CONTENTS. 



CHAPTER PAGE 



I. INTRODUCTORY . 1 



II. AMCEBA . . .18 



III.- THE GENERAL STRUCTURE OF ANIMALS . . 23 



IV. ORGANS OF DIGESTION . . 102 



V. THE BLOOD AND THE BLOOD-VASCULAR SYSTEM . 181 



VI. ORGANS OF RESPIRATION . . 210 



VII. ORGANS OF NITROGENOUS EXCRETION . . > . 247 



VIII. ORGANS OF SPECIAL SECRETIONS . 265 



IX. PROTECTING AND SUPPORTING STRUCTURES . . 274 



X. ORGANS OF MOVEMENT . . 370 



XI. VOCAL ORGANS . . 387 



XII. THE NERVOUS SYSTEM AND ORGANS OF SENSE . 393 



XIII. ORGANS OF REPRODUCTION . .472 



XIV. THE DEVELOPMENT OF THE METAZOA . . .525 



