Mrs. Rittenhouse: But Captain, I thought polar bears lived in the frozen north?

Capt. Spaulding: They do. But this one was a rich bear and could afford to go away for the winter. You takes care of your animals and I'll take care of mine. And don't bring Lulu . . .

Mrs. Rittenhouse: But Captain, I thought polar bears lived in the frozen north?

Capt. Spaulding: They do. But this one was anemic. and he couldn't stand the cold climate. Besides he was a rich bear and could afford to go away in the winter . . .

--Excerpts from two versions of "Animal Crackers," which opened last night at Arena Stage.

WHEN Arena Stage associate producer Douglas Wager decided 14 months ago that he wanted to direct "Animal Crackers" this year, he was confronted with a basic problem: no script. There was a script, of course, when the Marx Brothers opened the play, which has the plot of a vaudeville circus, on Broadway in 1930, and when they took the show on the road later there was another script. Then they made a movie of it, and there was yet another script for that. But none of these was published.

The authors were George S. Kaufman and Morrie Ryskind. Kaufman's daughter, Ann Kaufman Schneider, didn't have a script or know where there was one, nor did Ryskind, now in his eighties and living in California. Toby Ruby Garson, composer Harry Ruby's daughter, hadn't a clue either.

So Wager sent Mark Bly, then Arena's associate literary manager, to the Library of Congress. It was to be the first of several trips.

Searching through files in the music division, he found a copy typed on frail onion-skin paper, probably the original rehearsal script. "We got a carload of dimes and Xeroxed it," Wager said. "Then we read it. It was overwritten, and there were stage directions that were physically impossible, like 'professor is suspended in mid-air.' "

"The more we read it, the more we realized it was missing songs," Bly recalled in a telephone conversation from his new job as associate dramaturg at the Guthrie Theater in Minneapolis.

Bly began calling theater collections and libraries. From a classified ad in a film magazine he got a list of Marx Brothers fan clubs and wrote to them. He scoured biographical material and bibliographies, looking for names of collections he hadn't heard of, contacted music historians and the American Society of Composers, Authors and Publishers. He tried, without success, to find the original conductor of the show through the musicians' and conductors' unions.

"It was sort of like detective work," said Bly, who, like Wager, is more bookish than flamboyant. "It was exciting, because the script had been lost to the stage for over 50 years."

Both could see it would be a long search, but worth the trouble. For Wager, George Kaufman was the main interest. "I think he is the great unsung American playwright. He was a ferocious craftsman."

The film version of the play, which was not shown until 1974 because it had been tied up in legal hassles for 20 years, was not very useful to the theater people. "It was more Marx Brothers and less Kaufman and Ryskind," said Wager.

Kaufman's daughter suggested they check the Sam Harris archives. Harris was the producer of "Animal Crackers," and in the collection of his papers at Princeton University, the sleuths found a program, which told them what songs they were missing. Bly figured that once they knew the titles of the songs, they could track them down in the Library of Congress' copyright division.

"Then I called Princeton back to ask them about some song, and they said they had found another copy of the script," said Bly. "That was really a breakthrough."

What came to be called the "Princeton script" had lyrics to all the songs--but no music. "Suddenly we had a music problem," Wager said. They commissioned Eric Stern, who was the music director for last year's "God Bless You Mr. Rosewater," to write a finale and two songs. At a loss for other songs, they searched through 150 written by Bert Kalmar and Harry Ruby, and came up with two others to add to the show.

Then Wager heard that the faithful Library of Congress had been given Groucho Marx's papers. They hustled over and, lo--a fourth script.

"We think it must be the script of the touring version," said Wager. "It had some changes in it--like by that time the stock market had crashed, in which Groucho had lost $250,000, and there were references to that in the script. And where the other scripts had stage directions that only said 'bubbles business' or 'bouncing check business,' this version actually described these old vaudeville tricks."

Bly soon left for his new job, and John Glore arrived to take his place. Glore's first task was to take all four versions and chart the differences, line by line. Then Wager decided which one was funniest. Or clearest to a modern audience that wouldn't know who someone like Grover Whalen, New York's official greeter, was. "At first I discredited the minor differences, but the more I read, the more important they became in terms of rhythm," Wager said.

Wager and Glore tinkered and tuned. Auditioning started without a final version.

To find four actors, Wager auditioned at least 700, including 200 here, an experience he does not remember with fondness. He went to Los Angeles five times. "It was pretty harrowing," he said. "We did not want impersonations, we needed people who understood the nature of four different clowns, who would give a hint of the mannerisms without trying to duplicate them."

He got Grouchos in full costume and Grouchos in plastic Groucho-glasses. "Plus they had to sing and dance." He eventually settled on Stephen Mellor, an old friend who had been in his thesis production at Boston University, and was later an acting intern at Arena in 1976. Mellor had to survive six auditions, including two in one day, and at one point spent 24 hours watching all the Marx Brothers movies in one sitting.

The Harpo character, "The Professor," is played by Charles Janasz of Arena's resident company, who played "Puck" in "A Midsummer Night's Dream," and Zeppo, "Jamison," is J. Fred Shiffman, a veteran of several Tim Grundmann musicals at New Playwrights' Theatre who has been an understudy at Arena for two seasons. Chico, or "Emanuel Ravelli," is Donald Corren, who understudied the part of Chico in "A Day in Hollywood/A Night in the Ukraine," a Marx Brothers takeoff on Broadway a few seasons back.

The concept of the play, as Wager describes it, is to take four anarchic clowns, place them in a world of high society, and let them wreak havoc. "On one level it's about actors trying to do a play and four other actors trying to stop them," he mused.

Take this speech by Capt. (Groucho) Spalding, as it may or may not appear on stage at Arena:

" . . . You takes care of your animals and I'll take care of mine. And don't bring Lulu. Well anyhow, there we were in the middle of Africa, by this time it was beginning to get dark and the jungle closes at 2, with the customary matinees on Wednesday and Saturday. I don't know whether any of you people have ever seen darkness descend on the jungle. It is so dark you can hear a pin drop. For a moment it is pitch black, then mysterious little lights appear in the distance. First a red light, and then a green light, so we knew it was the Lenox Avenue Express, and we got out at 135th Street, and found ourselves again in Africa. Are there any questions? . . ."