ON THE CAUSE OF THE ICE AGE 
15 
Wright * and Mr. Upham, two well-known authorities on 
glacial phenomena expressed the view that the northern lands 
must have been gradually elevated in Pliocene times, be¬ 
coming continuous before the Ice Age. Further particulars 
on this subject are contained in Dr. Spencer’s article f on 
high continental elevation. 
Sir Henry Howorth opposes this view, urging that Green¬ 
land, Scandinavia, and North America were all at a much 
lower level in so-called Glacial times than they are now. If 
this be so, then the epeirogenic theory has no base to stand 
upon. I do not think that Sir Henry Howorth’s J statement 
is applicable to southern Greenland or eastern North America. 
At any rate, it is not contended by anyone that the high level 
condition of these countries persisted during the whole of 
the Ice Age. 
The theory that the Ice Age or Glacial Epoch was brought 
about mainly by the closing of the Arctic Ocean to the influence 
of the Gulf Stream is a very tempting one. The temperature 
of the Atlantic Ocean would under such conditions have been 
higher than it is now, because its heat would not have been 
modified by cold arctic currents, as it is at present. Southern 
Greenland, Iceland, and the lands on both sides of the 
Atlantic should also have had a more favourable climate than 
obtains under existing circumstances, since the warm ocean 
would have had considerable influence upon their climate for 
a certain distance inland. There is evidence, on the European 
side of the Atlantic, that, at a not very distant geological 
period, and presumably at a time when the coasts of France, 
south-west of England and south of Ireland were still united, 
the southern fauna and flora crept steadily northward along 
the ancient shore-line. That this did not take place in very 
recent times is evidenced by the fact that the southern marine 
shore forms of mollusks, crustaceans and other' invertebrates 
have a somewhat discontinuous range on the west coast of 
the British Islands, and do not occur in the English Channel 
or in the southern part of the North Sea. 
* Wright, G. F., and Warren Upham, “ Greenland Icefields ” p. 331. 
t Spencer, J. W., “ High Continental Elevation.” 
t Howorth, H. H., “ Ice or Water,” Vol. I., p. 130. 
