The Ages of Life

already existing high circulatory levels of cortisol and the Circadian rhythm of cortisol production. The final paper presents a useful plot of cortisol against ACTH in plasma in the normal state and in syndromes involving pituitary-adrenal pathology. Good bibliographies accompany the papers and the editors have provided a glossary of abbreviations and formulas for pharmaceutical brand names occurring in the text. The committee is to be commended for the arrangement of the program, the contributors on the whole for their organization and style of presentation of material, and the members of the symposium for their constructive criticism and provocative questions which make this exchange of ideas most profitable for future progress in this field.