ress for some time, even a few years, before recognition. When once established, the course is slowly progressive, with a gradual evolution of delusions which are constantly being further systematized and made to encompass new environment. Several psychiatrists claim that the course of the disease presents definite periods according to the stages of evolution of the delusions. At first there is the prolonged period of insidious onset, by Regis called the period of subjective analysis, followed by the persecutory period with the development of delusions of persecution with hallucinations, and finally the ambitious period accompanied by a change of personality. The patients usually are quite orderly, present an unclouded consciousness, and for many years are capable of considerable labor, both mental and manual. After a duration of many years there appears a moderate degree of mental weakness. Patients become unable to apply themselves, take less notice of their environment and less care of themselves. In some cases the disease may seem to be at a standstill for years, while in others partial remissions occur when the patients for a time are able to rejoin their families, but are rarely in a condition to resume their accustomed occupations. The diagnosis depends upon the slow onset, the characteristic, coherent, and systematized delusions of persecution with retrospective falsifications of memory, often associated with a change of personality, unclouded consciousness, coherent thought, and absence of mental deterioration for many years. The paranoid forms of dementia præcox have already been differentiated from paranoia under the former disease. A few cases of dementia paralytica and melancholia may simulate paranoia. Dementia paralytica is to be distinguished by its rapid development, the early appearance of
