(Chapter 19) Footnote 73:

De medicina 8.1.15: “This [breastbone], a strong and hard bone, begins below the throat, is lunated on each side, and, when it becomes itself softened into cartilage, is bounded by the praecordia [the upper abdomen below the ribs].” Loeb trans. By W.G. Spencer. But Celsus purports to describe human bones and says nothing about the anatomy of apes or dogs. The 1555 edition adds “where he copied from some one of the ancients that the pectoral bone is crescent-shaped, etc.” Aulus Cornelius Celsus, a 1st century AD encyclopedist and medical writer, was sometimes accused of being a purely derivitave compiler. Vesalius more than once expresses this view in the 1543 Fabrica. On Celsus’ Greek sources, see Temkin 1935, 249-264.