LONDON (AP) — Curators at London's Wellcome Collection will not be surprised if lines form outside their new "Institute of Sexology" exhibition.

"It's free and it's got sex in the title," co-curator Kate Ford said Wednesday.

The collection is mostly a witty look at the study of human sexuality, featuring notables from Sigmund Freud to Playboy founder Hugh Hefner and director Woody Allen. It also has serious elements, including searing black-and-white film footage of the Nazis burning the library of noted German sex researcher Magnus Hirschfeld in 1933.

"He was openly gay and Jewish, so a natural (Nazi) target," Ford said. The new exhibit is named after Hirschfeld's original Institute of Sexology to honor him and other sex research pioneers.

The exhibit shows the world's changing views toward the human sexual experience, with displays devoted to innovators like Alfred Kinsey and the duo of William Masters and Virginia Johnson — including displays of the intimidating lab devices they used to measure sexual response.

The section on Freud includes a copy of a two-page handwritten note he wrote to a distraught mother assuring her that her son's homosexuality was not a disease.

Also included is an unusual full-size replica of Wilhelm Reich's experimental Orgone Accumulator, which he believed would help cure a variety of diseases — and a film clip from Allen's classic film comedy "Sleeper" that parodies Reich's invention with a device called the "Orgasmatron."

A Playboy magazine cover is included, in part because of Hefner's strong support of the research of Masters and Johnson.

"It shows how their ideas about the physiology of sex made its way into popular culture," said Ford, who says the exhibit also shows society's evolving tolerance of same-sex relationships.

The exhibit opens Thursday and runs until September.