Bob's brother was born invisible, but through chance we can only call miraculous, he survived the delivery room and those dangerous early days on the planet. In fact, no one noticed him, although Bob's mother did feel a second squeeze and jolt ten minutes after Bob was out. The doctor, holding them both by one leg, weighed Bob in at sixteen pounds, two ounces. Remarkably heavy, he thought, for such an average looking child. The mother thought the tug at her second breast was a reaction sympathetic to the first, the way one hand wants to help the other.

  Bob's birth wails were harmony.

  Later, things became less amusing. Bob's invisible brother was a bed-wetter. And how could Bob account for all the food, the extra napkin? The allowance had to be split two ways.