TABLE OF CONTENTS XV 



CHAPTER XVI 



Evolution- 339 



Darwin and the rise of the evolution theory — Evidence of evolution — What 

 evolution explains — Comparative anatomy — Comparative embryology — 

 Comparative physiology — Extinct animals — Geographical distribution — 

 Causes of evolution — Internal factors: mutations — Changes in the environ- 

 ment — Course of evolution — The course of evolution demonstrated or 

 surmised — Factors directing the course of evolution — Environment: use and 

 disuse — Natural selection: sexual selection — Direction of mutation — Ortho- 

 genesis — Evolution by hybridization — Artificial evolution — References. 



Glossary 364 



Index 413 



