A person will not read this book unless he is 

 interested in human welfare. If he is interested 

 in human welfare, he is quite competent to form 

 his own opinions from the facts as to what is 

 the best policy to pursue. For example, if it 

 clearly appears that improvements of the kind 

 which distinguish,' the higher iraces fr'om the 

 lower ones come only through the children pro- 

 duced in the later reproductive lives of their 

 parents, he will have no difficulty in forming an 

 opinion of laws which permit a fourteen-year- 

 old boy to marry a twelve-year-old girl, or of 

 customs which control births by shutting off all 

 but a few produced soon after marriage. 



I have given a few conclusions when the con- 

 text seemed to call for them, but for the most 

 part I have left the reader to draw his own 

 conclusions. In a good many cases they are so 

 self-evident as to need no comment. 



C. L. R. 



March, 1921. 



IV 



