The teaching chart that Ernst used for this overpainting depicted magnified views of brewer’s yeast cells.
Saccharomyces cerevisiae. Bierhefepilz (Saccharomyces cerevisiae. Brewer’s yeast). Chart 40 in Heinrich Jung, G. von Koch, and F. Quentell, Neue Wandtafeln für Zoologie und Botanik: Begleitheft (Darmstadt: Verlag Frommann & Morian, [1903?]). Universitäts und Landesbibliothek, Darmstadt
