It doesn't take a brain surgeon, or even a scientist, to figure out why the Franklin Institute has dumped its trendy shortened name.

It's because "The Franklin," the name created last year in a marketing campaign for the 185-year-old museum, was confusing the public.

So, recently, the Franklin Institute "quietly reverted back" to its original name, spokeswoman Stefanie Santo told the Daily News yesterday.

"It's a beloved name, and we welcome it back," said Meryl Levitz, head of the Greater Philadelphia Tourism Marketing Corp.

Institute had been dropped from the venerable museum's name last year "as part of a re-branding update," said Kat Stein, the institute's director of public relations and communications.

In response, "there was some confusion among the public," Stein said.

The name change affected only the museum, where generations of schoolchildren have learned about subjects ranging from the universe to the heart (via a walk-through giant heart) and, recently, the anatomy of the human body through an exhibit of preserved human cadavers.

The name of the nonprofit agency that oversees the science institution remained the Franklin Institute, Stein said.

That organization oversees not only the museum but also the Center for Innovation in Science Learning and the Franklin Center, home of the Benjamin Franklin National Memorial, Stein said.

"The Franklin Institute is the name that, for more than 185 years, Philadelphians have associated with innovative programming, exhibits and educational outreach," Stein said, frankly.