THE SALMON FAMILY 81 



The finnock go down to the sea during the winter with- 

 out spawning, and return next year as sea-trout. These 

 fish weigh two to three pounds, according to the length 

 of their stay in salt water ; they then spawn, and may 

 come back next time weighing five or six pounds. 



Now, though the salmon can be distinguished from 

 the sea-trout, and from the brown trout that has 

 acquired migratory habits, it is a very different matter 

 when one has to distinguish the sea-trout from a sea- 

 going brown trout. 



The sea-trout and the brown trout have each four- 

 teen scales along the oblique line referred to, and in 

 order to distinguish one from the other the naturalist 

 has to fall back on the arrangement of teeth and certain 

 appendages inside the digestive tract. 



The salmon, the sea-trout and the brown trout all have 

 teeth on the hard palate, along the middle line. In the 

 salmon these teeth are very few in number, but in the 

 brown trout they are very numerous, and in the sea- 

 trout the number of teeth are somewhere between the 

 two. 



Both the teeth and appendages are liable to a great 

 variation, and I am confident that many a brown trout 

 that has gone to sea, has been called a sea-trout on its 

 return journey. 



The complete change in the appearance of the brown 

 trout which causes him to be mistaken for a silvery sea- 

 trout, is accounted for by the food supply and change 

 of environment. 



