BLACKWATER FEVER 99 



Pathological Anatomy. No specific organism has been 

 discovered. Malarial parasites are present when the blood 

 is examined before the onset of the disease ; they dis- 

 appear in these cases very shortly after the onset of the 

 haemoglobinuria. In the great majority of cases of 

 blackwater fever, those examined only after the onset of 

 the disease, no parasites are found. 



In fatal cases, on microscopical examination of the 

 liver and spleen, finely divided intracellular black pig- 

 ment will be found as in recent malaria. Frequently 

 it is not abundant enough to be seen on inspection 

 with the naked eye. No parasites are found in the 

 organs, but sometimes pigmented leucocytes are present. 

 The blood examination shows an increase in the large 

 mononuclear elements, such as is found in malaria, but 

 this also occurs in other protozoal diseases. No piro- 

 plasmata have been found, and the blood and organs 

 are sterile as regards bacteria. The organs show all the 

 usual evidences of blood destruction. In the hepatic 

 cells, in the convoluted tubules of the kidneys, and in 

 the spleen, are abundant deposits of haemosiderin, and 

 other granules, not pigmented, are present which give 

 the reaction of iron in inorganic combination. This 

 evidence of blood destruction occurs to a less marked 

 extent in some cases of malaria and in other diseases 

 attended with haemolysis ; it is marked in the piro- 

 plasmosis of cattle. A further evidence of blood destruc- 

 tion is the great increase in the amount of urobilin in the 

 faeces. 



The kidneys in all cases show casts in the tubules 

 (figs. 52 and 33). When death has occurred from sup- 

 pression these casts are very numerous. They usually 

 show evidence of the presence of iron in inorganic 

 combination. 



The renal cells, except for the presence of haemosiderin, 

 are singularly little affected. The epithelium is neither 

 detached nor necrotic, but usually shows cloudy swelling 

 and sometimes fatty degeneration. The spleen may be 



