46 THE LIFE OF THE SALMON 
locked “salmon” of Lake Wenern, which seem in 
reality to be trout, are reported to have not un- 
commonly the same appearance. As the salmon 
grows after visiting the sea, the teeth on the shaft 
of the vomer bone disappear, and eventually the 
teeth on the head of the bone go also. Trout retain 
those teeth throughout life. In other words, the 
trout commonly retains the juvenile characteristics 
of the salmon, which develops fully only by visiting 
the sea. This retention by fresh water trout of the 
juvenile characteristics of the salmon does to some 
extent suggest that the salmon has developed from 
a trout-like origin, after acquiring the habit of 
migrating to the sea. If this is so, Salmo trutta 
and its varieties occupies an intermediate place 
between the fresh water trout and thesalmon. New 
Zealand trout rapidly acquire the migratory habit. 
But, on the other hand, and in view of the fact that 
the majority of the salmon family are purely marine, 
may we not have some cause for the view that our 
fresh water trout itself represents a species in which 
evolution has been arrested to a greater degree than 
is seen in the case of the salmon. The salmon fall off in 
condition after entering fresh water. Itis easy to say 
that they do so because they do not feed, but if fresh 
water is their original element, why should they not 
feed, and why should they fall off in condition ? 
I firmly believe that many of us have got into. 
the way of regarding the salmon as a fresh water: 
fish simply because we observe him almost ex- 
clusively in fresh water, where he spawns, and. 
further get into the way of regarding the silvery 
