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 the salmon. 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. It is 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 



