The Nymphs, Luck and Ill-luck

Two nymphs, named Luck and Ill-luck, who lived in a wood, wished to know which of them was more beautiful than the other. They went to a fox in the wood, and asked him for his opinion.

He turned to them and said, "I can give no opinion unless you walk to and fro for a while."

So they did. Quoth the fox to Luck, "Madam, you are indeed charming when you come in." Quoth he to Ill-luck, "Madam, your gracefulness is simply inimitable when you go out!"