TABLE OF CONTENTS 



Page 



I NTRODUCTION 3 



TABLE OF CONTENTS 5 



PART I 



OCCURRENCE OF ANAEROBIOSIS AMONG 

 INVERTEBRATES 



CHAPTER I 



METHODS OF INVESTIGATION 9 



1. Deteriuinatiou of the Oxygen Content of Va- 



rious Habitats 9 



2. Establishment of Experimental Anaerobic Con- 



ditions ^^ 



3. Anaerobic Metabolism 21 



CHAPTER II 



ANAEROBIC HABITATS 23 



1. Soils 23 



2. Water Basins 24 



3. The Intestinal Tract 31 



4. Tissues and Secretions 34 



CHAPTER III 



ST'RVEY OF INVERTEBRATES FOR ANAEROBIOSIS.. 39 

 I. PROTOZOA 39 



1. Non-parasitic Protozoa 39 



2. Parasitic Protozoa 53 



II. COELENTETRATES 60 



III. WORMS AND WORM-LIKE ORGANISMS 02 



1. Non-parasitic Species 62 



2. Parasitic Species '''4 



IV. ECHINODERMS 84 



V. MOLLUSCS 87 



1. Lamellibranchs ^'^ 



2. Gastropods 94 



3. Cephalopods ^^ 



