It was as a result of being shown some of Wolf's drawings, carried out in miniature following his apprenticeship with a lithographer, that Professor Schlegel commissioned Wolf to illustrate Schlegel and Wulverhorst's Traité de Fauconnerie, in 1840. Two drawings in miniature were included as lot 140 in the 15 March 1994 sale of Watercolours and Pictures of Birds in these Rooms (#1,200)