This is an original collection of exemplary emendations made by ancient and modern scholars. Single examples are analysed in order to extract a method of emendation. The author reviews some attractive interventions which offer a model of textual criticism: a kind of ideal museum of critical intelligence applied to corruptions or cryptocorruptions which have damaged some Greek and Latin literary texts. Advanced students and scholars are offered an orderly sequence of ‘cruces’ healed by great philologists so that a teaching route is granted.