72 DOCTRINE OF EVOLUTION 



periments dealing with the phenomena of heredity 

 in pure and mixed breeds have largely confirmed Weis- 

 mann's doctrine, and they have prepared the way for 

 a deeper investigation of the marvelous process of 

 biological inheritance. 



However much he may be interested in the details of 

 embryological science, the general student of natural 

 history is more concerned with the bearing of its pri- 

 mary laws upon the great problem of evolution. In the . 

 foregoing brief review of the fundamental facts and 

 principles of this subject, the purpose has been to show 

 how the phenomena of development are viewed by men 

 of science, and how they take their place in the doctrine 

 of organic evolution. And it has also been made plain 

 that comparative anatomy and comparative embry- 

 ology support and supplement one another in countless 

 ways and places, although each in itself is a complete 

 demonstration that evolution is a real and a natural 

 process. 



