CHAPTER VIII 



THE BIRTH-RATE 



The general result of the investigations followed in 

 this book cannot be mistaken. All the evidence we 

 have considered emphasizes the supreme importance of 

 heredity in determining the character of a race, and the 

 direction and rate in which that character changes. 



Our population is made up of elements of very 

 different nature. As we have seen, the ability of some 

 men must be reckoned as a hundred times the average. 

 Physical powers probably vary less ; but other mental 

 and moral characters show divergences as great as those 

 found in estimating ability. 



All characters, mental or physical, tend to be in- 

 herited ; and, if one element of the people reproduces 

 itself faster than the rest, it will soon exert a dominant 

 influence on the average character of the whole. Its 

 peculiarities become the normal characteristics of the 

 nation. 



The speed with which any specially fertile stock 

 increases proportionally to the rest of the community 

 does not seem to be generally understood. A few 

 figures may serve to make it plain. 



In order that a population should maintain its 



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