The electrical activity of the digestive tract of the sheep as an indication of the mechanical events in various regions.

1. A method is described in the conscious sheep for recording oscillographically the electrical potentials led from enamelled stainless-steel wires implanted in the wall of the stomach and intestine.2. Slow waves characterized by cyclically recurring and rhythmic fluctuation in voltage have been recorded, together with the superimposed fast activity or burst of spikes when the muscle is contracting. The whole activity comprised a distinguishable pattern of grouped discharge which is synchronous with mechanical events within different regions of the alimentary tract.3. Grouped discharge occurs at a regular frequency of 7/min in the pyloric part of the abomasum and 18/min from the intestine, but 13/min from the middle duodenum and proximal ileum. Only the major grouped discharges of the fore-stomach is correlated with the orderly sequential movements of the reticulum and rumen.4. The relationship between electrical and mechanical activity of the reticulo-rumenal movements was examined at rest, and during feeding and ruminating.5. Electrical correlates of motor activity in the small bowel were investigated under different dietary regimens.