FOREST, LAKE, AND RIVER 



the two trouts of Loch Leven are due to differ- 

 ences of food or residence is hardly tenable. 

 Every one is aware that trout, by the divine 

 law of adaptation, instinctively put on the tint 

 that harmonizes with their environment. I have 

 known our American brook trout entirely change 

 its coloration in twenty minutes. But no one 

 ever heard of a trout's losing all his fighting 

 qualities on running from a lake into a brook ; 

 or, on returning from brook to lake, of exchang- 

 ing his round, red, haloed spots for black crosses, 

 doubling the number of his cascal appendages, 

 modifying his fin-ray formula, altering the shape 

 of his maxillary, and generally refining his form, 

 pointing the rounded extremities of his tail, and 

 doffing the red tips of his adipose fin, — a mark- 

 ing never lost by the brown trout ; as soon 

 believe the saibling of Sunapee will become a 

 brook trout, if taken up Pike Stream and fed 

 on grasshoppers, or that a Chinaman will lose 

 his almond eye and musky pig-tail by swapping 

 his native diet of rice for Yankee crustacean 

 salads. Both species of trout live side by side 

 in Loch Leven, subjected to precisely the same 

 influences. Why do not all lose their silver 

 and stars (if all are brown trout), and why are 

 not all structurally the same ? Dr. Parnell, Yar- 



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