Identified by Choulant 1920, pp.148 f. and Cushing 1962, pp.28-32 as Johannes Dryander, alluded to in Bk. 2 ch. 7 as a “certain mathematician” who misrepresented the saw best suited for cutting the bone of the skull, and more courteously by name in Bk. 5 ch. 4. Appointed professor of mathematics and medicine at Marburg in 1535, his Anatomia capitis humani (Marburg,1536, 1537) was one of the first illustrated anatomy books. In 1541 he had plagiarized the illustrations in Vesalius Tabulae sex (1538).