_Bilious Remittent Fever._—This is the most common and the least dangerous of the pernicious manifestations but tends rapidly to produce malarial cachexia. Slight jaundice and bilious vomiting may appear in the course of an ordinary malignant tertian paroxysm and only severe types, with fatal tendency, should be classed as pernicious. It sets in with marked nausea followed by bilious vomiting and bile-rich stools. Jaundice shows itself by the second day; earlier than in yellow fever, but much later than the rapidly appearing jaundice of blackwater fever. The urine shows bile pigment and a yellow foam. Epigastric distress and liver tenderness are marked features and there may even be gastric haemorrhage. _Pneumonic and Cardiac Types._—Other recognized types are when, with the symptoms of a broncho-pneumonia, we find an element of periodicity and a response to quinine—the so-called pneumonic type. Again, usually in elevated regions, dilatation of the right heart and death have been noted as occurring in cardiac types of pernicious malaria. Another type is one in which the sweating stage is excessive, the so-called diaphoretic type. These cases may result in collapse and such a termination may be syncopal in character. =Relapses.=—Relapses are distinct features of malarial diseases, the tendency being most marked in quartan and least so in malignant tertian. A relapse after an interval of two years is very rare in malignant tertian but periods as long as nine years may intervene between attacks of quartan fever. Relapses are intimately associated with conditions which tend to lower the body resistance, so that exposure to cold or wet or hot sun may bring on an attack. Alcoholic or venereal excesses, as well as errors of diet, may be provocative. Persons returning home from the tropics often experience relapses as they approach the cooler climate of the temperate zone. It has been well stated that the old resident of the tropics owes his condition of health rather to education than acclimatization—experience has taught him discretion. There are three explanations of relapses of which the one supported by Ross and Bignami seems more reasonable and is that the disappearance of nonsexual parasites is only apparent and that they continue their cycle but in insufficient numbers to excite symptoms. _Parthenogenesis._—Schaudinn thought that, either spontaneously or as the result of treatment, there was a disappearance of the nonsexual forms and the male gametes, the female gametes however surviving and, eventually, through the process of parthenogenesis, producing a set of spores or merozoites which set up a nonsexual cycle. It would seem probable that Schaudinn saw red cells containing a merozoite along with a female gamete and interpreted his findings as a sporulating sexual form.