CONTENTS
EXPERIMENTAL  STUDY  OF  EVOLUTION

CHAPTER  I
INTRODUCnON

PAGE

The Experimental Method.........3

CHAPTER II

The Influence of External Conditions in causing Changes in the

Structure of Animals........12

Adaptive Responses      .        .        .        .        .        ,        .        .        .        .12

Non-adaptive Responses       .        ,        .        .        ,        .        .        ,        •      15

Influence of Temperature on the Coloration of Butterflies   .        .      15

Effect 'of Temperature on Caterpillars           .....      24

CHAPTER  III

The Influence of External Conditions in causing Changes in the

Structure of Animals (^Continued)......      29

Experiments on the Influence of the Food Plant   .....      29

The Influence of Light, Electricity, Centrifugal P'orce, Chemical Sub¬
stances, and Oxygen on the Caterpillars and Pupas of Moths and

Butterflies        ...........      37

The Influence of Humidity on the Characters of Moths and Butterflies        38

Experiments with Flatfish      .........      40

Experiments with Crustaceans       ........      40

Changes in Mammals and Birds........      41

CHAPTER  IV
The Inherited Effects of Changes induced by External Factors      43

CHAPTER V

The Inheritance of Acquired Characters......      50

Telegony............      59

Xenia.............      61

Theories of Transmission of Somatic Influences    .        .        .        .        .      61

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