Fae OT Rae ey eee NE eT a a ye a 
- from the bud and still fo 
of the Polar Regions, 65 
We may add other proofs to confirm our assertion. From the 
character of the flora of Spitzbergen at the Miocene period 
we may conclude that under 79° N. latitude the mean tempe- 
rature of the year was 5° C. (= 41° F.); at the same epoch 
that of Switzerland was 21° C. (= 69°8 F.), judging from 
the analogy of floras, There is consequently a difference of 
16° C. (= 28°8 F.); and for each degree of latitude the mean 
temperature has fallen 0°5 C. (= 0°9 F.) From this it fol- 
lows that at Spitzbergen, at 78° N. latitude, the mean was 
5°°5 C. (= 41°'9 F.), in Greenland, at 70°, it was 9°5 C. (= 
49°-1 F.), and in Iceland and on the Mackenzie, in latitude 65°, 
it was 11°55 C. (=52°-7 F.) These data suffice to explain the 
character of the flora of this period *. 
_ The difference of temperature between Switzerland, in N. 
lat. 47° (brought by calculation to that of the sea-level), and 
_ Spitzbergen, in N. lat. 78°, is at present 20°°6 C. (=37°-08 F.), 
which gives a diminution of 0°66 C. (=1°2 F.) for each 
degree of latitude. It is therefore evident that at the Miocene 
epoch the temperature was much more uniform, and that the 
mean heat diminished much more gradually in proportion as 
the pole was approached, so that then the isothermal line of 
0° (=32° F.) fell upon the pole, whilst now it is situated 
under 58° N. 
It has been asserted that at the Miocene epoch currents 
might transport wood and vegetable remains to great distances, 
as is the case now, and that it is very-possible that the plants 
which we find in the fossil state in the deposits of the polar 
regions may have been carried there in an analogous manner, 
and may not have lived on the soil where we find their 
remains. ‘This notion cannot be admitted, as will be easily 
seen if we consider :—1, the perfect preservation of the 
leaves; 2, the enormous accumulation of fossil plants in the 
beds of siderolitic iron-ore in Greenland, associated with great 
deposits of lignites; 3, the fact that insects are found with 
the plants; and, 4, the _ of beech-leaves just issued 
ded, as well as that of flowers, seeds, 
and fruits associated with the leaves. Certain seeds are found 
arranged in the same manner as in the berry which protected 
them ; this evidently indicates that the berry itself was buried 
in the mud. Now it is clear that a berry could not be carried 
by the waves to great distances. 
Whoever will examine, without preconceived ideas, the 
* For further details upon this subject consult the ‘ Flore fossile des 
Régions polaires,’ by Prof. O. Heer (Zurich, 1867), in which all the 
lants of the Miocene epoch discovered in these countries are described 
and figured. ~ 
Ann. & Mag. N. Hist. Ser.4. Vol. i. 5 
