Apart from direct violence, an enlarged spleen may rupture spontaneously, owing to sudden accession in size in the course of a fever fit.
Splenic ruptures are, of course, generally fatal. It sometimes happens that the presence of adhesions limits and restrains the hæmorrhage. Localized hæmorrhages of this description may, in time, lead to splenic abscess.
Hepatic enlargement.—— Like the spleen, the liver in malarial cachectics becomes enlarged during accessions of fever. Under the influence of a succession of acute attacks, hepatic congestion may gradually acquire a more or less permanent character. After death from such fevers the capsule of the liver is found to be tense; on section the highly vascular tissue of the organ is seen to be reddish-brown or almost black, according to the degree and kind of pigmentation. If this stage of congestion be long maintained, it tends to bring about various kinds and degrees of chronic hepatitis with hypertrophy of the intralobular connective tissue, and in time leads to hypertrophic or to different forms of atrophic cirrhosis. Thus irremediable organic disease of the liver, portal obstruction, and ascites may ensue.
Siderosis.—— It is in livers of this description that a form of what is called siderosis is produced a condition resulting from chemical changes undergone by the yellow pigment with which the various cells of the organ are charged. It has already been stated that, when first deposited, this pigment gives no ferrous reaction with ammonium sulphide, or with the double cyanide of iron and potassium; and that, as the deposit becomes older, chemical changes ensue, resulting in the elaboration of a form of iron which will then yield the characteristic black colour with the former, and blue colour with the latter reagent. Treated with ammonium sulphide, sections of liver, and also of spleen, kidney, and other hæmosiderin-charged tissues, from chronic malarials, may turn almost black to the naked eye, or, at all events, exhibit under the microscope abundance of blackened pigment. In such sections it is seen that the hæmosiderin is
