Since version 9 of the <hi xmlns="http://www.tei-c.org/ns/1.0" rendition="#i">ehd</hi>, a virtual "index" provides an overview of drawings and sketches from Humboldt's or other contemporary hand in the edited texts. Similar to the plant index, it is compiled automatically from the illustrations marked with <hi xmlns="http://www.tei-c.org/ns/1.0" rend="code">figure.</hi>