Audio-tutorial teaching, originated at Purdue University, employs an audio tape as a vehicle for guiding the student through a series of learning experiences. The student may be directed to use his textbook for an explanation of a diagram, to refer to his laboratory manual, or to observe the specimens and experimental materials prepared for his use. The freshman botany course at Purdue is taught using the audio-tutorial concept, supplemented by lectures, quiz sessions, and a research project. The system has produced no significant difference in learning as measured by the final examination. However it covers the material in less time than the conventional course, and is judged to be more interesting by the students. The text is supplemented by graphs of student performance and a list of references. (JY)