Plies and Fly-fishing. 307 



produced not the slightest effect on the trout, who rose 

 freely during the experiment to flies blown towards them 

 through a tube. I am therefore convinced that no sound 

 is injurious which does not communicate its vibration to 

 the water, such as conversation; but concussion upon the 

 side or bottom of a boat, or jumping from rock to rock, 

 or blows upon a hard bottom with the wading-staff or 

 with hobnailed shoes, I think are so conveyed through 

 and by the water, as to be in some measure perceptible 

 to the fish, and alarm them. 



That fish possess the sense of hearing, their anatomi- 

 cal structure goes far to prove, while that they are not 

 insensible to sounds produced in the air must be admit- 

 ted, unless the doubter is prepared to call in question 

 the numerous accounts by alleged eye-witnesses of their 

 coming to be fed at the sound of a bell, etc. This I, 

 for one, hesitate to do, notwithstanding I have never 

 been able to make a sound in the air which seemed to 

 produce the slightest effect on trout in the water to 

 which fish my experiments have been confined. It may, 

 however, well be that the sound was perceived, while the 

 fish were so habituated to the roar of the water- fall 

 and similar noises, without. any ill consequences ensuing, 

 that sound alone was not regarded by them as an indica- 

 tion of danger. 



To what extent the power of vision is developed in 

 trout remains to be considered. To the angler it is a 

 question second in importance to none, since upon its 

 answer depends a more or less perfect solution of the 

 problem how may the necessary connection between his 

 line and his fly be best disguised ? 



Every angler has heard, or taken part in, discussion of 

 the best color for leaders; and if it be permissible to judge 



