CONTENTS 



PAGE 



Preface . . . . . . . . . vii 



Acknowledgements ........ ix 



CHAP. 



1 Introductory ......... 1 



2 Water, Salts and Minerals ...... 28 



3 Body Fluids and Circulation ..... 84 



4 Respiration . . . . . . . . .135 



5 Nutrition and Feeding Mechanisms .... 202 



6 Digestion. ......... 254 



7 Excretion ......... 280 



8 Sensory Organs and Reception ..... 305 



9 Effector Mechanisms ....... 365 



10 Nervous System and Behaviour . . . . .415 



1 1 Pigments and Colours . . . . . . 469 



12 Colour Changes ........ 505 



13 Luminescence ........ 536 



14 Associations: Commensalism. Parasitism and Symbiosis . 582 



15 Skeletons, Shelters and Special Defences . . . 629 

 Appendix: Saline media . . . . . . .675 



Index 683 



XI 



