(Chapter 6) Footnote 149:

Vesalius cites book 4 of De anat. adm. in the margin, where see 2.419.15f.; but the point of Galen’s reference to such material is to dismiss inquiries about it as ignorant and misguided: “Is it not then disgraceful that people ignorant of many such facts [about muscle fibers] should [idly] inquire if there be not some cartilaginous or bony element in the pineal gland?” (tr. Singer 1956 p. 93).