=Irregular and Severe Form--Chronic Malaria.=--This occurs in those who have lived long in malarial regions and have suffered repeated attacks of fever, or in those who have not received proper treatment. It is characterized by a generally enfeebled state, the patient having a sallow complexion, cold hands and feet, and temperature below normal, except occasionally, when there may be slight fever. When the condition is marked, there are breathlessness on slight exertion, swelling of the feet and ankles, and "ague cake," that is, enlargement of the spleen, shown by a lump felt in the abdomen extending downward from beneath the ribs on the left side. Among unusual forms of malaria are: periodic attacks of drowsiness without chills, but accompanied by slight fever (100 deg. to 101 deg. F.); periodic attacks of neuralgia, as of the face, chest, or in the form of sciatica; periodic "sick headaches." These may take the place of ordinary malarial attacks in malarial regions, and are cured by ordinary malarial treatment. =Remittent Form (unfortunately termed "bilious").=--This severe type of malaria occurs sometimes in late summer and autumn, in temperate climates, but is seen much more commonly in the Southern United States and in the tropics. It begins often with lassitude, headache, loss of appetite and pains in the limbs and back, a bad taste, and nausea for a day or two, followed by a chill, and fever ranging from 101 deg. to 103 deg. F., or more. The chill is not usually repeated, but the fever is continuous, often suggesting typhoid fever. With the fever, there are flushed face, occasional delirium, and vomiting of bile, but more often a drowsy state. After twelve to forty-eight hours the fever abates, but the temperature does not usually fall below 100 deg. F., and the patient feels better, but not entirely well, as in the ordinary form of malaria, where the fever disappears entirely between the attacks. After an interval varying from three to thirty-six hours the temperature rises again and the more severe symptoms reappear, and so the disease continues, there never being complete freedom from fever, the temperature sometimes rising as high as 105 deg. or 106 deg. F. In some cases there are nosebleed, cracked tongue, and brownish deposit on the teeth, and a delirious or stupid state, as in typhoid fever, but the distention of the belly, diarrhea, and rose spots are absent. The skin and whites of the eyes often take on the yellowish hue of jaundice. This fever has been called typhomalarial fever, under the supposition that it was a hybrid of the two. This is not the case, although it is possible that the two diseases may occur in the same individual at the same time. This, indeed, frequently happened as stated, in our soldiers coming from the West Indies during the Spanish-American War--but is an extremely uncommon event in the United States.