182 NATURAL SCIENCE. Marcu, 
the great depths must be very old or permanent ; so let us compare 
the character of the sediments near the existing coasts. 
The Old Red Sandstone is an extra-marine formation; yet the 
Old Red Sandstone runs out into the sea in the Orkneys, reappears 
in the Shetlands, and the same paleontological and extra-marine 
character is known in Spitzbergen. Old{Red exists on the north 
coast of Lapland, and on the White Sea. The plant-bearing beds 
of the Karoo run out tosea in British Kaffraria; they are repeated 
in India and Australia. The fresh-water beds of the Wealden pass 
over from England to the Continent; they not only reappear in 
Hanover, they run out into the Atlantic in the lower'Charente, and on 
the coasts of Spain and Portugal. Why must the continent which 
formerly bounded all these vast fresh-water basins have been limited 
within the existing 1,000- or 1,500- or 2,o00- fathom line? The 
breaking down of the bed of the A®gean Sea, described by Spratt 
and Neumayr, is of Post-pliocene date, for Pliocene fresh-water 
deposits form parts of the coast; and yet thedepths go far beyond 
1,000 fathoms. In 1892 the ‘‘ Pola’? measured 3,591 metres in 
lat. 35° 52 36’, long. 29° 1’ 24"’ E., quite near the south-west coast 
of Asia Minor, and close to the mighty Ak Dagh (10,000 feet); and 
this although the separation of the neighbouring island of Rhodes 
is so recent, that not only do the Pliocene fresh-water beds pass over 
from the Continent, but according to Bukowski also considerable 
masses of Middle Pliocene fluviatile conglomerates, originating in Asia 
Minor, have been deposited by a great river on this island. 
Now suppose the existing quantity of oceanic water to decrease, 
say by evaporation into the ether, as Zéllner once thought, or in 
any other way; we might by this gradual diminution of the entire 
quantity attain a beach-line 500 fathoms below the present shores. 
The continents would appear so much higher, and dry land would 
extend. Plains would successively appear, more or less similar to 
Holland, and our present rivers Shannon, Seine, Loire, &c., would 
flow through these plains. In most cases the rivers would be caused 
to cut back their valleys, new transverse and parallel lines of erosion 
would appear, and the plain would be diversified into hills and valleys. 
The hills south of the Shannon would probably show the rest of those 
anticlines and synclines which dip below the ocean in south-west 
Ireland, and we should be able to see a greater part of the northern 
Armorican arch. The Scilly Islands would appear as another 
granitic laccolite within the continued Armorican region of Cornwall. 
The gneiss of Eddystone would come up within this northern Armori- 
can arch, exactly as the gneisses of the Alps stand up within and 
behind the folded arches. In a similar way, in the south, the anti- 
clines and synclines of French Armorica, which disappear north and 
south of Brest, would begin to be visible; but in the north-west of 
Ireland we should see a plateau, ending in a steep cliff, the abrupt 
boundary of a deep channel, separating the great island of Rockall 
