INTESTINAL PROTOZOA OF MONKEYS 29 



Dobell and Laidlaw (1926) and Dobell (1928) have studied the 

 cultural aspects of E. histolytica, E. coli, E. nana, Chilotnastix, 

 Trichotnonas and Enteromonas of man and of monkeys in a very 

 thorough and extensive investigation. They apparently have con- 

 cluded that the three amoebae from monkeys v^ith which they have 

 v^orked, are identical with their cotypes in man. The complete 

 report of their investigation has not been pubHshed yet and they 

 have not made a final statement concerning the species identity of 

 intestinal flagellates. 



Kessel (1926 and I928<:/) also cultivated successfully E. his- 

 tolytica, E. coli, E. nana, lodainocba, Chilonmstix, Trichomonas 

 and Embadomonas from Macacus monkeys with which he was 

 working in Peking and concluded that on cultural grounds these 

 protozoa of man and of monkeys are identical. 



Hegner (1928a) has reported the successful culture of Trichom- 

 onas from the vagina and intestine of Macacus rhesus and 

 Knowles (1926) cultured an amoeba recovered from a monkey 

 suffering with acute amoebic dysentery. 



3. Cross-infection experiments 



Evidences of species identity of the intestinal protozoa of man 

 and of monkeys, based on cross-infection experiments, have been 

 presented by Walker (1913), who infected monkeys with Balan- 

 tidinm coli of man, Kessel (1924 and 1928) who infected monkeys 

 with E. histolytica, E. coli, E. nana, lodamwha. Trichomonas and 

 Chilomastix of man, and by Dobell ( 1926 and 1928) who infected 

 monkeys with E. histolytica and E. nana of man and also trans- 

 mitted E. nana from Macacus sinicus to man. These reports lend 

 strong evidence in favor of the species identity of the intestinal 

 protozoa of man and of monkeys. 



4. The pathological effects of proto::oa of man and of monkeys 



in kittens 

 The kitten has been used extensively in the study of amoebiasis 

 of man and ]\Iello (1923), Dobell (1925 to 1928) and Kessel 

 (1926 and I928<i) report acute experimental amoebiasis in kittens 

 infected with E. histolytica of monkeys. In the experience of the 

 writer the symptoms in kittens thus infected do not differ appre- 

 ciably from symptoms in kittens infected with the human dysen- 

 teric amoeba. Dobell (1925) mentions several points of difference 

 but has not described them in detail as yet. 



