Possible Clues:

• *Path through Oz
• What Dorothy follows to Oz
• Path taken by 37-Across to find the ends of 17-, 26- and 44-Across in [circled letters]
• One dollar 1 across wanting inoculation to show the way to fantastic city
• Path to 6 and 23 coloured 12 and black beside haystack, by the way
• Something to follow
• *It begins in the heart of Munchkin Country
• ''The Wizard of Oz'' pathway
• ''Follow the __'' (''Wizard of Oz'' instruction)
• Route in ''The Wizard of Oz''