WASHINGTON -- In the middle of the 19th century, people flocked to a different kind of circus -- the flea circus.

One such miniature circus came to Washington last month. Its two tiny stars, Midge and Madge, raced chariots, walked a tightrope and were shot through a ring of fire by a mini cannon as about 40 people watched.

Ringmaster Adam Gertsacov, a 42-year-old New Yorker, said the chariot race was the most difficult stunt to pull off.

"Sometimes one of the fleas won't run," he said. "I wish I could tell you why."

Gertsacov said his Acme Miniature Circus is one of a handful of flea circuses currently in business. They were popular 150 years ago and could be seen as late as 1957 in New York City's Times Square. Flea circuses also were featured in old cartoons and the 1952 Charlie Chaplin film "Limelight."

Gertsacov wouldn't reveal how he trains his fleas, but he did say that females are easier to train. For his show at the Palace of Wonders in Washington, he kept track of Midge and Madge with a magnifying glass and tweezers.

Though it was impossible for audience members -- even those in the front row -- to see the tiny performers, Gertsacov insisted that Midge and Madge do exist.

"It wouldn't be much of a flea circus," he noted, "without the fleas."