(Chapter 12) Footnote 34:

The rest of this entry was revised as follows for the 1555 edition: “It proceeds farther in the cuneiform bone, into which it is also carved, transmitting a small nerve [n. abducens] (d next to a in figs. 1 and 2, ch. 2, bk. 4) which because it begins not far from the fifth pair of cerebral nerves, we shall call a lesser root of this pair and shall describe together with the fifth pair. But because this foramen sometimes presents itself larger and, so to speak, more elongated, and contains, together with the small nerve mentioned, a thinner root [n. trochlearis] (L next to M in figs. 1 and 2, ch 2, bk. 4)) of the third pair of cerebral nerves exiting at other times with the second pair [n. oculomotorius] (K in the same figures)), you can see it in the left side of the third figure beneath G [n. opticus], shown differently than on the right side.