In the 64th plate from Ernst Haeckel’s ”Kunstformen der Natur” (1904), a number of algae are depicted classified as “Siphoneae”. Among them is “Acetabularia mediterranea” (no. 10 in plate 64), which belongs to the genus Acetabularia (also known as Mermaid’s Wineglass). This unicellular organism may grow up to 10 cm in height and harbours a single nucleus located at the base of its “stem” (only upon reproduction the nucleus divides). The image retrieved from Wikimedia commons (image modified by MIC). The cover is published under the Creative Commons Attribution (CC BY) license.