VIU CONTENTS. 



PAGE 



velopment of the Theory of Selection. — A Letter of Darwin's. — 

 The Contemporaneous Appearance of Darwin's and Alfred Wallace's 

 Theory of Selection. — Darwin's Study of Domestic Animals and 

 Cultivated Plants. — Andreas Wagner's Notions as to the Special 

 Creation of Cultivated Organisms for the good of Man. — The Tree 

 of Knowledge in Paradise. — Comparison between Wild and Culti- 

 vated Organisms. — Darwin's Study of Domestic Pigeons. — Import- 

 ance of Pigeon Breeding. — Common Descent of all Eaces of 

 'jtigeons ••• ••• ••• ••• ..( ,,, ,,t ,,, ,,, i.^0 



CHAPTER VII. 



THE THEORY OF SELECTION (DARWINISM). 



Darwinism (Theory of Selection) and Lamarckism (Theoiy of Descent). 

 — The Process of Artificial Breeding. — Selection of the Different 

 Individuals for After-breeding. — The Active Causes of Transmuta- 

 tion. — Change connected with Food and Transmission by Inheritance 

 connected with Propagation. — Mechanical Nature of these Two 

 Physiological Functions. — The Process of Natural Breeding : 

 Selection in the Struggle for Existence. — Malthus' Theory of 

 Population. — The Proportion between the Numbers of Potential 

 and Actual Individuals of every Species of Organisms. — General 

 Straggle for Existence, or Competition to attain the Necessaries of 

 Life. — Transforming Force of the Struggle for Existence. — Com- 

 parison of Natural and Artificial Breeding — Selection in the Life of 

 Man. — Military and Medical Selection ... ... ... ... 149 



CHAPTER YIII. 



TRANSMISSION BY INHERITANCE AND PROPAGATION. 



Universality of Inheritance and Transmission by Inheritance. — Special 

 Evidences of the same. — Human Beings with four, six, or seven 

 Fingers and Toes. — Porcupine Men. — Transmission of Diseases, 

 especially Diseases of the Mind. — Original Sin. — Hereditary 

 Monarchies. — Hereditary Aristocracy. — Hereditary Talents and 

 Mental Qualities. — Material Causes of Transmission by Inheritance. 

 — Connection between Transmission by Inheritance and Propaga- 

 tion. — Spontaneous Genei-ation and Propagation. — Nonsexual or 

 Monogonous Propagation. — Propagation by Self -Division. — Monera 

 and Amoeba. — Propagation by the formation of Buds, by the for- 

 mation of Germ-Buds, by the foi-mation of Germ-Cells. — Sexual or 

 Amphigonous Propagation. — Formation of Hermaphrodites. — Dis- 

 tinction of Sexes, or Gonochorism. — Virginal Breeding, or Parthe- 



