276 HASISADRA'S ADVENTURE vn 



time was generally received, as well as that of 

 various hypothetical deluges from that quarter, 

 must be seriously questioned. 



The Caspian and the Aral stand in somewhat 

 the same relation to the vast basin of dry land in 

 which they lie, as the Dead Sea and the lake of 

 Galilee to the Jordan valley. They are the 

 remains of a vast, mostly brackish, mere, which 

 has dried up in consequence of the excess of 

 evaporation over supply, since the cold and damp 

 climate of the pleistocene epoch gave place to the 

 increasing dryness and great summer heats of 

 Central Asia in more modern times. The 

 desiccation of the Aralo-Caspian basin, which 

 communicated with the Black Sea only by a com- 

 paratively narrow and shallow strait along the 

 present valley of Manytsch, the bottom of which 

 was less than 100 feet above the Mediterranean, 

 must have been vastly aided by the erosion of the 

 strait of the Dardanelles towards the end of the 

 pleistocene epoch, or perhaps later. For the 

 result of thus opening a passage for the waters of 

 the Black Sea into the Mediterranean must have 

 been the gradual lowering of its level to that of 

 the latter sea. When this process had gone so 

 far as to bring down the Black Sea water to 

 within less than a hundred feet of its present 

 level, the strait of Manytsch ceased to exist ; and 

 the vast body of fresh water brought down by the 

 Danube, the Dnieper, the Don, and other South 



