Note 340 — BOOK III
Arthur John Brock translation
It appears to me, from comparison between this and other passages in Galen’s writings (notably Use of Parts, iv., 8), that he means by the “two coats” simply the mucous and the muscular coats. In this case the “straight” or “longitudinal” fibres of the inner coat would be the rugae; the “circular” fibres of the inner intestinal coat would be the valvulae conniventes.