As a result of the excessive destruction of red cells the liver cannot convert the great amount of haemoglobin outpouring into bile pigment so that haemoglobinaemia and haemoglobinuria result. It has been estimated by Ponfick that if ⅙ of the red cells are destroyed the liver is unable to dispose of the liberated haemoglobin and haemoglobinuria results. A damaged liver would be less competent. Various discussions as to autolysins and complement content of serum have arisen. Dudgeon has demonstrated active haemolysins in the tissues and urine of blackwater fever cases which bodies he was unable to note in other conditions including malaria. There was no evidence of increased fragility of the red cells. There was no evidence of auto-haemolysis. Bile pigment in the plasma occurred in most of the cases which ended fatally. As a rule we have the pathological findings which go with malaria. As peculiarities of blackwater noted by Whipple and others may be mentioned congestion of the kidneys with purple-colored pyramids. In the spleen the Malpighian bodies are prominent and sharply outlined. Very striking are the necroses of the Malpighian corpuscles of the spleen and focal necroses of the liver. Whipple considers that this speaks for a powerful circulating toxin in blackwater fever which is not present in malaria. The liver cells in the area of the central veins show the most marked destruction. The myocardium shows fatty change and the fat lipoid content of the adrenal is reduced. The anuria is thought to be mechanical and due to the plugging up of the tubules by haemoglobin casts. The urine shows a reddish to black color and has a sediment made up of granular débris with haematoidin crystals and only rarely a red cell. It is not a haematuria. The absorption bands of methaemoglobin are usually noted spectroscopically. Urobilin and albumin are present in large quantities. SYMPTOMATOLOGY =A Typical Case.=—In a person who has lived in an intensely malarious region for one or two years or even long after he has left such districts and who has had several malarial attacks, there comes on what is considered as another malarial chill, which may or may not definitely be connected with some resistance-lowering influence, as exposure to tropical sun or rain, or indulgence in dietary or other excesses, or following in one to six hours the accustomed dose of quinine. This chill, however, is more prostrating than those formerly experienced and upon passing his urine the patient notes its reddish to black coffee color and himself makes the diagnosis of blackwater fever. The attack comes on suddenly with a very severe chill, marked prostration and pain over the region of the kidneys. The temperature in a typical case rapidly goes up to 104° to 105°F.