45 



T. evansi causes " Surra " in horses in Indo-Burmah, 

 and is said to be conveyed by the fly, Tabanus lineola. 



T. theileri has been suspected as the possible cause of 

 gall-sickness among cattle in the Transvaal. It is perhaps 

 spread by the fly, Hippobosca rufipes. 



T. equiperdum is the parasite of dourine or horse-syphilis 

 in the countries around the Mediterranean. It is conveyed 

 by coitus. 



How would you explain the Occurrence of Nagano, in a Dog 

 or a Horse in a wild Tract, of Africa where there 

 were no other Domesticated Animals ? 



As being due to transmission of Trypanosoma brucei 

 by tsetse-flies infected from a natural alternate host, e.g., 

 a buffalo, or a species of antelope. 



What is Leishmania ? Where is it found, and what is its 

 importance ? 



There are three known species of Leishmania. They 

 are minute and round or pear-shaped parasites found in 

 the blood of Man. They are intracellular, occurring in 

 the leucocytes or white blood corpuscles and also (more 

 abundantly) in the vascular endothelium (i.e., the flattened 

 cells which form the lining of the heart and blood-vessels). 



Leishmania donovani (the Leishman-Donovan body) is 

 the cause of the Tropical Fevers, Dum-dum, Kala-azar, 

 prevalent throughout Indo-Burmah, and usually fatal. 



Leishmania tropica (Wright's bodies) produces "Oriental 

 sore " or " Delhi boil," a localised skin disease. 



How do the Leishmania parasites reproduce ? 



They multiply by fission equal and unequal. A re- 

 markable feature of the unequal longitudinal fission method 

 is, that very thin portions are segmented off from one side 

 of the body, and neither of the two nuclei nor the flagellum 

 are involved in the process. 



