(Chapter 34) Footnote 11:

A marginal note refers to Book 2 of De anat. adm., where see 2.337.2-4, perai/nei d' ei\j th\n r(i/zan au)th\n ou) neu=ron mo/non, a)lla\ kai\ a)rthri/a kai\ fle\y, “Not only a nerve, but also an artery and a vein reach the very root.” (tr. Singer 1956, pp. 58f.). Here too Vesalius’ language closely follows Galen’s. Under the epithelium, a vascularized dermis (part of the nail bed), forming a distinct compartment, is anchored to the periosteum of the distal phalanx ( Gray 1995, p. 408).