The authors describe in detail the treatment of a delinquent boy. Their purpose is to illustrate the characteristics of play action and play acting, particularly in their relation to acting out. These phenomena, i.e. play action and play acting, are the childhood forerunners of the secondary process. The authors conceive of acting out as being composed of components from these early stages

of thought organization. A table is included, entitled 'The concept of acting out in relation to stages of impulse mastery and ego development', which helps to clarify the authors' exposition. Acting out reflects the failure to obtain stability in ego function and object relationships. In the case described the communication between patient and therapist consisted of play action and play acting. The transition to a verbal mode of communication was slowly achieved.