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
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CHAPTER XXXVII.

Laws which regulate the geographical distribution of species—Distinct provinces of peculiar species of plants—Their mode of diffusion

CHAPTER XXXVIII.

Distinct provinces of peculiar species of animals—Distribution and dispersion of quadrupeds, birds, and reptiles

CHAPTER XXXIX.

Geographical distribution and migrations of fish—Of testacea—Of zoophytes—Of insects—Geographical distribution and diffusion of the human race

CHAPTER XL.

Theories respecting the original introduction of species—Reciprocal influence of species on each other

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
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CHAPTER XLIII.

Creation of species—Whether the loss of certain animals and plants is compensated by the introduction of new species

CHAPTER XLIV.

Modifications in physical geography caused by organic beings

CHAPTER XLV.

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

CHAPTER XLVI.

Imbedding of the same in alluvial deposits and in caves

CHAPTER XLVII.

Imbedding of organic remains in aqueous deposits—Terrestrial plants—Insects, reptiles, birds, quadrupeds

CHAPTER XLVIII.

Imbedding of the remains of man and his works

CHAPTER XLIX.

Imbedding of aquatic animals and plants, both freshwater and marine, in aqueous deposits

CHAPTER L.

Formation of coral reefs