150 ANDREW JACKSON HOWE. 



and the Ural supply the basin with vast quantities of 

 fresh water, yet the evaporative agency is so enor- 

 mous that these great rivers scarcely supply the de- 

 mand, though they keep the sea less saline than the 

 ocean. 



The Aral is less salty than the Caspian, yet its 

 saltiness is increasing every year. The Aral once 

 communicated with the Caspian through a depression 

 still to be seen, but both seas have been gradually 

 sinking, till they are now below the surface of the ocean. 

 The increasing salinity of these inland seas is extin- 

 guishing many kinds of fish and aquatic animals; and 

 the plants are becoming more and more marine. If 

 evaporation be not on the increase in those seas, their 

 tributaries are furnishing less supplies. 



The steppes of the Volga embrace immense areas 

 of low lands which overflow during rainy seasons, 

 and in droughty weather present multitudes of brack- 

 ish basins. The river flows so sluggishly that in 

 places it is difficult to observe which way the water 

 runs. The country about the Caspian and Aral Seas 

 is practically a great depression in the continent, and 

 habitable only in restricted areas. 



The Caspian Sea, for convenience of description 

 may be considered in thirds : the northern or upper 

 end is kept comparatively fresh by the inflowing 

 rivers, arid shallow from the deposit of sediment ; the 

 middle third is deeper and salter, and its border is 

 broken into gulfs and bays, with sand-bars deposited 

 in front of their entrances. The largest of these 

 pockets is the Gulf of Scythia, which has an expanse 

 of several thousand square miles and has become in- 

 tensely saline from the circumstance that a current 

 from the sea is always setting into the basin. The 



