Andrew Lang, as you probably know was a Scotsman who collected fairy tales with the unique attribute of color--The Green Fairy Book, The Blue Fairy Book, etc. He also wrote some scholarly works on myths and legends such as this work on the origins of myth in which he prefigures Richard Campbell in offering copious evidence for multiple origins of the same story dating back to before recorded history. He believes that the story is the common theme, not the names, ranks and physical attributes of the Gods, heroes and demons in the various versions.