The experimental transfer of certain intestinal protozoa from man to monkeys.

The species identity of intestinal amóbae harbored by monkeys with the intestinal amóbae of man presents a difference of opinion among protozoologists, one group believing them to be identical with the common species found in man, and another group believing them to present distinct species differences. It seems that this question can best be settled by investigation from three main angles, first, by a study of the morphological characteristics, second, by experimental transfer of the protozoa from one species of host to another closely related host, and third, by a comparative study of the various forms under artificial culture conditions.

This paper is a preliminary report of the experimental transfer of certain of the intestinal protozoa from man to monkeys. The routine examination of the faeces of seven monkeys from Southern China, belonging to the genus, Pithecus, showed the presence of protozoa indistinguishable morphologically from E. dysenteriae, Endolimax nana, Endamoeba coli, Councilmania lafleuri, Iodamoeba bütschlii, and Chilomastix mesnili. To the knowledge of the writer this is the first report of the presence of Councilmania and of Chilomastix in monkeys.

All seven of the monkeys harbored amóbae morphologically indistinguishable from E. dysenteriae, and consequently no feeding experiments with E. dysenteriae from man could be performed. It should be noted, however, that successful transmission of E. dysenteriae from man to monkeys has been reported by Franchini 1 and Ujihara. 2 Certain of the monkeys of the present series were negative for one or more of the other protozoa in question, and feeding experiments were performed as indicated in the table.