A lioness and a vixen were talking about their young, as mothers do, praising their health, growth, beautiful coats, and resemblance to 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.