* 
ON THE MIOCENE FLORA OF NORTH GREENLAND. 313 
the extreme northern limit of their growth. This may have been the 
case with some of the species ; others, however, extended much farther 
north, for in the Miocene flora of Spitzbergen, lat. 78? N., we find the 
Beech, Plane, Hazelnut, and some other species, identical with those 
from Greenland. For the opportunity of examining these species, I 
am indebted to Professor Nordenskiold. At the present time the Firs 
and Poplars reach to alatitude 15? above the artifieial limit of the 
Plane, and 10? above that of the Beech. Accordingly, we may con- 
clude that the Firs and Poplars which we meet at Atanekerdluk and at 
Bell Sound, Spitzbergen, must have reached up to the North Pole, in 
so far forth as there was land there in the Tertiary period. The hills 
of fossilized wood found by M‘Clure and his companions in Banks's 
Land (lat. 74° 27' N.) are therefore discoveries which should not 
astonish us; they only confirm the evidence as to the original vegeta- 
tion of the Polar regions which we have derived from other sources. 
The Professor then proceeds to say that the whole course of reasoning 
which led him to the conclusion that the Miocene temperature_of 
Greenland was 16° C. higher than its present one, was too long to be 
included in a paper like the present one; it would be fully developed 
in his work * On the Fossil Flora of the Polar Regions," which wi 
contain descriptions and plates of the plants discovered in North 
Greenland, Melville Island, Banks's Land, Mackenzie River, Iceland, 
and Spitzbergen, and which he hopes to publish at an early date. 
He then selects Sequoia Langsdorfi, the most abundant of the trees 
at Atanekerdluk, and proceeds to investigate the conclusions as to cli- 
mate deducible from the fact of its existence in Greenland. Sequoia 
sempervirens, Lamb. (red-wood), is its present representative, and re- 
sembles it so closely that we may consider S. sempervirens to be the 
direct descendant of S. Langsdorfi. This tree is cultivated in most of 
the botanical gardens of Europe, and its extreme northern limit may 
be placed at lat. 53? N. For its existence it requires a summer 
temperature of 15° or 16° C. Its fruit requires a temperature of 18° C. 
for ripening. The winter temperature must not fall below —1 3°, and 
that of the whole year must be at least 9°5° C. Accordingly we may 
consider the isothermal of 9:5? C. as the northern temperature of the 
Sequoia Langsdorfi, and 9°5° C. as the absolute minimum of tempera- 
ture under which the vegetation of Atanekerdluk could have existed 
there. 
