AMOEBAE IN MONKEYS I31 



the dog when infected with E. histolytica. If Ware's conclusion is 

 correct, however, it emphasizes the resemblance between the Entamoeba 

 found in the dog and E. histolytica. 



It seems to me highly probable that the spontaneous amoebic 

 dysentery and liver abscess observed in dogs by Kartulis, Darling, and 

 Ware were all due to infection with E. histolytica. The cases all occurred 

 in countries where human faeces containing cysts of this parasite cannot 

 be uncommon : and the habits of the average native and the average dog 

 are quite compatible with the hypothesis that dogs, if susceptible, may 

 occasionally acquire an accidental infection with E, histolytica as a 

 consequence of ingesting cysts deposited by human carriers. It therefore 

 seems justifiable to conclude — in the absence of evidence to the contrary 

 — that Entamoeba " venaticum " Darling is a synonym of E. histolytica. 



The Amoebae Found in Monkeys. 



Many monkeys harbour species of Entamoeba which are not with 

 certainty distinguishable from those of man. As some of them have 

 received names, it is necessary to consider them. 



Kruse and Pasquale (1894) unsuccessfully attempted to infect a 

 monkey with amoebae from a case of dysentery. Musgrave and Clegg 

 (1904) believed that they were able to infect monkeys (Uacacns cynoniolgus 

 and M. philippinensis) with amoebae from their cultures, thereby pro- 

 ducing dysentery in them. Walker and Sellards (1913), however, were 

 unable to infect the same species with E. histolytica. Musgrave and 

 Clegg state that they " have occasionally observed cases of naturally 

 contracted amebiasis in monkeys" in the Philippines: which may 

 account for their " positive" results (obtained with harmless free-living 

 amoebae), and the ulceration of the colon described and figured in their 

 experimental animals. 



Wenyon (1908) records that he found " cysts of an amoeba indistin- 

 guishable from those of Entamoeba coli" in " the intestine of a monkey " 

 at Khartoum. Brumpt (1909) found a similar organism, with 8-nucleate 

 cysts, in Macacus sinicus. Attempts to infect 4 cats were negative. Noc 

 (1909) tells us further that the "macaques" of Saigon commonly pass 

 amoebic cysts 10-12 /x in diameter in their faeces, and that they suffer 

 from spontaneous dysentery. 



Castellani (1908) described a spontaneous case of amoebic liver abscess 

 in a Ceylon monkey (Macacus pileatus) , and named the parasite Entamoeba 

 mittalli. He found no lesions in the bowel, and from his account and 

 figures (from dried films) the organisms cannot be identified, as all 

 cytological details are lacking. According to Kartulis (1913) Strong 

 observed a case of amoebic appendicitis and liver abscess in an orang- 

 utan at Manila. Chatton (191 2 «) found small amoebae — many containing 

 chromatoid bodies — in the faeces of a dead Macacus sinicus. They closely 

 resembled the precystic forms of E. histolytica, but he found no mature 

 cysts, and no lesions in the large intestine, and therefore did not name 

 the organism — beyond referring it to his genus Loschia {= Entamoeba). 

 Franchini (191 2) claims to have infected "a monkey" with "Amoeba 

 tetragena " from a human case of dysentery, but his figures and description 

 are far from convincing. * Ujihara (1914) also claims to have infected a 

 monkey with this species, but his experiment is very questionable, 



• Some of the " amoebae " figured appear to be Lamblia. 



