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.—Is 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. ( Vide 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 , 
