PROGRESS IN BIOLOGICAL INQUIRIES, 1921. 9 
connection with the fact that the majority of the tributaries of the 
lower river enter on the right bank. 
Fishermen recognize the succession of phases in the run—the 
chums which accompany the king salmon being of relatively small 
size and poor quality, after which there is a run of bright fish of 
good quality, but inferior size (“silvers”), and finally the last run 
of “silvers” of a bright rich form and of distinctly larger size. 
This last run of “silvers” is ordinarily of short duration and fur- 
nishes the most highly prized fish of the season. A further more 
detailed study of the characteristics of the chums at different times 
and in different localities and the distribution of the various strains 
to their respective spawning areas would offer results of importance 
from the biological and equally from the strictly practical points of 
view. 
The investigators record their opinion that the king salmon of 
the Yukon is the richest in oil of any known king salmon,‘and ex- 
press the same view with even greater emphasis regarding the Yukon 
chums. In this connection it is remarked that in other river basins 
the chums do not travel far from the sea, but enter late in the 
season to seek spawning beds not far inland, while the best of the 
Yukon chums travel 1,000 to 2,000 miles up a river known for its con- 
sistently rapid current. 
Consideration was given to the passage through which the salmon 
enter the river, and the investigators considered it not beyond the 
bounds of probability that nine-tenths of the salmon run enter by the 
Kwikluak Pass and its subsidiary channel, the Kwiguk. 
CHEMICAL STUDIES OF SALMON, 
Without expense to the Bureau, Prof. C. W. Greene, of the Uni- 
versity of Missouri, has continued his chemical studies of material 
collected several years ago to determine the changes in salmon ovaries 
and tissues during the period of migration from sea to breeding 
grounds. The results of such studies can at first be given only 
technical expression, but they are none the less likely to yield in the 
end data of direct economic value. 
The chemistry of the king salmon ovaries during their develop- 
ment in the migration period followed in the year 1908 on a series 
of samples collected on the Columbia River and its tributaries has 
been tabulated and prepared for publication. 
These studies show the following major points: First, the growth 
of the ovary takes place primarily during the migration while the 
salmon is fasting. The average increase in weight is from about 135 
to 150 grams at the end of the feeding period to 2,000 to 2,500 grams 
at maturity. In short, about 90 per cent or more of the development 
takes place during the prolonged fast of the migration. 
Chemical analyses of developing ovaries show that between the 
500-gram stage and the mature-egg stage there is a remarkable uni- 
formity of chemical composition. The proteins are high, averaging 
from 29.38 to 31.16 per cent. This is undoubtedly all stored protein. 
The neutral fats decrease with the development and migration, from 
an average of 14.15 per cent at the mouth of the river to 10.83 per 
cent at the spawning. Phospholipins average 4.78 at the mouth of 
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