3-^ 



DISEASES DUE TO PROTO'ZOA 



Wenyon has reproduced the disease in cats, but if it is commonly 

 present in animals is not known. 



It should not be forgotten that the drv spores can be carried by 

 flies and wind (Vedder). 



Some afifirm that the presence of intestinal bacteria, e.g., paracolon 

 bacillus, is necessary for the growth of the amoebae (Lesage). 



Flies are blamed as mechanical carriers of the parasite from faeces 

 to food (Wen3'on). 



PATHOLOGY. 



Microscopic. — The spores enter the body with drinking water and 

 food, producing young amoebie in the large bowel. These enter the 



Entamaba colt : life cycle, a — <;, stages in binary fission : A — Z), schizogony, with formation 

 of eight merozoites ; 2 — lo, cyst formation or sporogony, with formation of eight nucleate cysts. 

 (After Castellani and Chalmers.) 



mucosae by Lieberkiihn's follicles, entering the lymphatics, and pass- 

 ing to the submucosa, they feed upon the tissue cells and erythrocytes 

 of the blood. They may destroy the tissue and enter the tributaries 

 of the portal vein or branches of the mesenteric artery, sometimes 

 causing thrombosis. They find their way to the liver, causing hepatitis 

 and liver abscess in 15 per cent, of cases. 



Patches of the mucosa become oedematous and infiltrated bv small 



