182 
ISLAND LIFE. 
[part I. 
repeated alternation of warm and glacial climates between the 
present time and the earliest geological ages .” 1 And again, in 
his Sketch of the Geology of Spitsbergen, after describing the 
various formations down to the Miocene, he says : “All the 
fossils found in the foregoing strata show that Spitzbergen, dur- 
ing former geological ages, enjoyed a magnificent climate, which 
indeed was somewhat colder during the Miocene period, but 
was still favourable for an extraordinarily abundant vegetation, 
much more luxuriant than that which now occurs even in 
the southern part of Scandinavia ; and I have in these strata 
sought in vain for any sign, that, as some geologists have of late 
endeavoured to render probable, these favourable climatic con- 
ditions have been broken off by intervals of ancient glacial 
periods. The profiles I have had the opportunity to examine 
during my various Spitzbergen expeditions would certainly, if 
laid down on a line, occupy an extent of a thousand English 
miles; and if any former glacial period had existed in this 
region, there ought to have been some trace to be observed of 
erratic blocks, or other formations which distinguish glacial 
action. But this has not been the case. In the strata, whose 
length I have reckoned alone, I have not found a single 
fragment of a foreign rock so large as a child’s head .” 2 
Now it is quite impossible to ignore or evade the force of 
this testimony as to the continuous warm climates of the north 
temperate and polar zones throughout Tertiary times. The 
evidence extends over a vast area, both in space and time, 
it is derived from the work of the most competent living 
geologists, and it is absolutely consistent in its general tendency. 
We have in the Lower Cretaceous period an almost tropical 
climate in France and England, a somewhat lower temperature 
in the United States, and a mild insular climate in the Arctic 
regions. In each successive period the climate becomes some- 
what less tropical ; but down to the Upper Miocene it remains 
warm temperate in Central Europe, and cold temperate within 
the polar area, with not a trace of any intervening periods of 
Arctic cold. It then gradually cools down and merges through 
1 Geological Magazine , 1875, p. 531. 
2 Geological Magazine, 1876, p. 266. 
