The richest body of psychological and sociological facts is found in the files of the institutions for the care of the mentally disordered, although the material available in general hospitals is of value. The case history of a patient in a good mental hospital is a document to which many have contributed. There is a report of the physical condition of the patient as it is revealed in the routine examination on his admission to the institution. This may be supplemented by transcripts of previous and subsequent examinations. There is also to be found the rating attained by the subject on several general-intelligence and special-aptitude tests. There is a report of the preliminary interview and the diagnosis by the psychiatrist. This is amplified by a summary of the proceedings at staff conferences to which the patient is presented, and which is attended by the whole body of physicians and psychiatric social workers attached to the hospital. The usual routine is for the physician and social worker in charge to present a summary of the case, to introduce the patient for observation, and to engage in general colloquy upon the diagnosis and therapy after the patient has been escorted out of the room. The patient may be brought before several staff conferences for the purpose of discussing whether he is in a condition permitting of release, parole, or transfer. During his stay in the institution the nurses, as well as the physicians who make rounds, add their descriptive comments upon his behavior. The social service department gets in touch with relatives and acquaintances and prepares a biography of the subject. Occasionally the patient will volunteer an autobiography, which is filed with the general record. Correspondence with individuals who have interested themselves in the case will often disclose valuable details. The exhibits frequently include letters written by the patient before, during, and after his illness, together with published works, drawings, paintings, and plastic productions. In some instances the record of a single patient who has been admitted, released, or transferred becomes very voluminous.