(Chapter 18) Footnote 87:

A marginal note cites “the end of chapter 11 [of De ossibus], where he seems carelessly to provide the same exit for the first pair as for the second and third.” Here again we may suspect a corruption or mistranslation in the Latin translation by Ferdinando Balamio used by Vesalius in 1543, though by 1555 he would have seen the 1543 Greek text published by Martin Grégoire and Joannes Sylvius (see n. 89 below). 762.9-14 says about the sacrum “The nerves from the spinal cord, issuing through its foramina, pass out of its would-be ‘vertebrae’ just as they do along the spinal column as a whole, yet not from the sides but internally and externally. There are three pairs of them.” ( tr. Singer 1952, p. 772). The chapter which follows likewise separates the nerve pairs issuing from the bones of the coccyx.