There are recognizable stages in the emergence of a scientific field from the part-time or particular interest of one or more practitioners to a profes­ sional subgroup whose members practice exclusively in a well-defined field. Nineteenth and early twentieth century specialization-like the new and developing specialty fields today-was reflected in the special interest of individuals and in scientific societies rather than in the formation of specialist regulating bodies. More recently, there appears to have been a certain com­ pulsion for relatively large groups of specialists to become self-regulating branches of medicine with their own postgraduate examinations and with a powerful interest in advancing the status of their specialty. Improvement in standards is a primary motivation, but this is inevitably linked with improv­ ing prestige. The Royal College of Physicians and the Royal College of Surgeons were very early examples. Two recent claimants for similar status are pathology and psychiatry, described in this chapter.