BENSALEM, Pa. — What professional team sport featured men and women, black and white, playing side by side from the 1930s to the '70s? And what sport, after falling into the athletic abyss, is experiencing a revival on the will and wheels of its women participants?

The answer is the 70-year-old sport of roller derby.

"Tennis was the only other sport I remember where women could compete and make money," said Billy Bogash, who was a roller derby skater from 1935 to 1958. "If a woman wanted to be a professional athlete, roller derby was one of their few choices." He said that in the 1930s and '40s, women and men skaters were always paid equally, earning as much as $10 a week.

Now roller derby is back, but it's purely a woman's league. And locally, you can catch the Penn Jersey She Devils practice at the Cornwells Roller Skating Center in Bensalem. They should be ready for real competition next spring, says their coach, former roller derby queen Judy Sowinski, who now lives in Philadelphia.

When Greg Spencer and Ken Sikes of New Jersey formed the She Devils this past spring, a former player read about it on the Internet and asked Sowinski, 64, to coach them voluntarily.

"I decided to work along with them to help them skate the proper type of game," said Sowinski. "The girls improved considerably. They're doing really well. I enjoy coaching them, and the team enjoys having me."

Sowinski skated professionally from 1959-'76. In the late '50s, she was given a chance to travel with a track team, but preferred roller derby because she liked being rough.

"The opportunities just weren't there in the '50s like they are now," said Sowinski. "Roller derby was a great way for me to let out my aggression."

And Philadelphia roller derby fans saw the aggressive Sowinski compete from the late '60s to the mid '70s. She skated for the Philadelphia Warriors team, which wore the metaphoric white hats, and also for the "black-hatted" New York Bombers and Los Angeles Thunderbirds.

No matter where Sowinski competed, she preferred wearing the black hat because she could cause mayhem and let out her anger. However, that had a price: dealing with hostile fans.

"In Philadelphia, security guards always escorted me to my car and I had to drive away quickly because these crazy fans threw rocks at my car as I tried to leave," said Sowinski.

Among the She Devils is Levittown resident Bianca Berridge (Bashing Binky) and Pam Duffy Wick (the Irish Roller) of Bristol. Berridge says that practicing reduces day-job stress. "I sell insurance, and I'm a part-time waitress," said Berridge. "I'm learning how to block and to take hits."

Berridge and the others won't be quitting their day jobs anytime soon.

"Most of the players skate for free," said Sikes. "If the team makes something (at the gate), most players have agreed to funnel that money back into the league."

Nationally, there are 18 leagues in the United States Rollergirls Association, with 65 teams in 13 states.

Most of the women's roller derby leagues currently skate on flat tracks, unlike the past when banked tracks were used.

Another difference is that today all roller derby skaters use stage names.

"That makes the game interesting," said Spencer. He doubts that the nicknames will make people think the sport is an offshoot of professional wrestling. Spencer and Sikes and the She Devils swear that today's roller derby leagues won't have theatrics or scripts like the old derby.

In 1937, roller derby creator-promoter Leo Seltzer and the sports writer Damon Runyon changed roller derby from an endurance race, in which couples competed to see who could cover 3,000 miles first, to a physical game. Two teams of five men and five women played against each other for eight 12-minute periods. Men and women skated alternate periods.

The two offensive players — the jammers — scored points by passing opposing skaters, while two blockers tried to stop them. The pivot had the option of blocking or jamming. Offshoots of this were thrown chairs, pulled punches and grudge matches. The evolution of roller-skating into a contact sport attracted athletic women with a taste for mayhem.

As former roller derby skater and Las Vegas resident Loretta Behrens (played 1950-1959) said: "It was unheard of for a woman to be aggressive and physical in the '50s. I was always a tomboy so the roller derby was perfect for me."

And now that opportunity is there again.

"These leagues are opportunities for women to be aggressive and athletic and feminine all at the same time," said Natily Blair (Ginger Snap), who plays for the Manhattan Mayhem in the Gotham Girls Roller Derby league.

Blair credits the latest roller derby revival to the fact that skaters run these leagues. She said that the women have the drive to do this simply because they love to skate.

"It's empowerment," Blair said.

And there were other women who joined because they wanted revenge. Leslie Sisson (Rolletta Lynn), co-captain of the Queens of Pain, said: "I took up roller derby because I caught my boyfriend cheating with a roller girl back in Texas. So I joined the roller derby so that I could beat her up." However, the two women became friends immediately after Sisson joined.