88 THE MAMMOTH CAVE. 



The fish are of a peculiar species, and are of 

 a class known as viviparous, which give birth to 

 their young alive, and do not deposit eggs after 

 the manner of most other fish. They have ru- 

 diments of eyes, but no optic nerve, and are 

 therefore incap <ble of being affected by any de- 

 gree of light. We are indebted to Dr. Wright, 

 who is perfectly familiar with the facts, for this 

 statement. 



The eyeless crawfish give birth to their young 

 in the same manner as those provided with eyes. 

 Both the fish and the crawfish are of a color 

 almost white. 



Ordinary fish and crawfish are sometimes 

 washed into the Cave from Green River. Frogs, 

 also, are occasionally washed into Echo River, 

 and, at times, may be heard croaking to the 

 echo of their own voices. 



It has been proven that the ej eless fish prey 

 upon each other. In shape they somewhat re- 

 semble the common catfish, and rarely exceed 

 eight inches in length. One of these fish was 

 caught by the guide in our presence, placed in 

 a bottle of water, and taken out of the Cave 

 alive, and might have been brought home with 

 us, without impairing its vitality, if supplied 

 daily with fresh water. They are captured by 



