GENERAL FEATURES 59 



8. In fish of equal weight the margin of the sea-trout's tail is less 

 forked than that of the grilse. 



9. The scales of the salmon are generally actually, and always 

 relatively, larger than those of the sea-trout. 



10. In the oblique line of scales traced forwards from the adipose 

 fin to the lateral line, the salmon has, as a rule, 10 scales, the sea-trout 

 14- 



11. The rings of annual growth shown on the scales of salmon and 

 sea-trout widely differ, those of the sea-trout, weight for weight, 

 generally indicating greater age. 



We may now turn to the question whether there are any structural 

 differences between sea-trout and trout, a question which 1 have warned 

 the reader would crop up again and again throughout these pages. 

 For the scientific answer we are forced back upon Mr. Regan's dictum 

 that " there are no structural differences." 



I have already stated that, failing proof to the contrary, Mr. Regan's 

 dictum must be accepted, and I for one have no conclusive rebutting 

 evidence to offer. I may say indeed that I have again and again, with 

 sea-trout and trout of equal weights before me, examined them minutely 

 to see whether I could detect any particular part, or even outline, which 

 could fairly be held to differentiate the one fish from the other. 

 Hitherto (with the doubtful exception of a different rate of scale growth) 

 I have been unable to do so. It must be said, however, that in general 

 outline the trout of some rivers have a clumsier appearance than the 

 sea-trout caught in the same stream, while fin and tail have the 

 appearance of being coarser in texture. But on the other hand river 

 trout differ as greatly from the better proportioned trout which can be 

 caught in almost any lake. 



In the general case it will be found that with equally well- 

 proportioned fish it is the colouration alone that enables one to distin- 

 guish whether a particular fish is a migratory or a non-migratory trout. 



