These remarkable examples of "medical folk art" date back to 1908, when a student doctor was waiting to be called to deliver a baby at Guy's Hospital in London.
With nothing else to do, the student, whose identity is not known, decided to carve the date, his initials and a vaguely gynaecological scene into the panelling.
This idle act of vandalism set in motion a tradition that lasted until 1954.
The complete series of carvings is now housed in the Gordon Museum, on the Guy's campus of King's College London.
It depicts many national and international events, from general elections and wars to the birth of radio, the German Zeppelin attack on London and sporting victories, although always with a gynaecological twist.
Topics such as "labour unrest" and "Tube strike" are interpreted in predictable ways. Less likely is the version of the Loch Ness Monster rearing up from the depths.
Send suggestions for this series on the sector's treasures, oddities and curiosities to: matthew.reisz@tsleducation.com.