SELECTION IN RELATION TO SEX.

By CHARLES DARWIN, M.A., F.R.S., &c.

IN TWO VOLUMES.—Vol. I.

WITH ILLUSTRATIONS.

LONDON:
JOHN MURRAY, ALBEMARLE STREET.
1871.

[The right of Translation is reserved.]

BY THE SAME AUTHOR.

ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION; or, The Preservation of Favoured Races in the Struggle for Life; Fifth Edition (Tenth Thousand), with Additions and Corrections. 1869. Murray.

THE VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION. In two vols. With Illustrations. 1868. Murray.

ON THE VARIOUS CONTRIVANCES by which BRITISH AND FOREIGN ORCHIDS ARE FERTILISED BY INSECTS; and on the Good Effects of Crossing. With numerous Woodcuts. Murray.

A NATURALIST‘S VOYAGE ROUND THE WORLD; or, A Journal of Researches into the Natural History and Geology of the Countries visited during the voyage of H.M.S. ‘Beagle,’ under the command of Captain FitzRoy, R.N. Eleventh Thousand. Murray.

ON THE STRUCTURE AND DISTRIBUTION OF CORAL REEFS. Smith, Elder, & Co.

GEOLOGICAL OBSERVATIONS ON VOLCANIC ISLANDS. Smith, Elder, & Co.

GEOLOGICAL OBSERVATIONS ON SOUTH AMERICA. Smith, Elder & Co.

A MONOGRAPH OF THE CIRRIPEDIA. With numerous Illustrations. 2 vols. 8vo. Hardwicke.

ON THE MOVEMENTS AND HABITS OF CLIMBING PLANTS. With Woodcuts. Williams & Norgate.

LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET, AND CHARING CROSS.

CONTENTS.

Introduction	Page [1-5]
PART I.
ON THE DESCENT OF MAN
CHAPTER I.
The Evidence of the Descent of man from someLower form.
Nature of the evidence bearing on the origin of man—Homologousstructures in man and the lower animals—Miscellaneous pointsof correspondence—Development—Rudimentary structures,muscles, sense-organs, hair, bones, reproductive organs, &c.—Thebearing of these three great classes of facts on the origin ofman	[9-33]
CHAPTER II.
Comparison of the Mental Powers of Man and theLower Animals.
The difference in mental power between the highest ape and thelowest savage, immense—Certain instincts in common—Theemotions—Curiosity—Imitation—Attention—Memory—Imagination—Reason—Progressiveimprovement—Tools andweapons used by animals—Language—Self-consciousness—Senseof beauty—Belief in God, spiritual agencies, superstitions	[34-69]
CHAPTER III.
Comparison of the Mental Powers of Man and theLower Animals—continued.
The difference in mental power between the highest ape and thelowest savage, immense—Certain instincts in common—Theemotions—Curiosity—Imitation—Attention—Memory—Imagination—Reason—Progressiveimprovement—Tools andweapons used by animals—Language—Self-consciousness—Senseof beauty—Belief in God, spiritual agencies, superstitions	[70-106]
CHAPTER IV.
On the Manner of Development of Man from someLower Form.
Variability of body and mind in man—Inheritance—Causes ofvariability—Laws of variation the same in man as in the loweranimals—Direct action of the conditions of life—Effects of theincreased use and disuse of parts—Arrested development—Reversion—Correlatedvariation—Rate of increase—Checks toincrease—Natural selection—Man the most dominant animalin the world—Importance of his corporeal structure—Thecauses which have led to his becoming erect—Consequent changesof structure—Decrease in size of the canine teeth—Increasedsize and altered shape of the skull—Nakedness—Absence ofa tail—Defenceless condition of man	[107-157]
CHAPTER V.
On the Development of the Intellectual and MoralFaculties during Primeval and Civilised Times.
The advancement of the intellectual powers through natural selection—Importanceof imitation—Social and moral faculties—Theirdevelopment within the limits of the same tribe—Naturalselection as affecting civilised nations—Evidence that civilisednations were once barbarous	[158-184]
CHAPTER VI.
On the Affinities and Genealogy of Man.
Position of man in the animal series—The natural system genealogical—Adaptivecharacters of slight value—Various smallpoints of resemblance between man and the Quadrumana—Rankof man in the natural system—Birthplace and antiquityof man—Absence of fossil connecting-links—Lower stages inthe genealogy of man, as inferred, firstly from his affinities andsecondly from his structure—Early androgynous condition ofthe Vertebrata—Conclusion	[185-213]
CHAPTER VII.
On the Races of Man.
The nature and value of specific characters—Application to the racesof man—Arguments in favour of, and opposed to, ranking theso-called races of man as distinct species—Sub-species—Monogenistsand polygenists—Convergence of character—Numerouspoints of resemblance in body and mind between the most distinctraces of man—The state of man when he first spread over theearth—Each race not descended from a single pair—The extinctionof races—The formation of races—The effects of crossing—Slightinfluence of the direct action of the conditions of life—Slightor no influence of natural selection—Sexual selection.	[214-250]

PART II. SEXUAL SELECTION.
CHAPTER VIII.
Principles of Sexual Selection.
Secondary sexual characters—Sexual selection—Manner of action—Excessof males—Polygamy—The male alone generallymodified through sexual selection—Eagerness of the male—Variabilityof the male—Choice exerted by the female—Sexualcompared with natural selection—Inheritance at correspondingperiods of life, at corresponding seasons of the year, and as limitedby sex—Relations between the several forms of inheritance—Causeswhy one sex and the young are not modified throughsexual selection—Supplement on the proportional numbers ofthe two sexes throughout the animal kingdom—On the limitationof the numbers of the two sexes through natural selection	[253-320]
CHAPTER IX.
Secondary Sexual Characters in the Lower Classes ofthe Animal Kingdom.
These characters absent in the lowest classes—Brilliant colours—Mollusca—Annelids—Crustacea,secondary sexual charactersstrongly developed; dimorphism; colour; characters not acquiredbefore maturity—Spiders, sexual colours of; stridulation by themales—Myriapoda	[321-340]
CHAPTER X.
Secondary Sexual Characters of Insects.
Diversified structures possessed by the males for seizing the females—Differencesbetween the sexes, of which the meaning is notunderstood—Difference in size between the sexes—Thysanura—Diptera—Hemiptera—Homoptera,musical powers possessedby the males alone—Orthoptera, musical instruments of themales, much diversified in structure; pugnacity; colours—Neuroptera,sexual differences in colour—Hymenoptera, pugnacityand colours—Coleoptera, colours; furnished with greathorns, apparently as an ornament; battles; stridulating organsgenerally common to both sexes	[341-385]
CHAPTER XI.
Insects, continued.—Order Lepidoptera.
Courtship of butterflies—Battles—Ticking noise—Colours commonto both sexes, or more brilliant in the males—Examples—Notdue to the direct action of the conditions of life—Coloursadapted for protection—Colours of moths—Display—Perceptivepowers of the Lepidoptera—Variability—Causes of thedifference in colour between the males and females—Mimickry,female butterflies more brilliantly coloured than the males—Brightcolours of caterpillars—Summary and concluding remarkson the secondary sexual characters of insects—Birdsand insects compared	[386-423]