CONTENTS. 



PBEFACE r 



LIST OF WOODCUTS ri 



CHAPTER I. 

 THE NATURAL HISTORY OF THE COMMON CRAYFISH . . 1 



CHAPTER II. 



THE PHYSIOLOGY OF THE COMMON CRAYFISH. THE MECHANISM 



BY WHICH THE PARTS OF THE LIVING ENGINE ARE SUPPLIED 

 WITH THE MATERIALS NECESSARY FOR THEIR MAINTENANCE 

 AND GROWTH 46 



CHAPTER III. 



THE PHYSIOLOGY OF THE COMMON CRAYFISH. THE MECHANISM 

 BY WHICH THE LIVING ORGANISM ADJUSTS ITSELF TO SUB- 

 BOUNDING CONDITIONS AND REPRODUCES ITSELF ... 87 



CHAPTER IV. 



THB MORPHOLOGY OF THE COMMON CRAYFISH. T^B STRUCTURE 

 AND THE DEVELOPMENT OF THB INDIVIDUAL . . 137 



