(Chapter 23) Footnote 25:

Beginning here, some sixteen lines of the 1543 version are rewritten as follows in the 1555 edition: “The sixth will be counted the second of the muscles that supinate the radius; it too takes its beginning chiefly from the lowest part of this outer tubercle of the humerus. The posterior region of the tubercle, covered by muscles that extend the forearm, has a depression (R in fig. 2) carved in the humerus next to the outer side (M in fig. 2) of the trochlea in which the fourth (F in figs. 2, 3, Ch. 11, Bk. 4) of the nerves going to the arm is conveyed. In the same way as the outer side of the humerus projects on its lower end, so too from the inner side (L in figs. 1, 2) of the trochlea of the humerus a large sharp process (S in figs. 1, 2) arises for muscles and nerves, which we shall with good reason call the inner tubercle of the humerus; it does not project for any articulation as does the outer tubercle (P in fig. 2), which is articulated to the radius. From its tip, which is somewhat broad, a muscle (P bringing out l in the 3rd table of muscles) originates which goes to the inner skin of the hand with a long tendon; also two flexors (L, m in the 3rd table of muscles) of the wrist. From the lowest part of this tubercle arises a portion of the muscle (Q in the 7th table of muscles) which will be considered the superior of the pronators of the radius, with an obscure part of the beginning of certain muscles (Q in the 5th table of muscles, C in the 6th) that flex the digits. On account of nerves for which this tubercle provides a convenient passage and acts as a bulwark, it displays a lightly carved depression (T in fig. 1) on its anterior surface next to the trochlea, etc.” It rejoins the 1543 version near the top of page 107.