The Evolution of Clwiates.—Ma7ison. 97 
"has in cooling passed from a condition of universal warmth 
"to a more and more frigid state until the present conditions 
"were attained. This is the least tenable of all theories, for it 
"neglected the now evident fact that there had been changes 
"from cold to warmth and back again to cold. However, as it 
"was invented before the existence of glacial periods was sus- 
"pected, it long commanded a general assent and was the 
"opinion that held the ground until near the middle of this 
"century."* 
2. Changes in the Elevation of Land and Consequent Varia- 
tiotis ifi the Distribiitio?i of Land and Water. 
The second theory may be accepted as a local and corre- 
lated phenomenon, but cannot be accepted as a primary 
cause, since glaciation did not depend solely in the same lati- 
tudes upon elevations above sea level: besides the changes of 
temperature in the ocean — although more gradual — were quite 
as marked as those upon the land. Of this upheaval and de- 
pression hypothesis, Dr. Jas. Geikie very properly remarks: 
"It is true that many movements of depression and elevation 
"occurred during the glacial period, but none of these was on 
"the great scale required by this hypothesis. Further, we may 
"admit that a causal connection probably obtained between 
"these movements and glaciation. Elevation, however, did 
"not bring about general glaciation, but the latter was perhaps 
"the cause of depression, for with the disappearance of glacial 
"conditions, the sunken areas rose again. f 
There is, however, an able and earnest school of geol- 
ogists, J the members of which, following the ingenious argu- 
ments and explanations of Sir Charles Lyell and Prof. Jas. D. 
Dana, find a cause for glaciation in the upheavals and depres- 
sions occurring during the Quaternary. 
Submarine Channels as Evidences of Upheaval and De- 
pressiofL In many of the attempts to prove that upheavals 
were the prime cause of glacial conditions, there are facts 
*Shaler & Davis — Glaciers; p-. 70. 
tThe Great Ice Age, p. 790 (Ed. 1894). 
JThe Epeirogenic Theory of the Causes of the Ice Age. — Prof. 
Warren Upham. Glacialists' Magazine, Vol. I, No. 10, May, 1894. 
p. 211, et seq. 
