I do not mean these microscopic illustrations of single cells shown by Hooke (1665) or Leeuwenhoek (1676); see Gest H., Notes Rec. R. Soc. Lond. 58: 187–20, 2004 [DOI 0.1098/rsnr.2004.0055]. I rather mean illustrations of mass occurrences or blooms in frescoes or paintings (of course not known as being of microbial origin at these times). Are there any?