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of the bull-trout. The albuminous nature of 

 this sort of food, which the trout availed them- 

 selves of, was believed to be the cause of their 

 colour ; since other trout procured at the same 

 time from localities where no such food could be 

 obtained, were of the usual dark colour of that 

 season of the year.* 



Mr. Stoddart, in his "Art of Angling as 

 practised in Scotland," mentions an interest- 

 ing experiment made with trout, some years 

 ago, in the south of England, in order to 

 ascertain the value of different food. " Fish 

 were placed in three separate tanks, one of 

 which was supplied daily with worms, another 

 with live minnows, and the third with those 

 small dark-coloured water-flies which are to 

 be found moving about on the surface under 

 banks and sheltered places. The trout fed 

 with worms grew slowly, and had a lean 

 appearance; those v nourished on minnows, 

 which, it was observed, they darted at with 

 great voracity, became much larger ; while 

 such as were fattened upon flies only, attained, 

 in a short time, prodigious dimensions, weigh- 

 ing twice as much as both the others 



* "The colouring-matter is not in the scales, but in the 

 surface of the skin immediately beneath them, and is pro- 

 bably a secretion easily affected by the health of the ani- 

 mal." Sir H. Davy. 



