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 arn 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, 
G 
