DISTOMUM HAEMATOBIUM. 285 



tion of the pelvis and calyx, with complete atrophy of the 

 substance of the kidney, also occur. The aggregations of eggs of 

 the Distoma are not unfrequently the nuclei of deposits of gravel 

 and stones, consisting principally of crystals of uric acid, in the 

 kidneys, ureters, and bladder, and thus give rise to the well- 

 known consequences of stone and gravel. This is the Uthiasis of 

 the Egyptians, already described by Prosper Alpinus in his 

 ' Medicina Egyptiorum/ 



That these uropoetic disturbances have an injurious action 

 on the whole organism in time is a matter of course. They 

 lead to general illness, and finally death, -which, after the 

 complete destruction of the constitution, usually results from 

 pneumonia (perhaps that kind of mechanical pneumonia indi- 

 cated by Viichow, in which the coagulum and similar insoluble 

 bodies borne along by the circulation, stop up the capillaries 

 of the lungs), diarrhoea, or other disorders. Inasmuch as 

 these animals live upon the blood, they might probably cause 

 chlorosis, but no case appears to Griesinger to show that the 

 Distoma alone could be the cause of this. 



Action upon the intestinal mucous membrane. — In the large 

 intestine changes not unfrequently take place exactly similar to 

 those described in the bladder. We find apoplexy, deposits in 

 and upon the submucous and supra-mucous tissues, verrucose and 

 lobate fungous excrescences, and also the aggregations of the 

 eggs of the Distoma in the vessels of the mucous membrane, 

 where the eggs are often fixed in rows in the tissues of the 

 mucous and submucous membranes, in and beneath the croupous 

 exudations upon the intestinal ulcers, and, lastly, after the 

 rupture of the vessels, upon the free surface of the mucous 

 membrane. For a moment the thought might occur to us that 

 this Distoma bears the same relation to the endemic, acute, and 

 chronic dysenteries of the large intestine in Egypt, as the 

 Acarus to the itch (Bilharz) ; but Griesinger, and afterwards 

 with him Bilharz, convinced themselves that this is certainly a 

 coincidence, but a purely accidental one, standing in no relation 

 of cause and effect, as in very many dysenteries the Distoma are 

 entirely wanting. 



Action upon the liver. — The entire trunk of the portal vein is 

 sometimes found filled with mature animals, with eggs in the 

 substance of the liver, and it is not impossible that the Distoma 



