For two hours the students skipped, danced, scampered and tumbled around the cadets, like a swarm of gnats. Half the cadets, with ever-straight faces, practiced marching drills and the others ran obstacle courses and races.

Since it was the first field practice for the students enrolled in the Army's Reserve Officer Training Corps, many were without uniforms, dressed in suits and ties or jeans and shirts.

The radicals' demonstrations started somewhat hesitantly at first, at 8am on the dust-covered field at Lewisohn Stadium.

"Brothers!" called a long-haired youth over a portable public address box. "Frisbee classes are now beginning in Lewisohn Stadium. You people in R.O.T.C., we're getting some orange juice. You're welcome to have some and join us.

Red, white and blue Frisbees began to soar on one half of the field while a group of cadets stood at attention on the other. As the cadets began to drill - "Attention! Right face! Forward march!" yelped the student lieutenants - some of the demonstrators shouted: "Let's have a snake dance."

"What's a snake dance?" a student asked.

"Gather round, children," said Ronald McGuire, a 20-year-old student from the Bronx. "I'll show you."

Snake Dance Falters

A six-foot pole was produced and Mr. McGuire stood on one side of it, holding it in front of him at waist level.

Twenty-one students, in rows of three, aligned themselves on the other side, the first rank of three holding the pole and the ranks behind holding the belts of the lines in front.

"The idea of a snake dance," he said, "is to set up a beat." He lifted his left foot high, then his right. "One, two, three, four."

"Hut, two, three, four," echoed the student soldiers across the field.

The snake group caught on - almost. They began to prance, chanting "Hell No, Don't Go!" for 10 feet, when their feet got tangled and they tripped to a halt.

The cadets went on drilling to commands of "About Face! Forward march!"

The dancers, representing the C.C.N.Y. commune, Students for a Democratic Society, and the Youth International Party (Yippies), tried again, unsuccessfully.

"No, no, you're doing it all wrong." said the leader, who was marching backwards facing his squad. "Lift your feet high. There's a tendency for people to speed up the cadence."

"Now," he continued, "let's try Washoi. Washoi."

"What's Washoi?" someone called.

"Down with imperialism. Up the Establishment," came some answers.

"Washoi," Mr. McGuire said, "is Japanese and means whatever you want it to mean. It's the thing of the future, so let's learn now how to use it."

Washoi is a Japanese word that has no literal meaning, but is used in religious festivals when heavy, portable shines are carried through the streets. Japanese leftist students borrowed the term for their "dragon marches" when huge crowds of students trot along briskly together. The word produces rhythm and spirit, just as the English term "rah" generates fervor at football games.

But Washoi didn't help the snake dance, and people began to fall off the line. "Well, that's enough discipline for me," said a girl dressed in a bright pink sari and sandals, as she stalked away.

It was about 8:30 as a second group of about 25 cadets ran across the field, dressed in fatigues, to an area laid out with hurdles and taped lines.

"It's all yours," shouted a student leader. "Let's march in our nonmilitary way and take it." They followed the cadets in fatigues and from then on, had a field day.

They somersaulted over each other, played leap frog, waved their arms in amorphous dances, and raced with the cadets who were crawling, running and jumping obstacle courses.

The radicals excelled in this phase of their antiwar demonstration, which they called "A Celebration of Life."

They joined in a drill where the cadets raced carrying other cadets on their backs, in fireman fashion.

The civilian students came in first, second, third and fifth among four other teams made up of cadets.

They lampooned the cadets continuously, marching behind them, running in front of them, shouting slogans.

The black flag of anarchy appeared and was used to lead cadets running around the field track.

Polite, Lively Dialogue

Then, resting intermittently from the strenuous exercise, the civilian students began to engage the military students in political conversations. The dialogue was lively, intelligent and polite.

"You have a free will and it is your right to exercise it," a radical student said to a uniformed cadet. "It is morally impossible to support this war."

"I have that free will," the other countered, "and I choose to support this war."

Mr. McGuire explained why the students were demonstrating. "We think R.O.T.C. is a destructive thing on campus," he said. "The university should not teach people how to kill. We want a society dedicated to life."

Until they left at 10 o'clock, the students celebrating life did not interfere physically with the cadets. No police appeared.