THE HABITS AND HAUNTS OF FISH. 11 



phere, while those of the fish are better adapted to the 

 stronger pulsations of a denser element. Thus, though 

 the inhabitants of the waters are insensible to atmos- 

 pheric sound, they are very susceptible to vibrations of 

 the earth which are communicated to the water, and are 

 undistinguishable by us. 



Who has not observed the terrified agitation of the 

 fish, as far as the eyes can penetrate the water, at the 

 least perceptible vibration caused by the stamp of the 

 foot on the bottom of a punt or boat? We have frequently 

 ourselves seen fish clear the water altogether in ponds and 

 lakes at a distance of forty yards from the point or focus 

 of concussion. That sound is not communicated only by 

 the external ear may be seen by the following experiment: 

 Take an ordinary tuning fork, strike it, and take the full 

 volume of the sound quite close to the ear, then strike 

 again and place the handle against or between the teeth, 

 when, though at some distance from the ear, the sound 

 will not be found to be diminished. Vibrations vary in 

 intensity according to the degree of solidity and density 

 of the conductive bodies. Thus, we are told that in the 

 atmosphere sound travels at the rate of something like 

 one thousand feet per second on bright, clear days, but 

 eleven hundred in murky, dull and hazy weather. In 

 water, however, sound travels very much quicker, being 

 at the rate of five thousand feet per second, and where 

 wood is the medium quicker still, sixteen thousand feet 

 per second being its rate of progress. If, therefore, a 

 solid substance is the conductor of sound, it naturally 

 follows that the sound will be more distinct. The opera- 

 tor upon the violin has a keener perception of the vari- 

 ous strains of the instrument than the ordinary listener, 

 since wood is the sole conductive body in his case. The 

 organ of hearing being enclosed in the hard case of the 

 head is, in the case of fishes, susceptible therefore to no 

 slight variation of sounds; no noise that does not occa- 



