104 Th^ ^^f^ Story of the Fish 



telephone instrument in it, and submerged the whole thing 

 in water. Next he defined hearing in fish. "Any disturbance," 

 he said, "that produces hearing through the human ear . . . 

 calls forth hearing in fish if it acts through the ear and not 

 simply through the skin or some other organ." Having 

 cleared the atmosphere of quibbling, he was ready to go 

 ahead with his experiment. 



He produced on his instrument a series of tones beginning 

 with 43 double vibrations per second, and going up through 

 86, 172, and so on, doubling the number each time. He 

 found that normal goldfish responded to all vibrations from 

 43 to 2,752 — a much smaller range than that of our hearing, 

 which extends from 30 to 30,000, with middle C at 256. He 

 then performed some operations — and this, incidentally, is a 

 simple matter in fish. All that is necessary is to place a little 

 of some anesthetic, like urethane, in the water, and when the 

 fish go to sleep, cut them up. No sterilization of instruments 

 or other complicated antisepsis is necessary because their in- 

 sides are very resistant to infection. He first removed the 

 sacculus, with its lagena — ^which, you recall, is the nearest 

 approach in fish to a spiral cochlea. This destroyed response 

 to 1,376 and 2,752 double vibrations per second. He next 

 removed the utriculus, and found that this destroyed re- 

 sponse to 344 and 688. Conclusion: vibrations from 344 to 

 2,752 are sensed by the ear and, therefore, heard. But with 

 both of these organs gone, the fish still responded to 43, 

 86, and 172, and he concluded that these lower frequencies 

 came through the skin or the lateral line, and were thus by 

 definition excluded from hearing. Tests on the catfish showed 

 that it received vibrations only up to 688, and that below 172 

 the skin played a part. In the weakfish, it was found that 

 removal of the utriculus and its three semicircular canals 

 made practically no difference in hearing, but that elimina- 

 tion of the sacculus did. 



