ility of Continents with
Constant Change of Form--Effect of Continental Changes on the Distribution
of Animals--Changed Distribution Proved by the Extinct Animals of Different
Epochs--Summary of Evidence for the General Permanence of Continents and
Oceans.

_Pages_ 83-105

CHAPTER VII

CHANGES OF CLIMATE WHICH HAVE INFLUENCED THE DISPERSAL OF ORGANISMS: THE
GLACIAL EPOCH

Proofs of the Recent Occurrence of a Glacial Epoch--Moraines--Travelled
Blocks--Glacial Deposits of Scotland: the "Till"--Inferences from the
Glacial Phenomena of Scotland--Glacial Phenomena of North America--Effects
of the Glacial Epoch on Animal Life--Warm and Cold
Periods--Palaeontological Evidence of Alternate Cold and Warm
Periods--Evidence of Interglacial Warm Periods on the Continent and in
North America--Migrations and Extinctions of Organisms Caused by the
Glacial Epoch

_Pages_ 106-124

CHAPTER VIII

THE CAUSES OF GLACIAL EPOCHS

Various Suggested Causes--Astronomical Causes of Changes of
Climate--Difference of Temperature Caused by Varying Distances of the
Sun--Properties of Air and Water, Snow and Ice, in Relation to
Climate--Effects of Snow on Climate--High Land and Great Moisture Essential
to the Initiation of a Glacial Epoch--Perpetual Snow nowhere Exists on
Lowlands--Conditions Determining the Presence or Absence of Perpetual
Snow--Efficiency of Astronomical causes in Producing Glaciation--Action of
Meteorological Causes in Intensifying Glaciation--Summary of Causes of
Glaciation--Effect of Clouds and Fog in Cutting off the Sun's Heat--South
Temperate America as Illustrating the Influence of Astronomical Causes on
Climate--Geographical Changes how far a Cause of Glaciation--Land Acting as
a Barrier to Ocean-currents--The Theory of Interglacial Periods and their
Probable Character--Probable Effect of Winter in _aphelion_ on the Climate
of Britain--The Essential Principle of Climatal Change Restated--Probable
Date of the Last Glacial Epoch--Changes of the Sea-level Dependent on
Glaciation--The Planet Mars as Bearing on the Theory of Excentricity as a
Cause of Glacial Epochs

_Pages_ 125-168

{xiv}

CHAPTER IX

ANCIENT GLACIAL EPOCHS, AND MILD CLIMATES IN THE ARCTIC REGIONS

Mr. Croll's Views on Ancient Glacial Epochs--Effects of Denudation in
Destroying the Evidence of Remote Glacial Epochs--Rise of Sea-level
Connected with Glacial Epochs a Cause of Further Denudation--What Evidence
of Early Glacial Epochs may be Expec