312 The Trouts of America 



tread ever so lightly on the low bank of a pool, 

 and the fish are affrighted. 



Again, fish do not seem to hear any sound pro- 

 duced by concussion on the bottom of a pool, of 

 which my personal experience gave an instance. 

 In a shallow and small indentation of the Schuyl- 

 kill River (Pennsylvania), where some years ago 

 fly fishing for black bass was glorious, I had 

 moored my boat to a stake, the upper end of 

 which protruded about two feet from the water. 

 Having occasion to visit the little craft, I noticed 

 three or four eight to ten inch bass lying in 

 repose some twenty feet away from the stake, and 

 in somewhat deeper water. Experimentally, I 

 struck, with a short, heavy stick that was at hand, 

 the top of the stake very hard, at least a dozen 

 times, and doubtless created a strong concussion 

 between the bottom of the river and the stake. 

 To my surprise the fish remained undisturbed. 

 Going ashore quietly, I selected a flat stone, and 

 threw it into the water, at least fifty feet from the 

 spot where the bass were lying, and on returning 

 stealthily to the boat, found they had disappeared. 

 In the first instance no vibrations on the bottom 

 and thence upward were caused by hammering 

 the stake, and in the second, sufficient concussion 



