Erratum.
In the article by Jane Menken et al. "Age and infertility" (26 Sept., p. 1389), the first sentence under the sidehead "Diagnosus of infertility by failure to conceive within a year" (p. 1390, column two, paragraph two) should have read: "The historical evidence indicates that the proportion of women who were sterile increased rather slowly and almost linearly from the 20's until the early 40's.