102 THE LIFE OF THE SALMON 



as grilse but remain in the sea till the grilse stage 

 is past are of course still maiden fish, and after 

 entering such a river as the Tay as small spring 

 salmon will spawn a year later than their fellows. 

 They merge into the run of 10-16 lb. summer fish 

 of the Tay which have completed their two annual 

 rings. The summer class of fish are, however, apt 

 to be mixed in a large river like the Tay, as we 

 have now reached a stage in the salmon's develop- 

 ment when fish which have previously been in the 

 river as grilse and which have spawned and de- 

 scended for the short period of marine sojourn may 

 be once more in the river. The proportion of such 

 fish is, however, comparatively small, at least in the 

 large rivers of Scotland. 



The study of the scales has prominently called 

 attention to the infrequency of spawning amongst 

 heavy fish. It comes as a surprise, for instance, to 

 learn that very many of the large spring fish of the 

 Tay — fish almost invariably about 20 lb. in weight 

 — have never spawned. The scale shows the third 

 annual ring in course of formation subsequent to 

 the two-year-old smolt stage ; i.e., they are approxi- 

 mately five years, yet their scales bear no spawning 

 mark. They are entering fresh water for the first 

 time, although many fish of smaller size have 

 already propagated their species. Such information 

 makes us realise with additional force the value of 

 protecting fish when they do breed. 



Now let us deal with the records of adult salmon 

 marked in fresh water as kelts and subsequently 

 recaptured as clean fish. And first I will take the 



