DARWIN, AND AFTER DARWIN

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 Caius College, Cambridge

III
POST-DARWINIAN QUESTIONS
ISOLATION
AND PHYSIOLOGICAL SELECTION

Chicago
THE OPEN COURT PUBLISHING COMPANY
1906


CHAPTER 1. COPYRIGHTED BY
THE OPEN COURT PUBLISHING CO.
1897.

The Lakeside Press
R. R. DONNELLEY & SONS CO., CHICAGO