FACTS AND FACTORS OF DEVELOPMENT 5 



is no mere logical inference from the doc- 

 trine of evolution, but a fact which has been 

 established by countless observations and ex- 

 periments. The essential oneness of all life 

 gives a direct human interest to all living 

 things. If "the proper study of mankind is 

 man," the proper study of man is the lower 

 organisms in which life processes are reduced 

 to their simplest terms, and where alone they 

 may be subjected to conditions of rigid ex- 

 perimentation. Upon this fundamental like- 

 ness between the life processes of man and 

 those of other animals are based the wonderful 

 advances in experimental medicine, which may 

 be counted among the greatest of all the 

 achievements of science. 



The experimental study of heredity, develop- 

 ment and evolution in forms of life below man 

 must certainly increase our knowledge of and 

 our control over these processes in the human 

 race. If human heredity, development and 

 evolution may be controlled to even a slight 

 extent we may expect that sooner or later the 

 human race will be changed for the better. At 

 least no other scheme of social betterment and 



