(Chapter 23) Footnote 29:

Vesalius notes in the margin “among other places, in De ossibus chapter 16.” See 767-68: “The lower end [of the humerus] divides into unequal condyles. The radius diarthroses with the outer, but no bone engages the inner, so that it seems much larger than the outer, though it is but little larger.” (tr. Singer 1952, p. 773).