CONTENTS 
EXPERIMENTAL STUDY OF EVOLUTION 
CHAPTER I 
INTRODUCTION 
PAGE 
THE EXPERIMENTAL METHOD . . F . : . . . ‘ 3 
CHAPTER II 
THE INFLUENCE OF EXTERNAL CONDITIONS IN CAUSING CHANGES IN THE 
STRUCTURE OF ANIMALS ; : 7 F ‘ é . 12 
Adaptive Responses. . : : : ‘ ‘ é » 12 
Non-adaptive Responses. . . . . . . » 15 
Influence of Temperature on 1 the Coloration of Butterflies . - 15 
Effect of Temperature on Caterpillars a . 5 . - 24 
CHAPTER III 
THE INFLUENCE OF EXTERNAL CONDITIONS IN CAUSING CHANGES IN THE 
STRUCTURE OF ANIMALS (Continued) . = ‘ ‘ 3 » 29 
Experiments on the Influence of the Food Plant . : 29 
The Influence of Light, Electricity, Centrifugal Force, Chemical Sub- 
stances, and Oxygen on the Caterpillars and Pup of Moths and 
Butterflies . . . - 37 
The Influence of Humidity on a the Gharasters of Moths and Hutterdies 38 
Experiments with Flatfish . . . : . . : 5 «40 
Experiments with Crustaceans. . . A : ‘ . + 40 
Changesin Mammalsand Birds . . . . . . «. « 4! 
CHAPTER IV 
Tue INHERITED EFFECTS OF CHANGES INDUCED BY EXTERNAL FACTORS 43 
CHAPTER V 
THE INHERITANCE OF ACQUIRED CHARACTERS . . . : . » 50 
Telegony . 7 ¢ “ - . . . . . . » 59 
Xenia . . . . . . . . . Or 
Theories of Tranuaiaion of Soiatie Teipeiges . 0 ‘ : . 61 
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