6 CONTENTS 



CHAPTER VIII 



INSTINCT 



Instincts comparable with habits, but different in their origin — Instincts 

 graduated — Aphides and ants — Instincts variable — Domestic instincts, 

 their origin — Natural instincts of the cuckoo, molothrus, ostrich, and 

 parasitic bees — Slave-making ants — Hive-bee, its cell-making instinct — 

 Changes of instinct and structure not necessarily simultaneous — Diffi- 

 culties of the theory of the Natural Selection of instincts — Neuter or 

 sterile insects — Summary 346 



