Contents ix 



CHAPTER XV 



THE FLY-HUNT 27 1 



CHAPTER XVI 



A PARASITE OF THE BEMBEX. THE COCOON . 284 



CHAPTER XVn 



THE RETURN TO THE NEST .... 305 



CHAPTER XVni 



THE HAIRY AMMOPHILA 323 



CHAPTER XIX 



AN UNKNOWN SENSE 341 



CHAPTER XX 



THE MODERN THEORY OF INSTINCT . . 354 



APPENDIX 379 



INDEX 387 



