CONTENTS. 



II. 



The Pabt plated by Wokms in the History of this Planet. 



They preserve Valuable Ruins 



They prepare the Ground for Seed 



Intelligence of Worms .... 



42 

 43 

 46 



III. 



The Laws of Variability with respect to Animals and Plants. 



Inherited Effect of Changed Ilabits 



Effects of the Use and Disuse of Parts 



Vague Origin of our Domestic Animals . 



Descent of the Domestic Pigeon 



Origin of the Dog ..... 



Origin of the Horse .... 



Causes of Modifications in the Horse 



" Making the Works of God a mere Mockery " 



Variability of Cultivated Plants . 



Savage Wisdom in the Cultivation of Plants . 



Unknown Laws of Inheritance 



Laws of Inheritance that are fairly well established 



Inherited Peculiarities in Man 



Inherited Diseases .... 



Causes of Non-Inheritance 



Steps by which Domestic Eaces have been produced 



Unconscious Selection .... 



Adaptation of Animals to the Fancies of Man 



Doubtful Species ..... 



Species an Arbitrary Term 



The True Plan of Creation 



48 

 50 

 62 

 63 

 65 

 67 

 58 

 59 

 61 

 62 

 64 

 66 

 61 

 68 

 69 

 11 

 73 

 74 

 75 

 77 

 79 



IV. 

 The Struggle for Existence. 

 Death inevitable in the Fight for Life 

 "Inexplicable on the Theory of Creation" 

 Obscure Checks to Increase .... 

 Climate as a Check to Increase . 

 Influence of Insects in the Struggle for Existence 

 No such Thing as ChanM in the Result of the Struggle 



82 

 84 

 85 

 86 

 88 

 90 



