64 Prof. O. Heer on the Miocene Flora 
nolia with coriaceous leaves (M. Inglefieldi), and a Plum (Pru- 
nus Scotti’) ; 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 Laurinee ; four others (Macclintockia and Hahea) 
are probably Proteacee. 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 MacQuarrti) which was diffused 
through all the polar regions, and occurred in Spitzbergen at 
78° N. latitude, as also a species of Alder (Alnus Kefersteinit). 
From Greenland we have species of Rhamnus, Paliurus, Cor- 
nus, Ilex, Crategus, Andromeda, and Myrica, which ascend to 
70° N. latitude. Sarmentose plants were not wanting ; a species 
of Ivy (Hedera MacClurii) 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 thesé 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 meee the pole, or at least the 
lands nearest to 1t; for they advance at present 15° further to 
the north than the Planes. It is a natural conclusion from 
this, that the extreme limit of trees then followed a line ve 
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. 
