xiv Contents 



CHAPTER IV. INFLUENCE OF ENVIRONMENT 



A. RELATIVE IMPORTANCE OF HEREDITY AND ENVIRON- 



MENT 



1. Former Emphasis on Environment 



2. Present Emphasis on Heredity 



3. Both Indispensable to Development 



B. EXPERIMENTAL MODIFICATIONS OF DEVELOPMENT 



I. DEVELOPMENT STIMULI 



1. Physical Stimuli 



2. Chemical Stimuli 



II. DEVELOPMENTAL RESPONSES 



Dependent upon (a) Nature of Organism, (b) Nature of 

 Stimulus, (c) Stage of Development 



1. Modifications of Germ Cells before Fertilization 



2. During Fertilization 



3. After Fertilization 



C. FUNCTIONAL ACTIVITY AS A FACTOR OF DEVELOP- 



MENT 



D. INHERITANCE OR NON-INHERITANCE OF ACQUIRED 



CHARACTERS 



E. APPLICATIONS TO HUMAN DEVELOPMENT: EUTHEN- 



ICS 



CHAPTER V. CONTROL OF HEREDITY : EUGENICS 



A. DOMESTICATED ANIMALS AND CULTIVATED PLANTS 



I. INFLUENCE OF ENVIRONMENT IN PRODUCING NEW RACES 

 II. ARTIFICIAL SELECTION 



1. The Methods of Breeders 



2. How has Selection acted? 

 III. METHODS OF MODERN GENETICS 



1. Mendelian Association and Dissociation of Characters 



2. Mutations 



3. Causes of Mutation 



B. CONTROL OF HUMAN HEREDITY 



I. PAST EVOLUTION OF MAN 

 II. CAN HUMAN EVOLUTION BE CONTROLLED? 



1. Selective Breeding the only Method of Improving the Race 



2. No Improvement in Human Heredity within Historic Times 



3. Why the Race has not Improved 



