In collecting data for teaching purposes regarding mega-esophagus, I was impressed with the lack of any full account of this condition in English. Thieding's1 monograph, the outstanding contribution on this subject to date, published in German in 1921, contains nothing of the work of Plummer and Vinson, not to mention other important American or British writers. Beside this, Thieding's paper is given over to an attempt to prove that cardiospasm is a part of autonomic imbalance and that as such it is symptomatic of psychoneurosis. It has therefore seemed worth while to connect and publish my notes, using Thieding's paper freely and referring to his large bibliography, exhaustive, doubtless, within the limits of the literature available to that author at that time. Data collected from 13 personally observed cases, during five years of existence of the group service of gastro-enterology in the New York University division of Bellevue Hospital,