344 



Marked anaemia and progressive emaciation. (4) 

 Opacities in the eye, leading to blindness. The symp- 

 toms are most typical in the horse. Death occurs in a 

 few weeks or months, the appetite being retained to the 

 end. In cattle the disease is less typical ; and in other 

 animals, e.g., goats, the symptoms are slight, the course 

 chronic, and recovery may take place. 



Incubation.-^-ls generally about ten days after the 

 bite of the fly. 



Blood Examination. Parasites generally first appear 

 with the onset of a rise of temperature, and they are 

 most easily found during a rise in the temperature curve. 

 The number is very variable, and if not found the 

 oedematous areas should be examined. If the result is 

 still negative, inject five to ten c.c. of blood into a rat, 

 intraperitoneally. 



Morphology. 26-27^ in rats. 28-33^ in horses. 

 The nucleus lies almost in the middle. The blepharo- 

 plast is almost quite round. The flagellum is generally 

 separated from it by a slight interspace. (Fide also 

 under < T. evansi.) 



Pathology. There is generally great enlargement 

 of the spleen, liver and lymphatic glands. 



The spleen contains much haemosiderin, the 

 reticulum of the pulp is hyperplastic and contains cells 

 resembling myelocytes. The subcutaneous tissue is 

 oedematous, and effusions occur into the serous cavities, 

 e.g., pericardium. The serous membranes may shew 

 ecchymoses. Parasites are found in the exudates, and 

 in large numbers in the bone-marrow. In the spleen 

 they are few, but on the contrary many degeneration 

 forms occur here. In the rabbit there is a round cell 

 infiltration of the- testes, and an almost complete 

 degeneration of the seminal tubules. 



Transmission. This is effected by Gl. morsitans, 



