Contents 



i'age 



Vrefiice ^ 



Introduction 



Chapter 1.— The World of Living Things 6 



Chapter 2. — The Origin and Evolution of Organic Life . . . . 9 



(a) Theory of the Fixity of Species or Special 

 Creation ' 



(b) Theory of Evolution or Descent with Modifi- 

 cation 9 



(c) Lamarck and Lamarckism 11 



(d) Darwin and Daf-winism 13 



(e) Orthogenesis 20 



(f) Protoplasm and the Origin of Life 21 



*" Chapter 3. — Variations — Kinds and Causes 22 



Chapter 4. — Distribution of Animals and Plants 32 



(a) DeCandolle's Law 32 



(b) Laws of Distribution of Animals 32 



Chapter 5. — Origin of Domesticated Animals and Cultivated 



Plants 33 



(a) Origin of Domesticated Animals 33 



(b) Origin of Cultivated Plants 35 



/Chapter 6. — Reproduction in Animals and Plants 39 



(a) Kinds of Reproduction 39 Germ Cells.. 40 



(b) Fertilization in Seed Plants 41 



(c) Fertilization in Animals 41 



(d) Development of the Embryo in Seed Plant-.... 41 



(e) Development of the Embryo in Animals 43 



Chapter 7. — Heredity and Inheritance 45 



J Methods of Investigating Heredity 45 



(a) The Statistical Study of Heredity 46 



(b) Law of Ancestral Inheritance 47 



(c) Law of Filial Regression 47 



(d) Value of Biometric Studies 49 



Chapter 8.— Unit Characters 49 



(a) Correlation of Characters 50 



(b) Coefficient of Correlation 51 



Chapter 9.— The Transmission of Characters 52 



(a) Darwin's theory of Pangenesis 52 



(b) DeVries' Pangen theory or Intracellular Pan- 

 genesis 53 



(c) Weismann and Weismannlsm . . . 53 



Chapter 10. — Congenital and Acquired Characters 57 



(a) Inheritance of Acquired Characters 58 



(b) Telegony gj 



(c) Maternal Impressions 62 



Chapter 11.— 'DeVries' Mutation Theory . . . . \[ "q^ 



(a) DeVries' Experiments ^ ' gg 



(b) Gates' Study of the Chromosomes of OEno- 

 theras go 



(c) Origin of Adaptations 70 



Chapter 12. — Johannsen' Pure Lines [ , [ 70 



Selection of Hooded Rats ' ' 73 



Selection of Paramoecia 74 



Selection of Leptinotarsa 74 



Chapter 13.— Types of Bisexual Inheritance 74 



Chapter 14.— Hybrids and Hybridization . . 7t, 



