n Persons who have never 



CIIAPTEK 



IV. Summary of All Reports, and Discussion or Certain Points op 

 Paktioular Interest 

 A. The Incidence of Pi-otozoal Infections 

 left Britain . 

 General Results 



(1) Entamoeba histolytica 



(2) Entamoeba coli 



(3) Endolimax nana . 



(4) lodamoeba hutschlii 



(5) Bientamoeba fragilis 



(6) Giardia intestinalis 



(7) Chilomastix mesnili 



(8) Trichomonas hominis 



(9) Other Protozoa . 

 B. The Spread of Infections in Britain 



V. Recent Observations on the Occurrence of 

 Holland, and Germany . 



VI. CoNCLUDiNe Remarks 



References 



E. histolytica in France, 



page 



39 



39 

 39 



42 

 -18 

 49 

 50 

 50 

 51 

 52 

 53 

 54 

 54 



57 

 63 

 69 



CHAPTEE I. INTRODUCTORY. 



Pkioe to the outbreak of war in 1914 little was known con- 

 cerning the occurrence of intestinal protozoa in the population 

 of the British Isles : for although many British investigators 

 had devoted their attention to the study of the intestinal protozoa 

 of man in tropical countries, it seems to have occurred to nobody, 

 until very recently, to carry out similar investigations at home. 



The reasons for this — which seems, at first sight, somewhat 

 curious — are not difficult to discover. Diseases due to intestinal 

 protozoa were not generally recognized as occurring in Britain. 

 They were — and still are— regarded by most practitioners as 

 peculiar to the tropics ; and it therefore appeared unnecessary to 

 look for the ' causes ' of such diseases in a country wherein they 

 seemed generally absent. Moreover, Protozoology, as a serious 

 study, has usually been regarded as entering into the purview of 

 those physicians only who devote themselves to the study of 

 Tropical Medicine: and consequently there were few medical 

 men who were able — or, if able, who saw any necessity — to study 

 the intestinal protozoa of the resident population of Britain. 

 And, on the other hand, those zoologists who might have been 

 disposed to take up this work were usually debarred from doing 

 so by the difficulty, or the impossibility, of obtaining adequate 

 material. 



All this was soon changed by the War. Large bodies of troops 



■ were raised in Britain and sent to all the theatres of military 



operations, where they contracted divers intestinal diseases with 



which later they returned home. On their return they were 



subjected to careful examination, in order to diagnose their 



