SEPTEMBER 231 



cranial cavity and a sac or sacs containing bony con- 

 cretions termed otoliths. This apparatus in the herring, 

 carp, perch, and other fishes is connected with the air- 

 bladder by more or less complicated processes. In 1851 

 or thereabouts it was discovered that the internal ear 

 of all mammals is furnished with a special mechanism, 

 known as the organs of Corti, supposed to be indis- 

 pensable to the transmission to the brain of those 

 vibrations which cause the sensation of sound. Now, 

 whereas fishes are the only vertebrate animals destitute 

 of the organs of Corti, Professor Korner argues that 

 fishes must be deaf. Nature, says he, is strictly economical 

 in equipping her creatures for the battle of life ; of what 

 use, he asks, would ears be to fishes which exist in a 

 world of silence ? None ; therefore Nature has not wasted 

 ears upon them. The pike makes no sound in darting 

 upon the trout; no warning footfall tells the herring of 

 the approaching hake; where there is nothing to hear, 

 there is no need for listening. 



Is there not too much assumed in this reasoning ? A 

 body passing swiftly through water makes no sound 

 audible to human ears, but there can be no doubt that 

 certain vibrations to which human ears are insensible 

 cause the sensation of sound in the brain of other animals. 

 For it should be remembered that objective sound has no 

 existence. The vibration of the conducting medium, be 

 it air or water, must be conveyed to the sensorium before 

 sound takes place. Testing the hearing of some friends 

 two or three days ago with a Gal ton whistle, I found one 

 who was insensible to the note produced by 5000 vibra- 

 tions per second. His hearing for ordinary purposes is 

 perfectly normal, and he enjoys music, but he has never 



