438 VETERINARY BACTERIOLOGY 



fractory. It evidently is a highly specialized commensal. The 

 organism, with its flagellum, measures about 24 to 25 [i in length 

 by 1.5 U in width. Protoplasmic granules are frequently present. 



THE GENUS HERPETOMONAS 



This genus includes certain flagellates that have an essentially 

 trypanosome-like structure, without an undulating membrane. 

 The cell is elongated in the typical Herpetomonas; the closely 

 related genus Crithridia comprises those forms in which the body 

 is much shortened. The flagellum is anterior, the blepharoplast 

 distinct, as in the trypanosomes, and the nucleus centrally located. 



Organisms of this genus have been frequently reported from 

 the gut of the mosquitoes and flies. Certain of the trypanosomes 

 sometimes assume shapes that resemble closely the Herpetomonas. 

 The genus assumes pathogenic significance, principally because 

 of the tentative classification of certain protozoa known as the 

 Leishman-Donovan bodies as members of this genus. Three 

 species have been described. 



Herpetomonas donovani 



Synonyms. Leishman-Donovan bodies; Leishmania dono- 

 vani; Trypanosoma donavani. 



Disease Produced. Kala-azar, cachexial or Dumdum fever 

 in man. 



Leishman, in 1900, observed this parasite in smears from 

 the spleen of a patient that had died of Dumdum fever. His 

 account was published in 1903. 



Distribution. Throughout southern Asia and northern Africa. 



Morphology. The organism as it occurs in the body is com- 

 monly intracellular. It is found principally in the spleen, liver, 

 bone-marrow, and lymph-glands. It is oval, spherical, or pear- 

 shaped, usually between 2 u and 3.5 ^ in length and 1.5 to 2 fi in 

 width. Two staining granules occur in the interior, the larger 

 spherical, and the smaller, and more deeply staining granule, 

 somewhat elongated. The organisms multiply by a preliminary 

 division of both of the chromatic granules (nucleus and blepharo- 

 plast), followed by a constriction of the cell. In cultures typical 

 flagellates are produced. The organism elongates somewhat, 



