Bernice Collins, 25, holds a circus hoop overhead in each hand. She has been a clown and a showgirl, and now she wants to be a tiger trainer.

Two 300-pound Bengal tigers launch off pedestals behind her. As they pass over her head, one bursts through his paper-covered hoop, but the other swats his away in passing, spinning Collins halfway around. She lowers her eyes; she knows what's coming next.

"That's because you got no strength in your upper arms," Charly Baumann growls disgustedly. He is 54, a gruff German, survivor of 35 years with lions and tigers and four serious maulings. When Baumann speaks, nobody says anything. Like his tigers, he creates around him an air of expectancy, even danger. He is not only the tiger trainer, but the performance director--the top sergeant--of the Blue Unit of Ringling Bros. and Barnum & Bailey Circus. Get out of line and you answer to Charly.

"Am Platz!" Collins orders the cats back to their pedestals, using her whip and Baumann's German commands. But as the animals move they watch Baumann, not Collins.

"You don't mean it, what you say to them," he snarls. "Use your voice like you mean it." The tigers behind her snarl, too, and in a moment Collins is dismissed from the cage.

That was in Charlotte, N.C., where the circus paused for a week on its way to Washington. It opens tonight at the D.C. Armory, and sometime during the two-week run Bernice Collins expects to make her debut as an assistant tiger trainer. By 1984, if things go right for her, she will be a featured attraction of The Greatest Show on Earth. Charly Baumann, with his hundred scars, will be out of the tiger cage, and Collins will be in it.

They are people of the new circus--the one that Washington entrepreneur Irvin Feld has saved from oblivion, streamlined and made economically healthy again. But it is still an otherworldly institution, a showplace of the strange skills and slightly different lives of Bulgarian acrobats, Mexican aerialists, Hungarian midgets, human cannonballs and women who hang by their teeth. It is a spectacular throwback to ancient Rome that, in the age of the computer, continues to play twice a day and three times on Saturday. And in a world that has come to rely on videotape for the repetition of wonder, the circus still does its replays live.

When Feld bought the circus in 1967, the average age of the performers was 46. This year the average age is 23. Charly Baumann is coming to the end of the line, and he knows it. Bernice Collins is at the beginning, and she knows it.

Baumann: "My tigers are very well trained. But there is no way I can guarantee that Bernice isn't going to get her a-- chewed up."

Collins: "Charly has scars. I may have a few scars, too."

She was a receptionist in her home town of Kansas City. "Just what I was afraid I'd wind up," Collins said over a slice of pizza in Charlotte at 11 p.m. The daughter of a postal employe, by age 18 she could play the piano, the violin, the oboe and the alto saxophone, and had trained her house cat to roll over, sit up and stay.

She talked her way into Clown College--a facility founded by Irvin Feld in Venice, Fla., to train a new generation of clowns for his circus--in 1979. She wrote 10 letters--one a month--from Kansas City, "telling them how great I was." She graduated as the first black female clown in the 113-year history of The Greatest Show on Earth. Now is her chance at the tigers.

Charly Baumann's chance came in 1951, at Circus Williams in Germany. He was an assistant horse trainer who passed by the cage of a lion tamer named Jean Michon. Two of the lions were holding Michon down and a third was eating him when Baumann entered the cage and beat the cats back with a sledgehammer handle. Michon was five months recovering.

Bernice Collins has perfect skin and wide eyes and a bubbling laugh. Over beer and pizza, she laughingly tells about the "Saturday morning weigh-in" for showgirls (starvation Friday, gorging at a pancake house Saturday); about her dad teaching her the piano; about her girlfriends on the circus train. But the two men with her are suddenly glum. They are remembering, as she chats happily, the start of Charly Baumann's career. When Baumann went to rescue Michon, at first he could not see the trainer under the pile of lions. To find him, Baumann followed the trail of blood gushing under their fur.

Yes, she says, her friends are frightened for her. But she has faith in Charly. "Charly is my agent, and he doesn't let me forget. 'When we come to sign a contract, remember I get 10 percent,' Charly says.

"The first thing you do if there's trouble is turn the whip around. Use the other end to hit them on the nose. I haven't had to hit them hard, yet. Really, it's okay when Charly's there. It's when he gets scared that it gets scary."

The apprentice tiger trainer considers her costume. Perhaps a tiger skin, for that queen-of-the-jungle effect. Perhaps the chic white jumpsuit that Baumann suggested she buy. But why not white tie and tails?

"Oh, I don't think there'll be any tails. No tails, no feathers, nothing like that. That's one of the horror stories. There was a woman trainer in Europe who wore tail feathers. It excites the animals. Four cats jumped her and tore her apart."

The two men peer into their beer glasses.

She has been a clown and a showgirl, but something in her--some love of audiences that does not go unrequited--demands more. "Damn Everything but the Circus," her T-shirt reads. She wants to be somebody.

Elvin Bale is somebody--a daredevil who runs on his Wheel of Death 50-feet high without a net. Yanka Silagi is somebody--she is a blond Bulgarian who is catapulted from a teeterboard to a five-man high. Karl Wallenda was somebody to the end, when at 73 he fell 120 feet from his wire between the Condado Holiday Inn and the Flamboyan Hotel in San Juan.

Irvin Feld wants a new tiger act by 1984, and maybe Collins will be it: Somebody.

There must be easier ways. Perhaps if she went to Hollywood, she could get in the movies.

"Are you kidding?" Collins said. "Too much competition. I always like to be different."

In his dressing room, set off by curtains and containing a six-foot-high case of whips, Baumann reposes on a couch. He has gotten a bit thick around the middle now, but he is still Charly Baumann.

"I just went in swinging wild," he says of that day in 1951. "What you should do is pick up a pedestal and hold it in front of you, and use a stick to get the lion off the man. And, of course, you don't go alone to the cage."

In England, he recalls, a trainer went on a Friday to work with his animals. No one else visited the cage until Monday. They found a shoe. Inside, at the toe, too far for a lion's tongue to reach, were remains. And at the top of the cage, where the trainer was impaled on a spike as he tried to climb out, "there were just some dry, stringy bits."

Baumann hasn't been mauled since 1963. "Oh, scratches and bites. A finger bitten mostly off a few years ago. But that's like catching a cold."

He grew up in Berlin, the son of a movie stunt man. When the war came, his parents were caught helping a Jewish family escape to Spain. His mother was sent to Ravensbru ck, where she survived medical experiments, and his father to Bergen-Belsen, where he died in a gas chamber. Charly spent a year in a Nazi orphanage, later was drafted into the German Navy, subsequently was captured by Americans and interned near Hamburg. He escaped when an unexploded bomb in the camp went off, killing 200 prisoners.

After the war, he joined a small Berlin circus, Circus Williams--where he was an assistant horse trainer and young Gunther Gebel, he says, was a shoeshine boy. Both were taught the skill of animal training by the legendary Harry Williams, from whom Gunther Gebel-Williams--who headlines the Red Unit of Ringling Bros. and Barnum & Bailey--got his hyphenated name. Both of them saw Harry Williams fatally injured when he turned over a chariot while teaching them a more spectacular way to ride it.

Gunther Gebel-Williams became the most famous tiger trainer in the world, but Baumann may had had more fun. He once wrote that "something in human psychology drives females to pursue males who train wild animals." The author concedes he was never a fast runner. He once put his head into a lion's mouth because a shapely apprentice circus promoter named Anna suggested it would be good publicity. The lion bit him severely. When he broke off an affair with an English equestrian, she set his white Mercedes convertible on fire. For a long time he performed his act in a Tarzan loincloth: that was with Circus Roland, in Europe; he was living with the owner, and it was her idea. Now he is married and wears a sequined tuxedo, but nobody makes fun of him, not even the tigers.

He is quite aware that if he is successful in teaching his trade to Bernice Collins, he will be out of a job.

"I have to get out now, one way or the other," he says with a shrug. "It's my 20th season in the center ring, and you cannot torture audiences forever with Charly Baumann's tiger act. I'm trying to stay in management. I'm trying to work closely with Kenneth Feld Irvin's son, and co-impresario , but it's difficult to break into their group. To be one of them, it's difficult.

"It's a very insecure place, the circus. They can say any time they don't need you anymore." His voice is low, not at all the u bermeister, the chief of discipline, the taskmaster, the hot-tempered performance director and terrifier of the tardy, errant or insecure. "Since 1946 the circus is my life. Thirty-three years training wild animals, I don't know anything else. The day I get fired it will be heartbreaking. A bookkeeper, all he leaves is some books. But I've seen the show develop; I've done my part. When my day comes it's not going to be easy.

"Start over? I'm 54. I'm too old for that s---. I'd rather work in a car wash someplace than go to somebody else's circus and work somebody else's animals. Not when you've been in The Greatest Show on Earth . . .

"Ah," he says, resuming a brisker pace. "It's hard on Bernice, too. I'm telling you, she hasn't cut it yet. I can't repeat everything over and over, there just isn't going to be time. You know, she was my idea. Well, of course, Kenneth Feld said we needed a new act for 1984. And I guess she had mentioned her interest to Mr. Feld. Anyhow I put two and two together. I said I'd do my best.

"It's worrisome, though. I mean, for me to say she's working out if she isn't. What is right for me to do? Bernice knows it can go either way. But I'll tell you, Irvin Feld is the P.T. Barnum of our time. Barnum knew how to see latent talent and bring it out, and Mr. Feld sees something in Bernice.

"I've had 30, 40 kids come to me over the years who want to learn the act. They don't have discipline, though. In European circuses, discipline is everything. It was hard for me to learn it's not the same here. For example, when I was first named performance director, I was in a position to tell people off. I got quite rough with a lot of them, and they complained, and Mr. Feld didn't quite agree with me. Let it go, he said. So I had to change.

"People, ah," he says with a growl, rolling his eyes. "I am most relaxed in the tigers' cage. The performers today don't know they're in a circus anymore. If the water's not warm, if it's drafty in their dressing rooms, they're complaining. I say, 'You never worked in a tent, with an ice storm blowing in one end? You're complaining because your air conditioner doesn't work? Ten years ago, when you came over here from some backward country, you didn't know what an air conditioner was.'

"Yes, I'm not a very liked man. But there has to be discipline. What happens is, you have a drink with somebody some night, and then the next day they take advantage. Suddenly they think they can chew gum or miss the opening or something. They think things change because you had a drink. Ah, the hell with it. I have my wife and my two dachshunds. It's enough."

He stares moodily. "But I would like to be closer to the Felds than I am now."

Near the end of the week in Charlotte there was another rehearsal, in which Collins worked with all 11 tigers for the first time. It was late morning in the empty coliseum, with a half-dozen spectators outside the steel cage.

"King hier," said Collins, snapping her whip. "Am Platz! Sitz!" Several tigers were directed to lie down and roll over together. "Und rrrroll!" said Collins, who seemed to have developed a distinct German accent.

Shortly, she was abruptly dismissed so Baumann could work with Axel, Prince and Assur, 8-month-old, 100-pound "babies." Suddenly patient, he kissed and prodded and made fun of the clumsy, big-pawed kittens, cajoling and spanking them through a parody of the snarling precision of his adult animals. This interlude drew absolute quiet. Baumann himself broke it, finally: "Don't let the cage door slam, idiot!"

Later, to Collins, as they stood together in the pungent air of tigers, he said brusquely: "You were fair today. Not good, fair. But better than last time. All you need is 30 more years' practice."

Tomorrow: Two human cannonballs.