Paraphrasing from her recent book "The First Sex: The Natural Talents of Women," she adds: "That's a huge percentage and women are deeply driven to have their husbands think that a child is theirs because if it isn't, he may not give resources or he may abuse the child."

That women have a choice of surnames at all is only a relatively recent development in legal history. Originally, patrilineal names were part of the British and American common law called "coverture," in which a woman lost her legal right to own property, to enter into contracts or sue another party as soon as she got married.

Sexist property laws began being dismantled 150 years ago, but even in the 1970s, many state bureaucracies still prohibited women from keeping their own names after marriage and giving their children their surnames.

Interestingly, the last legal battles of patrilineage were not fought over love or tradition or civil rights, but the true blood of our society: money. According to Hendrik Hartog, Princeton legal historian and author of the forthcoming "Man and Wife in America" (Harvard University Press, May 2000), it only became truly irrelevant whether a woman wanted to keep her own name after it was established that women did indeed have the right to have their own credit cards. Before that, a married woman could only obtain a credit line if she had her husband's surname.

I could find no current laws prohibiting women from keeping their surnames after marriage or giving their names to their children. The state-by-state battles of the 1970s are all over. So why haven't our naming rituals also changed? Hartog maintains that despite the societal campaign that began in the 1900s to "reinvent marriage," much of what people do in marriage continues to be done out of habit -- even when the tradition has no legal or financial roots.

"People find it very difficult to imagine being married and not doing what their parents did," he explains. "There's a powerful pull toward the reproduction of tradition. Of course, there's enormous divorce and people having children outside of marriage but still, when people get married, they're doing something that's historically grounded."

And as Stevens, Chodorow and Fisher have observed, even the most arbitrary traditions remain remarkably resilient when they have a biological seed.

Names flutter abstractly on bureaucratic forms and even a feminist woman, filled to the brim with a child of her own blood and bone, may see the symbolism of giving her last name as a trifle compared to the visceral bond she already shares with their baby. Even as our legal system evolves to accept the notion that families are essentially cultural-political institutions in which each parent must have equal influence, the body stealthily intrudes.

But just because women are blessed and cursed with the vital umbilical connection, it doesn't mean that we have to relent on every symbolic front. Long after my husband hacks through that bloody rope, long after my breast milk has dried up and my pregnancy leave is but a sleep-deprived memory, we will both be parents, working equally, I hope, inside and outside the home.

My husband won't need to brand our daughter to compensate for the fact that she is in his care less often than she is in mine. He won't need any exterior sign to remind him of his responsibility, his connection, his importance.

Yesterday I felt the tiny kicks and stretches of our first collaboration in reproductive love. After much discussion, we decided: She's getting both our last names (no hyphen) -- with mine as the last, last name.

Biological motherhood is an awesome process but its powers won't last as long as the symbolic gift to my daughter of her mother's last name. And when she is old enough to ask me why she has the name she has, I won't need to come up with some justification that I don't even believe myself.

Order "Mothers Who Think: Tales of Real-Life Parenthood" from the editors of Mothers Who Think.