before the Geographical Society, May 27,1867. 25 
Hecateus and Herodotus down to the tenth century of our 
era—i. e. to the days of the Arab geographers El-Istachry and 
Ebn Haukal—the event of the separation of the Aral and 
aspian remounts to a geological epoch, which like the sepa- 
ration of the Euxine and the Caspian, or the opening out of 
the Dardanelles and Straits of Gibralter, are all ante-histori- 
eal, or far beyond any human tradition.” 
In sustaining this view it is to be ama that, whilst 
the Aral Sea trends from north to ager the Syr Daria and 
its embrachment the Kuvan Daria, hich flow into it from 
the east, have had courses at right aus to that sea itself ; 
thus favoring the geological view that the great movement 
which produced the plateau of the Ust-Urt, separated the 
of Aral from the Caspian, and left the chasm occu pied by the 
Aral, was also accompanied (as is usual in such slengsions) by 
transverse flanking openings in the and on the east, 
south of it, is remar 
If the Jaxartes ever soe ee to the southwest, as suggested 
by Sir H. Rawlinson, it must have joined the Oxus long before 
the united streams fell into the Caspian, which is very distant 
from the nearest point of the valley of the Oxus. But if such 
an union of the great streams ever existed in so southern a lati- 
tude, it must have been perfectly well known to the ancients, 
and they have made no allusion to it. On the contrary, they 
believed and have stated, that ane rivers fell vat ma 
by the old a eli traveller Jenkinson, to whom he refers. It 
will also be present] i iati 
pher Semenof would explain the desiccation of the former or 
Caspian branch of the Oxus in another manner. The stop- 
page of that iene ee an usual line of ae 
untains, a 
let Balke: near the ancient desiccated beste of the ‘Oxus: 
Such a change of level may, indeed, have been caused by the 
same subterranean forces which, in this — evolve, at the 
present day, the fires of Baku, and have recently thrown. up - 2 
* Humboldt, ‘ Asie Centrale,’ vol. ii, p. 146. 
