398 FAMILY: TRYPANOSOMID^ 



trypanosomes, but later came to the conclusion that they were herpeto- 

 monas (leptomonas) developed by growth of the leishmania. Leishman's 

 original view as to the flagellate nature of the bodies was thus fully estab- 

 lished. It was not till four years later that Nicolle (19086) and Nicolle 

 and Sicre (1908) obtained a similar culture from the leishmania of oriental 

 sore, an observation which demonstrated more clearly the close relation- 

 ship of the two parasites. Subsequent work established the fact that the 

 parasites were the actual causes of the two diseases, which were shown to 

 have a wide distribution in the Old World, while cutaneous leishmaniasis 

 was found to occur also in South and Central America, where Vianna (1911) 

 gave the name L. hrasiliensis to the parasite. It was further demonstrated 

 that dogs are liable to the same two diseases. 



The organisms belonging to the genus Leishmania, which infect human 

 beings, are thus to be regarded as flagellates of the leptomonas type, which 

 in man and the dog are almost invariably in the leishmania stage, though 

 very rarely the leptomonas form has been observed. There occur, 

 however, certain flagellate infections of other vertebrates in which the 

 predominating forms are of the leptomonas type. These organisms also 

 will be considered as belonging to the genus Leishmania. Button and 

 Todd (1903) stated they had seen a flagellate of the leptomonas type in 

 Gambian house mice, but a later examination of stained films led Todd 

 (1914) to the view that the flagellate was really a trypanosome (T. acomys). 

 Balfour (1916) called attention to the fact that he and Archibald some years 

 earlier had seen such a flagellate in the gerbil in the Sudan, but in neither 

 of these cases was the structure of the organism accurately determined. 



The Sergents, Ed. and Et. (1907), observed flagellates of the lepto- 

 monas type in a stained blood-film of a pigeon in Algiers. The body of 

 the organism was 17 to 20 microns in length, while the flagellum measured 

 19 to 35 microns. The figures show an organism very similar to Herpeto- 

 monas muscarum. It was only found in a film made on one occasion, and 

 has never been rediscovered. Knuth (1909a) found similar forms in 

 smears of the heart blood of a roebuck in Africa, but the animal had been 

 dead some time, was partly devoured and decomposed, and was infested 

 with fly larvae, so that the origin of the flagellates was doubtful. They 

 may have been deposited by flies. Fantham and Porter (1915) gave a 

 figure and description of a similar form observed by them in the living 

 condition in a mouse in England. As the flagellate was seen only in the 

 fresh blood, and was described as very active, it is difficult to understand 

 their statement that the drawings were made with the camera lucida. 

 A nucleus and kinetoplast, which are exceedingly difficult to detect 

 without staining, are clearly shown. 



The Sergents, Lemaire, and Senevet (1915) demonstrated the presence 



