Physical Theory of Secular Changes in Climate. 91 
Lyell maintained that it would only do so when geographical 
conditions were favorable” (p. 186). Here we have a complete 
misapprehension of the relation between Sir Charles Lyell’s 
views and mine; for I would certainly maintain (and, I pre- 
sume, Dr. Geikie also) as emphatically as Sir Charles could do, 
“that it would only do so when geographical conditions. were 
favorable.” For undoubtedly, according to the theory advo- 
cated in ‘Climate and Time,’ no glacial epoch could result 
without geographical conditions suitable for the operation of 
the physical agencies; and this is virtually what Sir Charles 
maintains. The Glacial epoch resulted during the last period 
of high eccentricity because the geographical conditions suit- 
able for the effective operation of the physical causes then 
existed. 
6. It is assumed in ‘Climate and Time’ that, the general 
distribution of sea and land, and other geographical conditions, 
with the exception of those resulting from oscillations of sea- 
as I knew we had no evidence of the existence of any such 
conditions. Besides, my aim was to account for that epoch 
se. 
Although Mr. Wallace so frequently alludes to the impor- 
fature occasion, I am unable to agree with this conclusion. Professor Geikie, 
however, does not believe that the climatic condition of that period was in any 
way due to this change. 
