ALBACORA 111 



"We know," Rivas said, "it's a sixth sense. We think 

 it is some means of picking up very low vibrations." 



"Why, that's like sound," I said. "Sound is vibra- 

 tions." 



"That's right," Rivas said, "but these vibrations are 

 different." 



"But fish can hear," I said. "I heard about a Ben- 

 edictine Monk in Austria who rang a dinner bell before 

 he fed his trout lunch, and after a while the trout began 

 answering the bell just as cattle or people might." 



"We know more than that," Luis said. "Enough tests 

 have been made to prove that goldfish can hear vibra- 

 tions from 344 to 3,752 cycles per second. Do you have 

 Hi-Fi?" 



"Our phonograph is old." 



"Well, just to let you know what I'm talking about, 

 then," Rivas said, "the human ear can hear from 30 to 

 30,000 cycles per second. That's the range Hi-Fi aims 

 at. No fish has a hearing range like a human's, but bill- 

 fish can hear quite well. They make noise, too. They 

 grunt and whistle and groan." 



"But about lateral line?" I prodded. 



"It doesn't appear to be exactly like hearing," Rivas 

 said. "It's some other means of picking up vibrations. 

 A boat vibrates, other fish vibrate, the Humboldt itself 

 vibrates out there in the Pacific. Somehow this lateral 

 line in fish enables them to pick up vibrations. With 

 it they can also pick up temperature changes, which is 

 how they find the edges of the Humboldt and how they 



