vii HASISADRA'S ADVENTURE 277 



Russian rivers was cut off from the Caspian, and 

 eventually delivered into the Mediterranean. 

 Thus, there is as conclusive evidence as one can 

 well hope to obtain in these matters, that, north 

 of the Euphrates valley, the physical geography 

 of an area as large as all Central Europe has 

 remained essentially unchanged, from the miocene 

 period down to our time ; just as, to the west of 

 the Euphrates valley, Palestine has exhibited a 

 similar persistence of geographical type. To the 

 south, the valley of the Nile tells exactly the 

 same story. The holes bored by miocene 

 mollusks in the cliifs east and west of Cairo bear 

 witness that, in the miocene epoch, it contained 

 an arm of the sea, the bottom of which has since 

 been gradually filled up by the alluvium of the 

 Nile, and elevated to its present position. But 

 the higher parts of the Mokattam and of the 

 desert about Ghizeh, have been dry land from 

 that time to this. Too little is known of the 

 geology of Persia, at present, to allow any positive 

 conclusion to be enunciated. But, taking the 

 name to indicate the whole continental mass of 

 Iran, between the valleys of the Indus and the 

 Euphrates, the supposition that its physical geo- 

 graphy has remained unchanged for an immensely 

 long period is hardly rash. The country is, in 

 fact, an enormous basin, surrounded on all sides 

 by a mountainous rim, and subdivided within by 

 ridges into plateaus and hollows, the bottom of 



