THE SCALES OF SALMON 101 
what the scales show, but it must be remembered 
that salmon similar in size and appearance that have 
spawned during the previous winter as small grilse 
are also caught at this season, and it is only by the 
spawning mark on the scales and sometimes maggots 
in the gills that the difference can be detected, 
though it sometimes becomes apparent when the fish 
comes to table. 
‘These small unspawned fish constitute the bulk 
of the spring run in the northern rivers, and are 
comparatively more important to them than to the 
Tay, where larger fish a year or more older come in 
during the winter and the spring.” 
Illustrations of those wired grilse and spring fish 
scales are given in Plate V. In each case the 
smolt scale will be noticed in the centre, and as the 
eye passes from the centre of growth along the long 
axis of the scale to the anterior border, will be seen 
the large area of growth resulting from the first 
summer of feeding in the sea; then subsequently 
the contracted-looking band of small growth, mark- 
ing the first winter in the sea. In the grilse scale 
a short period of spring feeding in 1906 is repre- 
sented by only six lines, after which the fish entered 
the river Tay and was killed. In the small spring 
fish scale, on the other hand, the second summer in 
the sea is seen to have been completed and followed 
by a second winter, making an addition of 27 lines, 
after which the record of this fish ends like a tale 
that is told. 
The grilse which enter our rivers spawn in the 
autumn. Those fish which do not enter our rivers 
