Chapter III: Preface: • v

LIST OF WOODCUTS • xi

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 surrounding conditions and reproduces itself • 87

CHAPTER IV.

The Morphology of the Common Crayfish. The structure and the development of the individual • 137

CHAPTER V.

The Comparative Morphology of the Crayfish. The structure and the development of the Crayfish compared with those of other living beings • 227