THE SALMON FISHEK. 31 



Idaho, and in tributary lakes of Lake Superior, 

 where "it is called red trout by the natives and 

 grows to the size of 40 Ibs., and is not to be con- 

 founded with the common lake trout (8. namaycush) 

 whose flesh is white." [L. H. Smith, of Strathroy, 

 Canada, in London Field.] In fact, one well informed 

 writer (Dr. Shufeldt), whose opinion reflects the 

 modern scientific acceptation, remarks that the Fam- 

 ily Salmonidse is one which we now 4mow dates back 

 as far as the tertiary period. Analogy would indi- 

 cate that they developed in the fresh waters of the 

 Northern Hemisphere in obedience to the law of 

 equal conditions, and some of them gradually 

 acquired the habit of going to sea, and thus, as in 

 the case of the salmon, became permanent. In obe- 

 dience to the law of evolution which requires each 

 individual to pass through, in his short cycle, the 

 same changes which his various forms of ancestors 

 have in the slow progress of ages, the young must 

 be born and live for a time at least in fresh water ; 

 and hence we find our salmon coming into the rivers 

 to deposit their spawn. It is probable that at the 

 opening of the glacial epoch the fresh waters of 



