CONTENTS

CHAPTER I

WHAT WE OWE TO DARWIN

Biographical-Darwin's Books-The Naturalist's Problems-The

first Question: What is This ?-The second Question: How does

This work ?—The third Question: Whence is This ?-The fourth

Question: How have Present-day Organisms come to be as they

are ?-Manifoldness of Darwin's Services-The Web of Life-The

Struggle for Existence-Variability of Living Creatures-Natural

Selection-Vindication of the Evolution Idea-The Evolution

Theory, a Modal Interpretation-Darwin's Argument-Comparison

of Evolution Formula and Gravitation Formula-The Descent and

the Ascent of Man-Liberation of Intelligence-Ideal of Scientific

Mood and Method-Characteristics of Scientific Mood: Passion and

Reverence for Facts-Scientific Caution-Clearness of Vision-

Sense of Interrelations-Darwin's Method of Working-Darwin on

his own Success—Darwin's Achievements-Co-operating Influences

-Particular Reasons for Darwin's Success

pp. 3-42

CHAPTER II

THE WEB OF LIFE

Correlation of Organisms as well as Correlation of Organs-What

the Metaphor of "The Web of Life" suggests-Dependence of Living

Creatures upon their Surroundings-Nutritive Chains-Nexus

between Mud and Clear Thinking-Correlation between Catches of

Mackerel and Amount of Spring Sunshine-Nutritive Chains in the

Deep Sea-Dependence of one Organism on another for the Con-

tinuance of the Species-Darwin's Instance of the Connection

between Cats and Clover-Scattering of Seeds-Interrelations

between Freshwater Mussels and Fishes-Life-histories of Parasites

-Far-reaching Influence of Certain Animals: Earthworms-Ter-

mites, or White Ants-The Hand of Life upon the Earth-Practical

Importance of a Realisation of the Web of Life.

• pp. 45-65

CHAPTER III

THE STRUGGLE FOR EXISTENCE

The Idea not so Simple as it seems-The Anthropomorphism of

the Idea-Different Forms of the Struggle for Existence-Struggle

for Existence in the Plant World-Illustration of the Complexity

of the Struggle for Existence-Reasons for the Struggle for Existence

-Results of the Struggle for Existence-Breadth of the Darwinian

Concept of the Struggle for Existence-The other Side of the

Struggle for Existence-Mutual Aid-Application of the Concept

to Human Life

pp. 69-94

CHAPTER IV

THE RAW MATERIALS OF PROGRESS

Organic Progress Primarily depends on Variability-Darwin's

Position-Progress since Darwin's Day in Regard to Variation—

Variations more Abundant than even Darwin supposed-Proportion

between Frequency and Amount of Variations-Correlation of

Variations—Brusque Variations more Frequent than was formerly

supposed-Discontinuous Variations—Mutations-Darwin's Posi-

tion in Regard to Mutations-Origin of Variations-Germinal

Selection-Variational Stimuli-Modifications or Acquired Charac-

ters-Indirect Importance of Modifications-Modification-Species-

Individual Plasticity-Relation to Human Life

pp. 97-120

CHAPTER V

FACTS OF INHERITANCE

Progress during the Darwinian Era-Demonstration of Heritable

Qualities-Heredity, a Term for the Genetic Relation between

Successive Generations-Appreciation of Distinction between

Nature and Nurture—The Idea of the Continuity of Generations—

Critical Attitude in Regard to Various Conclusions-Mendelism—

Methods of Studying Heredity-Microscopical Study of the Germ-

cells-Statistical Study: Filial Regression-Galton's Law of

Ancestral Inheritance-Experimental Study-Pairing of Similar

Pure-bred Forms-Blending-Particulate Inheritance-Exclusive

Inheritance-Reversion-New Departures-Mendelian Inheritance

-Unit Characters-The Case of Andalusian Fowls-Waltzing Mice

-Occurrence of Mendelian Inheritance-Practical Importance of

Mendelism-Much Progress but Great Uncertainty-Transmission

of Acquired Characters-Disease-Facts and Possibilities-A

Striking Case-Logical Position of the Question-Cases where

the Theory of Modification-inheritance is Inapplicable-Im-

portance of Environment and Function Remains-Selection and

Stimulus-Indirect Importance of Modifications-Practical Im-

port of the Question as to the Transmission of Acquired

Characters-Inheritance of Moral Character-Three General

Conclusions

pp. 129-177

CHAPTER VI

SELECTION ORGANIC AND SOCIAL

Influence of Malthus-Darwin's Position-The Theory stated-

The Theory of Natural Selection to be tested as an Interpretative

Formula-Illustrations of Natural Selection-Objections and

Criticisms-Adaptations-Changes since Darwin's Day-Evidences

of Natural Selection-Lessening the Burden of the Theory-Sexual

Selection-Isolation-Gradual Diminution of Natural Selection in

Mankind-Contrast between the Human Race and the Animal

World-Some Natural Selection persists in Mankind-The Dilemma

of Civilisation-The extreme laissez-faire Position-Social Surgery

-Is Social Selection compensating for Diminished Natural Selec-

tion ?-Reversed Selection in Human Society-Practical Considera-

tions-Summary of the General Argument in regard to Human

Selection-Constructive Suggestions-Selection of Eutopias

Selection of Healthful Occupations-Eugenic Selection

pp. 181-249

REPRESENTATIVE BOOKS ON DARWINISM. pp. 253-258

III. NUTRITIVE CHAINS: MACKEREL, COPEPODS, IN

IV. INTER-RELATIONS: CATS, VOLES, HUMBLE-BEES,
PURPLE CLOVER .

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