78 The American Geolovist. Webraary, 
thousands of feet above the narrow sheltered valleys; by the 
presence of glaciers in the fjords of Chile 600 miles south of 
palm groves; by the perpetual snows of the Himalayas 15,000 
or 20,000 feet above the hot Indian plains and two or three 
hundred miles north of them; and by the forest growth of the 
Malaspina glacier in Alaska. 
It will be noticed that all these instances are of glaciers of 
the Alpine type except the last. No one disputes that the nar- 
row tongues of Alpine glaciers can descend even thousands of 
feet below snow line into a temperate climate, so long as there 
is a sufficient snowfield on the mountains to keep up the ice 
flow ; but how long would they last if spread out on a compara- 
tively level surface near Cleveland, Ohio? The case of the 
Malaspina glacier is more to the point, since it is a piedmont 
glacier spreading out somewhat widely near sea level; but here, 
too, the supply of ice is furnished by the highest mountains 
in North America with a snow line only 3,000 or 4,000 feet 
above the sea. It is doubtful if the Alaskan piedmont glaciers 
would survive a century if there were no mountains behind 
them. In comparing the conditions at Malaspina with those 
of interglacial eastern America it must be remembered also 
that the luxuriance of the Alaskan forest is due to the moisture 
and not to the warmth of the climate. The forest is subarctic, 
not warm temperate. That mountain-fed glacier ice can sub- 
sist close to a tangle of cedars and spruces along the chill and 
rainy north Pacific does not prove that an ice sheet not nour- 
ished by high lands could maintain itself beside forests of oak, 
maples, elms, hickories, pawpaws and Osage oranges. 
There is no example in the world of a wide expanse of 
snowfields and glacier ice in the immediate neighborhood of 
even a cold temperate forest growth without highlands behind 
to supply the waste from thawing; and if this is true of the 
moist cool shores of Alaska, how much more improbable is it 
that glacier ice spread out on a plain thousands of feet below 
snow line and exposed to the strong dry heat of a Pennsylvan- 
ia summer should long survive. 
It must be remembered that such a climate existed for 
hundreds of years to the north of Toronto, as proved by the 
annual rings of the forest trees, and that Toronto is only 500 
miles south of Hudson bay and 700 miles southeast of the cen- 
