PROGRESS IN BIOLOGICAL INQUIRIES, 1921. if 
RESULTS OF MARKING EXPERIMENTS, 
Mr. Rich has also submitted a report on “ Returns from the ex- 
periments on the marking of young chinook salmon on the Columbia 
River.” The experiments were started in 1916-17 and described in 
Economie Circular No. 45. 
The percentage of returns of marked salmon was rather low, but the 
results obtained are of some significance. Examination of the scales 
of the marked fish which have returned after a period of three to 
four years corroborates the theory that the arrangement of the con- 
centric rings (circuli) provides an accurate record of the previous 
history of the fish. A study of the scales of these marked fish will, 
moreover, aid very materially i in the solution of perplexing problems 
which have arisen in interpretation of the scales of the chinook 
salmon. 
Facts gathered during the investigation throw some light upon 
the rate of spawning migration of adult chinooks, indieating that 
the rate is approximately ‘the same as that previously determined for 
sockeye salmon passing through Puget Sound and the Fraser River, 
that is, some 10 to 15 miles per day. 
Perhaps the most interesting and important contribution which 
these experiments have made to our knowledge of the biology of the 
salmons relates to the hereditary character of the factors determin- 
ing the time of the year at which the adults enter fresh water and 
begin their upward migration to the spawning grounds. It is an 
important practical question whether or not it is necessary to breed 
from fish of the spring run in order to produce the spring-run fish, 
which are more desired than the fall-run fish. The evidence of 
the marking experiments gives some indication that spring-run fish 
will be derived from spring-run parents and fall-run fish from fall- 
run parents. 
A comprehensive program of experiment has been planned to ex- 
tend over a period of several years. Two new marking experiments 
have been started on the Columbia River in cooperation with the 
Oregon Fish and Game Commission, nearly 100,000 young chinooks 
having been marked at Little White Salmon station and the State 
hatchery at Bonneville. 
SALMON INVESTIGATION IN YUKON RIVER.” 
During 1920, from May until September, Prof. Charles H. Gilbert, 
temporary investigator, and Henry O?Malley, field assistant in 
charge of Pacific coast work, conducted an investigation in Yukon 
River with reference to the runs of salmon, the commercial packs 
in and near the mouths of the rivers, and the requirements of the 
natives and others dependent on the runs of salmon in the Yukon 
River system. Data were secured for a comparison of conditions 
prevailing in 1919 and 1920. The primary object was to determine 
whether or not commercial fishing for export should be allowed in 
the Yukon River and its tributaries. 
While all five of the Pacific coast species of salmon make their 
appearance at the mouth of the Yukon, only three species have sub- 
* Cooperative investigation by Divisions of Fish Culture, Alaska Fisheries, and Scientific 
aioe Only the biological data are summarized here. The full report is published on 
128-154 in Alaska Fishery and Fur-Seal Industries in 1920, by Ward T. Bower, Ap- 
pene VI, Report of the U., 8. Commissioner of Fisheries for 1921, B. F. Doc. No. 909. 
