GEOLOGY. 



657 



beneath dark vaults, the windings of which are indented by 

 a thousand rocks. In this subterranean river, the course of 

 which we follow in a boat, dwells a very peculiar fish, the 

 Cyprinodon, which is said to be blind, and which, in fact, 

 ought to be so ; for what purpose could eyes serve in the 

 midst of waves where the most perfect darkness reigns ! 



245. Dead Sea in the Mammoth Cave of Kentucky. 



Further on, in this immense Mammoth Grotto, filled with 

 rivers, cataracts, and subterranean lakes, the traveller is 

 astonished to find himself beside a large sheet of water, on 

 which glide slowly a few boats, the dull glare of their 

 torches being lost in the obscurity of the distance, without 

 lighting up the banks and projecting rocks. 1 This dark and 

 calm mass of water is called the Dead Sea. 



1 The Mammoth Cave is always an object of great curiosity with the Amer- 



