CHAP. IX.] 
MILD ARCTIC CLIMATES. 
191 
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 accumu- 
lation 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 Carolina, which 
by the Gulf Stream is transferred 20° northwards to our islands, 
might certainly, under the favourable conditions which prevailed 
during the Cretaceous, Eocene, and Miocene periods, have been 
carried another 20° 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. 1 
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 
1 The objection has been made, that the long polar night would of itself 
be fatal to the existence of such a luxuriant vegetation as we know to have 
existed as far as 80° N. Lat., and that there must have been some 
alteration of the position of the pole, or diminution of the obliquity of the 
ecliptic, to permit such plants as magnolias and large-leaved maples to 
flourish. But there appears to be really no valid grounds for such an 
objection. Not only are numbers of Alpine and Arctic evergreens deeply 
buried in the snow for many months without injury, but a variety of 
tropical and sub-tropical plants are preserved in the hot-houses of St. 
Petersburg and other northern cities, which are closely matted during 
winter, and are thus exposed to as much darkness as the night of the 
Arctic regions. We have besides no proof that any of the Arctic trees or 
large shrubs were evergreens, and the darkness would certainly not be 
prejudicial to deciduous plants. With a suitable temperature there is 
nothing to prevent a luxuriant vegetation up to the pole, and the long con- 
tinued day is known to be highly favourable to the development of foliage, 
which in the same species is larger and better developed in Norway than in 
the south of England. 
