TABLE OF CONTENTS ix 



PAGE 



C. PANCREATIC, GASTRIC, HEPATIC, AND ACCESSORY FORMS OF DIGES- 

 TIVE TISSUES ........... 297 



CHAPTER XVI 

 THE DUCTLESS GLANDS 304 



CHAPTER XVII 



A. THE TISSUES OF RESPIRATION 319 



B. AIR-BREATHING TISSUES OR LUNGS 321 



C. WATER-BREATHING TISSUES OR GILLS 326 



CHAPTER XVIII 

 THE GAS-SECRETING TISSUES OF ANIMALS 333 



CHAPTER XIX 

 THE EXCRETORY OR NEPHRIDIAL TISSUES 339 



CHAPTER XX 



A. INTEGUMENT, MECHANICAL PROTECTION -358 



B. OFFENSIVE MECHANICAL PROTECTION AND THE PRODUCTION OF 



POISONOUS FLUIDS 375 



C. TISSUES THAT PRODUCE LUBRICATING FLUIDS ..... 387 



D. TISSUES THAT PRODUCE ATTRACTIVE AND REPULSIVE ODORS . . 4OO 



E. TISSUES OF ADHESION AND SPINNING 409 



CHAPTER XXI 



A. TISSUES OF REPRODUCTION 418 



B. MALE REPRODUCTIVE CELLS AND NURSE CELLS OF THE SPERMATO- 



ZOON 423 



C. FEMALE REPRODUCTIVE CELLS AND NURSE CELLS OF THE OVUM . 453 



CHAPTER XXII 

 NlDAMENTAL TISSUES, USED TO FORM COVERINGS FOR THE OVA* AND 



SPERMATOZOA 478 



ERECTILE TISSUES 490 



CHAPTER XXIII 

 NOURISHING MEMBRANES AND TISSUES OF THE PARENT AND OF THE YOUNG 492 



CHAPTER XXIV 

 TECHNIC . .502 



INDEX . . ... 509 



