"The witty Dean Swift once wrote: "So Nat'ralists observe, a Flea "Hath smaller Fleas that on him prey. "And these have smaller Fleas to bite 'em, "And so proceed ad infimitum. An ox might worry about a flea of ordinary size—a small creature of the first order of smallness. But he would probably not trouble himself about a flea's flea, being of the second order of smallness, it would be negligible. Even a gross of fleas' fleas would not be of much account to the ox."