This book includes a survey of the historical literature on pica in humans, reports on pica in domestic animals, a designation of recent studies on the incidence of pica, and a report of findings of a study in which Dr. Cooper has been active. The clinical findings of this latter study come from children referred for mental-hygiene guidance to the Mothers Advisory Service which is conducted by the Division of Mental Hygiene, Johns Hopkins School of Hygiene, in co-operation with the Eastern Health District of Baltimore, Maryland.