PHYSICAL EVOLUTION 223 



It only remains very briefly to consider the question what Elimina- 

 proportion of the total number of deaths is really selective, ^ "Elective 

 and what proportion due to accidental causes. Professor Karl 

 Pearson calculates that no less than 80 per cent, of the death- 

 rate is selective. It may be questioned whether the data are 

 available for so exact a calculation. But premature death can 

 in so many cases be traced to some defect, physical or moral, 

 that the estimate can hardly be considered excessive. 



We have seen now that Natural Selection eliminates over Summary 

 48 per cent, of the population before the age of marriage. 

 And owing to Reproductive Selection, which is a form of 

 Natural Selection, 25 per cent, of the married couples in each 

 generation are the parents of half the next generation. To this 

 we have to add, what I believe is a very large addition, the 

 influence of Sexual Selection. Natural Selection, thus fortified 

 and supplemented, still works among civilised men with an effec- 

 tiveness which must not be underestimated because it is impossible 

 to express it in figures. Whether its stringency is sufficient to 

 prevent degeneration I shall discuss later on. 



Natural Selection deals not only with individuals but with 

 groups : there is a constant struggle among nations, success 

 depending as much on moral as on physical qualities. 



Ill 



MITIGATION OF THE STRUGGLE FOR EXISTENCE 



THE struggle for existence must be distinguished from the General 

 struggle for success. If only our successful men survived, surve y 

 our population would indeed decline. 



It is not difficult to show that the mass of English people 

 live in greater comfort now than they did near the beginning 

 of the century or fifty years ago. After Waterloo there was a 

 time of terrible distress. Bad harvests and heavy taxation made 

 life hard. Mouldy corn was not given to the pigs as it is now, 

 but was made into bread and eaten by human beings. Till the 



