The cat maiden

The gods were once disputing whether it was possible for a living being to change its nature.
Jupiter said “Yes,” but Venus said “No.” So, to try the question, Jupiter turned a Cat into a Maiden, and gave her to a young man for a wife. The wedding was duly performed and the young couple sat down to the wedding-feast.
“See,” said Jupiter, to Venus, “how becomingly she behaves. Who could tell that yesterday she was but a Cat? Surely her nature is changed?”
“Wait a minute,” replied Venus, and let loose a mouse into the room. No sooner did the bride see this than she jumped up from her seat and tried to pounce upon the mouse.
“Ah, you see,” said Venus.