CONTENTS 



CHAPTER I. 



PAGE 



SOME FUNDAMENTAL FACTS AND CONCEPTIONS CONCERN- 

 ING THE COMPARATIVE PHYSIOLOGY OF THE CEN- 

 TRAL NERVOUS SYSTEM ...... i 



CHAPTER II. 



THE CENTRAL NERVOUS SYSTEM OF MEDUSAE. EXPERI- 

 MENTS ON SPONTANEITY AND COORDINATION . . 16 



CHAPTER III. 

 THE CENTRAL NERVOUS SYSTEM OF ASCIDIANS AND ITS 



SIGNIFICANCE IN THE MECHANISM OF REFLEXES . 35 



CHAPTER IV. 

 EXPERIMENTS ON ACTINIANS 48 



CHAPTER V. 

 EXPERIMENTS ON ECHINODERMS 61 



CHAPTER VI. 



EXPERIMENTS ON WORMS 7 2 



CHAPTER VII. 

 EXPERIMENTS ON ARTHROPODS 101 



CHAPTER VIII. 



EXPERIMENTS ON MOLLUSKS 128 



vii 



fill 



