McGill University's WorldCat Catalogue contains information on almost all of the printed holdings in the various branches of the McGill Library and elsewhere, as well as articles and other material.
Suggestions for browsing at the Osler Library: look in N to NC: Art section; there are some works here on medical book illustration (N 8223) and artistic anatomy (NC 760); QS: Anatomy; some works analyze representation; TR 600 to 780: Photography, including medical illustration; WZ 17: History of Medicine: Atlases, Historical Works and WZ 348: History of Medicine: Medical Illustration (general). Check both the regular shelves and Folio ones. Works on representation are also classified within other specific subject categories, such as Biography (WZ 100) or Pathology (QZ).