16 THE ROYAL SOCIETY OF CANADA 
1) one sees a dark oval or kite-shaped area, surrounded by a clear line 
(represented by stippling in the figure) and representing the nucleus. 
A narrow dark band bounded by a clear line seems to represent the ad- 
dition to the ossicle during the period spent by the fish in fresh-water. 
Then follows a usually broad dark area representing the growth of the 
first summer spent in the sea, and this is succeeded by a narrow clear 
line which indicates the growth of the first winter in salt water. Then 
follows another dark band, much narrower than the preceding one, and 
another narrow clear line, the two representing the second year in the 
sea. The material added to the otolith in the succeeding two summers 
and winter is relatively small, but the clear winter line that should 
occur between the two dark summer bands is always recognizable, close 
to the lower edge of the ossicle, though sometimes only in the neigh- 
bourhood of the lower posterior angle. 
The otoliths, therefore, confirm in a general way the results ob- 
tained from the study of the scales, but the story is told with much less 
precision and detail. The clear rings are not always distinctly marked 
out and they are rarely, if ever, complete rings, usually fading out 
towards the anterior portion of the ossicle and being most distinct at 
its upper and lower posterior angles. 

Text-fig. 3.—Right Sagitta of grilse Sockeye Salmon, 46 cm., in length seen from the 
lateral surface. 
The otoliths of Sockeye grilse also confirm the conclusions drawn 
from the scales, that these are two year old fish. Thus in a fish measur- 
ing 46 em. in léngth the sagitta (Text-fig. 3) had a length of 4.25 mm. 
and a greatest diameter of 2.75 mm., and it showed clearly the central 
nucleus, the area of the first winter’s growth surrounding this and sepa- 
rated by a clear line from the dark zone representing the first summer 
inthesea. This is succeeded by a dark line, representing the first winter 
in the sea, and beyond this is a dark zone, extending to the margin of 
the ossicle and representing the second summer in the sea, during which 
the fish was taken on its way to fresh water. 
