726 PATHOGENIC PROTOZOA 



last two authors was especially complete and firmly established the 

 entity of this disease in America. In 1902 Jiirgens differentiated the 

 pathogenic ameba from the harmless, and in 1903 the epoch-making 

 work of Schaudinn appeared. This author, who was a zoologist by 

 training, showed clearly that there were two forms of parasitic amebae 

 and he followed out most of the details in their life history, renaming 

 them Endameba histolytica and Endameba coli. Schaudinn 's work 

 has been generally confirmed, in this country by Craig, Whitmore, 

 Walker, Darling and others. 



CLINICAL DYSENTERY 



Dysentery as a disease has been known from the earliest times and 

 references are found to it in Sanscrit and Egyptian literature and in 

 early Greek and Roman writings. Until recent years its etiology was 

 obscure, but we now recognize two separate forms, bacillary and 

 amebic; the former has already been described under the dysentery 

 bacilli. Amebic dysentery is a distinct clinical entity, and runs a 

 course quite different from the bacillary form. It begins gradually, 

 and in some cases is chronic in character from the start. Usually there 

 is no rise in temperature nor any great change in weight or health 

 until the disease has existed some time. The bowel movements become 

 gradually more frequent and the fecal matter is accompanied by 

 larger and larger amounts of mucus and blood. As the disease pro- 

 gresses and more and more of the colon is involved the amount of blood 

 and mucus increases until the stool contains little else. The colicky 

 pains increase in frequency and severity and there is added tenesmus 

 and finally nausea and vomiting. The patient loses flesh and strength 

 and when the stools increase to 20 and 30 daily, becomes bed-ridden. 

 The abdomen is concave and tender on pressure, especially over the 

 colon. The course of the disease, if untreated, tends to progress with 

 periods of remission, and spontaneous cure probably does not occur. 

 Bacillary dysentery, it will be remembered, is a disease with a short in- 

 cubation period and an acute onset ; after two or three days ' illness the 

 bacillary case is confined to bed, is pale, weak, emaciated and presents 

 every evidence of profound toxemia; an amebic case, sick the same 

 length of time, will be up and about and perhaps will not have applied 

 for treatment. 



Complications. A common and most dangerous complication is 

 abscess of the liver. The amebae travel from the ulcers in the colon by 



