CONTENTS 



PAGE 



PREFACE v 



CHAPTER 



I. THE CONTINUITY OF LIFE i 



II. THE PHYLOGENESIS OF VERTEBRATES 26 



III. THE ONTOGENESIS OF VERTEBRATES .... . . . 48 



IV. THE INTEGUMENT AND THE EXOSKELETON ... 76 

 V. THE ENDOSKELETON . . . . 122 



VI. THE MUSCULAR SYSTEM 189 







VII. THE DIGESTIVE AND RESPIRATORY SYSTEMS . . . 257 



VIII. THE VASCULAR SYSTEM 317 



IX. THE URO-GENITAL SYSTEM 365 



X. THE NERVOUS SYSTEM 406 



XL THE SENSE-ORGANS 465 



XII. THE ANCESTRY OF THE VERTEBRATES 506 



APPENDIX . . . . 539 



