Our fascination with circuses may have a bizarre psychological explanation, but who cares? Greatest shows on earth are there to see, not analyze. This year’s new edition—-the company’s 108th—-features the debut of animal trainer Benny Williams, who works with a leopard and an elephant. He joins aerialist Elvin Bale and the Romanovi troupe of bareback riders in the circus’ “blue” unit, which this month plays Birmingham, Ala., Greensboro, N.C. and Richmond. Meanwhile veteran clown Lou Jacobs and leopard and tiger tamer Gunther Gebel-Williams anchor the “red” unit (edition No. 107), which also has a singing ringmaster, Kit Haskett. The red unit will spend February in Lakeland, Fla., Atlanta and Savannah, Ga.