M. L. is nineteen years of age, of a rather limited intelligence. He works as a shopboy amidst surroundings of poverty, and leads a hard life, full of privations. He is undersized and underfed, and looks as if he has never had enough to eat. Born in New York, of parents belonging to the lowest social stratum, he was treated with severity and even brutality. The patient has never been to any elementary school and can neither read nor write. His mathematical knowledge did not extend beyond hundreds; he can hardly accomplish a simple addition and subtraction, and has no idea of the multiplication table. The names of the President and a few Tammany politicians constitute all his knowledge of the history of the United States. Family history is not known; his parents died when the patient was very young, and he was left without kith and kin, so that no data could be obtained. Physical examination is negative. Field of vision is normal. There are no sensory disturbances. The process of perception is normal, and so also is recognition. Memory for past and present events is good. His power of reasoning is quite limited, and the whole of his mental life is undeveloped, embryonic. His sleep is sound; dreams little. Digestion is excellent; he can digest anything in the way of eatables. He is of an easy-going, gay disposition, a New York “street-Arab.” The patient complains of “shaking spells.” The attack sets in with tremor of all the extremities, and then spreads to the whole body. The tremor becomes general, and the patient is seized by a convulsion of shivering, trembling, and chattering of teeth. Sometimes he falls down, shivering, trembling, and shaking all over, in an intense state of fear, a state of panic. The seizure seems to be epileptiform, only it lasts sometimes for more than three hours. The attack may come any time during the day, but is more frequent at night. During the attack the patient does not lose consciousness; he knows everything that is taking place around him, can feel everything pretty well; his teeth chatter violently, he trembles and shivers all over, and is unable to do anything. The fear instinct has complete possession of him. He is in agony of terror. There is also a feeling of chilliness, as if he is possessed by an attack of “fear ague.” The seizure does not start with any numbness of the extremities, nor is there any anaesthesia or paraesthesia during the whole course of the attack. With the exception of the shivers and chills the patient claims he feels “all right.”