C TABLE OF CONTENTS. 



CHAPTER IV. 



Page 



HISTORICAL REVIEW ........ 131139 



Aristotle 



Pliny .... 



Renaissance of Sciences in Sixteenth century . 



"*j 194 



Linnaeus ......... . 



Cuvier 



St. Hilaire, Goethe, Oken 



Classification of the present day 



CHAPTER V. . 

 MEANING OF THE SYSTEM ..... 139179 



Species ..... 



Varieties ..... 



Sterility of hybrids . 



Fertility of hybrids . 



Sterility and fertility of mongrels 



Lamark ..... 



Lyell's influence on Geology . 



140 

 141 

 142 

 143 

 143 

 144 

 144 



THEORY OF DESCENT BASED ON NATURAL SELECTION (DARWINISM) . 144 

 Darwin ........ .I 



Natural selection -1 



Origin of vaiieties, races and species 



Progressing divergence of characters, and disappearance of inter- 

 mediate forms 1 



Species according to the theory of evolution 150 



Natural system 150 



EVIDENCE IN FAVOUR OF THE THEORY OF DESCENT . . . 151 



Evidence from Morphology ..... 151 



frnm Dimorphism and Polymorphism 152 



Sexual selection 152 



Sexual dimorphism of parasites ....... 153 



Polymorphism of animal communities . * . . . .155 



from mimicry 155 



from rudimentary organs ......... 156 



from rmlryvlogy 157 



Retrogressive metamorphosis 158 



fnoit the facts of Geographical Distribution 159 



Zoological Provinces 160 



from Piil/>'iiiiti>Jiiiji) 163 



Incompleteness of the geological record 1C7 168 



Transitional forms between allied species ..... 170 



Relation of fossil forms to living species . ..... 170 



Succession of similar types ........ 171 



Kxtinrt, Mammalia, transitional between living groups . . . 172 

 Extinct transitional Reptiles and Birds 175 



Progressive perfection 177 



Fauna of the various geological pcrio la 177 



Incompleteness of the explanati >n . . . . . . . 118 



