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III] aphasia, Broca's convolution; and so on. By microscopical examination of properly prepared sections of the brain in fatal cases, such a plugging of the vessels can generally be readily observed. The earlier students of malarial melanæmia had remarked the presence of hæmozoin in the cerebral capillaries in many cases of this description, and, overlooking the including parasite, attributed the associated symptoms to thrombosis by the hæmozoin.

Malarial amblyopia.—— In rare instances a comatose pernicious attack eventuates in blindness. The amblyopia is usually transient, lasting for an hour or two only. On the other hand, it may be persistent; in which case, according to Poncet, optic neuritis, peripapillary œdema, extravasation of leucocytes, plugging of retinal and choroidal vessels by parasites or pigmented leucocytes, and consequent multiple hæmorrhages, may be found in the fundus. If the hæmorrhages are minute they are discoverable by the microscope only. These fundus changes differ from those in quinine amblyopia. In the latter, depending on retinal anæmia from toxic spasm of the arterioles, the amblyopia is more persistent; the discs are white and the vessels shrunken; there are no inflammatory symptoms; and central vision is the first to recover. (See Table on p. 76.)

The algide forms of pernicious attack, as indicated by the name, are characterized by collapse, extreme coldness of the surface of the body, and a tendency to fatal syncope. These symptoms usually coexist with elevated axillary and rectal temperature. Gastric form.—— This may be associated with, and in a measure be dependent on, acute catarrhal dyspeptic trouble. It is accompanied by severe epigastric distress, tender retracted abdomen, and incessant vomiting. The vomited matter may contain blood.

Choleraic form.—— Malarial attacks are sometimes accompanied by choleraic symptoms. The stools suddenly become loose, profuse, and numerous. They