CONTENTS 



PAGE 



Preface v 



CHAPTER I 



THE BIOLOGY OF HOST-PARASITE RELATIONS 

 BETWEEN MAN AND HIS INTESTINAL 

 PROTOZOA 3 



I. Introduction 3 



1. PROTOZOOLOGY 3 



2. HOMOLOGIES AND ANALOGIES BETWEEN FREE- 



LIVING AND PARASITIC PROTOZOA .... 6 



3. THE INTESTINAL PROTOZOA LIVING IN MAN . 16 



4. TERMS USED IN THE STUDY OF PARASITIC PRO- 



TOZOA 17 



II. General Account of the Biology of Host-Parasite Re- 

 lations between Man and His Intestinal Protozoa 19 



1. EPIDEMIOLOGY OF TRANSMISSION .... 20 



(i) Infective Stage . 20 



(2) Avenues of Infection 21 



2. clinical and parasitological periods dur- 



ing the course of a natural infection . 27, 



(1) PARASITOLOGICAL PERIODS (PrEPAT- 



ENT, Patent, Subpatent) ... 23 



(2) Clinical Periods (Incubation, 



Symptoms, Convalescent, Latent, 

 Relapse) 25 



3. distribution AND LOCALIZATION OF PARASITES 



WITHIN THE HOST 26 



(i) Distribution 26 



(2) Primary Site of Infection ... 27 



(3) Secondary Sites of Infection . . 28 



4. PASsn^ (natural) resistance of the host 29 



5. passive (natural) resistance of the para- 



site 30 



ix 



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