644 Dysentery 



Pathogenesis. — Schaudinn was the first to prove the pathogenic 

 action of the organism. He inspissated the evacuations of a case 

 suffering from dysentery, so that it contained considerable numbers 

 of encysted amebas. When this was fed to kittens they died in two 

 weeks with the typical lesions of dysentery. Musgrave and Clegg 

 had less satisfactory results with cats, dogs, and other laboratory 

 animals, but were quite satisfied with the results secured with 

 monkeys, which took the disease and sometimes died. The lesions 

 resembled, but were less severe than those in man. Musgrave and 

 Clegg would not admit that there were non-pathogenic intestinal 

 amebas, but this was not in accord with the work of any other 

 investigators, and was strongly opposed by Craig,* who found both 



Secondary abscesses 



Falciform ligament 



SmalL abscesses ^^^ ^^^^^ 



I Secondary abscess in 



Main abscess Lymphatic spigelian lobe 



gland 



Fig. 262. — Multiple amebic abscesses of the liver (J. E. Thompson, in Interna- 

 tional Clinics, vol. 11, 14th Series, J. B. Lippincott Co., Publishers). 



varieties, and though he was never able to infect animals with 

 Entamoeba coli, was successful with the pathogenic varieties, and 

 succeeded in infecting 50 per cent, of the kittens he experimented 

 upon, by injecting the amebas into the rectum. 



Lesions. — The gross morbid appearances of the intestinal lesions 

 in both forms of dysentery are sufl&ciently distinct in t3^ical cases 

 to enable an experienced pathologist to differentiate them, yet not 

 sufficiently distinct to make them easy of description. The one 

 great characteristic feature of the amebic dysentery is abscess of 

 the liver which occurs in nearly 25 per cent, of the cases, but which 

 almost never occurs in bacUlary dysentery. 



The distinct and somewhat rigid ectoplasm of the Entamoeba 

 ■histolytica is supposed to make it easy for the organisms, which it 

 * "Journal of Infectious Diseases," 1908, v, p. 324. 



