289 



The urine is acid, contains haemoglobin (? methae- 

 globin) red cells and, not uncommonly, casts and bile 

 pigment. The tissues are more or less pallid, and 

 there may be icterus more or less pronounced. 



The spleen is enlarged. The liver is enlarged 

 and often fatty. The kidneys may be normal, or may 

 in haemoglobinuric cases be greatly congested. In 

 old standing cases they may shew few or no changes, 

 or may be large and pale. The bone marrow is foetal 

 in character. The urine may contain haemoglobin 

 or be dark yellow in colour, but even in acute cases it 

 is often clear and free from blood pigment. In 

 chronic cases it is normal in appearance. 



Transmission. H. leachi is a known carrier in 

 Africa. Takes infection in adult stage, gives infection 

 in subsequent adult stage. Eu. sanguineus, the 

 most widely spread dog tick of the world, is a carrier 

 in India. Takes infection in adult stage, gives infection 

 in following nymphal and adult stage. 



Corresponding to this we have the following 

 cycle of development : 



Development in the Tick (Christophers). (i) The 

 parasite enlarges in the gut of the tick and becomes a 

 motile club-shaped body, which then leaves the gut and 

 penetrates an ovum becoming in the substance of this 

 a ' zygote ' ; (2) This zygote increases in size and breaks 

 up into ' sporoblasts,' which are found disseminated 

 in the tissues of the larva ; (3) These sporoblasts 

 further divide up and accumulate as ' sporozoits ' in 

 the salivary glands of the nymph ; (4) Sporozoits 

 accumulate also in the salivary glands of the adult 

 tick. They resemble the parasite in the blood except 

 that they are much smaller. In infected ticks they 

 are present in immense numbers (Plate III). 



Cultivation. Prepare a number of test tubes 



