6 TABLE OF CONTENTSo 



CHAPTEE IV. 



Page 

 HISTORICAL REVIEW 131139 



Aristotle 133 



Pliny . 1S2 



Renaissance of Sciences in Sixteenth century 133 



Ray 134= 



Linnaeus 134 



Cuvier 135 



St. Hilaire, Goethe, Oken 137 



Classification of the present day . . . . . .138 



CHAPTER V. . 

 MEANING OF THE SYSTEM 139179 



Species 140 



Varieties 141 



Sterility of hybrids . 142 



Fertility of hybrids 143 



Sterility and fertility of mongrels 143 



Lamark 144 



Ly ell's influence on Geology 144 



THEOEY OF DESCENT BASED ox NATURAL SELECTION (DARWINISM) . 144 



Darwin 145 



Natural selection 145 



Origin of vaiieties, races and species 148 



Progressing divergence of characters, and disappearance of inter- 

 mediate forms 149 



Species according to the theory of evolution 150 



Natural system 150 



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



Evidence from Morphology 151 



from 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 embryology 157 



Retrogressive metamorphosis 1.58 



from the facts of Geographical Distribution 159 



Zoological Provinces 160 



from Palaeontology 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 



Extinct Mammalia, transitional between living groups . . . 172 

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



Progressive perfection 



Fauna of the various geological pcrio Is . " - > " * 

 Incompleteness of the explanation . . T s 118 



T 



