'Body Worlds," the traveling show that straddles the somewhat sensationalist realm between real science and P.T. Barnum, is coming back to the Franklin Institute.

"Body Worlds 2 & The Brain" opens at the museum Oct. 17 for an 18-week stay. Tickets go on sale today.

Like the first "Body Worlds" - which attracted 603,000 visitors during its six-month Philadelphia stay in 2005-06 - the exhibition uses real human bodies, preserving them with a process its creators call plastination to highlight various organs, specific systems, and entire cadavers.

Franklin officials call this latest iteration of format, created by the Institute for Plastination, a for-profit company run by German doctors Gunther von Hagens and his wife, Angelina Whalley, a "holistic meditation on the brain that merges anatomy, neuroscience, and philosophy that resonates with everyone."

Franklin Institute president/CEO Dennis M. Wint says he does not expect "Body Worlds 2" to match the first one in attendance.

"It has a shorter run - 18 weeks rather than six months," Wint says. "So we're looking at 300,000 to 350,000. We'd love to do better, but the uncertainty of the economy is a factor."

Tickets are expensive - between $13.75 and $27, depending on the time of visit and age of the visitor.

Whalley says that while elements of the show will explore the brain, "Body Worlds 2" (one of six shows the company currently has in circulation) is much like the first one.

Human bodies, the skin removed, will be on display - some whole, others in part, a few represented by just a thin slice of an organ. A camel is included, as are human fetuses. Frozen in various poses, their muscles or organs tinted to make them more colorful, the cadavers tend to look more like art than once-real people.

So who are they?

"These are people like you and me [who] bequeathed their bodies so they should be available after death for being on public displays," Whalley said in a call yesterday from her company's Heidelberg headquarters. "We set up a body-donation program in the early '80s, and since then we received 700 people dead, and now have more than 11,000 living people in our files. The vast majority are from Germany, but we also have a body-donation program in the States."

The fetuses, she says, came "from very, very old anatomical collections, 80 or 90 years old."

Once donated, specimens undergo a process that Whalley says was invented by her husband more than three decades ago: "We first dehydrate the specimen with solvents. Then the fluids are replaced with silicone or polymers."

In the end, according to Whalley, 70 percent of what you see in a plastinated specimen is synthetic material, with 30 percent actual human tissue.

Somewhere between 180 and 200 human bodies will be seen, in whole or in part, at the Franklin. "I am not so concerned with the exact number," says Whalley.

With two exhibits running in the United States, one in Israel, one in London, and two in Germany, the "Body Worlds" empire has become a big operation. Whether it's profitable is a question Whalley is asked twice but doesn't answer.

"From its very beginning, whatever the exhibits generate finance our research work and the development of exhibits as well as the plastination process," she says. "We have 350 people working with us worldwide.

"What I should also mention is that we are doing very unusual projects. We are currently working on an elephant, and you must understand that in plastination with such a large animal you need a really large vacuum tank that is large enough to hold that huge animal."

For the Franklin Institute, the show and other traveling exhibitions like it have been good for the balance sheet.

Some of these shows are straight rentals; others come with a revenue-sharing agreement between the producer and the venue. But in general, Wint says, traveling shows have become an important part of the museum's income stream.

"One of our goals years ago was to diversify our revenue base so that we were not too dependent on any one source," Wint says.

Some of these shows are only loosely connected to science - a recent one was based on the Narnia movie franchise, for instance. But there's no arguing that "Body Worlds" is a potent dose of pure anatomy.

Whalley says the mission is to remind visitors that the choices they make in life have repercussions beneath the skin.

A normal lung is shown alongside one blackened from smoking. An Alzheimer's-shrunken brain contrasts with a healthy one (although no one would argue a choice was involved for either donor).

"I want to make the people know that the brain is so flexible, the brain has a very complicated wiring process going on, particularly when we are growing up in infancy and early adulthood, and that this flexibility continues and that our mental faculties depend on our readiness to think hard," says Whalley. "If we don't use our brain we lose something."

Contact culture writer Peter Dobrin at 215-854-5611 or pdobrin@phillynews.com. Read his blog at www.philly.com/philly/blogs/artswatch/.