The importance of the continuity of the muscle coat and of the presence of an intraluminal bolus for the peristaltic performance of the Rhesus monkey esophagus was studied. Transection and reanastomosis with muscle-to-muscle contact in the striated muscle part of the esophagus did not interfere with the progression of primary peristaltic contractions. However, when the transection with reanastomosis was performed in the smooth muscle part of the gullet the peristaltic progression of the deglutitive contraction waves in the segment below the transection was affected. After deviation of the swallowed bolus either in the cervical striated esophagus or in the smooth muscle part of the thoracic esophagus, primary peristaltic contractions were seen to progress over the entire length of the gullet; however, in the thoracic esophagus the presence of a bolus facilitated the peristaltic progression of primary waves. These studies also indicate that the extramural vagal innervation is involved in secondary peristaltic contractions of the smooth muscle esophagus.