3552281 MS Hunter 251 f.43r, Full page illustration of use of surgical instruments in operation for fistula-in-ano, c.1475-1500 (pen & ink and tempera on vellum) by English School, (15th century); Glasgow University Library, Scotland; (add.info.: Medical treatise by John of Arderne concerned with the treatment of anal fistula The instruments depicted to the left, from left to right, are: the \'sequere me\' (\'follow me\') a flexible probe, so called because it was the guide to be followed by other instruments; a syringe; the \'Acus rostrata\' or snouted needle, a grooved director along which the scalpel was passed; the \'fraenum Caesaris\' or strong thread, a ligature that constricted the rectal side of the fistula; the \'tendiculum\', which was used to keep the ligature taut whilst the fistula was being divided; another syringe. The \'cochlear\' (or shield) is shown at the top; this was probably held by the surgeon\'s mate and was used to protect the rectum during the operation. At the bottom is another snouted needle accompanied by a razor like scalpel.); 穢 University of Glasgow Library ; English, out of copyright.