S OME YEASTS PRODUCE SEXUAL SPORES (ascospores) in a variety of shapes and surface ornamentations. These intriguing structures have hitherto been used only in yeast classification. Here, we propose the likely primary function of spore shape and ornamentations, in water-driven movement, as aiding the dispersal of the spores from enclosed containers (asci). This interpretation of the mechanics involved might find application in nano-, aero-and hydro-technologies with the re-scaling of these structures.