PROGRESS IN BIOLOGICAL INQUIRIES, 1926 533 
after their adipose and right ventral fins were removed, were lib- 
erated from the hatchery at Herman Creek in February, 1924. As 
a result of this marking, approximately 2,300 four-year-olds returned 
to the Columbia River and were taken in the commercial fishery. In 
addition, 96 of these fish succeeded in evading the commercial fishing 
gear and returned to the hatchery from which they were liberated, 
and their spawn was taken for artificial propagation. These 96 
spawners produced a stock of eggs greater by one-half than that 
required to produce the fingerlings that were marked. Additional 
returns from this experiment are to be expected in 1927. Results 
such as these give promise of the possibility of maintaining commer- 
cially significant runs of salmon by artificial propagation. 
A second experiment with sockeyes yielded 2,500 four-year-olds 
from 100,000 marked yearlings. In this experiment, however, none 
returned to the tributary in which the fingerlings were liberated. 
Why they did not return to their home tributary is an important 
question, to which there is no reliable answer as yet. This problem 
will be given special attention when future returns are being studied. 
The importance of this question lies in the fact that unless the fish 
return to the place of liberation the run can not be perpetuated by 
artificial propagation. A hatchery that is able to produce an entirely 
satisfactory return to the commercial fishery may fail in the long run 
because of inability to secure a breeding stock. 
An experiment with chinook salmon conducted at the Big White 
Salmon River hatchery yielded 265 four-year-olds in 1926, bringing 
the total of returns from the experiment to 359. With the 5 and 6 
year olds yet to return, this experiment gives promise of being the 
most successful of those with chinooks to date. As was pointed out 
a year ago, the greater returns from this experiment than from those 
in which fingerlings of the same class of fish were liberated at an 
older age, would indicate that the best time to liberate fingerlings 
of the fall run of chinooks is during the spring of their first year. 
More direct information on this important question is being sought 
by means of a series of experiments in which fingerlings from a single 
lot of eggs will be marked and liberated at various ages. A similar 
experiment is already under way with chinooks of the spring run. 
Comparison of the results of these two experiments should be en- 
lightening, and it is hoped that they may point the way to more suc- 
cessful hatchery operations. For a more complete account of this 
work see p. 645. 
Mr. Holmes also has continued an investigation of the blueback 
salmon of the Columbia River. The most important development 
during the past season was the observation that the seaward migrants 
from the Okanogan River spawning beds were so heavily infested 
with the encysted larvee of tapeworms as to have their vitality 
greatly reduced thereby. An effort is being made to discover the 
alternate host of the tapeworm, in the hope that the infestation of the 
salmon may be reduced in the future. 
HERRING OF ALASKA 
During the season of 1926, George A. Rounsefell continued the 
herring investigation in Alaska, confining his activities to Prince 
William Sound, Cook Inlet, and Shuyak Straits. Preserved samples 
