Ninety-seven healthy newborns with a Sydney line in 143 palms were re-examined between the ages of 10 and 14 months. The Sydney line was no longer present at follow-up in 58.8 per cent of these infants and in 66.4 per cent of the palms. It appears that the Sydney line, unlike the simian line and its variants, is age-dependent and is not a permanent structure of early intrauterine origin.