Does the world truly need a live impression of the Marx Brothers in "Animal Crackers," even a very good one, when their own performance has been preserved on film?

Never mind. The world definitely does need a full chorus of grown people in yellow leotards and molting feathers, running in and out of a golden cage, portraying a flock of excited and romantic boy and girl canaries. That, too, is part of the Arena Stage version of "Animal Crackers," the George S. Kaufman and Morrie Ryskind show that the Marx Brothers did on Broadway in 1928, on tour in 1929 and as a movie in 1930.

Arena's funny and inventive production is directed by Douglas C. Wager on Zack Brown's slick set, through which such jokes as the canary cage and Harpo's fantasy harp rise majestically. The portrayals of the chief roles are smooth and purposely uninventive: Conceding that only the Marx Brothers could interpret this comedy, they have created ersatz Marx Brothers.

Stephen Mellor is Groucho as Captain Spalding, Donald Corren is Chico, and Charles Janasz is Harpo's Professor. J. Fred Shiffman has the Zeppo role, which seems to be there because Mama Minnie made the others take him along; Peggy Hewett is the quintessential rich lady lassoed by her own pearls (the Margaret Dumont film role).

They are all amazingly successful, considering how easy it is to compare them with the much-beloved originals, and yet a theatrical price has been paid: Doing impressions is not the same thing as acting. All but one of these actors is making an Arena Stage debut -- how many repertory companies have someone on hand who both looks like Chico and can play the piano?

The pleasure Arena audiences take in the versatility of familiar performers is limited in this show to admiring the range of Janasz, who was such a fine Puck earlier this season, and Arena stalwarts Richard Bauer and Halo Wines, in the minor roles of Hives the butler and his former employer.

Using actors to imitate the work of other actors is part of the curious attitude toward originality that characterizes this production. A plot device has a young artist proving his artistic worth by his ability to copy exactly a great work of art, which would hardly be respectable today. Yet reverence for exactitude led Arena to painstakingly research the original script and reconstruct the songs of Bert Kalmar and Harry Ruby. Additional music by Eric Stern fills in the blanks.

All this is to celebrate the Marx Brothers, whose genius lay in the Vaudevillian abilility to improvise, adapt and generally create havoc out of any material.

ANIMAL CRACKERS -- An extended run at Arena.