This investigation of the teaching of science in secondary schools is based upon the analysis of 58 courses in general science, 45 courses in biology, 27 courses in physics, and 30 courses in chemistry. The courses were obtained from schools in response to a request from the Office of Education for courses which had been revised since 1925. Some courses were also secured from the Division of Research of the National Education Association. Twenty-six States are represented by one or more courses of study. In addition to the data obtained from the courses of study, visits were made to schools in 14 cities in various parts of the United States. Fifty-five classes were visited. The purpose of the classroom visiting was twofold: (1) To discover the extent to which the courses of study actually functioned in dictating the subject matter presented and the technique of instruction employed; and (2) to discover promising innovations in classroom technique. Most of the visits were made to cities in which revised course outlines had been prepared. Individual sections contain footnotes. (Contains 8 tables.) [Best copy available has been provided.]