Contents 



{part I 



Chapter I 

 INTRODUCTORY 



PAGES 



I. DARWIN'S THEORY . . . . . . . 3-7 



Evidence that evolution has taken place, p. 4 Arguments in support 

 of Darwin's Theory, p. 6. 



II. THE EARLY STAGES OF EVOLUTION . . . . . 7-13 



Unicellular organisms, p. 7 From Protozoa to Metazoa, p. n. 



III. THE DEVELOPMENT OF THE INDIVIDUAL . . . . 13-18 



Chapter II 

 HEREDITY, VARIATION AND DEATH 



The ancient theory, p. 19 Brief statement of Weismann's views, p. 19 

 Estimate of Weismann's theory, p. 23 Darwin's Pangenesis, p. 26 

 Epigenesis, p. 27 Reproduction of lost parts, p. 28 Evolution of Weis- 

 mann's views, p. 30 Weismann's theory of the evolution of death, p. 31 

 A theory of the cause of variations and of death, p. 33 Bacteria, p. 37 

 Summary, p. 38 Some general reflections on evolution, p. 38. 



Chapter III 

 THE LAMARCKIAN PRINCIPLE 



Introductory, p. 42 The difficulty of transference from a bodily organ 

 to the reproductive cells, p. 43 Supposed instances of the inheritance of 

 acquired characteristics, p. 46 The opinion and practice of breeders, 

 p. 46 Disease, p. 47 The environment cannot change the inherent 

 character of an organ or organism, p. 49 Flowers and Lamarckism, 

 p. 52 The gardener and the breeder as environment, p. 53 Exercise 

 and the origination of organs, p. 53 Exercise and growth, p. 54 Disuse, 

 p. 55 Vestiges, p. 56 The stag's antlers, p. 57 The skill of neuter 

 insects, p. 58 The skill of caterpillars, p. 59 The Yucca moth, p. 60 

 Lamarckism and Weismannism side by side, p. 61 Reproduction of lost 

 parts, p. 63 Selection of food, p. 64 A seeming concession, p. 66 

 Summary, p. 66. 



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