THE MEDITEREANEAN DURING THE PLEISTOCENE AGE. 167 
The elevation of these African moraines above the sea is as 
nearly as possible the same as those of Asia Minor, about 6,000 
feet and upwards. If the mountains of Atlas and Lazistan shared 
in the upward movement of the Mediterranean area, the addi- 
tion of 3,000 feet to the height could not fail to leave marks 
behind of the low temperature thereby induced. It is very 
probable that during the time the Mediterranean was reduced 
to two land-locked seas, these mountains were covered with 
snow-fields, and constituted the ice-sheds of glaciers, just as we 
have reason for the belief that Wales, Ireland, Cumbria, and 
the Pennine chain and a great portion of Scotland were clad 
with ice at the time that Britain formed part of the European 
mainland. 
From the range of the mammalia we have inferred the ex- 
istence of land barriers extending across from Africa to Spain 
and Italy and from Candia to Grreece, and their actual existence 
beneath the sea has been proved by soundings, which neces- 
sitate an elevation of about 500 fathoms to bring them above 
the sea level. We have also seen that the higher mountains, 
which most probably participated in this upward movement, 
bear traces of a lower temperature in the moraines of Atlas 
and Lazistan. The hypothesis of such an elevation during the 
Pleistocene Age may therefore be taken to be proved so far 
as it explains widely different classes of facts. 
The substitution of land for a stretch of sea in the Medi- 
terranean could not fail to cause the summer heat to be more 
intense in the region to the north than at the present time, 
while the increased elevation would produce a greater severity 
of winter cold, as Mr. Grodwin Austen has pointed out in the 
case of the hills of Devonshire. When, indeed, we consider that 
the Pleistocene land surface extended from the snowy heights 
of Atlas as far north as the hundred fathom line off the coast 
of Ireland, we might expect to find that African animals, such 
as the spotted hysena and Felis caffer, ranged as far north as 
Yorkshire, for the only barrier to their migration would be that 
offered by the severity of a Pleistocene winter. 
The submergence of the barriers and the constitution of the 
Mediterranean as we find it now, have probably taken place 
but a short time ago, from the geological point of view, though 
we know that for the last three thousand years the Medi- 
terranean has been on the whole unchanged, except by the 
silting out of the sea by the sediment of rivers such as the Po, 
and the elevation and depression of small areas by volcanic 
energy, as at Santorind. The physical character of the shores 
testifies to the truth of this view, 
“On entering the Straits of Gribraltar,” Mr. Maw writes, 
“ from the Atlantic, a notable change takes place in the aspect 
