648 AMCEBIC DYSENTERY 



probably explains a fact pointed out by Manson, that examina- 

 tion of the contents first removed may give a negative result, 

 while they may be detected in the discharge a day or two later. 

 The action here on the tissues is of an analogous nature, namely, 

 a necrosis with softening and partial liquefaction, attended by 

 little or no suppurative change. There is, however, evidence 

 that the amoebae may infect the liver without causing actual 

 abscess formation, merely a hepatitis, and that this may be 

 followed by cirrhosis. Abscesses are also met with in the lungs, 

 and in such cases the amoeba have -been found in the sputum ; 

 as also when a liver abscess has ruptured into the lung, which 

 not very infrequently happens. There have also been recorded 

 a considerable number of cases of cerebral abscess in which the 

 amoebae have been found ; most of these have been secondary to 

 lung infection. 



Experimental Inoculation. — Dysentery occurs occasionally in 

 animals, e.g., in monkeys, but it is of comparatively rare occur- 

 rence. The disease sometimes results in the dog by experimental 

 inoculation with dysenteric material. Kartulis, for example, 

 records two cases, in one of which liver abscess was present. 

 Cats are, however, found to be more susceptible, especially young 

 animals. Dysenteric changes have been produced in this animal 

 by Kartulis, Kruse and Pasquale, and others. The method 

 generally adopted is the introduction of a small quantity of 

 mucus from a dysenteric case into the rectum. The resulting 

 disease is of an acute character, and sometimes leads to a fatal 

 result. The changes in the large intestine resemble those found 

 in the human disease, and microscopic examination shows the 

 amoebae penetrating the wall of the bowel in the characteristic 

 manner. Kruse and Pasquale obtained corresponding results 

 when the material from a liver abscess, containing amoeb* 

 without any other organisms, was injected. Quincke and Roos 

 obtained no effects when the amoebae were administered by 

 the mouth, but they obtained a fatal result in two out of four 

 cases when the cystic forms were given. Schaudinn obtained 

 from China dysenteric material containing cysts and, after 

 drying thoroughly portions of it and administering it to cats, 

 was able to produce typical dysentery, the E. histolytica being 

 found in the stools. The most important experiments, however, 

 are those carried out by Walker and Sellards on the human 

 subject. They administered to Filipinos, who acted as volunteers, 

 various amoebae and entamoebas or their cysts, the material being 

 mixed with magnesium oxide or starch, and enclosed in gelatine 

 capsules. In the case of the cultivable amoebic, they found 



