Description:In the psychiatric service of the French army operating in Algeria, the author had an excellent opportunity to observe the mental symptoms associated with malarial fever. Other writers in describing these symptoms have attached more importance to the condition of mental confusion than to anxiety states. Anxiety may exist independently, although it is more often associated with confusion. The anxiety itself in severe cases causes the mental confusion. The clinical picture is marked by labored breathing, tremors, vertigo, extreme motor incooerdination, fear of death, etc. The delirium is impoverished, being circumscribed by the conditions of military life. The reactions are violent, the patients frequently being suicidal and hostile toward the attendants. Severe disorders are preceded by a period of uneasiness, and after the fever has subsided the patients are frequently nervous and restless. The author recognizes the importance of certain predisposing causes such as the severity of the climate, fatigue due to lack of sleep, faulty diet, infections, etc., and certain psychogenic factors such as length of exile from civilization, scarcity of leaves, the irregularity of the mail service, the hostility of the native population, etc., but is inclined to attach more importance to certain organic disturbances of the liver, spleen, and, secondarily, of the heart. He finds the hypothesis of the malfunctioning of the visceral reflexes more satisfactory than Lange's hypothesis of peripheral vasomotor disturbances, although he admits that little is known concerning the physiology of these processes.