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 



