Now, finally, the enormity of the American tragedy that one week ago shattered the tropical isolation of this tiny nation on the edge of South America is known.

More than 900 bodies a much larger number than anyone here had feared, have been removed from Jonestown, the agricultural colony of Jim Jones' Peoples Temple cult that for nearly five years had been a little known outpost, reachable from here only by water or air, in the dense rain forest of northwestern Guyana.

The story of these macabre deaths began with the ambush murder of a U.S. congressmen and our of those accompanying him in the jungle. It grew in increasingly ugly chapters throughout the week until the final revelation of the almost unbelievable number of bodies lying in layers throughout the colony that was to have been utopia for Jones' followers.

The bodies had bloated and rotted in the humid heat as the week dragged on. There had been diplomatic confusion over whether to bury them there or return them to the United States. There had been logical problems for the U.S. military task force finally ordered to airlift them out of the jungle. And, just Friday, there had been the stunning shock of discovering more than twice as many dead as the estimate of 400 that everyone had lived with for almost a week.

The bodies had been bunched so tightly together that the ground could not be seen - bodies of men, women and children, bodies of blacks and whites, bodies of several hundred elderly residents of Jonestown, and bodies of small babies, many born there.

"There were bodies under bodies in layers, in some places with blankets between the layers," the U.S. military spokesman here. Air Force Capt. John J. Moscatelli explained in his expressionless briefing manner. "There were smaller bodies under larger bodies and children under them. There were more small babies than anticipated."

The dead had fallen roughly within a circle into which they had been crowded by armed Jonestown guards around the altar of an open-air central pavilion. It was there on so many other nights that Jones had held forth for hours - never preaching about God, but exhorting his followers to greater productivity in the fields, warning of conspiracies by enemies plotting to invade and destroy them, and then preparing them for the "white night" when they would all gather around him to meet death.

There had been many rehearsals, say the few survivors. At least one a week, sirens would awaken Jonestown late at night and the commune's 50 or so heavily armed guards would move from building to building, rounding up everyone for another meeting at the pavilion. There, Jones would tell them they were about to be attacked from the jungle and should be prepared to die.

On more than one occasion, it was a dress rehearsal in which everyone was ordered to drink a small glass of red liquid they were told contained poison. When they did not die, Jones praised their loyalty but told them the day would come when the poison would be real.

The "white night" ritual, as well as everyday life in Jonestown, were examples of group psychology run wild. Some Jonestown residents did not have the same blind faith in the increasingly paranoid Jones as his most fanatical followers, or as the many elderly whom Jones called "my seniors" and warehoused in tightly packed barracks that one of last weekend's visitors, lawyer Mark Lane, compared to "a slave ship."

The doubters questioned the seven-day, 70-hour work week in the fields, the increasingly poor meals, the growing mind control, the atmosphere of suspicion and paranoia, the armed guards, the concentration camp-like confinement to Jonestown of all but the most trusted Jones lieutenants.

Some of the doubters tried to escape. But they were tracked down by security guards and punished by forced labor on chain gangs, confinement in a three-foot-high punishment box or drugging with the sedative Thorazine, according to some of the Jonestown survivors. The drugs reportedly were administered by an idealistic young doctor from San Francisco, Lawrence Schacht, who was attracted to Jones and his work with the underprivileged in California.

Ultimately, survivors said, Schacht was to brew the mixture of Kool-Aid, cyanide, other poisons and tranquilizers administered under emotional duress and at gunpoint to the more than 900 residents of Jonestown last Saturday.

This deed, which followed the killing of Rep. Leo J. Ryan and four others, has shocked the world. But actually of a surprise. Those few Peoples Temple members who had managed to leave and many relatives of those who were still in the fold had long been campaigning to have the cult exposed in the American press and Jonestown closed down by the American government.

Tales of repression in the cult had been aired by the media in California, where Jones recruited and trained most of his followers. He leaves a larger installation in San Francisco. The State Department in Washington and the small U.S. Embassy here also had been inundated with complaints and questions from parents, siblings and children and even grown grandchildren of Jonestown residents. Court suits were filed and an extraorally, it should not have come as much dinary affidavit from a Jonestown resident who succeeded in leaving earlier this year, Deborah Layton Blakey, spelled out the horrors of Jonestown in meticulous detail.

But it all was to no avail. Whatever else he was, Jones was a smart, charismatic man who had a genius for group psychology, propaganda, politics and diplomacy. The Peoples Temple strongly and convincingly denied what it characterized as wild allegations about it and the Jonestown commune. It moblized its members and friends, including politicians charmed by Jones to flood officials with letters praising Jones and Jonestown.

When a U.S. consular officer made visits to Jonestown this year to interview residents whose relatives had expressed concern about them, none of 40 to 50 he interviewed would admit to being mistreated or confined there or expressed a desire to leave.

The officer concluded from the inspection, according to the State Department, that "the colony had made a lot of progress, that they had built buildings, they had expanded, they seemed to be going ahead. There seemed to be a lot of spirit in the colony."

Jones also retained civil liberties lawyer Charles Garry to defend him and the cult and asked the even better known Mark Lane to represent his interests when Ryan, a California Democrat, announced earlier this year he would make a fact finding trip to Jonestown.

Lane informed Ryan before the trip that "various agencies of the U.S. government have somewhat consistently oppressed the Peoples Temple," apparently referring to U.S. customs searches of some goods bound for Jonestown and recent insistence by the U.S. Department of Health. Education and Welfare that U.S. officials here deliver Social Security checks personally to retirees living in Jonestown.

"Some of the members of the Peoples Temple have had to flee from the U.S." Lane told Ryan, "in order to experience a fuller opportunity to enjoy rights which were not available to them within the U.S."

This apparently also was the attitude of the government of Guyana toward the Americans who had settled here and turned from jungle to a thriving agricultural community nearly 4,000 acres leased for a nominal fee from the government, which had been encouraging development and cultivation of its vast unpopulated rain forest.

Only today, as the Jonestown death toll climbed over 900 and the last bodies were brought out in plastic bags for shipment in aluminium coffins to the United States, the official newspaper of Prime Minister Forbes Burnham's People's National Congress Party said in an editorial:

"That so many people should want to leave the "comfort" of the United States to come and settle in Guyana's hinterland reflected adversely on the American way of life. That they could have done so successfully would have caused great anger and dissatisfaction in many quarters. . .

Burnham, who has been prime minister since before independence from Great Britain in 1966, only recently won a referendum to postpone new parliamentary elections. Peoples Temple leaders, government officials acknowledge, campaigned actively on Burnham's behalf.

His vision for Guyana is of a model socialist republic that would be among the leaders of the Third World and the Caribbean. The socialist agricultural cooperate that Jonestown purported to be fit into Burnham's vision well.

Jones also helped himself here by befriending Deputy Prime Minister Ptolemy Reid, who was chosen by the Burnham government to deliver its statement to parliament Friday on the events at Jonestown and the governments response. Since founding Jonestown in early 1974, Jones had met frequently with Reid, who flew to the Jonestown site by helicopter with Burnham's wife the day after the bodies were discovered there.

There have been reports in the opposition Marxist press and accusations by opposition leaders that Burnham's government knowingly allowed Jones to evade customs on goods moving in and out of Jonestown by sea and to bring into Jonestown without permits perhaps 100 firearms, many of them automatic rifles, and large quantities of ammunition.

"With regard to the possession of guns and ammunition by persons at Jonestown," Reid said in his statement to parliament. "Our records show that four licenses were granted after applications had been made.

Even Rep. Ryan and his party of aides, lawyers, newsmen and relatives of Jonestown residents initially were impressed with what they saw when they were allowed to enter Jonestown last Friday after days of tense negotiations here between Ryan and Jones conducted largely by Lane.

The buildings were numerous and substantial, the farm fields productive, the evidence of modern technology visible everywhere in the middle of a tropical jungle. And, true to Blakey's June 15 affidavit, the food was good and plentiful while the visitors were there.

But while music blared, NBC news correspondent Don Harris, a tall anchorman from San Francisco who was wandering around the periphery of the commune, was approached by individual residents who begged help to leave.

While most of his party slept Friday night on the floor of a bar six miles away in Port Kaifuma, Ryan and aides, along with lawyers Lane and Gary, stayed in Jonestown interviewing those who wanted to leave.

On Saturday, after he discovered that people were asking to leave, Jones grew increasingly agitated. His responses to questions from reporters were alternately combative, conciliatory and morose. He rambled on about betrayal and death.

Then, when an entire family of six said early Saturday afternoon they wanted to leave, Jones told Garry: "They never stop. This is the finish. It's finished."

Lane, who had heard about drugs and guns at Jonestown and rumors of plans for mass suicide, said later he was worried at that point. But he thought the solution was to persuade Jones that Ryan's visit had actually gone well and would help rather than hurt Jonestown.

Saturday afternoon, when most of Ryan's party went to board the two dump trucks that would take them down the rough dirt track to the Port Kaituma airstrip. Ryan stayed back to confer with Jones, Garry and Lane. It was then that one of Jones' lieutenants, Don Sly, grabbed Ryan from behind and held a fishing knife to his neck. Lane, the 69-year-old Garry and Peoples Temple members helped wrestle Sly away, cutting his hand and splattering blood on the congressman's clothes.

"Does this change things," asked Jones, who had watched the incident without moving.

Ryan answered that he had still seen many positive things in Jonestown but that his impression had been changed somewhat by the attack. Ryan was then given a clean suit by Peoples Temple members and he left with the others while Garry and Lane stayed with Jones.

When the group, including 14 defectors from Jonestown, reached the landing strip, Jonestown resident Larry Layton, who had pretended to be one of the defectors, boarded one of the two chartered planes apparently with the assignment to wait until Ryan's plane took off and then shoot the pilot, knocking the plane out of the sky. But Layton began shooting too soon, wounding some of the Jonestown defectors aboard the plane before being disarmed by another of them, Dale Parks.

Layton ran off the plane as four to six other Jonestown gunmen approached in a tractor-pulled trailer. They shot and killed Ryan. Harris, NBC news technician Robert Brown, San Francisco photographer Greg Robinson and Jonestown defector Patricia Parks, Dale Parks' mother. Twelve others were wounded.

When the gunmen returned to Jonestown, Jones ordered Lane and Garry put under guard.

Meanwhile, Jones apparently met with the assassins and learned that there were many survivors of the airstrip massacre. The order went out to the guards to assemble everyone in Jonestown around the end of an open air pavilion where an altar was. Poison was brought out in a large soup kettle and put on the ground outside the pavilion near the altar.

"We've all got to kill ourselves," Jones told everyone, according to Odell Rhodes, one of the few Jonestown residents who witnessed the beginning of the mass suicide and escaped. One woman, Christine Miller, protested, Rhodes said, "but the crowd shouted her down."

The poison was given to the babies first, Rhodes said, which would explain why they were found Friday and today at the bottom of the piles of bodies. The armed guards, many of whom apparently also perished, prevented the reluctant from escaping. A few did escape, however, by hiding during the roundup before the suicide began. Rhodes pretended to help one of the commune's nurses look for a stethascope back at the medical building, then ran into the forest.

Lane and Garry slipped off into the forest, from which they emerged safely the next day. As they hid in the underbrush, they heard Jones shouting over the loudspeaker about the "beauty of dying . . . It's an important part of what we've done . . . Let's not fight among ourselves," Jones finished. Lane said, by wailing, "Mother . . . mother . . . mother . . .* "

Then there was silence, Lane said, followed by a series of gunshots. Jones himself and at least two others were later found to have been shot to death, although it is not known exactly how or why.

News of the airstrip massacre and the subsequent deaths in Jonestown seeped out slowly. According to Reid's statement to parliament, the Guyana defense force reacted as quickly as possible by taking the most seriously wounded victims to a hospital that night and evacuating the others the next morning.

After Rhodes reached the outpost of Matthews Ridge, about 20 miles distant, to report the horror he had escaped at Jonestown, Guyana defense force troops moved in by foot and train.

Nothing was offcially reported about the hundreds dead in Jonestown until around midnight Sunday, when an announcement was made by the Guyana Ministry of Information. By that time, this capital already was being inundated by American correspondents coming to report the ambush at the Port Kaituma airstrip.

On Monday morning, Minister of Information Shirley Field-Ridley met with the assembled reporters in what was to be the beginning of a process in which information about the twin catastrophes came, painfully, slowly, one little piece at a time, but always with great courtesy and cordiality.

The most important piece of information disseminated that day turned out to be the most cruelly misleading - the estimates of just over 400 dead in Jonestown based on a count by Guyana defense force officers who dared not touch the bodies.

That count, compared to the estimates of 800 to 1,000 people living in Jonestown that nearly everyone present there last week agreed on, left a disturbing mystery about where hundreds more could be. Their relatives still had hopes that they might have escaped into the surrounding forest.

Only 32 including the Jonestown defectors who survived the airstrip massacre, turned up the first few days, no one else emerged from the forest after that, although a few more Jonestown residents have since been found on two of the commune's boats, one river from Port Kaituma and the other in Trinidad. A third boat is missing.

Speculation spread through this city about mass executions in the rain forest or, more hopefully, mass escapes, planned in advance, to encampments of the indigenous Amer-indians who had been befriended by some Jonestown residents.

The recovery of the dead in Jonestown meanwhile was slowed considerably by the necessity to fly them out of the Jonestown area, wher landing strips could not accomodate U.S. military cargo planes. At one point, the U.S. government authorized the Guyanese government to simply bury the bodies here, but was told that Guyana wanted them out, probably so that the cumbersome process of identification and claims by relatives could take place in the United States.

The airlift finally began Tuesday, utilizing huge "Super Jolly, Green Giants" helicopters of the kind that had been used to recover soldiers in Vietnam. U.S. military personnel discovered early Friday that although they had put nearly 400 bodies into plastic body bags for transport by helicopter and then cargo plane to the United States, there were still hundreds more bodies to go.

There also was a local police investigation under way. Larry Layton had been taken into custody at the Port Kaituma airstrip where survivors of the massacre handed him over to police. Two other of Jones's lieutenants, Mike Prokes and Time Carter, were arrested by police in Port Kaituma when they were reportedly found carrying large sums of money. They were released from custody tonight.

There also were 46 other Peoples Temple members in the cult's Georgetown headquarter including a large number described as Jonestown security guards and trusted Jones aides.

They have been under house arrest by heavily armed Guyana defense force troops since another Peoples Temple member living there, Sharon Amos Harris, and her three children were found dead with their throats slashed last Saturday night.