big 
a 
‘ 
# 
upon it, its temperature cannot be raised above the freezing-point 
comes filled with fog, and this keeps off the sun-heat, and then 
snow falls even during summer, and the stored-up cold does not 
the adjacent ice. It follows that; towards the equatorial limits 
For'the past nineteen years I have been maintaining that, 
when a country ig covered with ice, it becomes a permanent 
all along maintained this to have been one of the chief causes” 
Which led to the country being so deeply covered with ice. 
Ih fact, had it not been for some such conservative, power In 
the - a glacial epoch resulting from the causes which I have 
na 
ll next consider Geological and Paleontological facts 
é - a 
40 relation to Mr. Wallace’s modification. 
~ AM. Jour, Sor.—Tairp Series, VoL. XXVII, No. 160.—ApRu, 1884. 
19 
