42 THE SEA-TROUT 



tail " to be a more frequent feature of eastern sea-trout than western 

 sea-trout, that there is no more warrant for claiming the " bull trout " 

 as a separate species, or even race, on account of its round tail alone, 

 than there is for making such a claim on behalf of the tailless trout of 

 Loch-na-Maorachan, in Islay, or the " bull-nosed " trout of which 

 some reservoirs can show a high percentage. Conclusive evidence of 

 distinction must be sought along other lines. 



I have, personally, an open mind on this really important subject, 

 and would be glad if it could be scientifically settled once for all. It 

 seems to me that careful scale examination may help to solve the 

 difficulty, and later in these pages I shall give more precise reasons for 

 so thinking. In the meantime it is enough to say that there may quite 

 well be a distinct race, or even species, of sea-trout which has nothing 

 in common with ordinary fario, except that, like the salmon, it spawns 

 in very much the same way in our rivers, while at the same time there 

 may be another race, or species of sea-trout, in reality ordinary fario, 

 of which some individuals retain and some lose the migratory habit, its 

 retention or loss being at any time entirely dependent upon the nature 

 of the fish's environment. There is really nothing definite known of 

 the matter, but I can easily imagine that naturalists might yet come 

 to agree that there are sufficiently distinctive points of difference to 

 justify the grouping of three species, namely (i) the salmon {S. salar), 

 (2) the migratory true sea-trout {S. iruttd) — in other words, the " bull 

 trout " — and (3) the trout (5. fario), which last may be indifferently 

 migratory or non-migratory. 



I may conclude the whole discussion with Dr. Day's remark : — " If, 

 as seems probable, we merely possess one very plastic species subject 

 to an almost unlimited amount of variation, that its largest race is found 

 in the ocean, while in order to breed it ascends streams, but usually (to 

 which there are many exceptions) not so far as the salmon, unless it 

 permanently takes up its abode in the fresh waters, we at once obtain a 



