This Atlas is principally based on the Brush Foundation Study of Human Growth and Development, conceived in 1929 by Professor T. Wingate Todd of Western Reserve University School of Medicine. This intensive study collected data on the maturation of human anatomy through the meticulous X-raying of a series of research subjects enrolled in the study as juveniles—some as young as three months—and thereafter routinely weighed and measured at three-month to one-year intervals, depending on their age. This Atlas utilizes not only the X-ray films to which Todd had access but, also, those which were obtained in the six years subsequent to Todd's publication of his Atlas of Skeletal Maturation of the Hand. The X-ray standards in the present volume are, therefore, the first to be based exclusively on the research of the Brush Foundation Study.