xii CONTENTS 



CHAPTER III 



THE NATURAL HISTORY OF MAN 



FAGE 



Objections to the doctrine of Natural Selection — The 

 impossibility of proving Natural Selection by a study 

 of wild Nature — Man no longer evolves along ancient 

 lines — Social and moral evolution a myth from a bio- 

 logical standpoint — Proof of the actuality of Natural 

 Selection obtainable from the study of human death- 

 rates — Zymotic disease the principal cause of human 

 elimination — "Parasitic" and " saprophytic " diseases 

 — Evolution against disease — Acquired and inborn 

 immunity — Acquired eiTects of disease not transmis- 

 sible to offspring ....... 24 



CHAPTER IV 



THE ROOTS OF EMPIRE 



The part played by malaria in the natural and political 

 history of man— The part played by consumption — 

 The world's greatest tragedy — The part played by 

 disease in the fortunes of Anglo-Saxons — The part 

 played by disease in the fortunes of other races — The 

 building of an empire . . . . . . 37 



CHAPTER V 



A THEORY OF RETROGRESSION 



The different parts of the higher animals were evolved at 

 different though overlapping periods of a long extend- 

 ing past— Evolution is due to stringent selection, which 

 affects only a few parts at a time— Cessation of selection 



