Announcing a new title in the P-H Junior Research series: There are 8 short stories purporting to show how children or childhood experiences led to significant advances in medical knowledge. Six of the stories are valid. For instance, Leopold Auenbrugger learned to tap kegs as a child to guess how much was in them and grew up to develop a system for tapping backs and chests to diagnose congestion; Jenner used a young boy for his first inoculation experiment; Pasteur's second rabies series was used on a shepherd boy whose recovery confirmed t he vaccine; and Lister's second patient to be washed with carbolic was a boy who survived without infection. There are three stories that strain at the point: because Captain Cook took to sea as a cabin boy he got an early start observing effects of scurvy?; Florence Nightingale doctored sick animals in girlhood and was thus led into pioneer nursing?; Robert Koch and his boyhood collection of botanical/geological specimens foreshadowed his patient experiments in bacteriology?; Diagnosis -- small areas of spotty logic. Prognosis -- the patient comes from a long series of sturdy stock and falls in a subject area where the interest is infected early.