Into the St. John's High School gym they tread, brown bags and thermoses in hand, Pro-Keds and Nikes on their feet and basketball on their minds.

No backpacks or 10-mile hikes at this day camp. For the next two weeks, life becomes fundamentals, jump shots, taking the charge and charging the ref.

They have come from as far away as Connecticut to receive tutelage from the coach who has led De Matha to more than 700 victories and helped every one of his graduating starters get a college scholarship. Star or no star, they have come to play basketball for Morgan Wootten. So have I, for a day at least.

The youths range in age from 8 to 18, and in talent from a budding Dr. J to a boy told by one coach: "You know, soccer could be more your sport." At $140 a head, they are paying a collective $28,000 to breathe basketball.

But this is the Metropolitan Area Basketball School, not league, so they will do more than just play. Report cards and training programs are distributed at camp's end. Films are shown, lectures given and whistles blown to start the day and divide the periods.

At 9 a.m. on the second day of camp, the gym fills with about 200 fidgety campers. Jack Bruen, the Archbishop Carroll coach, tells everyone to get where they're supposed to be, and the stampede begins.

"It's staggering to think of all the kids who have been through here in 21 years," Wootten says. "A guy at the airport once looked at my ticket and said, 'I went to your camp 15 years ago, coach.' "

The day is divided into six periods, two each for fundamentals, films and games. Each player is rated and placed on a team in one of three levels.

There also are talks by guest speakers: former Globetrotter Bobby Hunter will come today, and Ralph Sampson, says De Matha assistant Mike Brey, "will come whenever he wants."

Each of the 26 teams has a coach, a local high school player sweating his way through the summer. The coaches become so involved that they end up fast-breaking, pressing, and basically running the court right along with their players.

"Sometimes with the juniors, the coach will go out there and pick a kid up and move him if he's in the wrong place," Wootten says, a tinge of jealousy in his gravelly voice.

A quick jumper earns the red team a 17-2 lead, and earns the shooter a high-five from his coach almost before he hits the floor. "We try to make it so that every game will go down to the wire," Wootten says, "but it's tough."

After the first period my group heads toward a little green outpost for films. The session should be called Films/Steambath because one portable electric fan is not much competition for the 90-degree heat. Coach Hank Iba appears on the small screen watching his players demonstrate "good defense" one minute and drink "ice-cold Coca Cola" the next, a tortuous film to watch, considering the situation.

Off to fundamentals. Wootten has just left to deliver a talk at his girls camp, so Bruen is left the honor of teaching fast-break basketball.

Today's lesson: how to stop after making the pass. Bruen assumes the defensive position on a two-on-one break and gets in front of an out-of-control passer. "If I didn't have a date tonight I'd have taken the charge," he shouts. The attentive group simply nods. "And if the defensive man gives you the short jumper, take it! A basketball player can have no conscience."

I follow his advice and pull up on a three-on-two break, nailing a short jumper, but then growl as I stand alone under the basket and watch my break-mate throw a pass right into the defender's arms.

On the next play, I both charge and throw the ball away. "You know what stop means?" I hear. If that isn't bad enough, I also have thrown the misguided pass with my wrong hand: outside instead of inside. "Good play!" some tyke chuckles in the line behind me. Enough of fundamentals. Lunch time. Grab a quick hot dog and go shoot around some more. "These guys come in, gobble their lunch down, go right out and get sick," Bruen says.

Later on, Hunter and Sampson are no-shows. Rod, the 14-year-old with the Virginia Cavaliers shirt, says he now will have to wash it again tonight in hopes for tomorrow. Adrian Dantley, once a coach here and now an annual guest, will not show until later in the week, so the staff all-stars must entertain the throngs.

Fifth and sixth periods go quickly by, with an unexpected dunk here and there. Soon, carloads of looking-to-be-proud parents congest the parking lot. Wootten and codirector Joe Gallagher, the St. John's coach of 35 years, have been doing this for so long that they seem to have camp down to a science: sit, play, learn, eat, drink, rest, watch, play and go home. But the enthusiasm of the various coaches and youngsters instills a little madness in the method and gives this basketball school its freshness.

At 4 p.m., with thermoses empty and bags tossed away, they return home to prepare for tomorrow. I also head home, intent on learning my inside hand from my outside.