308 
SIMPLICITY OF THE ARALO-CASPIAN FAUNA. 
and that others which are abundant as fossils are unknown in existing nature. Yet 
here we must observe, that as the bottom of the Caspian has never, we appre- 
hend, been explored by that searching instrument the dredge , nor its contents fully 
laid open by it, like those of the iEgean Sea through the labours of Professor E. 
Forbes, it must be impossible to say to what precise extent the submarine fauna 
of the former and larger Caspian agrees or disagrees with that of the present sea. 
We have already endeavoured to account for the partial intermixture of purely 
marine shells with brackish water remains in some of the rocks of the isthmus ot 
Taman ; and explaining the phenomena by a modern analogy, have sought to lead 
our readers to understand, how the inhabitants of our ancient Aralo-Caspian being 
shut out from the ocean, may have lost the oceanic and assumed the brackish 
water type. The present Caspian, for example, isolated and excluded from all 
communication with the ocean, is so slightly saline, that even in a part of it far 
removed from rivers and streams, its waters are said to be potable 1 ; and, 
according to Eichwald, as stated in his Fauna, the greater number ot its fishes 
1 Lieutenant Felkener (Annuaire des Mines de Russie, annee 1838, p. 155) states, that in the Isle of 
Tcheleken, which is saturated with saline springs, the Turkoman inhabitants drink no other water than that 
of the adjacent Caspian Sea. With such a fact before us we cannot subscribe to the view of M. Hommaire 
(Bulletin de la Soc. Geol. de France, vol. xiv. p. 263), drawn from a belief that the Caspian of the present 
day is more saline than the Black Sea. M. Hommaire has, indeed, a theory to sustain, which, in our opinion, 
is at variance with the geological and physical structure of the surrounding regions. That author contends, 
that the Caspian is simply a portion of the ancient Black Sea, which since its separation has been lowered 
to its present level through a diminished supply of fresh water from the rivers Volga and Ural, and also by 
evaporation ; and hence its supposed greater saltness. Granting that the Volga and the L T ral, no longer 
flowing through vast undrained and uncultivated forests, do not afford so great a volume of fresh water 
as of old, and that the level of the Caspian may consequently have somewhat subsided, there is no reason 
to apprehend that this cause can continue to operate to any great extent. In regard to the alleged excessive 
saltness of the Caspian, the statements of M. Gobel, the chemist, (who makes the water less salt than that 
of the ocean) are at variance with those of M. Hommaire. We venture, however, to believe, that both ana- 
lyses may be true, and that they depend upon the portion of the sea from whence the samples were taken. 
We have, indeed, no difficulty in understanding why such parts of this sea as happen to be fed with intensely 
saline springs issuing from beds of rock salt, may not be exactly as they are represented by M. Hommaire; 
but whilst he attributes this excess of salt in the water to evaporation, we distinctly refer it to ancient 
geological causes, viz. rock-salt and salt springs of previous epochs. Our readers will, in truth, perceive, 
that the theory of M. Hommaire requires no other refutation than the simple fact, that Caspian shells 
lie in rocks 700 feet above the Caspian Sea. Would that author lower the great Aralo-Caspian Sea 
from such heights by evaporation ? We shall presently assign geological reasons which exclude the 
possibility of such former high levels of that sea, and which at once destroy the reasoning of Pallas and 
many of his successors, as to certain historical deluges in Greece and the rupture of the Dardanelles 
being due to the letting off of these inland bodies of water. 
