A group of eleven girls suffering from congenital ovarian insufficiency (Turner's syndrome) presented this psychiatrist-pediatrician team a unique opportunity to explore the complexities of the hormonal role in the psychology of female

adolescence. As always, a multiplicity of variables—such as multiple hospitalizations, other somatic problems, and immature appearance and stature—muddles the methodology of 'experiments in nature'. Growth-impairing defenses are described and an attempt is made to separate those common to chronic illness generally and those specifically related to this arrested sexual development. The younger girls predictably coped less well than the older group. Once treatment had resulted in perceptible somatic changes, adolescent psychological movement became evident. However, it remained laggard and incomplete. A brief but excellent discussion of genetic and hormonal factors in 'drive endowment' makes vivid the uncertain state of current knowledge.