LAC EMMURAILLE 



any disturbing factor an exact balance is 

 bound to establish itself between the total 

 weight of trout and the sum of available 

 food. However much the fisherman might 

 prefer that this total weight should be di- 

 vided into a few large units, rather than 

 many small ones, nature orders it otherwise, 

 unless she is thwarted, and trout degenerate 

 to the standard which fits with their habitat. 

 Our inability to discover why degeneration 

 proceeds further in one lake or stream 

 than another — multiplying the units at 

 the expense of weight — rests upon the 

 impossibility of ascertaining the whole 

 of the facts which control a fish's existence. 

 Shifting to the converse aspect of the ques- 

 tion, there seems no reason to doubt that all 

 degenerates are capable of rapid and in- 

 definite improvement in a better environ- 

 ment. It follows that you cannot command 

 good results from stocking an indifferent 

 water with some exceptionally fine breed 

 of fish, and that, when the water is suitable, 

 little is gained by selecting the stock. 



But nothing in the above helps to ex- 

 plain how it comes about that in most riv- 

 ers, and in a few lakes, some trout emerge 

 from their fellows, to attain great size. 

 Cannibalism ofifers the only clue that sug- 

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