HUSAVIK, Iceland -- Sigurdur Hjartarson is missing a human penis. But he's not worried: four men have promised to donate theirs to him when they die.

Hjartarson is founder and owner of the Icelandic Phallological Museum, which offers visitors from around the world a close-up look at the long and the short of the male reproductive organ.

His collection, which began in 1974 with a single bull's penis that looked something like a riding crop, now boasts 261 preserved members from 90 species. The largest, from a sperm whale, is 70 kilograms and 1.7 meters long. The smallest, a hamster penis bone, is just 2 millimeters and must be viewed through a magnifying glass.

One species conspicuous by its absence is Homo sapiens, but that may soon be rectified since a German, an American, an Icelander and a Briton have promised to donate their organs after death, according to certificates on display.

Hjartarson said the Icelandic donor, a 93-year-old from nearby Akureyri, was a womanizer in his youth who thought having his penis in the collection might bring him eternal fame.

But vanity may make him rethink the offer. "He has mentioned lately that his penis is shrinking as he gets older and he is worried it might not make a proper exhibit," Hjartarson said.

A growing number of people from all over the world view the collection each year, 60 percent of them women.

"We had 6,000 visitors last summer and actually made a profit," Hjartarson said with a smile.

Most of the specimens were donated by fishermen, hunters and biologists. Hjartarson has paid for only one -- an elephant penis nearly 1 meter long that hangs, stuffed and mounted on a wooden board, in the museum's "foreign section."

He said he began collecting penises 24 years ago, when working as a school administrator, with little notion he would one day be running a museum devoted to the subject.

"It was just a hobby," he said.