But here a difficulty occurs. In one very important particular the Kerko Porta, as described by Ducas, does not correspond to the character of the entrance with which it has been identified. The gate which the historian had in mind led to the peribolos, the terrace between the two Theodosian walls, whereas the gate below Tekfour Serai opens on the parateichion, the terrace between the Outer Wall and the Moat. This discrepancy may, however, be removed to some extent by supposing that under the name of the Kerko Porta. Ducas referred to the postern which Dr. Paspates[388] found in the transverse wall built across the northern end of the peribolos, where the Inner Wall of Theodosius terminates abruptly a little to the south of Tekfour Serai. The postern was discovered in 1864, after some houses which concealed it from view had been destroyed by fire. It was 10-½ feet high by 6 feet wide, and although the old wall in which it stood has been, for the most part, pulled down and replaced by a new construction, the outline of the ancient postern can still be traced. Such an entrance might be buried out of sight, and be generally forgotten; and to open it, when recalled to mind in 1453, was to provide the defenders of the city with a secret passage, as they hoped, to the peribolos and the rear of the Outer Wall, where the contest was to be maintained to the bitter end. The suggestion of Dr. Paspates that this was the entrance at which the incidents recorded by Ducas occurred may, therefore, be accepted. But, from the nature of the case, an entrance in such a position could not have been, strictly speaking, the Gate of the Circus, and to call it the Kerko Porta was therefore not perfectly accurate. That was, properly, the name of the gate below Tekfour Serai. Still, the mistake was not very serious, and, under the circumstances, was not strange. Two entrances so near each other could easily be confounded in the report of the events in the neighbourhood, especially when the postern in the transverse wall had no special name of its own. Dr. Mordtmann[389] thinks that the postern near the Kerko Porta was the one which Giustiniani, according to Critobulus,[390] opened in the Inner Wall to facilitate communication with the peribolos. The latter postern, however, is represented as near the position occupied by Giustiniani and the emperor, while the former is described as far from that point.[391] Footnote 287: Codinus, p. 97. Footnote 288: See below, p. 81. Footnote 289: Sozomon, iv. c. 2. Footnote 290: Anonymus, i. p. 38. Footnote 291: Procopius, _De Æd._, i. c. 3. Footnote 292: _Synaxaria_, Octob. 25. Footnote 293: See below, pp. 76, 77. Footnote 294: _Synaxaria_, Oct. 25. Footnote 295: Procopius, _De Æd._, i. c. 3. Footnote 296: _Synaxaria_, June 10. Footnote 297: _Ibid._, April 23. Footnote 298: _Ibid._, April 22. Footnote 299: Nicephorus Callistas, xii. c. 14. Footnote 300: Phrantzes, p. 253.