74 DAYS AND NIGHTS OF SALMON FISHING. 



bottom of the waters in which they are found. The 

 final reason for this may be traced to the protection 

 such a power affords to secure them from the attacks 

 of their enemies, and exhibits another beautiful 

 instance of the care displayed by Nature in the pre- 

 servation of all her species. Dr. Stark often observed 

 that on a flat, sandy coast, the flounders were coloured 

 so very much like the sand, that, unless they moved, 

 it was impossible to distinguish them from the bottom 

 on which they lay.' 



" Mr. Shaw, who has the charge of the salmon cruive 

 at Drumlanrig, has observed that the Salmon taken in 

 it change their colour in consonance with the turbid or 

 refined state of the water. In the experiments he has 

 made with Parr in different- coloured earthenware 

 vessels, the change of colour is perfected in the space 

 of four minutes. If Parr is taken from the dark- 

 coloured vessel, and put immediately to the Parr in 

 the light-coloured one, the difference of colour between 

 the two fish will be found strikingly observable. 



" Mr. Scrope himself had observed that the Trout at 

 Castle Combe are white in a chalky spate, resuming 

 their colour when the water clears ; and that in all 

 the rivers in which he had fished, the fish are clear in 

 a gravelly bottom, and dark in that overhung with 

 trees. All this he considered as resulting from the 

 same principle of preservation by which the ptarmigan 

 and alpine hares have their colours changed with the 

 approach of snow. 



" Notwithstanding these distinct statements by so 

 many observers in whom confidence might be placed, 



