The above quotation from the writings of Sir William Osier is fully appropriate. It has been an honor for me to work in the Fels Longitudinal Study. Indeed, all the members of the Fels staff are fully conscious of their debt to those who laid the foundations for the studies that are summarized in this volume. Although much has been achieved, all realize that those who follow will greatly extend our present limited horizons.

This book describes the progress that has been made during the first 60 years of the Fels Longitudinal Study of Growth, Maturation and Body Composition. The remarkable nature of the study justifies this volume. Very few, if any, investigations of human beings are so longlived. Despite its longevity, the Fels Longitudinal Study continually becomes more vigorous and active. Few studies have been responsible for equally important research related to serial changes in physical growth and maturation and body composition in normal individuals.

The Fels Research Institute was founded in 1929 with a single complex research project that came to be called the Fels Longitudinal Study. As the name implies, this was a serial study and it was multidisciplinary.