17 



must have been going on — probably more slowly — for centuries : 

 but it is only recently that attention has been devoted to the 

 subject, and that any considerable body of observations has been 

 amassed. The outbreak of war in 1914 forms a convenient 

 dividing line for my present purposes, and I have therefore 

 called all records prior to this date ' old ', and all those since 

 ' new '. 



In the next chapter I shall now analyse, as briefly as possible, 

 all the old records which I have been able to find in the literature. 



CHAPTER II. THE OLDER RECORDS OP THE OCCUR- 

 RENCE OF INTESTINAL PROTOZOA IN THE POPU- 

 LATION OF BRITAIN. * 



The occurrence of intestinal protozoa in the population of the 

 British Isles — that is, in residents who have never been abroad — 

 has been the subject of serious inquiry only since the outbreak of 

 the "War. Consequently almost all that has been definitely 

 ascertained has been the product of the last half-dozen years. 

 Nevertheless, it was known prior to 1914 that amoebic dysentery 

 and liver abscess do occur sporadically in Biitain, and several 

 apparently indigenous cases had been recorded. Of such c.ases 

 I have been able to find but five for which the evidence appears 

 at all convincing. I shall summarize them briefly at this point, 

 as they are of interest in two respects : first, from a historic 

 standpoint ; secondly, because they show that JS. histolytica 

 occurred in the population of Britain before the War — that is, 

 before the recent demonstration of its presence. 



Although it was doubtless well known to many people before 

 the War that E. coli, Giardia, and other non-pathogenic species 

 of intestinal protozoa occur in the resident population of the 

 British Isles, I have been unable to discover any printed records 

 of this in pre-war literature. Consequently this chapter will 

 deal entirely with records relating to the occurrence of E. histo- 

 lytica. 



The older evidence for the existence of E. histolytica in persons 

 who have never left Britain is, of course, mainly pathological and 

 clinical. But the symptoms and lesions of such infections are 

 very characteristic ; so that, notwithstanding the fact that the 

 certain recognition of E. histolytica is a comparatively recent 

 achievement, it is possible to draw conclusions from several of the 

 older records with some degree of certainty. 



I shall now review, in their historic sequence, all the " old ' 

 records which I have been able to find. 



Dickinson's two cases. — The earliest British case of E. histo- 

 lytica infection known to me is that recorded by W. Howship 

 Dickinson (1862). His patient was a woman aged 37, who came 

 under observation at St. George's Hospital. ' She had never been 

 out of England.' She was ' sallow ', and complained of ' pain in 

 the right hypochondrium ', and a tumour could be felt extending 



