64 Prof. 0. Heer on the Miocene Flora 



nolia with coriaceous leaves [M. Inglefieldi), and a Plum [Pru- 

 nus Scottii) ; and in Spitzbergen a large-leaved Lime-tree ( Tilia 

 Malmgreni). Side by side with these trees, which are analo- 

 gous to those of the present epoch, we observe several excep- 

 tional forms, from the presence of which it is difficult to draw 

 any conclusions. One of these species, which possesses large 

 coriaceous leaves {Daphnogene Kanii), probably belongs to 

 the family Laurinese ; four others {Macclintockia and Hahea) 

 are probably Proteacese. It is difficult to judge what would have 

 been the habit of these plants. With regard to others, however, 

 analogy indicates that, in all probability, they were shrubs. Thus 

 we find a Nut-tree ( Corylus Mac Quarrii) which was diffused 

 through all the polar regions, and occurred in Spitzbergen at 

 78° N. latitude, as also a species of Alder {Alnus Kefersteinii) . 

 From Greenland we have species of Rhamnus, Paliurus^ Gor- 

 nus, Ilex, Cratcegus, Andromeda, and Myrica, which ascend to 

 70° N. latitude. Sarmentose plants were not wanting ; a species 

 oilvy [Hedera MacGlurii) has been found on the shores of the 

 Mackenzie, and of Vines two species in Greenland, and one in 

 Iceland : these species approach certain American Vines. It 

 is not difficult to form an idea of the vegetation of the polar 

 regions, at the Miocene epoch, from the indications which we 

 have just given. It consisted of forests of very various leafy 

 and resinous trees, many of which had large leaves of very 

 diverse forms ; vines and ivy entwined these with their 

 branches ; and beneath their shade grew numerous shrubs and 

 elegant ferns. 



What a contrast between this picture and that presented to us 

 by these countries in their present state ! Now-a-days Green- 

 land is nothing but an immense glacier, which covers the whole 

 country and sends even into southern latitudes mountains of 

 ice which cool the climate ; we can scarcely say that a narrow 

 belt along the shores is freed in summer and enabled to cover 

 itself with a little vegetation. In the Miocene period the limit 

 of Limes, Taxodia, and Platani was at 79° N. latitude ; that 

 of the Pines and Poplars, if we may judge from what we see 

 in the present day, must have attained the pole, or at least the 

 lands nearest to it ; for they advance at present 15° fui'ther to 

 the north than the Planes. It is a natural conclusion from 

 this, that the extreme limit of trees then followed a line very 

 different from that which we can trace at the present day : it 

 now follows the isothermal line which gives a mean of 10° C. 

 (= 50° F.) in July — that is to say, about 67° N. latitude; so 

 that it scarcely passes the polar circle, whilst then it reached 

 the pole itself. 



This fact alone indicates that the climate was very different. 



