God only knows why, but they rolled in Joe Louis in a wheelchair right in the middle of a Muhammad Ali press conference. The old champ had his heart repaired three or four years ago and he has had three strokes since. The Brown Bomber's skin is yellow gray, the color of old newspaper clippings. He can't see or speak much. But they wheeled him in, Caesars Palace did, probably because they still pay him, and Ali hurried around the table to touch him.

"Joe, I'm gonna put a whuppin' on him," Ali said. This was for the television cameras. Ali said this at a scream for the microphones. A job's a job and he and Joe would do the job.

"You gonna be there, Joe?"

Joe Louis sat there in his wheelchair. He wore a cowboy hat and boots. A man from Caesars said Joe was to have been at Ali's workout for Thursday's heavyweight championship fight here against Larry Holmes. It took too long to dress the champ, the man from Caesars said.

"Joe, I watched films of you the other night, Joe; you and Schmeling," Ali said. "Your combinations were somethin' else, Joe. That one-two you hit Schmeling with in the first round, that's what I'm gonna hit Holmes with. One round, Joe, I might do it in one round. So don't be late, Joe, you might miss it."

Joe Louis sat there. The hands that hit Schmeling lay dead in his lap.

Ali touched the old champ's knee. Softly, not for the cameras or the microphones, Ali said, "You feelin' any pain, Joe, feelin' any pain?"

There came from Joe Louis an animal grunt. His head moved a inch in a nod.

"You eatin' good, Joe, you eatin' good?"

Another chilling grunt. This one meant no.

To the cameras, Ali said, "Thanks for comin' by, Joe, it's gonna be a great fight," and then Ali bent low to this warrior once mighty, saying in a whisper, "I'll try to come see you, Joe, before I leave. I'll come to your house."

They are brothers, Louis and Ali, made kin not by blood but by life, for they rose to fame as inimitable prizefighters, the best of their times, and then they stayed too long at the party. Louis was a sad shell at 37 trying to make money against Marciano. The kid butchered him. And outside the ring, Louis was sadder yet, a sail without wind. Caesars paid him to show up. It still does. And if Ali, at 38, wonders about the pain of Louis, now 66, it is because he looks at the Brown Bomber and sees himself. That must hurt like hell.

I came to Vegas thinking I would see a pitiable Ali. Only three months ago, in Montreal, there to shill for the Leonard-Duran fight, Ali was a rheumy-eyed whale who slurred his words. His hair was graying and he affected a ridiculous mustache. Against a young Larry Holmes at the top of his game, against a Holmes who had defended his title with seven straight knockouts, I believed Ali would be hurt badly.

It is utterly amazing what Ali has done in three months. From 253 pounds this spring, he is down to 220. He looks as firm in the upper body as he has for six years. He jiggles, but not much. The waistline is trim. "He came to camp as Fat Albert," says his longtime friend and business adviser, Gene Kilroy, "and he left as Muhammad Ali."

Ali now uses "a little black hair rinse" to wash away the gray. The mustache is gone "because I just let it grow to make everybody think I was gettin' old." The fat fell away, Ali says, when he ate a plateful of fruit every day for six months and stayed off the sweet stuff he likes so much. As for the sickly eyes, slurred speech and bloated face that marked him pathetic in Montreal, Ali says, "That was my thyroid glands actin' up. I took two pills a day for a month and it's all cleared up now."

The promoters of the fight called in a doctor to announce that Ali was in excellent physical condition, with none of the brain damage alleged by a London doctor who made the diagnosis bylistening to tapes of Ali speaking. To see Ali in the ring dancing, and to hear him at a press conference, lecturing, was more than enough to convince veteran Ali-watchers that he is, if not the Ali of his youth, at least reminiscent of the Ali we once knew.

In a matter of 10 minutes, lecturing, Ali can drop the names of Brezhnev, Qaddafi, Khomeini, Carter, Billy Graham, Oral Roberts, Jesus Christ and Ben Vereen. Ali talks of his pet project, something called WORLD, which he says will take in $500,000 a day to feed the world's poor people. He's talked about WORLD for four years now and all anyone sees of it is a four-color brochure. But he keeps talking. Amazingly, people keep listening.

They won't always, though. There is an end coming for Ali just as it came for Joe Louis.Without the ring, Ali is a piece of history, nothing more.To make a few bucks last summer, he shilled for a grocery store, coming to Washington to "fight" Mr. Tooth Decay on the Washington Monument grounds. Mr. Tooth Decay was a broken-down pug in a white body stocking and white cape. Maybe 500 people came to see it.

And that is why Ali is making this fight against Holmes. "The Last Hurrah," the promoters are calling it. Ali is fighting because he needs the attention. He is a sail without wind, a painter without canvas, if he is taken from the ring. If the State Department sends him to Africa on a diplomatic mission, as it did last summer, it quickly learns the limits of Ali's appeal. As a fighter unparalleled, he is a curiosity; people will tolerate his babblings because his celebrity dazzles. But when he can no longer fight, Harvard will not pay him $8,000, as it did this summer to make a speech charitably described as simplistic balderdash.

So he is back on the only stage that gives him the adrenaline fix he craves. "Nothing has changed with Muhammad," said his trainer, Angelo Dundee, who has worked with Ali for 20 years. "Comes a knock at the door of his suite the other day. It's a chick with a baby in her arms. Muhammad saw her in the lobby and told her to come up. 'Let her in,' he says. A man from Mars comes to the door -- beep, beep -- and Muhammad would say, 'Let him in.'

"Sometimes, I think Muhammad might be a man from Mars himself. He sure ain't a normal human being, I know that. No normal human being could have done what he's done to get ready for this fight. I didn't believe he could get rid of the flab around his waist. But he did. He's trim. Muscle tone underneath, too. No hollow shell. The body's right.

"The continuing saga of Muhammad Ali goes on.

"We're in his room," Dundee said, "and Ali says, 'I'm gonna go until 1985.' Just playing around, I guess. So Kilroy says, 'Yeah, and I'll be like this,' and he walks around shaking like a guy 90 years old. And I say they'll have to devise a crane to get me up the ring steps.

"But Ali, he'll be bright-eyed and bushy-tailed, still doing his exercises and getting ready for a fight."

It was a joke, that story, but there is a touch of melancholy truth in it, and later, in Ali's suite, as he watched a videotape of his Harvard speech, as he glanced from the televison set to the mirror, as the old champ looked at his images to remind himself he existed, the Ali on the TV was saying, "Youth never ends."