Middle-earth
Another example is C. S. Lewis's "Space Trilogy," in which Earth is also called Middle-earth. Lewis's novels are situated at the approximate time of World War II, with the last novel, "That Hideous Strength," taking place in post-war England, and they specifically bring in references to Tolkien's legendarium (at that time largely unpublished) and treats these references as primary fact within Lewis's fiction. Merlin, of King Arthur fame, is treated as a successor to the Atlantis magic found within "Numinor" (Lewis's unintentional misspelling of Númenor), and similarities can also be found in the Quenya name for Númenor, which is "Atalantë," and Lewis specifically references the earth as Middle-earth twice, both in Chapter 13, "They Have Pulled Down Deep Heaven on Their Heads". Lewis's borrowings came directly from Tolkien himself: they were close friends and shared each other's literary creations. Lewis encouraged Tolkien to persevere with his Middle-earth writings.A small selection from the many books about Tolkien and his created world:
Proverb
Probably the most famous user of proverbs in novels is J. R. R. Tolkien in his "The Hobbit" and "The Lord of the Rings" series. Herman Melville is noted for creating proverbs in Moby Dick and in his poetry. Also, C. S. Lewis created a dozen proverbs in "The Horse and His Boy", and Mercedes Lackey created dozens for her invented Shin'a'in and Tale'edras cultures; Lackey's proverbs are notable in that they are reminiscent to those of Ancient Asia - e.g. "Just because you feel certain an enemy is lurking behind every bush, it doesn't follow that you are wrong" is like to "Before telling secrets on the road, look in the bushes." These authors are notable for not only using proverbs as integral to the development of the characters and the story line, but also for creating proverbs.