6 
BULIvETIN of the bureau of fisheries 
deal with the sockeye, the king salmon, and the coho. Thus the sockeye grilse is a 3-year 
and not a 2 -year fish, a fact which we learn with some relief, in view of the very large 
numbers of grilse which regularly make their appearance three years after each quad- 
rennial big run in the Fraser and the small numbers which can be observed in the inter- 
vening years. For reasons which will appear later, McMurrich’s initial error did not 
to the same extent affect his interpretation of the scales of the humpback and dog 
salmon. 
Our knowledge of the life history of the young sockeye is founded first on the 
important researches of Commissioner J. P. Babcock for the Fraser River (Report Fish- 
eries Commissioner for British Columbia, 1903), and later of Chamberlain, for certain 
streams in Alaska. These investigators agree that in the early spring two sizes of 
young sockeye may be found together in the streams on their downward migration to 
the sea. The smaller of these comprise fry of the year hatched from eggs of the preceding 
fall, and are then about inches long. Those of larger size are yearlings, which instead 
of running out to sea the previous spring as fry, have remained in the lake during their 
first year and have grown during that time to a length of 3 or 4 inches. 
The relative proportions of fry and yearling migrants in such streams as the Fraser 
and the Karluk are unknown. More fry have usually been captured in the fine-meshed 
nets employed for the purpose, but the superior strength and wariness of the larger 
yearlings have doubtless affected the result. It is also unknown whether in the same 
stream these two groups remain relatively constant in size or fluctuate widely from year 
to year in accordance with changing conditions of unknown nature. Chamberlain has 
pointed out that in the Naha River, Alaska, all the young remain in the lake during 
their first year, and migrate in their second spring as yearlings. It seems very probable 
that the chances of survival of yearling migrants is better than that of the fry, in which 
case a larger proportion of adults might be derived from that group, even in streams 
where considerable numbers migrate as fry. As will be shown below, the scales develop 
differently in the- two groups. The history of each group can therefore be traced and the 
proportions which attain maturity can be determined. 
In his interpretation of the sockeye scale McMurrich assumes that 13 of the 14 
specimens which he examined belonged to the group which migrated as fry, the central 
close-ringed area of the scale having been formed during their brief life in fresh water. 
But, as a matter of fact, at the time when young fry migrate no scales whatever have 
made their appearance. In this group, therefore, the adult scales contain no record of 
life in lake and stream, even the innermost rings having been formed under marine 
or estuarial conditions. The close-ringed area which forms the center of the scale in 
McMurrich’s specimens, as well as in the great majority of Fraser River sockeyes (pi. ii, 
fig. 4) , designates members of the second group, which have remained in their native stream 
or lake until their second spring. It presents, therefore, such record as we have of 
approximately the first year and a half of their life cycle. Plate iii, figure 5, represents 
a scale, enlarged 40 diameters, of a 5^earling 3^ inches long, taken in the Fraser River in 
April, 1903, by J. S. Burcham, working under instructions of Commissioner J. P. Babcock. 
