The Gastro-Intestinal Tract.— Except in a few instances, the gastro-intestinal tract shows but little change other than that arising from the deposit of pigment. Microscopically the capillaries of the mucous membrane may be found to con tain parasites as well as pliagocytic cells containing pigment in greater or less amount.
It has been shown by Bignami,however, that in certain instances the gastro-intes tinal tract may constitute the point of chief localization of the infecting para sites. These cases, clinically-, usually pre sent the manifestations characteristic of the choleraic form of pernicious fever. Microscopically there may be intense in jection of the mucous membrane of the stomach and intestines, with numerous punctiforrn hmmorrhages. The capil laries of the mucous membrane may be crowded and their lumina obstructed with parasites, which may be contained within phagocytes, or red blood-cor puscles, or may exist free. These throm boses result in necrosis of the epithelium of the mucous membrane with super ficial ulceration. Barker (Johns I-Iop kins Hosp. Reports, vol. v, '90) reports a case in which the capillaries, of the mu cous membrane were so blocked with parasites contained within mononuclear macrophages that numerous small, cir cumscribed areas of necrosis of the mu cosa resulted.
The Lungs.—In many cases areas of broncho-pneurnonia or infarction are to be observed. and it is somewhat note worthy that the areas of broncho-pneu monia do not, as a rule, show the presence of pigment. Microscopically the capil laries of the alveoli are found to be filled with infected blood-corpuscles and ma crophages.
The capillary endothelium infre quently contains pigment, although the large number of phagocytes contained within the alveolar capillaries may lead to necrosis. It is unusual to find pig ment-containing leucocytes in the in terior of the alveoli.
The Heart and Illuscles.—The cardiac muscle is frequently pale, softened in consistence, and shows the evidences of fatty degeneration; the same changes may be observed in the general muscular system. This degeneration of the myo
cardium and of the voluntary muscles may in part be due to the blocking up of the capillaries with parasite-contain ing blood-corpuscles and cells.
Many authors believe that malaria may cause definite heart-lesions, but again there is not a single case reported which is of convincing evidence, and as negative proof against this theory La veran and the other authorities on malaria hold the opposite view. Norton (Amer. Jour. Med. Sci., Feb., '93).
The Bone-marrow.—The bone-marrow is of brown-red color, sometimes almost black; it is soft, almost diffluent. The vessels are found to contain developing, as well as sporulating, parasites, and crescents are usually present in abun dance. About the periphery of the lu mina of the vessels macrophages contain ing pigment may be found in consid erable numbers. Nucleated red blood corpuscles, which sometimes exist in grreat numbers, do not contain parasites (Mannaberg).
The Brain.—Macroscopically the brain may show but slight evidence of change, and inclanosis may not be present. Usu ally, however, a distinct localization of the infected blood-corpuscles appears to take place in the cerebral capillaries, and then melanotic discoloration, especially . e •.:.. .r mar he observed.
\I., rot,on tin cortex may . • t injuction of tlit.‘ .1 ._ I, D.)I infrequently, •.•iir.c:, form lia,morrhages.
I -• • art to be particularly ob -Lr. wst,•1•Lk ,f pernicious fever of • r-s- f -rm. and in such cases the - tlild n are remarkable.
• •1 ,t.i.,,srts of development, t,, sta,,c usually predonii r thL ctrLbral capillaries un • Ls. complete obstruction Or ;. .)f their lumina takes place.
•.:ras:tt,. although commonly seen I-, • • red blood-corpuscles. may be •r cAitained. together with pigment '.1,-.,.1-Lorpuscles, within phagocytes. T.-., r mav be macrophages, leuco vt• ..r may be derived from the endo ..l..• ..f the capillaries.