352 THE PRINCIPLES OF HEREDITY 



future betterment of mankind. It must be remembered 

 how greatly Darwin benefited thought and knowledge by 

 calling the attention of men of science from the exclusive 

 study of the individual to the scrutiny of the race. A 

 similar work awaits medical men. Owing to improvements 

 in medical science and the consequent survival of the 

 hitherto unfit, tremendous problems have arisen, the solution 

 of which cannot long be delayed without disaster to the 

 species. 



