NOTE ON AN INTESTINAL FLAGELLATE IN MAN.' 



By Aldo Castellani 2 and Albebt J. Chalmers. 3 



Eeeently we have observed a flagellate in the stools of cases of agchylos- 

 toniiasis suffering with diarrhoea. A brief description of the organism is 

 as follows : 



. Fresh preparations. — The parasite is extremely motile in fresh preparations 

 from the liquid stools. Two forms are generally present — a slender, and a larger, 

 more rounded one. It measures about 8 to 15 /t in its greatest diameter, but 

 the shape varies very much because the parasite is capable of ameeboid movements, 

 although no true pseudopodia are emitted. Two long flagella originate from one 

 pole by means of which locomotion takes place. There is no evidence of any 

 undulating membrane nor of contractile vacuoles. The protoplasm is homogeneous, 

 but a few vacuoles may be observed in fresli preparations. The nucleus is not 

 visible. 



Stained preparations. — In preparations stained by Romanowsky's method the 

 parasites appear globular, nearly round, or pear-shape, and the protoplasm is of 

 a bluish color; a small, rather eccentric, approximately round nucleus is visible, 

 which is rich in chromatin. In some individuals one or more other small chromatic 

 granules may be observed in the protoplasm in addition to the nucleus. One of 

 these chromatic masses often is situated close to that pole of the parasite from 

 which the flagella originate. In successful preparations two flagella are visible 

 which stain a pinkish or purplish color. 



Cultures. — The flagellate can be grown in symbiosis with bacteria in various 

 liquid media and in the water of condensation of several solid media. 



Acid agar, maltose-agar, serum. — The organism remains alive three or four 

 days in the water of condensation of the tubes inoculated directly from the stools, 

 but it does not multiply and cultivation generally does not succeed in transplanta- 

 tion. 



Saccharose agar. — The parasite remains'alive for several days, but subcultures 

 fail in the majority of cases. 



Sabouraud's agar, acid maltose-agar {2 to 4 per cent), albiimen-agar lactose- 

 agar {2 to Jf per cent) . — The parasite remains alive and multiplies in the water of 

 condensation for from eight to ten or more days. Subcultures are successful. At 

 present we have the thirty-second subculture and the parasite apparently grows 



1 Read at the first meeting of the Far Eastern Association of Tropical Medicine 

 held at Manila, March 12, 1910. 



= Professor of Tropical Medicine and Lecturer on Dermatology Ceylon Medical 

 College; delegate from the government of Ceylon. 



3 Registrar and Lecturer on Pathology and Animal Parasitology, Ceylon Medical 

 College. 



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