The small nodular formations seen frequently in the periphery of the normal iris and first described by Wölfflin1 in 1902, hence called Wölfflin spots, were observed on 870 persons, 398 males and 472 females, of the age of a few months to 96 years. The study confirms the findings of other authors that there is no sex preference and that there is greater incidence of the Wölfflin spots in blue and gray than in brown irides. Although the number of persons was not very large, there was a recognizable tendency for steadily increasing incidence of irides with well recognizable Wölfflin spots with age up to approximately the fourth decade. Many irides show a few atypical spots, some of which are difficult to classify as Wölfflin spots. Irides with such more or less questionable spots are more frequent than those with the certain Wölfflin spots. The questionable spots also increase in incidence with age up to approximately the fourth decade and then show a decrease to their initial level Some probable mechanisms of formation of the Wölfflin spots are discussed. More studies, especially longitudinal studies, would be necessary in order to detect the true mechanisms. Attention was drawn to these spots in order to emphasize their differentiation from pathological nodules and also to demonstrate that such obviously insignificant features of the iris nevertheless may yield interesting problems for research.