The Lioness and the Vixen

A lioness and a vixen were talking together about their young, as mothers will, and saying how healthy and well-grown they were, and what beautiful coats they had, and how they were the image of their parents.
“My litter of cubs is a joy to see,” said the fox; and then she added, rather maliciously, “But I notice you never have more than one.”

“No,” said the lioness grimly, “but that one’s a lion.”

Quality, not quantity.