This paper is based on a study of 20,000 cases delivered at the Jewish Maternity Hospital during the eleven years from 1909 to 1920. The series includes 340 cases in which labor was induced or aided by mechanical means. Of the latter, 290 cases have been analyzed in detail. Though we have taken into consideration, and given due heed to the teachings of obstetricians at home and abroad, we have arrived, from a study of our own cases, at conclusions not always in accord with the practices of other institutions. DEFINITION Induction of labor refers to the production of pain and termination of pregnancy beyond the twenty-eighth week of gestation. At this time the fetus becomes viable. The cases that require induction can be divided into two groups. In one group labor is induced for the sake of the child; in the other, pregnancy is terminated for the welfare of