CONTENTS XV 



PAGE 



172. List of theories 457 



173. Summary ^gg 



Chapter XXI. Conclusions 47I 



$ 174. Introduction 47]^ 



175. Abstract of the investigation 47I 



176. Equilibrations 474 



177. Alternative studies of the same material 475 



178. Contributions made 476 



179. Conclusions concerning physiological constancies 477 



180. Retrospect 473 



References 4gO 



Index 494 



