APPENDIX D. 



AMCEBIC DYSENTERY. 



In a previous chapter it has been pointed out that the term 

 "dysentery" has been applied to a number of conditions of 

 different etiology, and the relations of bacteria as causal agents 

 have been there discussed (vide p. 382). We shall here consider 

 that variety of tropical dysentery which is believed to be due to 

 an amoeba, and hence often known as amoebic dysentery. 



Amongst the early researches on the relation of organisms to 

 dysentery probably the most important are those, of Lb'sch, who 

 noted the presence and described the characters of amoebae in 

 the stools of a person suffering from the disease, and considered 

 that they were probably the causal agents. Further observations 

 on a more extended scale were made by Kartulis with con- 

 firmatory results, this observer finding the same organisms also 

 in liver abscesses associated with dysentery. Councilman and 

 Lafleur, working in Baltimore, showed that this variety of 

 dysentery can be distinguished from other forms, not only by 

 the presence of amoebae, but also by its pathological anatomy! 

 The intestinal lesions, to which reference is made below, are 

 of a grave character, mortality is relatively high, and recovery, 

 when it occurs, is protracted on account of the extensive tissue 

 changes. The subject was, however, complicated by the fact 

 that a similar organism — the amoeba coli — had been previously 

 found in the intestine in normal conditions and in other diseases 

 than dysentery (by Cunningham and Lewis and others), and 

 additional research confirmed these results. The characters of 

 the common amoeba of the colon and an amoeba of dysentery 

 were carefully worked out by Schaudinn, who recognised them 

 to be quite distinct species, and gave to them the names of 

 entamoeba coli and entamoeba histolytica respectively. Viereck 

 afterwards described an entamoeba of dysentery, which in the 

 encysted stage divided into four cells, and was for this reason 

 called entamoeba tetragena. This organism was shown to have 



41 641 



