AMONG GLACIERS RECENT AND EXTINCT. 
177 
by ice. Then when we extend our observations to our own 
-country, it wonderfully increases our interest on a tour in North 
Wales, or Scotland, or among the green hills of Ireland, to 
mark the signs of vanished glaciers in vales around Snowdon, 
nr Ben Nevis, or by the Lakes of Killarney. I have gathered 
Alpine flowers from a roche moutonee , or clustering beneath a 
bloc perche, by the waters of Liya Lydaw (Snowdon), or the 
summit of Macgillicuddy’s Reeks, or away among the deer 
forests of Sutherland or Ross. Six glaciers once flowed from 
the mountains of Snowdon down the valleys. The ice has 
vanished, but the evidence of its former existence still lingers, 
and few things are pleasanter during a summer’s ramble than 
to trace the old glacier relics to their sources among the wild 
valleys of wild Wales. But all these proofs of the existence 
of Frost action and Ice action , where now there is none, take us 
back to the Glacial Epoch, during a portion of which epoch 
the great glaciers I have alluded to filled the valleys of Switzer- 
land and Italy, and great erratic masses of rock were carried 
by land ice, and other erratics were borne by floating icebergs 
over the seas which then washed over large parts of Europe 
and North America. So intense was the cold during a portion 
of the Glacial Epoch that Scotland and North Wales were 
wrapped in ice as Greenland is now, while the ice covered every 
hill and valley under one continuous field of ice. Again, we 
learn that during this epoch there were great changes in the 
level of land and sea ; and that it was during the submergence 
of large areas in Europe and America that great angular 
fragments of rocks were transported by icebergs far from 
1 the parent rocks to which they belong, and were deposited over 
wide areas of what now is dry land upraised from those glacial 
| -seas. 
Such is the history of the ice-borne boulders which overlie 
the submerged forest of Cromer on the coast of Norfolk. They 
are wanderers from the rocks of Norway and Sweden, embedded 
in marine boulder clay ; for there are associated with them 
marine shells which lived and died on the sea-bed where the 
, erratics were stranded on the melting of the ice which bore 
them over the seas. The species of shells, too, testify of the 
cold climate which affected the seas as well as the land, when 
icebergs floated down to the latitude of the Norfolk shores. 
The “Forest-bed ” itself is an ancient land surface on which, long 
, ages ago (Pliocene or Preglacial times), there grew large forests 
which swept over what is now the German Ocean. And these 
f forest lands were inhabited by great quadrupeds — elephants, 
j hippopotami, and rhinoceri — whose remains are found in large 
quantities in old lake sites of that period, associated with plants 
and fresh-water shells. These animals belonged to a southern 
VOL. XV. — NO. LIX. N 
