As defined by Barker[250] pellagra "is a disease characterized by peculiar cutaneous, digestive, nervous and mental disturbances, usually running a chronic course, with periodic exacerbation, but sometimes developing acutely and proceeding quickly to a fatal termination." He speaks of the disease as developing during the winter months usually with neurasthenic manifestations—fatigability, insomnia, slight vertigo, and feelings of apprehension, followed by digestive disturbances later in the spring. The parts of the skin surface exposed to the sun develop an erythema followed by a dermatitis. Nervous and mental symptoms may appear later. In some cases the disease tends to recur every spring. The skin lesions have been described as a characteristic "mask" shown on the face, the pellagrous collar, a bandlike eruption on the neck, Casal's "necklace" extending downwards over the sternum, the pellagrous "butterfly," "gauntlets," etc. The more common digestive disorders are stomatitis and glossitis, gastric disturbances and diarrhea. Neurological symptoms observed include hyperesthesia, paresthesia, anesthesia, tremors, paralyses, muscular pains, increased reflexes and occasional convulsions. The literature of pellagra and its associated mental disturbances has been elaborately reviewed by Babcock.[251] The following references appear in a comprehensive study of this subject made by him in 1910. Griesinger[252] described the pellagrous psychoses as characterized by a vague, incoherent delirium, accompanied by loquacity and loss of memory without any violent excitement or special disorder of the intelligence. The depression gradually develops into a torpor of all the mental powers together with muscular weakness, a condition resembling general paresis. Mongeri[253] states that the psychoses usually begin with a period of depression accompanied by hypochondriacal ideas. This is followed by confusion and hallucinations of hearing. Delusions of persecution appear, with a marked tendency to suicide by drowning. Crimes of various kinds may be caused by the paranoid condition which usually terminates in deterioration. In speaking of chronic and acute forms Bianchi[254] says: "The former is characterized by general depression, melancholia, confusion, slow dementia, paresthesias and ataxic gait. Contractures and subsulti are absent, although in most instances the reflexes are exaggerated. In the acute form we have rapid elevation of temperature, 39° to 41° C.; intense neuro-muscular excitement, subsulti, contractures, muscular rigidity, exaggerated reflexes and confusion with phases of exaltation. There are numerous intermediate forms in which we observe a great variety of psychical phenomena, and also alternations of excitement and depression. Phases of remission and of apparent recovery are observed, especially at certain seasons." Régis[255] is quoted as follows: "It is recognized that the most common form of psychosis in pellagra is mental confusion