Heer — Miocene Flora of the Polar Regions, 277 



been floated, or brought by water, from a great distance to the arctic 

 zone. This cannot possibly have been the case, for the leaves are in 

 beautiful preservation, and lie together in great masses : they are 

 found in connection with great beds of coal ; and amongst the speci- 

 mens there are flowers, fruits, and seeds (nay, even berries them- 

 selves), and young, tender, and even unfolded beech leaves ; and 

 moreover, insects are found with them. Any one who, with a 

 sound, unprejudiced mind, looks over the great variety of speci- 

 mens of plants so beautifully preserved as those which fill the rocks 

 of Atanekerdluk, in Northern Greenland, must come to the conclusion 

 that they came from the immediate neighbourhood : in addition to 

 which, the fact that the Spitzbergen plants are found in a fresh- 

 water formation is a decisive proof that they were not the waifs of 

 the sea. 



II. 

 Professor Heer having been asked how he could explain the great 

 change of climate indicated by the Miocene flora, gave a second 

 lecture on this particular subject. In the first place, he discussed the 

 conditions of the globe itself, which here come into consideration. A 

 change of the pole, in the way which has lately been brought for- 

 ward by Mr. Evans, is opposed by the fact that both in the Arctic zone 

 and in the more southern latitudes, the same phenomena are observable 

 all round the globe. We nowhere find indications of the pole having 

 been displaced ; and we cannot, therefore, ascribe the change of cli- 

 mate to any such cause. Much greater weight seems due to the idea 

 that the climatic changes have arisen from a new distribution of land 

 and water on the earth's surface. At the present time the proportion 

 of land to water is about as 1 to 2|-. The greater part of the land is 

 in the northern hemisphere, more especially in that part of it which 

 is beyond the tropics. The earth, therefore, at the present moment 

 is in an abnormal condition : what we should consider as the normal 

 condition being a proportionate distribution of land and water over 

 every zone of the earth, by which the temperate and cold zones would 

 enjoy a warmer climate than they do at present. But even if we 

 could imagine such a favourable apportionment of land and water, 

 we should still not find such conditions as would enable us to extend 

 the flora before mentioned from 70 to 79 degrees N. Lat. If we 

 were to place all the main land under the tropics, and only a few 

 islands in the north, the latter would, indeed, have the highest pos- 

 sible medium annual temperature, and the winters would relatively 

 be very mild, but the summer heat between 70 and 80 degrees N.Lat. 

 never could rise so high as to produce so rich a forest flora. Besides 

 this, there was apparently in the Miocene age a great quantity of 

 main land in the temperate zone of the northern hemis23here, and it 

 must also have extended a considerable distance into the polar regions, 

 as may be proved by the spread of the Miocene plants ; for many 

 kinds of trees and shrubs may be traced from the Mackenzie through 

 Greenland up to Spitzbergen. Had there been only some scattered 

 islands in the arctic zone at that time, these plants would never have 

 spread so far. 



