worth 
considering. If the full growth is attained in 24 to 36 months, the average gain in 
weight is from 12 to 16 ounces a month. As the gain is necessarily slight at first, it 
must be much more than a pound a month later. Any extension of time for living- 
in salt water is an increase of the rapid-growing period, as the early period of slight 
increase in weight must be passed through in any case. This argument holds good 
only on the supposition that the individual would leave the ocean in a particular 
month. But the great variation in the time in which the Sacramento salmon leaves 
