LEISHMANIA TKOPICA 437 



organisms. Thus, trichomonas in faeces will appear quite unaltered in the dejecta 

 of the fly five minutes after being taken up. 



With reference to the cutaneous leishmaniasis of South America, there has been 

 much speculation as to the transmitting host. Biting flies and ticks of various 

 kinds have been blamed, but little definite observation has been carried out. Town- 

 send (1915) inoculated a guinea-pig in the skin with flagellates he found in a Chiro- 

 nomid {Forcipomyia). A i^apule developed at the site of inoculation, and bodies 

 supposed to be of the nature of leishmania were found in it. As the flagellates occur 

 neither in the proboscis nor salivary glands of the fly, he believes that transmission 

 is effected by deposition of fly dejecta in the skin, and subsequent contamination of 

 the puncture wound inflicted. No proof was produced that the organism, if an 

 organism at all, in the papule was in reality L. tropica. The experiments conducted 

 by Aragao (1922), which have been noted above, suggest the possibility of Phleboto- 

 miis intermedius being the vector of the South American cutaneous leishmaniasis, 

 while the observations of Strong (1924) suggest a possible connection with the 

 flagellates of Euphorbias. 



ACTION OF DRUGS ON LEISHMANIA TROPICA.— As in the case of 

 L. do))ova)i L tartar emetic and the corresponding sodinm salt have a specific 

 action on the parasites. Cures may be eiTected by scraping, excision, 

 and tlie use of strong reagents, which not only destroy the parasites, but 

 the tissues as well. Such are crystals of permanganate of potash, carbolic 

 and nitric acids, solid carbon dioxide, and methylene blue. Tartar emetic 

 may be used as in the case of kala azar, or in the form of an ointment 

 locally. Emetin, as first pointed out by Photinos (1920), brings about 

 death of the parasite and a cure of the disease w^hen injected into the lesion. 



Possibility of Confusing Leishmania with other Organisms. 



Huntemliller (1914) described under the name of Plasmosoma jeri- 

 choense an organism he had found in sections of tissue removed from 

 a " Jericho boil." He considered it to be an entirely new Protozoon. 

 The wTiter was able to examine the sections, which showed the organism 

 to be badly-stained Leishmania tropica, which is often very difficult to 

 stain in tissues, especially when unsuitably fixed. Similarly, Chalmers 

 and Kamar (1920) described as Toxoplasma pyrogenes certain structures 

 obtained from the spleen of a fatal case of splenomegaly in the Sudan. 

 From information the writer has received, there is no doubt that the 

 supposed toxoplasma was merely degenerating or badly-fixed Leishmania. 



Similarly, the yeast-like organism Cryptococcus farcinimosus, which 

 was discovered and named by Rivolta (1873), was regarded by many 

 observers as a Protozoon, though its original discoverer had recognized 

 its true nature. Pocha Lima (1912) drew attention to the fact that yeasts, 

 as seen in stained smears, often simulated leishmania (Plate IIL, p. 394). 

 Such a fallacy has always to be borne in mind when the organs of animals, 

 especially those which have died and the tissues of which may have been 

 invaded by bacteria or yeasts, are examined for Leishmania. 



