CHAPTER V 



LEISHMAN BODIES AND LEISHMANIASIS 



Leishman Bodies in General. — While investigating tlie cause 

 of a deadly disease of tropical India known to the natives as 

 kala-azar or dumdum fever, Leishman, in 1903, and at about the 

 same time, Donovan, discovered in the spleen of victims numerous 

 little round parasites. These looked to Leishman exactly like the 

 non-fiagellated stage of a trypanosome (see Chapter VI), and he 

 naturall}" took them to be developmental stages of trypanosomes, 

 and added another terrible disease to the credit of those murder- 

 ous animals. Later, however, it was found that while these little 

 round organisms resemble a certain stage in the life history of a 

 trypanosome, yet they never reach this fully developed form. 

 Nevertheless it was discovered that when transferred to the in- 

 testine of certain insects, or when grown on artificial cultures, 

 they undergo a wonderful transformation. They become elon 

 gate in form and develop a waving flagellum, assuming what is 

 known as a " Herpetomonas " form (see Fig. 14L), and they move 

 about so actively that it is difficult to believe that they are really 

 transformed from the un-animal-like round bodies found in 

 diseased human bodies. Such flagellates, under the name " Lcp- 

 tovionas " or ''Herpetomonas," had been known before, and were 

 recognized as common parasites of insects, belonging to a primi- 

 tive gi'oup of the class Flagellata. They wer(> also known to 

 present, during their development, this unffagellatod round 

 condition, but alwa^ys in the bodies of insects. Here was a 

 vicious form of the parasite which was not content with life in an 

 insect, but must adapt itself to live in the bodies of warm-blooded 

 animals. There is reason to believe that some of the flagellates 

 which normally live exclusively in the intestines of blood-sucking 

 in.sects have the power, if injected into warm-blooded animals, 

 to adapt themselves to the conditions they find there, causing 

 more or less local inflammation and sores. Tn Panama, for 

 instance, sporadic cases of sores occur in which are found Leish- 



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