Cases of dementia præcox occurring in different members of the same family are by no means uncommon. The first example given is of brother and sister both admitted to the asylum during the same year. The family history is bad. The father died æt. 63; he was an alcoholic, was irritable and prone to anger, suspicious, and seclusive. He was also influenced by ideas of persecution; stated to have had syphilis. All the family on the paternal side nervous and unstable. A nephew. was an idiot. Mother healthy. There were five children, of whom the first two died in infancy of meningeal trouble. The eldest of the three surviving children is normal. The other two are the patients noted. The brother was nervous and fretful as a child. The symptoms of dementia præcox appeared when he was 17½ years old, a month after a fall from a bicycle, when he was unconscious for several hours. He was suspicious, restless, destructive, and deluded, believing that people interfered with him and prevented him from working. Then for several months he was mute. He became increasingly apathetic.