Of the many technical methods employed in the study of gastrointestinal motility, none fully escapes criticism. Objections commonly fall into three groups: The animal is, as a rule, anesthetized; a certain amount of trauma is usually entailed, and, finally, the methods of recording are to a certain degree deceptive and misleading in that intestinal activity is either visibly perceived or recorded as a volumetric change in the lumen. In this paper a new method and its application will be presented. While all the objections are not overcome, especially in regard to trauma, the method possesses distinct advantages over any other in use at present. The experiments are conducted on unanesthetized animals; the action of both muscular coats is individually recorded, and, finally, it is possible to apply stimuli to the mucosa in a manner simulating the passage of normal fecal contents. The paper will be presented in two parts, the