From Man to Woman and Back Again: Tiresias, Vat. Myth. 1.16

Name:  Vatican Mythographers Date:   10th century CE Region:   Unknown Citation:   Vatican Mythographers 1.16

While Tiresias was wandering through the woods, they saw two snakes mating. When they struck them with a stick, they were changed into a woman. Eight years later, when they saw snakes mating in a similar fashion, they struck them again, and returned to their original shape (in pristinam naturam).

Teresias dum iret per silvam, vidit duos serpents coire, quos cum virga percussisset, in feminam mutatus est. Post octo annos dum videret eos similiter concumbentes et eos rursus percuteret, in pristinam restitutus est naturam. 

Vatican Mythographers [10th century CE?] Little is known about the author or origin of the collection of myths known as the Vatican Mythographers, but the work’s first editor Angelo Mai found the collection on a manuscript dating back to the 10th century CE. This volume is a collection of three different mythographers who have assembled various Greco-Roman myths; although many of these myths are basic summaries in Latin, some of them are either analyzed as allegories or compared to Christian thought.