WASHINGTON—Four American scientists—[plant] geneticist Barbara McClintock, thermodynamicist Josiah Willard Gibbs, mathematician John von Neumann, and physicist Richard P. Feynman—were honored with postage stamps dedicated in a special ceremony at Henry R. Luce Hall, Yale University, New Haven, Connecticutt.

As host to the event, New Haven holds the unique distinction of being the only city in the nation where the stamps became available May 4. The stamps also became available at post offices and philatelic centers nationwide May 5.

“These are some of the greatest scientists of our time; their pioneering discoveries still influence our lives today,” said John F. Walsh, a member of the U.S. Postal Service’s board of governors, who dedicated the stamps.

Joining Walsh were Paul A. Fleury, dean of engineering, Yale University; Michelle Feynman, Feynman’s daughter; Marina Whitman, Von Neumann’s daughter; Marjorie M. Bhavnani, McClintock’s niece; John Willard Gibbs III, Gibbs’s cousin; John Marburger, director, Office of Science Technology; and Victor Stabin, stamp artist. Honored guests included Richard Levin, president, Yale University and John DeStefano, mayor, New Haven.

“This is truly an honor, not only for science enthusiasts and scientists, but for our community as well,” said DeStefano. “As a lifelong resident of New Haven, I am thrilled these beautiful scientist stamps are being issued here.”

Barbara McClintock (1902–1992)

In 1983, the renowned geneticist Barbara McClintock received the Nobel Prize in the category “Physiology or Medicine” for discovering genetic transposition. McClintock’s research on Indian corn plants led to her discovery that genetic material can change positions on a chromosome or move from one chromosome to another. The discovery was confirmed immediately in corn, and in the 1960s and 1970s in bacteria and other organisms.

It was at Cold Spring Harbor Laboratory that McClintock discovered transposition in the course of experiments on mutations caused by broken chromosomes. She called her mobile genetic elements “controlling elements” to indicate that they controlled the action of other genes during development. McClintock was among the first biologists to think concretely about the way genetic material controls the development of the organism.