CONTENTS, 



PAGE 



PREFACE V 



LIST OF WOODCUTS xi 



CHAPTER I. 



The Natural History of the Common Crayfish . 



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 sur- 

 rounding CONDITIONS AND REPRODUCES ITSELF ... 87 



CHAPTER IV. 



The Morphology of the Common Crayfish. The structure 



AND the development OF THE INDIVIDUAL . ... 137 



