“I want Smith to be a place not just for women as we define them now,” said Elli Palmer, a sophomore who is a member of Q&A, a student group that opposes the school’s admissions policy. Students recall a meeting at which Ms. Smith said, “I don’t want to get to a point where we have a row of guys in the back of the class with baseball caps on.” Of course, that’s exactly what these schools already do have — in the form of transgender men who were admitted as women.

The rules for changing gender on government-issued documents vary wildly from one agency to the next and state by state. To change gender on a birth certificate, most states except California, Vermont and Washington require documentation that sex-reassignment surgery has been performed — but most doctors won’t perform such surgery on anyone under 18. Tennessee law forbids changing gender on a birth certificate under any circumstances. On United States passports, gender can be changed with proof of clinical treatment, which is broadly defined — downgraded from a surgery requirement in 2010. As for driver’s licenses, policies are all over the map: In New York, all you need is a doctor’s note, while about half the states require proof of surgery.

One of the women’s schools, Mills College in Oakland, Calif., relies on self-identification for gender. This is clearly the direction in which our society is moving, jurisdiction by jurisdiction and agency by agency. But Ms. Pasquerella of Mount Holyoke said she had concerns about a policy like the one at Mills. She asked: “What would prevent the male child of a faculty member who gets a tuition break for getting admitted from saying, ‘Well, I identify as female, so I want to go here and get a free education’?” But does anyone really believe that high school boys would pretend to be transgender for the sake of a tuition break?

The Barnard student government hosted a talk on April 9 called “Gender & Barnard: What Does It Mean to Be a Women’s College?” Dean Spade, a Barnard graduate and transgender man who founded the Sylvia Rivera Law Project, which provides free legal aid to transgender people, called for the full inclusion of transgender women at women’s colleges. He traced feminism’s history of exclusions, from lesbians to women of color. “This is another one of those moments,” Mr. Spade said.

On May 1, Barnard named Jennifer Finney Boylan as the school’s inaugural Anna Quindlen writer in residence. Ms. Boylan, an author and a professor at Colby College (as well as a New York Times contributing opinion writer), is a transgender woman and a chairwoman of Glaad, the gay-rights advocacy organization. Her appointment signifies a shift at Barnard, but to date no openly transgender women have attended the school.

“We don’t really have policies,” Barnard’s president, Debora L. Spar, said in an interview. “Part of it is a generational thing. I think most of us were raised to believe boys are boys and girls are girls. Period. Full stop.” Barnard will draft a policy “before too long,” she added.

This month, the first openly transgender woman at Smith College will finish her first semester after transferring from a coed school. “It’s way harder to get your gender stuff lined up for an application to Smith than it is to get it together for a passport change, and that’s really saying something,” she wrote in an email. (She requested anonymity for reasons of personal safety.) Having to go back and change documents from high school “felt like I was being asked to ‘cover my tracks,’ ” she wrote. “A sort of Don’t Ask, Don’t Tell effect.”

In 1960, there were more than 200 women’s colleges; today there are 46, and enrollment is dropping. It seems worse than shortsighted to deny admission to any women who want to attend. Founded in the spirit of advancing the rights of women, these schools should lead the way for society, and accept transgender women.