Ambiguity in definition and application of terms, more especially of terms of importance, is still a method of expression unfortunately of too frequent recurrence in descriptive obstetrics. Nor are these infelicities of expression of recent date, for, the need of uniformity in definition and nomenclature has long been recognized. Repeatedly, in monograph, in discussion, and in medical congresses, efforts have been made to overcome these and to establish greater clearness in definition and application of term and a more simple, yet accurate nomenclature.
Among the last to treat of this subject was Prof. A. R. Simpson of Edinburgh, with a committee of American obstetric teachers. Preparatory to its consideration, he had sent out the following question to various teachers of obstetrics throughout the world: "Do you consider it desirable to try to attain uniformity in obstetrical nomenclature?" The replies varied from "eminently so" to "certainly, but very difficult." At the