PROGRESS IN BIOLOGICAL INQUIRIES, 1936 27 
males. A sexing device so constructed that it was possible to observe 
and record the sex of each individual as it passed through the weir 
on its way to the spawning grounds showed that males were in excess 
during the first half of the run, but by the end of the season had 
reached a normal balance. Egg counts were also made to determine 
the number of eggs deposited by a female of this season’s run. The 
average number of eggs produced per individual in 1936 was 2,227 
eggs. These data furnish a means of determining the year’s seeding 
possibilities in the stream. 
A cooperative United States Weather Bureau Station was installed 
at Little Port Walter during the summer. A number of recording 
instruments are now in constant operation the year round and furnish 
a record of the climatic conditions prevailing at the station. Data 
thus collected will increase the scope of our knowledge regarding 
weather conditions and their effects upon salmon during the period 
spent in fresh water. It is known that rainfall directly affects stream 
conditions during spawning, a shortage of rainfall being detrimental 
to the eggs producing future populations. 
In cooperation with the National Canners Association of Seattle, 
Wash., a study of the physical and chemical changes that take place 
within the pink salmon during their period of spawning migration 
was again carried on at Little Port Walter. A small trap was built 
and set in the outer bay for the purpose of collecting samples with 
which to carry out the experiment. A number of salmon were tagged 
and released from the trap to determine the progress of migration 
through the bay and into the stream. From those fish taken in the 
trap and canned for the experiment, a chemical analysis will be made 
to determine seasonal changes in fat composition and quality of the 
fish from the opening of the season to the closing date. This infor- 
mation will aid the packers in formulating a standard gage by which 
salmon may be packed and graded. 
Throughout the season a number of samples of fish heads and 
muscular tissues were taken and preserved for future study. The 
heads, taken for brain samples which may show changes in the pitui- 
tary gland and its effect upon the individual during the onset of 
sexual maturity, were forwarded for study to Dr. B. M. Allen of the 
University of California. Tissue samples were taken for the deter- 
mination of casual factors governing flesh coloration. Color is also 
being determined in the samples of canned salmon to indicate the 
color changes in the flesh throughout the season. 
A second series of pink-salmon tagging experiments was carried on 
in the Clarence Strait region of southeastern Alaska in the summer of 
19386. On July 18 and 25, and August 1 and 15, 2,000 salmon were 
tagged from a trap located at McClean Point, about 7 miles north of 
the south entrance into Clarence Strait. On August 16, 500 salmon 
were tagged at a trap located at Point Colpoys, which is just outside 
the north entrance into Clarence Strait. These tagging experiments 
concluded the 2-year tagging program of consecutive weekly taggings 
in the Clarence Strait region. By means of this program a detailed 
analysis has been made of the migratory routes of pink salmon in 
Clarence Strait and adjacent channels during various times in the 
migrating season. The results indicate that the pink salmon enter- 
ing Clarence Strait during the first part of the season are bound for 
