PART I. THE DESCENT OR ORIGIN OF MAN.
CHAPTER I.
THE EVIDENCE OF THE DESCENT OF MAN FROM SOME LOWER FORM.
Nature of the evidence bearing on the origin of man—Homologous structures
in man and the lower animals—Miscellaneous points of
correspondence—Development—Rudimentary structures, muscles,
sense-organs, hair, bones, reproductive organs, etc.—The bearing of these
three great classes of facts on the origin of man.
CHAPTER II.
ON THE MANNER OF DEVELOPMENT OF MAN FROM SOME LOWER FORM.
Variability of body and mind in man—Inheritance—Causes of
variability—Laws of variation the same in man as in the lower
animals—Direct action of the conditions of life—Effects of the
increased use and disuse of parts—Arrested
development—Reversion—Correlated variation—Rate of
increase—Checks to increase—Natural selection—Man the most
dominant animal in the world—Importance of his corporeal
structure—The causes which have led to his becoming
erect—Consequent changes of structure—Decrease in size of the
canine teeth—Increased size and altered shape of the
skull—Nakedness —Absence of a tail—Defenceless condition of
man.
CHAPTER III.
COMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS.
The difference in mental power between the highest ape and the lowest savage,
immense—Certain instincts in common—The
emotions—Curiosity—Imitation—Attention—Memory—
Imagination—Reason—Progressive improvement —Tools and weapons
used by animals—Abstraction,
Self-consciousness—Language—Sense of beauty—Belief in God,
spiritual agencies, superstitions.
CHAPTER IV.
COMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS, continued.
The moral sense—Fundamental proposition—The qualities of social
animals—Origin of sociability—Struggle between opposed
instincts—Man a social animal—The more enduring social instincts
conquer other less persistent instincts—The social virtues alone regarded
by savages—The self-regarding virtues acquired at a later stage of
development—The importance of the judgment of the members of the same
community on conduct—Transmission of moral tendencies—Summary.
CHAPTER V.
ON THE DEVELOPMENT OF THE INTELLECTUAL AND MORAL FACULTIES DURING PRIMEVAL AND CIVILISED TIMES.
Advancement of the intellectual powers through natural
selection—Importance of imitation—Social and moral
faculties—Their development within the limits of the same
tribe—Natural selection as affecting civilised nations—Evidence
that civilised nations were once barbarous.
CHAPTER VI.
ON THE AFFINITIES AND GENEALOGY OF MAN.
Position of man in the animal series—The natural system
genealogical—Adaptive characters of slight value—Various small
points of resemblance between man and the Quadrumana—Rank of man in the
natural system—Birthplace and antiquity of man—Absence of fossil
connecting-links—Lower stages in the genealogy of man, as inferred
firstly from his affinities and secondly from his structure—Early
androgynous condition of the Vertebrata —Conclusion.
CHAPTER VII.
ON THE RACES OF MAN.
The nature and value of specific characters—Application to the races of
man—Arguments in favour of, and opposed to, ranking the so-called races
of man as distinct species—Sub-species—Monogenists and
polygenists—Convergence of character—Numerous points of resemblance
in body and mind between the most distinct races of man—The state of man
when he first spread over the earth—Each race not descended from a single
pair—The extinction of races—The formation of races—The
effects of crossing—Slight influence of the direct action of the
conditions of life—Slight or no influence of natural
selection—Sexual selection.
CHAPTER VIII.
PRINCIPLES OF SEXUAL SELECTION.
Secondary sexual characters—Sexual selection—Manner of
action—Excess of males—Polygamy—The male alone generally
modified through sexual selection—Eagerness of the male—Variability
of the male—Choice exerted by the female—Sexual compared with
natural selection—Inheritance at corresponding periods of life, at
corresponding seasons of the year, and as limited by sex—Relations
between the several forms of inheritance—Causes why one sex and the young
are not modified through sexual selection—Supplement on the proportional
numbers of the two sexes throughout the animal kingdom—The proportion of
the sexes in relation to natural selection.
CHAPTER IX.
SECONDARY SEXUAL CHARACTERS IN THE LOWER CLASSES OF THE ANIMAL KINGDOM.
These characters are absent in the lowest classes—Brilliant
colours—Mollusca—Annelids—Crustacea, secondary sexual
characters strongly developed; dimorphism; colour; characters not acquired
before maturity—Spiders, sexual colours of; stridulation by the
males—Myriapoda.
CHAPTER X.
SECONDARY SEXUAL CHARACTERS OF INSECTS.
Diversified structures possessed by the males for seizing the
females—Differences between the sexes, of which the meaning is not
understood—Difference in size between the
sexes—Thysanura—Diptera—Hemiptera—Homoptera, musical
powers possessed by the males alone—Orthoptera, musical instruments of
the males, much diversified in structure; pugnacity; colours—Neuroptera,
sexual differences in colour—Hymenoptera, pugnacity and
odours—Coleoptera, colours; furnished with great horns, apparently as an
ornament; battles; stridulating organs generally common to both sexes.
CHAPTER XI.
INSECTS, continued. ORDER LEPIDOPTERA. (BUTTERFLIES AND MOTHS.)
Courtship of Butterflies—Battles—Ticking noise—Colours common
to both sexes, or more brilliant in the males—Examples—Not due to
the direct action of the conditions of life—Colours adapted for
protection—Colours of moths—Display—Perceptive powers of the
Lepidoptera—Variability—Causes of the difference in colour between
the males and females—Mimicry, female butterflies more brilliantly
coloured than the males—Bright colours of caterpillars—Summary and
concluding remarks on the secondary sexual character of insects—Birds and
insects compared.
CHAPTER XII.
SECONDARY SEXUAL CHARACTERS OF FISHES, AMPHIBIANS, AND REPTILES.
Fishes: Courtship and battles of the males—Larger size of the
females—Males, bright colours and ornamental appendages; other strange
characters—Colours and appendages acquired by the males during the
breeding-season alone—Fishes with both sexes brilliantly
coloured—Protective colours—The less conspicuous colours of the
female cannot be accounted for on the principle of protection—Male fishes
building nests, and taking charge of the ova and young. AMPHIBIANS: Differences
in structure and colour between the sexes—Vocal organs. REPTILES:
Chelonians—Crocodiles—Snakes, colours in some cases
protective—Lizards, battles of—Ornamental appendages—Strange
differences in structure between the sexes—Colours—Sexual
differences almost as great as with birds.
CHAPTER XIII.
SECONDARY SEXUAL CHARACTERS OF BIRDS.
Sexual differences—Law of battle—Special weapons—Vocal
organs—Instrumental music—Love-antics and dances—Decorations,
permanent and seasonal—Double and single annual moults—Display of
ornaments by the males.
CHAPTER XIV.
BIRDS—continued.
Choice exerted by the female—Length of courtship—Unpaired
birds—Mental qualities and taste for the beautiful—Preference or
antipathy shewn by the female for particular males—Variability of
birds—Variations sometimes abrupt—Laws of variation—Formation
of ocelli—Gradations of character—Case of Peacock, Argus pheasant,
and Urosticte.
CHAPTER XV.
BIRDS—continued.
Discussion as to why the males alone of some species, and both sexes of others
are brightly coloured—On sexually-limited inheritance, as applied to
various structures and to brightly-coloured plumage—Nidification in
relation to colour—Loss of nuptial plumage during the winter.
CHAPTER XVI.
BIRDS—concluded.
The immature plumage in relation to the character of the plumage in both sexes
when adult—Six classes of cases—Sexual differences between the
males of closely-allied or representative species—The female assuming the
characters of the male—Plumage of the young in relation to the summer and
winter plumage of the adults—On the increase of beauty in the birds of
the world—Protective colouring—Conspicuously coloured
birds—Novelty appreciated—Summary of the four chapters on birds.
CHAPTER XVII.
SECONDARY SEXUAL CHARACTERS OF MAMMALS.
The law of battle—Special weapons, confined to the males—Cause of
absence of weapons in the female—Weapons common to both sexes, yet
primarily acquired by the male—Other uses of such weapons—Their
high importance—Greater size of the male—Means of defence—On
the preference shewn by either sex in the pairing of quadrupeds.
CHAPTER XVIII.
SECONDARY SEXUAL CHARACTERS OF MAMMALS, continued.
Voice—Remarkable sexual peculiarities in
seals—Odour—Development of the hair—Colour of the hair and
skin—Anomalous case of the female being more ornamented than the
male—Colour and ornaments due to sexual selection—Colour acquired
for the sake of protection—Colour, though common to both sexes, often due
to sexual selection—On the disappearance of spots and stripes in adult
quadrupeds—On the colours and ornaments of the Quadrumana—Summary.
PART III. SEXUAL SELECTION IN RELATION TO MAN, AND CONCLUSION.
CHAPTER XIX.
SECONDARY SEXUAL CHARACTERS OF MAN.
Differences between man and woman—Causes of such differences, and of
certain characters common to both sexes—Law of battle—Differences
in mental powers, and voice—On the influence of beauty in determining the
marriages of mankind—Attention paid by savages to ornaments—Their
ideas of beauty in women—The tendency to exaggerate each natural
peculiarity.
CHAPTER XX.
SECONDARY SEXUAL CHARACTERS OF MAN, continued.
On the effects of the continued selection of women according to a different
standard of beauty in each race—On the causes which interfere with sexual
selection in civilised and savage nations—Conditions favourable to sexual
selection during primeval times—On the manner of action of sexual
selection with mankind—On the women in savage tribes having some power to
choose their husbands—Absence of hair on the body, and development of the
beard—Colour of the skin—Summary.
CHAPTER XXI.
GENERAL A SUMMARY AND CONCLUSION.
Main conclusion that man is descended from some lower form—Manner of
development—Genealogy of man—Intellectual and moral
faculties—Sexual selection—Concluding remarks.