near Naples 493

CHAPTER XXX.
Elevation and subsidence of land in regions free from
volcanoes and earthquakes--Rising of land in Sweden 519

CHAPTERS XXXI. XXXII.
Causes of earthquakes and volcanoes--Theory of central
fluidity of the earth--Chemical theory of volcanoes--Causes
of permanent upheaval and depression of land 533, 545

BOOK III. (CHAPTERS XXXIII to L.)

OBSERVED CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS; FIRST,
NATURE AND GEOGRAPHICAL DISTRIBUTION OF SPECIES, AND THEORIES
RESPECTING THEIR CREATION AND EXTINCTION; SECONDLY, THE
INFLUENCE OF ORGANIC BEINGS IN MODIFYING PHYSICAL GEOGRAPHY;
THIRDLY, THE LAWS ACCORDING TO WHICH THEY ARE IMBEDDED IN
VOLCANIC, FRESHWATER, AND MARINE DEPOSITS.

CHAPTERS XXXIII. XXXIV. XXXV. XXXVI.
Whether species have a real existence in nature--Theory
of transmutation of species--Variability of
species--Phenomena of hybrids in animals and
plants 566, 578, 591, 600

CHAPTER XXXVII.
Laws which regulate the geographical distribution of
species--Distinct provinces of peculiar species of
plants--Their mode of diffusion 612

CHAPTER XXXVIII.
Distinct provinces of peculiar species of
animals--Distribution and dispersion of
quadrupeds, birds, and reptiles 629

CHAPTER XXXIX.
Geographical distribution and migrations
of fish--Of testacea--Of zoophytes--Of
insects--Geographical distribution and
diffusion of the human race 646

CHAPTER XL.
Theories respecting the original introduction of
species--Reciprocal influence of species on each other 665

CHAPTERS XLI. XLII.
Extinction of species--How every extension of the range
of a species alters the condition of many others--Effect
of changes of climate 677, 689

CHAPTER XLIII.
Creation of species--Whether the loss of certain animals
and plants is compensated by the introduction of
new species 701

CHAPTER XLIV.
Modifications in physical geography caused by organic beings 708

CHAPTER XLV.
Imbedding of organic remains in peat, blown sand,
and volcanic ejections