6 TABLE OF CONTENTS. 



CHAPTER IV. 



Page 



HISTORICAL REVIEW 181-139 



Aristotle ....... 



Pliny ..... 



Renaissance of Sciences in Sixteenth century . 



Ray i ......... I?" 4 



Linnaeus . 



Cuvier ...... .135 



St. Hilaire, Goethe, Oken . 137 



Classification of the present day ... . .138 



CHAPTER V. 

 MEANING OF THE SYSTEM .... 139179 



Species 



Varieties ......... 



Sterility of hybrids .... 



Fertility of hybrids ..... 



Sterility and fertility of mongrels . .143 



Lamark ........ 



Lyell's influence on Geology ..... 



THEORY OF DESCENT BASED ON NATURAL SELECTION (DARWINISM) . 



Darwin ............ 



Natural selection ...... 



Origin of vaiieties, races and species ... .148 



Progressing divergence of characters, and disappearance of inter- 

 mediate forms ...... 



Species according to the theory of evolution . . . . 1 50 



Natural system ........ .150 



EVIDENCE IN FAVOUR OF THE THEORY OF DESCENT . .151 



Evi<l e nri' from Morphology .... . .151 



from DhnorjfJtisni- and Polymorphism ....... 152 



Sexual selection ..... .152 



Sexual dimorphism of parasites 



Polymorphism of animal communities .... .155 



from ni'nii'icry ...... .155 



from rudimentary organs ..... 150 



from Embryology .... .157 



Retrogressive metamorphosis ..... .158 



from tin* facts of Geographical Distribution ..... 159 



Zoological Provinces .......... 160 



from Pal (font oloi/y .......... 103 



Incompleteness of the geological record ..... l'7 168 



Transitional forms between allied species ..... 1 70 



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



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



Extinct Mammalia, transitional between living groups . . . 172 

 Extinct transitional Reptiles and Birds ...... 175 



' Progressive perfection ......... 177 



Fauna of the various geological periods ...... 177 



Incompleteness of the explanation ....... 118 



