oducts of the American coast in the latitude of
Bordeaux.[25]

{86}

With these astounding facts before us, due wholly to the transference of a
portion of the warm currents of the Atlantic to the shores of Europe, even
with all the disadvantages of an icy sea to the north-east and ice-covered
Greenland to the north-west, how can we doubt the enormously greater effect
of such a condition of things as has been shown to have existed during the
Tertiary epoch? Instead of _one_ great stream of warm water spreading
widely over the North Atlantic and thus losing the greater part of its
store of heat _before_ it reaches the Arctic seas, we should have _several_
streams conveying the heat of far more extensive tropical oceans by
comparatively narrow inland channels, thus being able to transfer a large
proportion of their heat _into_ the northern and Arctic seas. The heat that
they gave out during the passage, instead of being widely dispersed by
winds and much of it lost in the higher atmosphere, would directly
ameliorate the climate of the continents they passed through, and prevent
all accumulation of snow except on the loftiest mountains. The formation of
ice in the Arctic seas would then be impossible; and the mild winter
climate of the latitude of North {87} Carolina, which by the Gulf Stream is
transferred 20deg northwards to our islands, might certainly, under the
favourable conditions which prevailed during the Cretaceous, Eocene, and
Miocene periods, have been carried another 20deg north to Greenland and
Spitzbergen; and this would bring about exactly the climate indicated by
the fossil Arctic vegetation. For it must be remembered that the Arctic
summers are, even now, really hotter than ours, and if the winter's cold
were abolished and all ice-accumulation prevented, the high northern lands
would be able to support a far more luxuriant summer vegetation than is
possible in our unequal and cloudy climate.[26]

_Effect of High Excentricity on the Warm Polar Climates._--If the
explanation of the cause of the glacial epoch given in the last chapter is
a correct one, it will, I believe, follow that changes in the amount of
excentricity will produce no important alteration of the climates of the
temperate and Arctic zones so long as favourable geographical conditions,
such as have been now sketched out, render the accumulation of ice
impossible. The effect of a high excentricity in producing a glacial epoch
was shown to be