272 CONTAMINATION OF FILMS BY MASTIGOPHORA 



in the heart blood of a dead mouse, and considered the flagellate had passed 

 from the intestine into the blood-stream; while Knowles, Napier, and Das 

 Gupta (1923) saw the flagellate in the liver and spleen of a rat during the 

 course of kala-azar investigations. In the case of human beings, the 

 writer (1920) found that the whole mucosa of the large intestine of a 

 case was invaded by Trichomonas, while Pentimalli (1923) saw the same 

 organism in the blood of a patient on two occasions at ten hours' 

 interval. Several instances of the occurrence of flagellates of the lepto- 

 monas type in the blood and intestine of lizards are mentioned below. In 

 the majority of these cases the invasion of the blood by intestinal flagel- 

 lates was discovered post-mortem, so that it is not improbable that it had 

 occurred either after or shortly before the death of the animal. In other 

 cases the animals were evidently ill and in such a condition that the 

 natural resistance to such invasion may have been absent. The fact, 

 however, that such an invasion may take place is some indication of the 

 possibility of intestinal flagellates acquiring the habits of blood parasites. 



FLAGELLATES WHICH MAY CONTAMINATE BLOOD AND ORGAN 



SMEARS. 



In this place may be mentioned a number of flagellates which have 

 been encountered in smears made from the blood and organs of various 

 animals. These forms have been regarded as parasites, but this is more 

 than doubtful, for a source of error which arises from time to time in blood 

 work has not been excluded. The distilled water used in laboratories 

 for E-omanowsky staining may become contaminated with free-living 

 flagellates in the bottle or even in the pipette used in the manipulations. 

 When the water is added to the film, either for the dehsemoglobinizing of 

 a thick film or for the dilution of the alcoholic stain on the slide, the 

 flagellates adhere to the film, and are found as blue-staining bodies with red 

 nuclei and one or more flagella according to the nature of the flagellate 

 in the water. The assumption that the flagellates occur in the blood is 

 easily made if their possible source is not recognized. Henry (1917) drew 

 attention to this fallacy in connection with Dymond's supposed h?emogre- 

 garine of trench fever. The writer has encountered this fallacy on several 

 occasions. In one case in particular he was asked to look at a remarkable 

 flagellate in a malarial blood-film. The organism appeared with a blue 

 vacuolated cytoplasm with red nucleus and flagellum. Red-staining 

 bacteria were also present. The possible origin of these was recognized, 

 and an examination of the distilled water which had been used for diluting 

 the Leishman stain revealed their presence. 



Franchini (1913) in Italy described a flagellate from the blood and liver 

 of a patient who had been in Brazil. The organism was also examined and 



