(Chapter 15) Footnote 30:

In the margin Vesalius cites book 12 of De usu partium, where see 4.1.3-6 (May p. 550), book 4 of De anatomicis administrationibus, where chapter 8 discusses the movements of the first and second vertebrae (460-463, see Singer 1956 pp. 112-114), and chapter 8 of De ossibus (756.11, see Singer 1952 p. 772). Galen does not discuss the meanings of head movements as gestures. The 1555 edition omits all mention of Galen at this point, transferring it to the end of the chapter.