CONTENTS. 



PART I. 



THE USES AND CONSTITUENT ELEMENTS OF A 

 NERVOUS SYSTEM. 



CHAPTER I. 



PAGE 



THE USES AND ORIGIN OP A NERVOUS SYSTEM ... 1 



CHAPTER II. 



THE STRUCTURE OF A NERVOUS SYSTEM NERVE FIBRES, CELLS, AND 



GANGLIA 26 



PART II. 



THE NERVOUS SYSTEM IN INVERTEBRATES. 



CHAPTER III. 



THE USE AND NATURE OP SENSE ORGANS . . . . . 55 



CHAPTER IV. 

 THE NERVOUS SYSTEM OF MOLLUSKS 70 



CHAPTER V. 

 THE NERVOUS SXSTEM OF VERMES ....... 86 



CHAPTER VI. 

 THE NERVOUS SYSTEM OF ANTHROPODS . 



