“…It was the opinion of Hurst and Rake (1929-30) that the cardiac sphincter failed to relax because of the absence of ganglion cells at that site, and that the dilatation of the gullet proximal to this was secondary. Some doubt has been cast on the observation of Rake that the narrowed segment is aganglionic, by the fact that Buscopan, a ganglion blocking drug, produces some widening of the narrowed portion and emptying of the gullet in the erect position (Wright, 1961) (Figures 8 (a), (b) and (c)). The work of Trounce, Deucher, Kauntze and Thomas (1957) is particularly relevant.…”