x Prefatory Note 



moving the crude physical checks which the 

 unrestrained struggle for existence places on 

 the over-fertility of the unfit, they may at the 

 same time be leading to a lessened relative 

 fertility in those physically and mentally 

 fitter stocks, from which the bulk of our 

 leaders in all fields of activity have hitherto 

 been drawn. 



To the lecture is added an Appendix con- 

 taining two recent letters to the Times 

 dealing with the problem of National 

 Deterioration. I have to acknowledge the 

 ready consent of the Times management to 

 their republication. 



K. P. 



