SALMON. 9 



confusion still exists. This, however, is not for 

 want of attention to the subject by naturalists. 

 The discrimination between species and varieties 

 is often a difficult matter, and in this connection, 

 no rule which has been laid down has held good 

 for any length of time. This is owing to the 

 fact that fresh-water fishes adapt themselves to 

 local circumstances more effectually and more 

 rapidly than any other class of creatures. In 

 fact, in the family under notice, it is hardly 

 known what are salmon and what are trout ; 

 and the only satisfactory division is that of 

 migratory and non-migratory species. These 

 include the salmon, brown brook-trout, bull-trout, 

 salmon-trout, gillaroo, sewin, short-headed salmon, 

 great lake-trout, Loch Leven trout, a number of 

 others, and some char. Many of these are no- 

 thing more than varieties with local peculiarities, 

 probably produced by different conditions of 

 food and water in their particular haunts. The 

 inclination of naturalists has been to evolve 

 species from mere varieties by a process of 

 hair-splitting ; but in the future, and as the laws 

 which govern evolution ^become better under- 

 stood, the tendency will probably be the other way. 

 The salmon- or sea-trout, is, as its name 

 implies, one of the migratory species. It is 

 common in most salmon rivers, and is widely 



