If? / r. 



AN EXPOSITION' OF THE DARWINIAN THEORY 



AND A DISCUSSION OF 

 POST-DARWINIAN QUESTIONS 



BY THE LATE 



GEORGE JOHN ROMANES, M.A., LL.D., F.R.S. 



Honorary Fellow of Gonville and Caz'us College, Cambridge 



III 



POST-DARWINIAN QUESTIONS 



ISOLATION 

 AND PHYSIOLOGICAL SELECTION 



Chicago 



THE OPEN COURT PUBLISHING COMPANY 

 1906 



