THE PHYSIOLOGICAL AND SYMBIOTIC RELATION- 

 SHIPS BETWEEN THE INTESTINAL PROTOZOA 

 OF TERMITES AND THEIR HOST, 

 WITH SPECIAL REFERENCE TO 

 RETICULITERMES FLA VIPES 

 KOLLAR.* 



L. R. CLEVELAND. 



CONTENTS. 



Page 



Introduction 1 79 



The Problem 180 



Material 181 



Acknowledgments 181 



General Considerations: 



1. The Termites: 



a. Castes 182 



b. Food Direct 184 



c. Food Indirect 185 



2. The Protozoa 185 



3. Biochemical Considerations 186 



Relation of the Protozoa to their Host: 



A. Historical: 



1. True Parasites 188 



2. Commensals 190 



3. Symbionts 191 



B. Original Observations: 



Attempts to free termites of their protozoa 194 



The incubation method 195 



Table 1 197 



Death of termites after incubation and the removal of the protozoa. 196 



Cause of death 196 



Incubation per se 196 



Loss of protozoa (defaunation) 199 



Table II 198 



Effect of incubation on other insects 199 



Sugars, starches, etc., are fed defaunatod termites in an effort to pre- 

 vent their death 200 



* From the Department of Medical Zoology, School of Hygiene and Public 

 Health, Johns Hopkins University, Baltimore, Maryland. 



This is the second of a series of papers on this subject. The first papri <>t th 

 scries, "Correlation between the Food and Morphology of Termites aii'l the 1 

 ence of Intestinal Protozoa," deals with the more .ym'i.il aspe< ts oi thr subject, 

 and will appear in the July (1923) number of the Am,-ri,<in Jmtmnl f 



178 



