“I think he made a lot of positive strides,” said Goodman, “but the next step he can take to prove his commitment to women in the sciences is to start tenuring them.”

Schuetz, a history of science concentrator, said that she and many of her friends e-mailed Summers individually to express their frustration with his remarks.

In his letter last night, Summers wrote that he “had learned a great deal from all that I have heard in the last few days.”

“The many compelling e-mails and calls that I have received have made vivid the very real barriers faced by women in pursuing scientific and other academic careers,” Summers wrote. “They have also powerfully underscored the imperative of providing strong and unequivocal encouragement to girls and young women interested in science.”

At the request of symposium organizers, Summers delivered a luncheon talk to 50 academics in which he presented several speculative hypotheses to explain the scarcity of female scientists at top universities. Summers has said that he did not expect the remarks to be published.

Last night’s apology came on top of a letter Summers sent responding to the Standing Committee Tuesday night in which he wrote that he “had hoped to stimulate research on many interrelated factors that bear on women’s careers in science.”

“I misjudged the impact of my role as a conference participant,” he wrote Tuesday.

Calls to Summers’ spokeswoman were not immediately returned last night.

The full text of Summers’ letter is available online at www.president.harvard.edu.

—Staff writer Daniel J. Hemel can be reached at hemel@fas.harvard.edu.

—Staff writer Zachary M. Seward can be reached at seward@fas.harvard.edu.